Advanced Problems in Organic Chemistry 9789352860371, 9352860373
Advanced Problems in Organic Chemistry comprises 10 chapters which are designed coherently to aid students in problem so
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Advanced Problems in Organic Chemistry for Competitive Examinations
Akshay Choudhary Mandakini Choudhary
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Copyright © 2017 Pearson India Education Services Pvt. Ltd Published by Pearson India Education Services Pvt. Ltd, CIN: U72200TN2005PTC057128, formerly known as TutorVista Global Pvt. Ltd, licensee of Pearson Education in South Asia. No part of this eBook may be used or reproduced in any manner whatsoever without the publisher’s prior written consent. This eBook may or may not include all assets that were part of the print version. The publisher reserves the right to remove any material in this eBook at any time. ISBN eISBN 978-93-528-6037-1 Head Office: A-8 (A), 7th Floor, Knowledge Boulevard, Sector 62, Noida 201 309, Uttar Pradesh, India. Registered Office: Module G4, Ground Floor, Elnet Software City, TS-140, Block 2 & 9, Rajiv Gandhi Salai, Taramani, Chennai 600 113, Tamil Nadu, India. Fax: 080-30461003, Phone: 080-30461060 www.pearson.co.in, Email: [email protected]
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Contents Preface
v
Acknowledgements
vi
About the Authors
vii
Chapter 1
General Organic Chemistry1.1–1.78
Chapter 2
Isomerism2.1–2.80
Chapter 3
Hydrocarbons3.1–3.60
Chapter 4
Alkyl Halides, Alcohols and Ethers4.1–4.68
Chapter 5
Carbonyl Compounds and Acid Derivatives5.1–5.68
Chapter 6
ESR Amines and Phenols6.1–6.70
Chapter 7
Biomolecules7.1–7.36
Chapter 8
Organic Reaction Mechanisms and Reagents8.1–8.76
Chapter 9
Practical Organic Chemistry9.1–9.12
Chapter 10
Nomenclature10.1–10.20
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Preface In order to understand a subject, it is important to gain an insight into its guiding principles and proof of concept. Theory is beneficial only when it can be successfully applied to solve problems. This book presents different types of problems to exemplify each and every theoretical discussion to help the student gain a masterly grasp of the subject. As the saying goes, ‘Practice makes a man perfect’, so we set forth in this practice book a multitude of problems to acquaint the student with the different types of questions that could be posed in the subject. This book includes all levels of problems in organic chemistry that every JEE aspirant needs to be skilled at solving. We hope this book helps students to achieve their target. Readers may send their suggestions to [email protected]. Akshay Choudhary Mandakini Choudhary
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Acknowledgements The editorial team at Pearson Education has been pivotal in encouraging this project, while my wife has very ably and diligently done the proof-reading of the complete manuscript. I am indebted to my family members Om Prakash Choudhary, Sita Devi, Hemant Choudhary, Kamla Choudhary, Shivani Choudhary, Ravindra Choudhary, and my uncle Shyam Lal Choudhary who have played a prime role in making me more focused. I am grateful to my daughter Sagarika and son Aatish whose joyful faces give me the patience to work. I thank my friends, P. B. Saxena, Ramashis Paul, Sunil Jangid, Kumud Ranjan, Rakesh Sharma, Mohit Choudhary, and Subkaran Choudhary for their valuable feedback and suggestions. I acknowledge the help provided by Sasikant Choudhary and Yogendra Singh Yadav in preparing the Solution Manual of this book. Suggestions for improving the book’s contents, queries, and criticisms are always welcome. Akshay Choudhary
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About the Authors Akshay Choudhary, a renowned faculty of organic chemistry, teaches IIT-JEE aspirants, assisting them to achieve their goal. Many students have been successful under his guidance and achieved top ranks in the IIT–JEE exam. The author is a postgraduate in chemistry as well as Junior Research Fellow from NCL, Pune. His has keen interest in the subject and strives to present it to students in a lucid style to help them ace the exams effortlessly.
Mandakini Choudhary, specializes in reaction mechanisms and intermediates. She is a dedicated teacher with four years’ experience and is popular among students for her zeal to help them with their board examinations.
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General Organic Chemistry
CHAPTER
1
Question Bank
Level 1 Arrange the items in Questions 1–38 in DECREASING ORDER (i.e., greatest, most etc. first) with respect to the indicated property. Use the following code to indicate your answers. 1. The acidity of the protons H in each of the following is O O (i) (ii) H C C 3 C H3C O CH3 H
(iii) H C 3
O
(a) i > ii > iii
O
O
C
C CH2
CH3 O
(b) ii > iii > i
(c) i > iii > ii
(d) iii > i > ii
2. Rate of reaction of HNO3/H2SO4 with each of the following is (i)
(a) i > ii > iii
OCH3 (ii) (b) ii > iii > i
CN
(iii)
(c) i > iii > ii
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CH3 (d) iii > i > ii
1.2
chapter one 3. Reactivity towards hydrolysis using aqueous acid of the following is CH3 CH3 H3C H3C Cl H3C N (i) C (ii) (iii) C C CH3 O O O (a) i > ii > iii (b) iii > ii > i (c) i > iii > ii (d) iii > i > ii 4. Reactivity of the following towards reaction with LiAlH4 is O H3C Cl (i) (ii) C (iii) O
(a) ii > i > iii
(b) ii > iii > i
(c) i > iii > ii
O OCH3
(d) iii > i> ii
5. The relative yield of the following alkenyl bromides from the reaction of 1,3-butadiene with HBr (dark, N2 atmosphere) at –15ºC is (i)
(ii)
Br (a) i > ii > iii
(b) ii > iii > i
Br
(iii) Br (d) iii > i > ii
(c) i > iii > ii
6. The amount of conjugate addition obtained in the reaction of the following with 3-butenone is (i) CH3Li (ii) CH3MgBr (iii) CH3O2C– CH–CO2CH3
(a) i > ii > iii
(b) ii > iii > i
(c) i > iii > ii
(d) iii > i > ii
7. The relative reactivity towards Br2 in CHCl3 of the following is
(i) CH2=CH–CO2CH3
(a) i > ii > iii
(ii) CH2=CH–CH3
(b) iii > ii > i
(c) i > iii > ii
(iii) CH2=CH–O–CH3 (d) iii > i > ii
8. The % of the para product produced in the reaction of Br2/FeBr3 with each of the following is CH3 (i)
NO2
C(CH3)3
(ii) (iii)
(a) i > ii > iii
(b) ii > iii > i
(c) i > iii > ii
(d) iii > i > ii
9. The number of enolizable protons in each of the following is O O O (i) (ii) (iii) O H C CH 3
(a) i > ii > iii
(b) ii > iii > i
(c) i > iii > ii
(d) iii > i > ii
general organic chemistry 10. The relative reactivity towards 1,3-cyclopentadiene of each of the following is O O O O (i) (ii) (iii) OMe
(a) iii > ii > i
(b) ii > iii > i
(c) i > iii > ii
(d) iii > i > ii
11. The relative rate of hydrolysis using dilute aq. NaOH of the following is O O O O (i) (ii) (iii) H3C H3CO CH3 H3C O CH3 Cl (a) i > ii > iii (b) ii > iii > i (c) i > iii > ii (d) iii > i > ii 12. The relative rate of reaction of isopropyl chloride/AlCl3 with each of the following is (i)
Cl (ii)
(a) i > ii > iii
(b) ii > iii > i
OH (iii) (c) i > iii > ii
NO2
(d) ii > i > iii
13. The relative acidity of the indicated H in each of the following is O O O (i) CH (ii) (iii) C C CH3 H3C H3C O H3C OH (a) i > ii > iii (b) ii > iii > i (c) i > iii > ii (d) iii > i > ii 14. The relative reactivity towards reaction with MeMgBr of the following is O O O (i) (ii) (iii) H H3C H OCH3 CH3 H (a) i > ii > iii (b) ii > iii > i (c) i > iii > ii (d) iii > i > ii 15. The relative nucleophilicity in polar, protic solvents of the following is – – – (i) CH3CH2S (ii) CH3CH2O (iii) CH3CO2
(a) i > ii > iii
(b) ii > iii > i
(c) i > iii > ii
(d) iii > i > ii
16. The relative rate of reaction with aq. EtOH/AgNO3 of the following is Cl (i)
Cl Br (ii) (iii)
(a) i > ii > iii
(b) iii > ii > i
(c) i > iii > ii
(d) iii > i > ii
17. The relative yield of the following products produced by the reaction of conc. H2SO4 with 1-methylcyclohexanol is (i)
(a) i > ii > iii
(ii) (b) ii > iii > i
(iii) (c) iii > ii > i
(d) iii > i > ii
1.3
1.4
chapter one 18. The relative yield of the following products produced in the nitration reaction of t-butylbenzene is C(CH3)3 C(CH3)3 C(CH3)3 (i)
(ii) NO2
(iii) O2N
NO2 (b) ii > iii > i
(a) i > ii > iii
(c) i > iii > ii
(d) iii > i > ii
19. The relative yield of the following products produced by the reaction of isopropyl benzene with Br2/uv light is Br (i)
(ii)
(iii)
Br
(a) i > ii > iii
Br (b) ii > i > iii
(c) i > iii > ii
(d) iii > i > ii
20. The relative reactivity towards dimethyl cis-butendioate (also called dimethyl maleate) of the following is (i)
(ii) (iii)
(a) i > ii > iii
(b) ii > iii > i
(c) i > iii > ii
(d) iii > i > ii
21. The acidity of the protons H in each of the following is O CH2C CH3 H3C (i) C (ii) C (iii) CH3COOH O H3C CH3 O (a) iii > ii > i (b) ii > iii > i (c) i > iii > ii (d) iii > i > ii 22. The relative nucleophilicity in polar protic solvents of each of the following is (i) CH3OH (ii) CH3SH (iii) CH3NH2 (a) i > ii > iii (b) ii > iii > i (c) i > iii > ii (d) iii > i > ii 23. Reactivity towards NH3 of each of the following is H3C O (i) C O (a) i > ii > iii
C CH3 O
(ii)
H3C
C
O
CH3
(iii) CH3COCl
O (b) ii > iii > i
(c) i > iii > ii
(d) iii > i > ii
24. Reactivity of the following towards reaction with NaBH4 is O O O (i) (ii) (iii) N(CH3)2 H3C H CH3 H H (a) i > ii > iii (b) ii > iii > i (c) i > iii > ii (d) iii > i > ii 25. The relative reactivity towards 1-buten-3-one of each of the following is (i)
(ii) (iii)
(a) i > ii > iii
(b) ii > iii > i
(c) i > iii > ii
(d) ii > i > iii
general organic chemistry 26. Rate of reaction of CH3COCl/AlCl3 with each of the following is O (i) H3C O
(ii)
(a) iii > ii > i
(b) ii > iii > i
Br (iii) (c) i > iii > ii
OCH3 (d) iii > i > ii
27. The relative stability of the following radicals is •
•
•
(i) CH 3 CH = CH − CH 2 (ii) CH = CHCH 3 (iii) CH 3 CHCH 3
(a) i > ii > iii
(b) ii > iii > i
(c) i > iii > ii
(d) iii > i > ii
28. The ortho/para product ratio produced in the reaction of Br2/FeBr3 with each of the following is CH3 C(CH3)3 CH3 H2C (i)
(ii) (iii)
(a) i > ii > iii
(b) ii > iii > i
(c) i > iii > ii
(d) iii > i > ii
29. The amount of the enol form present at equilibrium for each of the following is O
O (i) (CH3)3CCOH (ii) (iii)
(a) i > ii > iii
(b) ii > iii > i
(c) i > iii > ii
(d) iii > ii > i
30. The relative yield of the following alkenes produced by the reaction of trans-1-chloro-2methylcyclohexane with KOH/heat is (i) 1-methylcyclohexene (ii) methylenecyclohexane (iii) 3-methylcyclohexene (a) i > ii > iii (b) ii > iii > i (c) i > iii > ii (d) iii > i > ii 31. Identify correct C–O bond length order
(i)
O
H3C
O
(a) i > ii > iii
CH3
CH3
(ii) O (iii) CH3 H3C (b) ii > iii > i
(c) i > iii > ii
(d) iii > i > ii
32. The resonance energy of each of the following is (i)
(a) i > ii > iii
(ii) (iii) (b) ii > iii > i
(c) i > iii > ii
(d) iii > i > ii
1.5
1.6
chapter one 33. Identify order of per ring resonance energies of each of the following (i)
(ii)
(a) i > ii > iii
(b) ii > iii > i
(iii) (c) i > iii > ii
(d) iii > ii > i
34. Identify the correct boiling point order of each of the following (i) CH3CH3 (ii) CH3CH2CH2CH3 (iii) (CH3)3CH
(a) i > ii > iii
(b) ii > iii > i
(c) i > iii > ii
(d) iii > ii > i
35. The relative stability of the following carbocations is
+
(i) (ii) (iii) + +
(a) i > ii > iii
(b) ii > iii > i
(c) i > iii > ii
(d) iii > ii > i
36. The relative yield of the following products from the reaction of HCl with 1-methyl-1, 3-cyclohexadiene at 50ºC is
Cl (i)
(ii) (iii)
Cl
Cl
(a) i > ii > iii
(b) ii > i > iii
(c) i > iii > ii
(d) iii > ii > i
37. Which of the following systems are resonance contributors of the radical shown below? (select all that apply) ←⎯→?
(a)
(b)
(c)
(d)
38. Imidazole has a pKa = 7 with respect to its conjugate acid. Which N is protonated in this conjugate acid and why? 3
N imidazole
1
N H
(a) N1 because imidazole is an aromatic heterocycle where n = 1 as per Huckel’s rule. (b) N1 is protonated because it is sp3 hybridised. (c) N3 is protonated because it is sp2 hybridised. (d) N1 is protonated because the lone pair is part of the aromatic pi system.
general organic chemistry 39. Cyclopentadiene has a pKa = 15, whereas cyclopentane has a pKa > 50. This is because (a) Cyclopentadiene is particularly unstable. (b) Cyclopentane contains no lone pairs. (c) Cyclopentadiene is a 4π anti-aromatic compound. (d) Cyclopentadiene is a 4π non-aromatic compound and after deprotonation it is aromatic. 40. The α-hydrogens of esters typically have a pKa = 25, whereas for ketones pKa = 20. This is because: (a) There is no resonance stabilisation of the enolates of esters. (b) The inductive effect of the oxygen in the ester destabilises the ester enolate. (c) The electron donating alkoxy group in esters destabilises the enolate. (d) The electron donating alkoxy group in esters stabilises the enolate. 41. Which of the following is most likely to undergo a favorable hydride shift? CH3 Me + (a) (b) H3C (c) (d) + H CH3 CH2 H3C + + 42. Relative stabilities of the following carbocations will be in the order ⊕
(iii) H3C
⊕
CH2 (ii) CH2
CH3O (i) ⊕
⊕
CH2 (iv) CH3CH2
(a) i < ii < iii < iv (c) iv < ii < iii < i
(b) iv < iii < ii < i (d) ii < iv < iii < i
43. Which of the following forms most stable carbocation upon removal of OH–? (a) (CH3)3C – CH2OH (b) CH3CH2CH2CH2OH (c) C6H5CH2OH (d) C6H5CH2CH2OH 44. Which of the following carbonium ion is most stable? CH3 C2H5 C2H5 CH3 |⊕ |⊕ |⊕ | (a) (b) (c) CH3 – C (d) C2H5 – C⊕ CH3 – C C2H5 – C | | | | C2H5 CH3 H H 45. Which of the following carbocations would not likely rearrange to a more stable carbocation? + (a) + (b)
(c)
+
+
(d)
46. Which carbocation is the most stabilised? ⊕
⊕
(a) (b)
⊕
⊕
(c) (d) ⊕ (e)
47. Which of the following carbocation do rearrange? ⊕ ⊕ CH3 − C = CH2 (c) (a) (b)
(d)
⊕
1.7
1.8
chapter one 48. Which carbocation is the most stable? ⊕ CH2
⊕ CH2 (a)
⊕ CH2
⊕ CH2
(b) (c) (d) NO2
Cl
OH
CH3
49. Arrange stability of the given carbocations in decreasing order
(i)
⊕ CH2
⊕ CH2
⊕ CH2
⊕ CH2
(ii) (iii) (iv) NH2
OH OCH3 (a) iii > ii > i > iv (c) iii > i > ii > iv
Cl
(b) i > ii > iii > iv (d) ii > iii > i > iv
50. In each of the following pairs of ions, which ion is more stable? ⊕
⊕
C6 H 5 − CH 2 and CH 2 = CH − CH 2 (a) (i ) (ii) ⊕
⊕
CH 3 − CH 2 and CH 2 = CH (b) (i ) (ii) ⊕ CH2
(c)
⊕ CH2
and
(i)
(ii)
CH3 − CH − CH3 | (d) CH3 − C − CH3 ⊕ (i)
CH3 − N − CH3 | CH3 − C − CH3 ⊕ (ii)
and
(a) a–i, b–i, c–ii, d–ii (c) a–i, b–i, c–i, d–i
(b) a–ii, b–ii, c–ii, d–ii (d) a–ii, b–ii, c–i, d–i
51. Which of the following two carbonium ions is more stable? Explain why. (a) (I)
⊕
⊕
(II)
(a) a–ii, b–ii
⊕
(b) (I)
(b) a–i, b–i
(c) a–i, b–ii
⊕
NH2
(II) (d) a–ii, b–i
52. Consider the following statements: OH (i) H
⊕ NO2
CH3 is more stable than H
(a) i and ii both are correct (c) ii and reverse of i are correct
NO2
is more stable than (ii) ⊕ NO2 Cl H (b) i and reverse of ii are correct (d) i and ii both are incorrect
NO2
Cl OH
general organic chemistry 53. Which is the most stable arenium carbocation? CH3 CH 3
(a) ⊕
NO2 (b) H
H
⊕ NO2
CH3
CH3
(c) ⊕ H
(d)
H
⊕ NO2
NO2
CH3 | CH3 − C − CH3 ⊕ II I Which of the following statements is correct? (a) i is more stable than ii (b) ii is more stable than i (c) Both are equally stable (d) Stability criterion cannot be applied in this case
CD3 | 54. CD3 − C − CD3 ⊕
55. List the following carbocations in order of decreasing stability (starting with the most stable) + + + (ii) (iii) + (iv) (i)
(a) ii, iii, i, iv
(b) iii, iv, ii, i
(c) iii, iv, i, ii
(d) i, ii, iv, iii
56. Under thermodynamic control, which of the following products would predominate? H+ and then deprotonate (a)
(b)
(c)
(d)
57. Rank the following in order of stability (lowest to highest) (i) (ii) (iii)
(iv)
(a) iv < ii < iii < i (c) i < iii < ii < iv
(b) iv < iii < ii < i (d) iv < ii = iii < i
58. Rank, from the most stabilised to the least stabilised, the following free radicals according to their stabilisation energies. 2 CH 3 2 (ii) (i) CH CH 3 CH (iv) 2) (iii) (CH 3 )2 CH (CH 2 = CH − CH
(a) iv > iii > ii > i (c) iii > iv > i > ii
(b) i > iv > iii > ii (d) iii > iv > ii > i
59. How many tertiary hydrogen(s) are (is) there in the following structure?
(a) 1
(b) 2
(c) 3
(d) 6
1.9
1.10
chapter one 60. For the following incomplete Lewis structure, what are the correct formal charges for the carbon and the nitrogen attached to the carbon?
H C
N
H
(a) C:0, N:0
(b) C:–1, N:0
N
(c) C:–1, N:+1
(d) C:+1, N:–1
61. Which of the following are pairs of resonance structures? CH2
H3C O
H2C
CH
(i)
O
(ii)
H2C
CH
CH2
(iii)
O H3C ⊕ N
CH
CH2
H2C
C O
H3C
(iv)
O ⊕ O
H2C CH2
CH
C
CH2
CH2
(v)
N C
(a) i, ii, iii
O
O H3C ⊕ CH (c) ii, iv, v
(b) i, iv
CH
CH3 (d) i, iii, iv
62. Arrange the following alkenes in order of their stability (most to the least). (i)
(ii)
(iv)
(v)
(a) v > ii > iii > iv > i (c) v > ii > iii > i > iv
(iii)
(b) v > ii > iv > iii > i (d) v > i > iv > iii > ii
63. Which of the following compounds are aromatic compounds? H H N N (i) (ii)
O S (iii) (iv)
N H N ⊕ N O (v) (vi) O O (vii) (viii) N N N H
general organic chemistry OH
O H N (ix)
(x)
H N
N
N
(xi)
(xii)
N OH O (b) i, ii, iii, vi, viii, x, xi, xii (d) i, ii, iii, v, vii, viii, ix, x, xii
(a) i, ii, iii, iv, v, vi, viii, x, xii (c) i, ii, iii, iv, v, vi, vii, x, xii
64. For the following compounds, which nitrogen is the least tendency to be protonated? b N
N
c
N H
N
a
d
(a) Nitrogen indicated by arrow “b” (c) Nitrogen indicated by arrow “c”
(b) Nitrogen indicated by arrow “a” (d) Nitrogen indicated by arrow “d”
65. Using the VSEPR model, predict which atoms pointed by an arrow have SP2 hybridisation. (Note: not all the lone pair electrons are displayed) O H3C OH H2C CH2 (i) (iii) H3C C (ii) H H ⊕ (iv) H N
O
H CH3 (v) O
NH2 O (vii) H3C
C
(a) i, ii, iv, viii
CH3
O HC (viii) 3
Cl
HC C (vi)
N
(b) i, iii, v, vii
C O
H
(c) ii, iii, v, vii
(d) ii, iv, v, viii
66. Arrange the following compounds in order of their acidity. (most to least) (i) CH3CH2OH (ii) CFH2CO2H (iii) CF2HCO2H (iv) CF3COOH (v) CH3CO2H (a) iv > iii > ii > v > i (b) iv > iii > ii > i > v (c) v > ii > iii > iv > i (d) v > iii > iv > ii > i 67. Rank the following intermediates according to the stability (most stable first). Explain your choices. ⊕ ⊕ ⊕ ⊕ (a) CH 3 CH 2 CH 2 CH 2 , CH 3 CHCH 2 CH 3 , (CH 3 )2 CCH 2 CH 3 , (CH 3 )3 C •
•
•
|
|
|
•
(b) CH 3 CH 2 CH 2 CH 2 , CH 3 CHCH 2 CH 3 , (CH 3 )2 CCH 2 CH 3 , (CH 3 )3 C (c) CH 3 CH 2 CH 2 CH 2 , CH 3 CHCH 2 CH 3 , (CH 3 )2 CCH 2 CH 3 (d) CH2:, CH2CH:, C6H5CH:, (C6H5)2C:
1.11
1.12
chapter one 68. Which of the following base has the most acidic conjugate acid?
(i) NH3
pKb 4.74 (a) i
(ii) CH3CH2NH2 (iii) 3.19 (b) ii
NH2
NH2 (iv) O2N
9.37 (c) iii
13.0 (d) iv
69. What is the structure of p-nitrobenzenesulfonic acid? SO3H
CH2SO3H (a)
(b) O2N
O2N CO2H (c)
CH2CO2H (d)
O2N
O2N
70. Which of the following compound has the highest boiling point? (a) CH3OCH3 (b) CH3COCH3 (c) CH3CH2OH (d) CH3CO2H 71. Which are secondary alkyl alcohols among the following? (i)
(ii)
(iii) OH OH
Br (iv)
(v)
Cl (vi) F
(viii) CH3OH
(ix) CH3CH2I
OH (vii)
OH
(a) vii
(b) ii, iv, vi
(c) i, vi, x
(d) ii, vii
72. Which is the electronic configuration that describes Na+? (a) 1S2, 2S2, 2P6 (b) 1S2, 2S2, 2P6, 3S2, 3P6 2 2 (c) 1S , 2S (d) 1S2, 2S2, 2P6, 3S2 73. What is the Lewis structure of CH3 – CH2 – CH2 – CHO? H
H
H
(a) H C
C
C
H
H
H
H
H
H
(c) H C
C
C
H
H
H
H H H C C O (b)
C
H
H
C
O H
H
H
C (d) H C C
C
C
H
H
H
H O
H
H C H
H
H
O
general organic chemistry 74. Which Lewis structure(s) is(are) correct? (i) H O
H
O
H H N (iii)
⊕
O
(ii) H
H
N
N
H
H
H (iv)
H
H
C
Cl
H
(a) i, ii
(b) ii, iv
(c) iii, iv
75. Which molecules are non-polar? (i) NH3 (ii) CO2 (iv) CF4 (v) Br2 (vii) CH2Cl2 (viii) H2O2 (a) ii, iv, v, vi (c) iii, iv, v, vi
(d) i, iii
(iii) H2O (vi) BF3 (b) i, iv, vi, viii (d) i, iii, vii, viii
76. Which of the following is the most stable alkene? CH
CH3 (a) CH – C = C CH3 H H
CH3 CH3
C2H5 (b) C = C C2H5
CH3 CH3 (c) C = C CH3 CH3
(d)
(CH3)2CH (CH3)2CH
C2H5 C2H5
C=C
CH(CH3)2 CH(CH3)2
OH Conc. H+
77.
Major products?
COOH
(a)
(b)
COOH
(c)
O O
(d)
O
O
1.13
1.14
chapter one 78. Hyperconjugation is best described as: (a) delocalisation of p electrons into a nearby empty orbital (b) delocalisation of σ electrons into a nearby empty orbital (c) the effect of alkyl groups donating a small amount of electron density inductively into a carbocation (d) the migration of a carbon or hydrogen from one carbocation to another 79.
OH H+ H2O
Major product is?
OH
(a)
(b)
(c)
(d) O
OH
OH
80. Which of the following statements best explains why 1-propyne can be deprotonated by the ethyl anion (CH3CH2–)? (a) The acetylide anion is a stronger base than the ethyl anion. (b) Ethane has a lower pKa than acetylene. (c) The lone-pair orbitals in acetylide anions have more s character than those in alkyl anions. (d) The acetylide anion is a weaker base than an alkyl anion. 81. Which of the following statements is NOT true for ethylene (CH2 = CH2) molecule? (a) Both carbons are sp2 hybridised. (b) C = C bond length is shorter than the C–C bond length in ethane. (c) The two C = C bonds are equally strong. (one is pi and the other is sigma.) (d) The entire molecule has a planar geometry. 82. Which of the following is the product of the reaction between AlCl3 and CH3OCH3? Cl
CH3 (a) Cl – Al – O CH3 Cl –
+
Cl + +
(c) Cl – Al – O Cl
CH3 CH3
Cl +
–
(b) Cl – Al – O Cl
CH3 CH3
Cl
–
+
(d) Cl – Al – CH3OCH3 Cl
83. The acidity for the following compounds increases in the order Cl | (iii) CH3CH2CH2CH2OH (i) CH3CH2CH2CO2H (ii) CH3CH2CHCO2H
(a) i < ii < iii
(b) ii < iii < i
(c) iii < i < ii
(d) ii < i < iii
general organic chemistry 84. The relative acidity of the underlined H in each of the following is in the order (i) HO
O
H H O O (ii)
(a) i > ii > iii
(b) i > iii > ii
(iii) CH3–C≡C–H
(c) ii > i > iii
(d) ii > iii > i
85. Which of the underlined atoms in the molecules shown below have sp hybridisation? (a) CH2CHCH3 (b) CH2 CCHCl (c) CH3 CH2+ (d) HCCCH3 (e) CH3 CN (f) (CH3)2CNNH2 (a) d and f (b) d, e and f (c) a, c and d (d) b, d and e 86. A compound
shows a large dipole moment. Which of the following resonance
structures can be used to adequately explain this observation? (ii) + –
(i)
(a) i
(iii) – +
(b) iii and iv
87. The nitrogen in trimethylamine is (a) sp2 hybridised (c) sp hybridised
(iv)
(c) ii and iii
⊕
(d) iv only
(b) sp3 hybridised (d) sp3d2 hybridised
88. The acidity of the protons H: O O O O || || || || CH3CH2CCH3 (ii) CH3CH2OCCH3 (iii) CH3CH2OCCH2COCH2CH3 (i)
(a) i > ii > iii
(b) i > iii > ii
(c) ii > i > iii
(d) iii > i > ii
89. Which of the following is not a valid resonance structure of the others? (a) (c)
⊕
(b)
⊕
(d)
⊕
90. Which is(are) the correct orbital hybridisation (s) for the C and N atoms in the following structures? (i) CH3CH3 (ii) CH2=CH2 (iii) NH3 (iv) HC≡CH 3 2 sp sp sp sp2 (a) i (b) ii, iii (c) iii, iv (d) i, iii 91. Which allylic carbocation is the most stable carbocation? ⊕
(a) CH3 – CH = CH – CH 2 ⊕ CH3 − CH = CH − C − CH3 (c) | CH3
⊕
(b) CH3 – CH = CH – CH – CH3 (d) All have same stability
1.15
1.16
chapter one 92. Rank the following molecules in order of decreasing acidity (increasing pKa) O O O O O HO (i) (ii) (iii) (iv) OH OH H3C OH HO H OH O
(a) ii > iii > i > iv (c) i > iv > ii > iii
(b) iii > ii > i > iv (d) iv > iii > i > ii
93. Which among the following carbocations is most stable? ⊕ ⊕ ⊕ C (a) (b) C6H5– CH 2 (c) (d) CH 3 − CH − CH 3 ⊕
94. Which of the following statements about resonance structures is false? (a) Individual resonance structures are imaginary, not real. (b) Resonance forms differ only in the placement of their π- or non-bonding electrons or unpaired electron. (c) Different resonance structures of a substance do not have to be equivalent. (d) In valid resonance structures, all atoms from the second row of the periodic table must have an octet of electrons.
general organic chemistry
Level 2 Single and Multiple-choice Type 1. The strength of the following bases decreases in the order
(i) CH3O|
(a) i > iv > iii > ii (c) ii > iii > i > iv
O || CH3C − O (iii) NH2| (iv)
(ii) CH3|
(b) iii > iv > i > ii (d) iv > i > ii > iii
2. Which of the following is not a resonance structure of the others? O (a)
O
O (b)
O
(c)
(d)
3. Rank of the following three compounds in decreasing order of basicity is O NH2 NH2 NHCCH3 (ii) (i) (iii)
(a) iii > i > ii
(b) iii > ii > i
(c) ii > i > iii
(d) ii > iii > i
4. Compare the hybridisation of the central carbon atoms in carbon dioxide (CO2) and allene (H2C = C = CH2). Which statement is correct? (a) The hybridisation types of these two carbons cannot be compared because of large electronegativity difference between carbon and oxygen in CO2 that does not exist in allene. (b) The hybridisation of carbon in CO2 cannot be determined, because the lone electron pairs on oxygen do not allow for angle measurements that are necessary to determine the hybridisation involved. (c) In CO2 the carbon is sp2 hybridised, but in allene the central carbon is sp hybridised. (d) In CO2 the carbon is sp hybridised but in allene the central carbon is sp hybridised. 5. The strength of the following bases decreases in the order (i) Br| (ii) F| (iii) NH2| (a) iv > iii > ii > i (b) iii > iv > i > ii (c) ii > i > iii > iv (d) iv > i > ii > iii
(iv) CH3|
6. Choose the following species that would be predicted to be aromatic according to Hückel’s rule. H H H H N B (i) (ii) (iii)
(a) i
(b) ii
(c) iii
(d) i and ii
1.17
1.18
chapter one 7. Rank of the following three compounds in decreasing order of basicity is O NH2 NH2 NHCCH3 (ii) (i) (iii)
(a) iii > i > ii
(b) iii > ii > i
(c) ii > i > iii
(d) ii > iii > i
8. Which of the following phenol would be the most acidic? (a) HO
(c)
O
(b) HO
C
H3C
N
HO
9. Choose the correct formula for epinephrine. HO
CH3 N H OH
HO
10.
OMe
O
(d)
HO
(a) C10H13NO3
CH3
(b) C9H12NO3 dil. H2SO4
(c) C10H14NO3
Major product is?
OMe OH (a)
(b)
O (c)
(d)
(d) C9H13NO3
O
O
11. Which is an acceptable resonance structure for the following drawing? H ⊕ C–O H CH3 ⊕ CH3CH − OH (a) ⊕ CH2CH2O (c)
⊕ (b) CH2 = O − CH3 ⊕ CH3CH=OH (d)
12. In allene (H2C = C = CH2), the terminal carbons are sp2 hybridised. Each of the two terminal H2C groups are situated in such a manner that the two “terminal” planes are 90º from each other. Other compounds with double bonds on successive carbons may also exist. They are called cumulenes. What is the relationship between the two terminal H2C groups in a cumulene containing three consecutive double bonds (H2C = C = C = CH2)?
general organic chemistry
(a) They are in perpendicular planes. (b) They are in two planes 60º from each other. (c) They are in the same plane. (d) They are in two planes 120º from each other.
13.
OH
O
Conc. H2SO4
Product is ?
O (a)
O
O
(c)
O
(b)
(d) None of these
14. Alkyne hydrogens are more acidic than alkene or alkane hydrogens because (a) The alkyne carbon has higher ‘s’ character. (b) The anion formed is more stable. (c) The electrons in the sp orbital are closer to the nucleus. (d) All of the above. 15. Which of the following is expected to be the least basic? NH2
(a) CH3CH2CH2NH2
(b)
C–CH3 O
NH2 (c)
(d) (CH3)3N Me
16. HO
dil. H2SO4
HO
O
Me
(a) HO
(b)
HO
HO
O
O (c) HO
Major product is?
(d)
1.19
1.20
chapter one 17. The acidity of the protons H in each of the following is H H (i)
H (ii) (iii)
(a) i > ii > iii
(b) ii > iii > i
(c) i > iii > ii
(d) iii > i > ii
18. The acidity of the protons H in each of the following is O
HO
HO
O
(a) i > ii > iii
OH
O
HO (ii)
(i)
OH
OH O
(iii) O
O O (b) iii > ii > i
O
O (d) iii > i > ii
(c) i > iii > ii
19. Identify correct acidic strength order in the following compounds HO B HO OH HO OH B B OEt (ii)
(i)
(iii)
OEt
(a) i > ii > iii
(b) ii > iii > i
OEt (d) iii > i > ii
(c) ii > i > iii
20. Identify correct acidic strength order in the following compounds HO HO OH B HO OH B B NO2 (ii)
(i)
(a) i > ii > iii
OH
(iii) NO2
OH
(b) iii > ii > i
NO2
(c) i > iii > ii
(d) iii > i > ii
21. Identify correct acidic strength order in the following compounds H3C (i) H
O
H3C (ii)
H3C
O
(iii)
H N
(a) i > ii > iii
(b) ii > iii > i
(c) i > iii > ii
O
H N (d) iii > i > ii
general organic chemistry 22. Identify correct acidic strength order in the following compounds H (i) O
H
H N
O (ii) O
O
(iii) O
O O
(a) ii > i > iii (c) i > iii > ii
(b) ii > iii > i (d) iii > i > ii
23. Identify correct acidic strength order in the following compounds
(i) N
H
H
H O O (ii)
N
O O (iii)
N
N H
(a) i > ii > iii (c) i > iii > ii
(b) ii > iii > i (d) iii > i > ii
24. Identify correct acidic strength order in the following compounds
(ii)
H
H3C
CH3
(iii) H
H (i)
(a) i > ii > iii (c) i > iii > ii
(b) ii > iii > i (d) iii > i > ii
25. Identify correct acidic strength order in the following compounds (ii) HO O OH (i)
(a) i > ii > iii (c) i > iii > ii
OH (iii)
(b) ii > iii > i (d) iii > i > ii
O
1.21
1.22
chapter one 26. Identify correct acidic strength order in the following compounds O (ii) O H
(i) H
O H (iii)
(a) i > ii > iii
(b) ii > iii > i
(c) i > iii > ii
(d) iii > i > ii
27. Identify correct acidic strength order in the following compounds (ii) H
(i) H
(iii) H
S S
(a) i > ii > iii
(b) ii > iii > i
(c) i > iii > ii
(d) ii > i > iii
28. Identify correct acidic strength order in the following compounds H (ii)
(i)
CH2
HC
(a) i > ii > iii
(iii)
(b) ii > iii > i
(c) i > iii > ii
(d) iii > i > ii
29. Identify correct acidic strength order in the following compounds
(i) HO
O
(ii)
(iii)
HO
(a) ii > i > iii
OH
(b) ii > iii > i
(c) i > iii > ii
(d) iii > i > ii
30. The acidity of the protons H in each of the following is ⊕ NMe3
(i)
H
(a) i > ii > iii
⊕ PMe3
(ii)
(b) ii > iii > i
H
CH3 H
(iii)
(c) ii > i > iii
(d) iii > i > ii
general organic chemistry 31. The acidity of the protons H in each of the following is O O O S (i) S O
O (ii)
O (a) i > ii > iii
H
(iii)
S O
H
O (b) ii > iii > i
H
O (c) i > iii > ii
(d) iii > i > ii
32. Identify correct acidic strength order in the following compounds
(i) H
(ii)
(a) iii > ii > i
H
(b) ii > iii > i
(iii)
H
(c) i > iii > ii
(d) iii > i > ii
33. Identify correct acidic strength order in the following compounds (i)
H H (ii) (iii) H
(a) i > ii > iii
(b) ii > iii > i
(c) i > iii > ii
(d) iii > i > ii
34. Identify correct acidic strength order in the following compounds H H H (i) O
O
(ii) (iii) S S O S
(a) i > ii > iii
(b) iii > ii > i
(c) i > iii > ii
(d) iii > i > ii
35. Identify correct acidic strength order in the following compounds H NC (i)
CN
NC
NC
H
NC CN (iii)
(ii)
CN
H
CN
(a) i > ii > iii
NC
NC (b) ii > iii > i
(c) i > iii > ii
CN (d) iii > i > ii
36. Identify correct acidic strength order in the following compounds
(i)
OH
OH
OH
(ii) N N (iii)
(a) iii > ii > i
(b) ii > iii > i
(c) i > iii > ii
N (d) iii > i > ii
1.23
1.24
chapter one 37. Identify correct acidic strength order in the following compounds OH OH HOOC HOOC HOOC (i) (ii) (iii)
HO (a) i > ii > iii
(b) ii > iii > i
(c) i > iii > ii
(d) iii > i > ii
38. Identify correct acidic strength order in the following compounds t-Bu OH HOOC HOOC t-Bu (i) (ii) (iii)
t-Bu (a) i > ii > iii
(b) ii > iii > i
(c) i > iii > ii
(d) iii > i > ii
39. Identify correct acidic strength order in the following compounds HOOC
HOOC (i)
(ii)
NO2
CN
HOOC (iii) CH3
(a) i > ii > iii
(b) ii > iii > i
(c) i > iii > ii
(d) iii > i > ii
40. Identify correct acidic strength order in the following compounds HOOC
HOOC (i)
(ii) O2N
NO2
HOOC
NO2
NO2 NO2
(iii) NO2
(a) i > ii > iii
(b) ii > iii > i
(c) i > iii > ii
(d) iii > i > ii
41. Identify correct acidic strength order in the following compounds HO HOOC HO3S (i)
(a) i > ii > iii
(ii) (b) ii > iii > i
(iii) (c) i > iii > ii
(d) ii > i > iii
general organic chemistry 42. Identify correct acidic strength order in the following compounds HOOC
CH3
(i) H3C
HOOC
H
HOOC
(ii) CH3
(a) i > ii > iii
H
(iii) Cl
(b) ii > iii > i
CH3
H
(c) i > iii > ii
(d) iii > i > ii
43. Identify correct dipole moment order in the following compounds O O (i) (ii) (iii) H2C H3C CH CH3 H3C 3
(a) i > ii > iii
(b) ii > iii > i
(c) i > iii > ii
CH3
H3C
CH3
(a) i > ii > iii
NO2
NO2
H3C (i)
O
(d) iii > ii > i
44. Identify correct dipole moment order in the following compounds NO2
CH3
(ii)
(iii)
CH3
(b) iii > ii > i
(c) i > iii > ii
(d) iii > i > ii
45. Identify correct dipole moment order in the following compounds Cl
Cl
(i) H3C
(a) i > ii > iii
Cl
CH3
(ii)
Cl
(iii)
H3C
CH3
Cl
H
(b) ii > iii > i
Cl
(c) i > iii > ii
Cl (d) iii > i > ii
46. Identify correct dipole moment order in the following compounds Cl Cl Cl Cl (i)
(ii)
(iii)
Cl
(a) i > ii > iii
Cl
(b) ii > iii > i
(c) i > iii > ii
(d) iii > i > ii
47. Identify correct acidic strength order in the following compounds HOOC
CH3
(i) NC
(a) i > ii > iii
HOOC
H
(ii) CH3 (b) ii > iii > i
HOOC
H
(iii) Cl
CH3 (c) i > iii > ii
H
CH3
(d) iii > i > ii
1.25
1.26
chapter one 48. Identify correct stability order in the following compounds CH+2 CH+2
(i)
(ii)
H3C
(iii)
CH3
(a) i > ii > iii
CH+2
CH3
(b) ii > iii > i
(c) i > iii > ii
(d) iii > i > ii
49. Identify correct stability order in the following compounds C+
O (i) O
CH+ O O O O (ii) (iii) CH+
(a) i > ii > iii
(b) ii > iii > i
(c) i > iii > ii
(d) iii > i > ii
50. Identify correct stability order in the following compounds CH3
H3C CH
(a) i > ii > iii
+
H3C
(b) ii > iii > i
CH3 NH + CH H3C
CH3
NH + C CH3
(c) iii > ii > i
(d) iii > i > ii
51. Correct order of stability of the following carbocation is ⊕ ⊕ ⊕ CH2 CH2 CH2 (i)
(ii)
CD3
CH3
(iii)
(a) i > ii > iii > iv (c) ii > i > iv > iii
⊕ CH2 (iv)
CH3 H (b) i > ii > iv > iii (d) i > iv > ii > iii
52. Which nitrogen in LSD is most basic? (1) H–N
O
(2) N
(a) 1 (c) 3
(3) C–N(C2H5)2
CH3 (b) 2 (d) All are equally basic
CD3
general organic chemistry 53. Which one of the following ion is aromatic? ⊕ (a) (b) (c) (d) ⊕ H ⊕ OH 54. Arrange the following carbocations in decreasing order of their stability? CH3 ⊕ ⊕ (i) (ii) (iii) (iv) ⊕ ⊕ CH3
CH3
(a) i, ii, iii, iv
(b) i, ii, iv, iii
(c) i, iii, ii, iv
(d) iv, iii, ii, i
55. Arrange the following in decreasing order of their solubility in water or extent of hydrogen bonding with H2O (i)
O (a) i, ii, iii
(ii) (iii) O (b) iii, ii, i
O (d) iii, i, ii
(c) ii, iii, i
56. The decreasing order of basic strength is (5) H2N
(4) NH •• N (3)
••
(1) N
•• H2N
(a) i > v > iii > iv > ii (c) v > iv > i > ii > iii
•• N (2) CH3 (b) iv > i > v > iii > ii (d) iv > v > iii > i > ii
57. What is the major product obtained from the following reaction? O C – OH H – O – CH2– CH ⊕ H – N – HCl
1 mole NaOH
H O
O
C – OH
C – O
(a) H – O – CH2 – CH H–N H
(b) H – O – CH2 – CH ⊕ H–N–H H
1.27
1.28
chapter one O
O
C–O–H
C–O
(c) O – CH2 – CH ⊕ H–N–H
(d) O – CH2 – CH ⊕ H–N–H
H
H
58. All the following are the resonance structure of one another except ⊕ H2N H2N (a)
⊕
(b)
N+–O–
N+ – O–
O
O
H2N
H2N
(c)
O–
⊕
(d)
N+– O–
N+ – O– O
59. Which of the following shows minimum heat of combustion? (a)
(b)
(c)
(d)
60. Arrange the following in the decreasing order of their acidic strength HOOC HOOC H COOH (ii) (i) C = C C=C H H COOH H HOOC HOOC H H C=C (iii) (iv) C=C H H CH3 H
(a) i > ii > iii > iv (c) ii > i > iv > iii
(b) iv > iii > ii > i (d) i > ii > iv > iii
61. Arrange the following hydrogens in the order of their acidic behaviour H–C≡C (ii)
⊕ N
H (iii)
N H (i)
(a) i > iii > ii
(b) ii > iii > i
(c) i > ii > iii
(d) iii > ii > i
general organic chemistry 62. Which of the following acid gives evolution of CO2 with NaHCO3? HO (i)
OH
O
O (ii)
HO
NO2
HO (iii) HO
NO2
O
O O
COOH (iv)
COOH
(v)
COOH COOH
(a) i, iii, iv, v
(b) iii, iv, v
(c) i, ii, iii iv, v
(d) i, iii, iv
63. Maximum resonance energy is known for (a)
(b)
(c)
(d)
64. Arrange the following in the order of their heat of hydrogenation, when all of them are converted to n-pentane H3C (i) Me (iii)
(ii)
Me
CH3 Me (iv) CH
(a) ii > iii > i > iv (c) iv > ii > i > iii
(b) i > iv > ii > iii (d) ii > iv > iii > i
65. Most acidic hydrogen among the following is (a)HO OH(b)
O
OH(d) OH(c)
(a) a
(b) b
(c) c
(d) d
66. In which of the following molecule the mesomeric effect does not operate? ••
O ⊕ •• ⊕ O – CH3 N(CH3)3 N≡N NH–C–CH3 (a) (b) (c) (d)
1.29
1.30
chapter one 67. Which is not carbene out of the following?
••
Br C (a) : CH 2 (b) : CCl 2 (c) (d) : CCl 3 Cl 68. Out of the following reagents, pure electrophiles are
(P) R3N (Q) : CCl 2 (R) CH3⊕ (S) H2O (T) H3O⊕ (U) Na⊕
(a) Q, R, T, U
(b) Q, R
(c) Q, R, S, T
(d) Q, R, S, T, U
69. Select the correct statement •• (a) –NH2 is more basic than
••
N
O (b) N
is more basic than N H
O (c)
O is more basic than
–C
O
(d) All of them
70. Which of the following is most basic?
(a) N
(b)
O
O
(c)
N ••
(d) O
N
O
O
N ••
71. Which of the following is most basic? N N
(a)
N
(b)
(d)
N N (c)
N
N N
72. Which is the least likely protonation site in the conjugated alkene shown below? a c
b
d
(a) a
(b) b
(c) c
(d) d
O
general organic chemistry 73. Which of the following is the most stabilised carbocation? OMe
OMe
OMe
+ (b)
(a)
+
(c)
OMe (d)
+
+
74. Which one of the following compounds would you expect to be the strongest carbon acid? O (a)
(b) CH2(COOEt)2
O (c) CH3COCH2COOEt (d)
O
O 75. Which of the following is a pair of resonance structure? + (a) (b) O + (c)
+
OH +
(d) +
76. Rank the following carbocations in increasing order of stability
(i)
⊕
(ii)
(iii) ⊕
(iv) ⊕
⊕
(a) iv < iii < i < ii
(b) iv < i < iii < ii
(c) iii < ii < i < iv
(d) i < iii < ii < iv
77. In which of the following option correctly follow aromaticity? (i)
(ii)
N
(iv)
⊕
:
(vi)
H N
N CH3
(vii)
:
(v)
(iii)
CH3
N
(a) i, iii, iv, vii
(b) iii, iv vi, vii
(c) i, iii, iv, vii
(d) i, iv, vi, vii
78. Which of the following is the correct order for decreasing order of heat of hydrogenation (magnitude)? Me H (i) C=C H C=C H Me (iii) H
H H
(a) i > ii > iii > iv
Me H C=C (ii) H H Me H
Me H Me (iv) C=C H C=C H Me (b) ii > i > iii > iv
(c) iv > iii > i > ii
H CH2 Me H (d) ii > iii > i > iv
1.31
1.32
chapter one 79. Among the following canonical structures of pyridine, the correct order of s tability is ⊕ ⊕
N
(i)
N
N
(iii)
(iv)
N
(ii)
⊕
N
(a) (i = v) > (ii = iv) > iii (c) (i = v) > iii > (ii = iv)
(v)
(b) (ii = iv) > (i = v) > iii (d) iii > (ii = iv) > (i = v)
80. The correct order of stability among the following canonical structures is
O H
O
NH (i)
(a) i > ii > iii
H
H
O
NH
C
H
H
NH
C
(ii) (b) i > iii > ii
H
(iii)
(c) ii > i > iii
(d) iii > i > ii
81. The most stable canonical structure of the given molecule is
O
O⊕ ⊕ O O ⊕ (a) O (b) (c) ⊕ (d)
82. Which of the following order is correct for the acidity of indicated H-atoms? 3
H H2 O
O 1
(a) H 1 > H 2 > H 3 (c) H 2 > H 1 > H 3
H (b) H 3 > H 2 > H 1 (d) H 1 > H 3 > H 2
83. Which is the least likely protonation site in the conjugated alkene shown below? (c) (a)
(d)
(b)
(a) a
(b) b
(c) c
(d) d
general organic chemistry 84. Which of the following carbanion is most stable?
(a)
(b) Ph
(c)
C
(d) H2C
85. Identify correct order of electron cloud in benzene ring for the following compounds O O O (i) (ii) (iii) (iv) N H (a) iv > i > iii > ii (b) iii > i > iv > ii (c) i > iii > iv > ii (d) iii > ii > i > iv 86. Which of the following is antiaromatic? O N O N (a) (b) N (c) (d) B–H N
O
87. The correct order of pKa is OH (a)
COOH >
COOH OH >
HO
COOH OH
>
(b) HClO4 > H2SO4 > HNO3 > HNO2 (c) HOCl > HOF > HOBr > HOI (d) H2O2 > ROH > H2O (R = Et group)
•
88. Which of the following is the strongest base? H H •• • • N O N N •• (a) (b) (c) (d) •
••
89. Among the following compounds which nonaromatic? (a)
(b)
⊕ ⊕
(c) B H
(d)
90. Identify correct order of heat of hydrogenation (a)
i > iv (d) iv
1.41
1.42
chapter one 131. Which of the following pairs of phenol derivative are stronger acid than phenol? (a) i, ii, iv (b) ii, iv, vi (c) i, ii, vi (d) v, iii, vi Passage 2 In a covalent single bond between unlike atoms, the electron pair forming the σ bond is never shared absolutely equally between the two atoms; it tends to be attracted a little more towards the more electronegative atom of the two. This is generally represented as δ+
δ–
––C––Cl
––C––Cl
If the carbon atom bonded to chlorine is itself attached to further carbon atoms, the effect can be transmitted further as C–C–C––C––Cl 4
3 2
1
The effect of Cl on C2 is less than the effect of Cl on C1; however, the transmission quickly dies away in a saturated chain, usually being too small to be noticeable beyond C2. These influences on the electron distribution in σ bonds are known as inductive effects. Electron releasing groups w.r.t. the hydrogen atom are known to have +I effect and e lectron withdrawing groups are known to have –I effect. Electron donating group increases the stability of carbocation and withdrawing group increases the stability of carbanion. 132. Which of the following carbocation is expected to be most unstable? O –NO (a) –C–OH (b) 2 ⊕ ⊕ H2C H2C
–COO
(c) ⊕ H2C
(d) ⊕ H2C
133. Correct order of the stability of the given carbanion is
(i)
(ii)
(iii)
(a) i > ii > iii > iv (c) iv > iii > ii > i
COOH
N
CH3 COOH
(b) ⊕ NH3
CH3 COOH COOH
(c) ⊕ NH3
NO2
(iv)
(b) ii > i > iii > iv (d) iv > iii > i > ii
134. Most acidic compound in aqueous medium is ⊕ NH3 (a)
N
N
CN
COOH
(d) CH3
general organic chemistry Passage 3 Benzoic acid is more acidic than acetic acid. Acidity of formic acid is more than the benzoic acid. Among monosubstituted benzoic acid derivatives, the ortho derivative is most acidic due to ortho effect. Acidity of any acid can be explained by the stability of conjugate base of the acid. 135. Which of the following is most acidic in character? (a) o-nitrobenzoic acid (b) p-nitrobenzoic acid (c) m-nitrobenzoic acid (d) Benzoic acid 136. Which conjugate base is most stable? COO CH3 (b) (a)
(c) CH3
COO
COO
COO
(d) CH3
NO2
137. Arrange acidity of the given compounds increasing order (i) p-nitrophenol (ii) p-fluorophenol (iii) p-chlorophenol (a) (i), (ii), (iii) (b) (ii), (i), (iii) (c) (ii), (iii), (i) (d) (iii), (ii), (i) Passage 4 When (C–H) sigma electrons are in conjugation with pi bond, this conjugation is known as σ (C–H) π conjugation, excessive conjugation or hyperconjugation. (i) Compound should have at least one sp2-hybrid carbon of either alkene, alkyl carbocation or alkyl free radical. (ii) α-carbon with respect to sp2 hybrid carbon should have at least one hydrogen. (iii) Resonating structures due to hyperconjugation may be written involving “no bond” between the alpha carbon and hydrogen atoms. H H–C–CH=CH2 H
⊕ H H–C=CH–CH2 H
H ⊕ H C=CH–CH2 H
H
H–C=CH– CH2 H⊕
In the above resonating structures there is no covalent bond between carbon and hydrogen, and from this point of view, hyperconjugation may be regarded as “no bond resonance”. Actually the hydrogen atom is not free from the carbon. These resonating structures only suggest that: (a) there is some ionic character between C–H bond and (b) carbon–carbon double bond acquires some single bond character. We can explain the stability of alkene, carbocation and carbon free radical on the basis of hyperconjugation. 1 Stability of alkene ∝ number of α–H ∝ Heat of hydrogenation
138. Which of the following statements are correct for C6H5–CCl3? (a) CCl3 group is electron withdrawing due to the –I effect and reverse hyperconjugation. (b) CCl3 group is meta directing due to the –M effect. (c) CCl3 group is o, p-directing because it is +R group. (d) CCl3 group can exert +M effect.
1.43
1.44
chapter one 139. Which of the following has the lowest heat of hydrogenation? (a)
(b)
(c)
(d)
140. Carbon–carbon double bond length will be maximum in which of the following compounds? CH3
(a) CH3–CH=CH2 (b) CH3–CH=CH–CH3 (c) CH3–C=C–CH3 (d) CH2=CH2 CH3
Passage 5
For a compound to be classified as aromatic, it must fulfill both of the following criteria. (i) It must have an uninterrupted cyclic cloud of π electrons above and below the plane of the molecule (often called a π cloud). For the π cloud to be cyclic, the molecule must be cyclic. For the π cloud to be uninterrupted, every atom in the ring must have a p orbital. For the π cloud to form, each p orbital must be able to overlap with the p orbitals on either side of it. Therefore, the molecule must be planar. (ii) The π cloud must contain an odd number of pairs of π electrons. Benzene is an aromatic compound because it is cyclic and planar, every carbon in the ring has a p orbital and the π cloud contains three pairs of π electrons. The german chemist Erich Huckel was the first to recognise that an aromatic compound must have an odd number of pairs of π electrons. He described this requirement by what has come to be known as Huckel’s rule, or the 4n + 2 rule. The rule states that for a planar, cyclic compound to be aromatic, its uninterrupted π cloud must contain (4n + 2) π electrons, where n is any whole number. According to Huckel’s rule, then an aromatic compound must have 2 (n = 0), 6(n = 1), 10 (n = 2), 14 (n = 3), 18 (n = 4), etc. π electrons. Because there are two electrons in a pair, H uckel’s rule requires that an aromatic compound must have 1, 3, 5, 7, 9, etc. pairs of π electron. Thus, Huckel’s rule is just a mathematical way of saying that an aromatic compound must have an odd number of pairs of π electrons. For an anti-aromatic system a planar, cyclic compound must contain (4n) π electrons. 141. Which one of the following compounds is non-aromatic?
(i)
(ii)
(iii)
(iv)
(a) only i
(b) i and iv
(c) ii, iii, iv
(d) i and ii
general organic chemistry 142. Which of the following will show aromatic behaviour?
(a)
O
N N (b)
⊕
(c)
N H
(d) ⊕
143. Which of following is a non-aromatic system? (a) B H
O ⊕ (c) (d) O O (b) N H H
Passage 6 For each of the questions 149–154 about QUININE (shown right), select the answer from those provided. 10
9 3 2
4 8 7
HO
24
12
N
5
1
6
11
21
O
23
20 19 18
144. What is the oxidation state of C11? (a) +1 (b) 0
22
13
17
N
14 15
QUININE
16
(c) –1
(d) –2
145. Of the following list, which atom(s) is (are) sp3 hydridised? (a) O12 (b) N16 (c) C21
(d) N1
146. Which of the following carbon atoms are tertiary? (a) C24 (b) C19 (c) C20
(d) C22
147. Which carbon atom(s) is (are) ortho to a methoxy group? (a) C5 (b) C6 (c) C7
(d) C21
148. Which of the following functional groups are found in QUININE? (a) Alcohol (b) Amide (c) Ester (d) Ether 149. How many units of unsaturation are there in QUININE? (units of unsaturation are the same as the index of hydrogen deficiency or IHD) (a) 7 (b) 8 (c) 9 (d) 10 Passage 7 In the year of its launch, VIAGRA (below) was used by over three million satisfied customers. Each of the questions below refers to the structure of VIAGRA. Now select the answer(s) from the options provided.
1.45
1.46
chapter one H3C
H3C
21a
32
33
26
19
27
18 17 28
N
Me
23
22
24
31
O
14
20
N
21
5 12
15
N
N
25
13
O
N
CH3 9
4
11 16
H
6
S O
7
8
N 1
O
3 2
10
30
29
150. What are the oxidation states of C3 and N25? (a) -1, -2 (b) +1, -2 (c) -1, +3 (d) -1, -3 (e) +1, -3 151. What is the functional group in the circle? (a) amide (b) amine (c) aniline
(d) nitrile
152. What is the functional group in the rectangular box? (a) epoxide (b) amine (c) ester
(d) ether
153. How many units of unsaturation are there in VIAGRA? (a) 7 (b) 8 (c) 11 (d) 12 (e) 13 154. In VIAGRA, what are the hybridisations of O10, N4 and N28, respectively? (a) sp3, sp3, sp3 (b) sp2, sp3, sp3 (c) sp3, sp2, sp3 (d) sp2, sp3, sp2 155. In VIAGRA, what are the hybridisations of C2, C3 and N24, respectively? (a) sp3, sp3, sp3 (b) sp2, sp, sp3 (c) sp3, sp2, sp3 (d) sp3, sp3, sp2 156. How many carbon chiral centres are there in VIAGRA? (a) 0 (b) 1 (c) 2
(d) 3
Matrix Type 157. Column I (Groups)
Column II (Effect)
⊕
− N Me 3 (p) (a) +I ⊕
− P Me 3 (b) (c) –OMe (d) –CH3
(q) –I (r) +R (s) –R (t) +H
158. Column I
Column II
(a) and
(p) (i) compound has more heat of hydrogenation than (ii)
general organic chemistry
(b)
and
(c)
(q) (i) compound has more resonance energy than (ii) compound
and
(d)
and
(r) (i) compound is more stable than (ii)
(s) (ii) compound has more heat of hydrogenation than (i)
(t) (ii) compound has more degree of unsaturation than (i)
159. Column I
Column II
⊕ (a)
(p) Hyperconjugation
⊕ (b)
(q) All carbon atoms are sp2-hybridised
(c)
(r) Aromatic
CH3 ⊕ (d)
(s) Resonance
(t) Diamagnetic
160. Column I Column II
(a)
(b)
(c)
(d) C8H8
(p) Aromatic
(q) Antiaromatic
(r) Readily reacts with metal to form stable dianion (s) Paramagnetic in nature due to presence of unpaired electrons in molecular orbitals (t) Diamagnetic in nature due to presence of even electrons in molecular orbitals
1.47
1.48
chapter one 161. Column I Column II
⊕ N
(a)
H
(p) Aromatic
H H (b) B
(q) Antiaromatic H N
(c)
(r) Nonaromatic
N
N
H N
H
B (d) N H
H
B N B
(s) Degree of unsaturation = 3
H
H 162. Column I (Reaction)
Column II (Product)
+ D2 (1 Eq.) Ni → product
(a)
Me (b) H Me
H Me
4 + Br2 CCl → product
(p) Contains even chiral carbons
(q) Contains odd chiral carbon
Me I O /CH Cl
(c)
Me
3 2 2 → product II Mes S
−
+
CH3 S Na → product Br DMSO
(d) Me
(r) Optically inactive
(s) Contains plane of symmetry
163. Column I Column II O O
O O
(a) HO
O NH
(p) Total number of functional groups in the compound is even. [excluding >C=C< bond]
general organic chemistry S C – SH (b)
(q) Total number of functional groups in the compound is odd. [excluding >C=C< bond]
NHMe
C – OMe O (c) MeO
OH
(r) Degree of unsaturation in the compound is even
N Me O
O O
(d)
(s) Degree of unsaturation in the compound is odd
O
O
(t) Lactone is present as a functional group in the molecule
O
164. Column I
Column II
(a)
(p) Antiaromatic
⊕
(b)
(q) Aromatic
(r) Nonaromatic
⊕ (c) O (d)
(s) Degree of unsaturation (D.O.U) = 6
165. Column I (group) (a)
(b)
Column II (effect of group)
and
and
(p) Ist compound has more heat of hydrogenation than the IInd (q) Ist compound has more resonance energy than the IInd
1.49
1.50
chapter one
(c)
and
(d)
and
(r) Ist compound is more stable than the IInd
(s) IInd compound has more heat of combustion than the Ist
(t) IInd compound has more degree of unsaturation than the Ist
166. Column I (compound)
Column II (relationship)
OH (a)
(p) Aromatic
OH OH (b)
(q) Nonaromatic
OH (c)
O
(d)
(r) Dipolemoment is nonzero
(s) Antiaromatic
(t) Dipolemoment is zero
167. Column I Column II Me
(a)
(p) Compound which is optically active
Me
Me Me (b) Me
(q) Compound which is optically inactive due to the presence of plane of symmetry and gives optically inactive hydrogenation product (major product)
general organic chemistry Me (c)
(r) Compound which is optically active but gives optically inactive hydrogenation product (major product) with 1 equivalent of H2 and metal
Me (d)
(s) Degree of unsaturation in compound = 2 (t) Compound which give optically active product on ozonolysis
Integer Type 168. From the following compounds/ions: ⊕
⊕
(a) CH 3 (b) NH 4 (f ) PCl3 (g) PCl5
(c) BF3 (h) SbCl5
|
(d) NH3 (i) GaCl3
(e) NH2–NH2 (j) AlCl3
(k) F– (l) CN (m) CH3–Cl [“C” atom of halide] Identify value of “X”. Where “X” is the total number of E⊕/electrophiles.
169. From the following compound (a)
C8 H8 (b) C14H14 (c)
[ COT ]
N −2 4
+ 4
(d) C 4 H (e) C 4 H (f) N O H
(g) N H
(h) (i)
O Identify the total number of aromatic compounds. 170. The following compounds are phenol derivative OH (a) CH3
OH
OH NO2
(b)
(c)
NO2
OH
Cl
NO2 (d) (e) OH
OH
OH NO2
H3C
CH3
(f) NO2
CH3
1.51
1.52
chapter one If number of phenol derivative = x. Number of phenol derivative gives +ve test with NaHCO3 = y. Then, find value of x + y. 171. How many products will be aromatic ion when AgNO3 reacts with the following O compounds? (a)
Cl (b)
Cl (c)
(d)
Cl
Cl Cl
(e)
CH2 – Cl (f)
(h) H –C ≡ C –Cl
CH2 –Cl (g)
172. How many carbocations undergo rearragements? ⊕
⊕ C (ii) (iii) ⊕ OH
(i)
⊕ CH2
(iv)
(vii)
(x)
⊕
⊕
⊕ (viii) CH 2 = CH (ix)
Ph + CH 2 = CH − CH 2 (xii) (xi) Ph
+ HC – CMe2
173. How many compounds are soluble in aqueous NaHCO3? OH COOH
OH H3C (b)
(a) O–
N+
OH (d)
COOH HO HO OH (f) (e) HO
O O O O
OH
N
CH3 (c) H3C
O
CH3 (g)
Me
⊕ ⊕ C – CH3 (vi) Me C − CH − CH 3 2 2
(v)
OH ⊕ CH2
Me
(h) H –C ≡ C –H
general organic chemistry 174. How many compounds are soluble in aqueous NaOH? (a)
COOH
OH
HO
H3C (c)
(b) HO
O O–
OH
OH
COOH N+ O HO OH (e) (f)
(d) CH3
(g)
N+O–
+ O– N O
OH
OH
O
(h)
N
CN
175. How many compounds liberate hydrogen gas on reaction with Na metal? OH O (b)
(a) OH (d)
HO
(f) CH4
OH
O
HO
COOH CH3
OH
COOH HO OH (e)
CH3 O (g)
OH
H3C (c)
O (h) OH
Cl
176. How many transition states are formed during the following reaction? Con. H2SO4 OH
∆
177. How many transition states are formed during the following reaction? HO Con. H2SO4 ∆
1.53
1.54
chapter one
Answer Keys Level 1 1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
d
c
d
a
a
d
b
c
d
a
c
d
d
a
a
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
b
c
d
b
b
a
b
d
a
d
a
c
a
d
d
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
b
d
a
b
d
b
a
c
d
c
d
c
c
a
bc
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
d
ac
b
c
a
a
a
c
b
b
c
a
a
b
c
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
b
d
c
b
b
a
c
d
b
d
d
a
d
c
a
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
cd
c
a
c
b
d
b
b
d
d
a
c
b
b
c
91
92
93
94
c
a
a
c
Level 2 1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
c
d
b
d
a
b
b
c
b
c
b
c
a
abcd
b
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
d
a
b
c
b
b
a
b
b
d
a
d
c
a
c
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
a
a
a
b
d
a
a
c
a
a
d
b
d
b
a
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
a
a
a
b
c
b
b
a
a
a
b
b
c
a
d
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
d
c
d
d
c
a
d
b
c
c
c
a
d
a
a
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
a
b
d
a
b
b
a
a
c
b
a
a
c
d
bcd
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
ab
abc
abd
abcd
bcd
abd
bc
b
bcd
d
abc
ac
acd
cd
bc
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
ad
abc
bd
bcd
bc
acd
bc
b
bc
bc
c
ab
abcd
acd
acd
general organic chemistry 121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
ab
abc
acd
abcd
abd
bc
abc
abcd
d
a
a
b
d
c
a
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
d
c
a
d
c
c
b
b
a
ad
cd
d
ad
d
c
151
152
153
154
155
156
a
b
c
d
d
a
157(a) 157(b) 157(c) 157(d) 158(a) 158(b) 158(c) 158(d) 159(a) q
qs
qr
pt
p
p
qrs
st
qrst
159(b) 159(c) 159(d) 160(a) 160(b) 160(c) 160(d) 161(a) 161(b) 161(c) 161(d) 162(a) 162(b) 162(c) 162(d) qrst
qrst
p
qrs
qrs
pt
r
rs
qs
p
p
prs
prs
q
rs
163(a) 163(b) 163(c) 163(d) 164(a) 164(b) 164(c) 164(d) 165(a) 165(b) 165(c) 165(d) 166(a) 166(b) 166(c) pst
qs
qr
qst
q
166(d) 167(a) 167(b) 167(c) 167(d) rs
qs
prs
prst
prst
p
p
rs
rst
p
qrs
qrs
pr
qr
qr
168
169
170
171
172
173
174
175
176
177
8
5
8
4
8
4
7
6
5
7
1.55
1.56
chapter one
Workbook Exercises Exercise 1 Correct Acidic Strength of Compounds
1.
OH
OH
OH
2.
OH
OH
OH Cl
CH3
CH3
Cl Cl
CH3
3.
OH
OH
OH
4.
OH
OH
OH
Br
F
Br
F
Br
5.
OH
N+
O–
F
7.
OH
OH
O N+
6.
CN
CN CN
O–
OH
OH
O–
O
N+ O
OH
OH
OH
OH
8.
OH
OH
OH
OH
9.
O–
OH
NC
CH3 H3C
H 3C
OH
OH
F
OH
Cl
10.
N+
CN O
OH
H3C
CH3
D3C
OH
OH
T3C
general organic chemistry 11.
OH
OH
Br
Cl
13.
OH
O–
15.
12.
HN–
14.
OH
NC
19.
Cl
21.
COOH
COOH
OH
CH3
CD3
CT3
COOH
HO
H2N
COOH
COOH
20.
COOH
NC
COOH
22.
COOH
T 3C
D 3C COOH
H 3N +
OH
OH
COOH
H 3C
COOH
OH
N+
18.
Cl
F COOH
OH
O–
Br
COOH
H 3C
OH
16. O
17.
NMe3
OH
H 3C
OH F
+
H 3 N+ OH
OH
OH
H2N OH
OH Cl
OH
COOH
COOH
+
H 3C
NMe3
COOH
COOH
COOH
Cl O–
HN–
H3C
Cl Cl
COOH
23.
COOH
COOH
H3C
24.
COOH
COOH
COOH
HO
H3C
OH CH3
OH
1.57
1.58
chapter one
25.
COOH
COOH
COOH
COOH
26.
CH3
H3C H 3C CH3
H3C O–
N+
27.
CH3
O–
O
COOH HO
29.
N+
O–
O
N+ O
COOH HO
HO
N+
28.
COOH
OH
O–
CH3
H3C
CN
COOH OH
OH
OH
O
CH3
H3C
COOH
COOH
30. HO
OH B
CH3
N+
B O–
O–
31.
HO
OH
HO
OH
32.
B
B
OH
HO
O
N+ O
COOH
COOH
MeO
Cl
Cl OH
33.
N+
35.
OH
OH
O–
O–
OMe
O
O N+
34. O–
N+
O–
OH
O–
O
N+
H3C
CH3
OH
OH
OH
O
O–
O
O N+ – O
N+
N+ O
O
OH
O N+
N+ O
OH
O–
36.
O–
OH
N+
O
OH
O–
N+
O
OH
MeO
CH3
OMe O–
COOH
37.
COOH
N+
COOH
H2N
OMe
O
38.
COOH H3C
H 3C
COOH
COOH CH3 CH3
CH3 CH3
H 2N NH2
general organic chemistry
1.59
Exercise 2 Correct Carbocation Stability Order
1.
H2C+
CH3 H3C
+ 2 CH
1
3.
5.
H3C
CH3
3
H3C
C+
C+
C+
6.
H3 C
CH+2
10.
CH3
C+
CH+
3
CT3
CD 3 T3C T3C
C+
CH+2
2
C+
12.
3
CH+2
CH+2
CH3
CD3
2
3
CH+2
1
NO2
CH3
2
CH3
CH3
C+
D3 C
C+
CH+2
CH+2
2
3
CH3
CD3
CT3
CH+2
CH+2
CH+2
HC+
CH3
CH3 1
14.
3
H3C
CH+2
1 1
CH3
3
CN
H3C
NO2
3
CH+2
2
3
2
CH+2
8.
CH+2
CN
2
2
CH3 D 3 C
1
CH+2
CH3
3
CH3
H 3C
1
CT3
CH+2
C+
CH+
H3C
CH+
3
CD3
1
13.
CH3
H3 C
CH3
1
CH3 CH3
1
CH3
CH3
2
CH+2
11.
4.
CH+
2
9.
CH3 H2C+
C+ CH3
1
HC+
1
H3C
H3C
1
7.
2.
CH3
CH3
2
C+
HC+
1
CH3
C+
3
CH3
CH3 C+
CH3 H3C
2
CH3 H3C
CH+2
CH+2
Cl
2
3
Br
3
CT3
CH3
1.60 15.
chapter one CH+2
CH+2
CH+2
Ph
CH+2
16.
1
NH2
OH
1
2
C+ Ph
2
3
3
CH+2
17.
Ph
CH+
CH+2
CH+2
18.
CH3
CH+2
1
1
H3 C
19.
CH3
CH+2
2
CH+2
20.
21.
2
3
3
1
CH3
22.
H3 C
C+
CH3
CH3
CH+2
CH+2
CH+2
H3C
C+
HC+
1 2
3
2
CH+2
1
2
C+
3 1
23.
H3C
CH3
C+
CH3
H3C
CH3
H3C
2
24.
CH3
H3C
C+
CH+
1
2
H3C
CH + 1
27.
C+ HN HN 1
NH CH +
H3C
C+ 3 CH3
3
NH O
26.
CH+
3
C+ O
O
CH+ O O
CH+
CH+ O O
HN
NH
C+
H3C
CH+
2
CH3
NH
2
NH O
2
CH3
O
3
CH3
CH3
CH3 O CH+ H C 3
H3C
1
CH+
25.
C H+
3
CH3
CH+2
CH3
CH+
CH3
1
CH+ HN
NH
4
28.
2
3
CH +
CH+2 CH+2
1
2
4
H3C
C+ CH3
3
4
CH3
general organic chemistry 29.
H 3C
H 3C
CH+
H 3C CH3 H3C
H3C H3C
1
CH+
C+
32.
3
CH3 CH +
C+
34.
CH3
1
CH+
2
CH+
3
C+ CH+
CH3 H3C
2
2
CH+
2
CH3
H3C
3
CH+
3
O
O
CH+
CH+
1
3
H3C
CH+
1
CH+ 1
H3C
H3C H3C
CH3
2
30.
CH3
CH3 CH3
3
H3C
1
35.
CH 2 H C 3
2
C+
C+
+
CH+
1
33.
CH3
2
CH+
31.
H3C
2
O
3
CH+
1.61
1.62
chapter one
Exercise 3 Identify localised and delocalised lp in the following examples
1.
H N
..
..N
2.
..N
..
4.
.. ..
5.
N N
..N
N H
..
8.
..N
11.
13.
..O
..N
9.
..
N H
..
..
..O
12.
..O
..N
.. ..O
14.
NH
..O
H N
NH
15.
H
H
..N
..N
..N ..NH
..O 16.
..
..
NH
HN
..
NH
17.
..O
..
H 2N
..N
..
..N
..
..
..N
..
H2N
H
N
H N
NH2
6.
..
..
7. HN ..
N
N
10.
H2N
N
..N
3.
..O ..
18. H3C
..N ..N CH3
general organic chemistry
19.
..NH
..
HN
..N
20.
..
21.
NH
..N H
..
..NH
H2N
22.
2
..HN ..NH
23. N ..
..NH
..
..O
H
HN
..NH
26.
..
O
..N
..
..N 25.
24. HB
27.
H
..N
..NH2
H2N
..N
..N H
..
28.
NH2
29.
30.
NH
HN
NH NH2 NH
H3C
..NH
31.
.. ..NH HN
CH3
N
32.
..NH
H
..N ..N H
..O
..NH
1.63
1.64
chapter one
Exercise 4 Identify the site of electrophilic attack at benzene ring
1.
O
2.
O
4.
5.
O
7.
O
NH
6.
O NH CH3
H3 C
8.
O
9.
O
O
N
CH3
10.
O
CH3
H3C
O
O
NH
3.
O
O
O
11.
12.
CH3
CH3
CH3
CH3 H3C
13.
O– O
CH3
14.
H3C
CH3
CH3
15. H C 3
N+
CH3
CH3
CH3
CH3 O
CH3 O
CH3
16.
CH3
17.
18.
general organic chemistry O
19.
CH3
H3 C
20.
O
21.
O
CH3
H3 C
22.
23.
CH3
24.
H3C
CH3 CH3
N O
O
O
HN
O CH3
O CH3
25.
CH3
26.
27.
NH
CH2
N
O
–
28.
CH2 O
29.
O
O S
30.
O
NH
O
31.
O
NH
CH3
CH3
CH3 CH3
CH3
32.
O NH H2 N O
34.
H 3C H3C
NH
CH3
CH3
CH3
33.
O
CH3
CH3
CH3
1.65
1.66
chapter one
Exercise 5 Identify the correct order of resonance energy for the following pairs of compounds
1.
3.
O
O
2.
4.
O O
5.
7.
O
9.
S
11.
8.
O
H N
S
13.
6.
10.
O
CH–
CH+ H N
O
CH–
CH+
NH2
14.
HN
15.
CH+
12.
O
CH–
16.
S S
HN
17.
19.
NH2
NH2
O
O
18.
20.
H B
H2N B H
general organic chemistry 21.
23.
H B
H B
O
N H
CH+
CH+2
22.
24.
27.
29.
33.
35.
37.
30.
32.
CH+
CH+2
CH– CH–2
CH+2
28.
CH–
CH+
26.
CH+
CH+
O
25.
31.
CH+
34.
36.
CH–
CH –
CH +
CH –2
1.67
1.68
chapter one
Solution for Workbook Exercises Exercise 1 Acidic Strength of Compounds OH
OH
OH
OH
OH
OH
CH3
1.
Cl
2.
CH3 CH3
2>1>3
OH
OH
Cl Cl
3>2>1
OH
OH
OH
OH
F
Br
3.
4.
Br Br
F
3>2>1
OH
OH
OH
O
N+
+
N O
O N
5. −
F
OH
−
O
CN
O
6. CN CN
O
OH
OH
OH
OH
+
−
1>3>2
3>2>1
3>1>2 OH
OH
OH OH
7.
8.
OH
2>3>1 OH
O
F 1>2>3
Cl
−
+
N
O
OH
OH
OH
9. NC
CH3 H3C
H3C
OH
2>1
OH
10. H3C
T3C D3C 1>2>3
CH3 CN
OH
general organic chemistry OH
OH 11.
Br H2N 1>2>3
Cl
OH
OH
OH 12. H3N
+ H3C NMe3 1>2>3
+
OH OH
−
14.
−
HN H3C 3>1>2 OH
CH3 OH
OH
Cl 15.
−
16.
O
N
CT3
CD3 3>2>1 OH
O
Br
F
OH
OH
OH
OH
13. O
OH
+
OH
OH NC
2>1>3 COOH
COOH
COOH
COOH
17.
NC
H3 C
COOH
19.
1>2>3 COOH
COOH
Cl
20. H3 N
H2 N
HO
+
+
1>2>3
COOH
COOH
T3C
D3C
1>2>3 COOH
COOH
18.
Cl
F
COOH
COOH
COOH
H3 C
NMe 3
2>1>3 COOH
COOH
COOH
COOH
Cl
21.
–
O
HN
–
22.
Cl
H3 C Cl
3>1>2 COOH
COOH
1>3>2 COOH
COOH
COOH
COOH
HO
H3 C
23.
24. OH
H3 C
1>2>3
CH 3
OH
1>3>2
1.69
1.70
chapter one COOH
COOH
N+
O–
H3 C CH 3 O
26.
CH 3
O–
HO
28.
HO
1>2 OH
HO B
COOH
COOH
OH
OH
1>2
O
COOH
COOH
OH
B
CH 3
29.
OH
HO O N+
CH 3
O–
30.
1>2
N+
O–
2>1
MeO
Cl
32. 1>2
Cl
1>2 OH
OH
OH
O N+
33.
O–
O–
N
+
OH
N
O
O–
N
+
O
O–
N+
34. O–
CH 3
OH
OH
O–
O
N+
N
O–
N+
O
O–
N+
O
CH 3
3>2>1 COOH
O–
36.
OMe OMe
N+
O
3>1>2
COOH
37.
COOH
COOH
H2 N
38.
H3 C
H3 C
H2 N
2>3>1
OH
OH
MeO
35.
COOH
O
3>1>2 OH
H3 C
OH
+
O–
3>2>1 OH
O–
OH +
N+ O
O
OMe
O
–
N+ O
O
O
COOH
COOH
B
B
31.
OH
HO
OH
O
2>1
27.
HO
N+
O–
O
COOH OH
H3 C
N+
2>1
HO
N+
CH 3
H3 C
CN
COOH
O–
CH 3
H3 C
25. H3 C
COOH
COOH
NH 2
2>3>1
COOH CH 3 CH 3
CH 3
CH 3
general organic chemistry
Exercise 2 Carbocation Stability order +
1.
H2C
CH3
CH3 H3C
+
CH
C
3>2>1 CH3
CH3
3.
H3C
C+
CH3
+
CH3
2.
H3C
CH3
+
C
CH 3
+
CH3
CH3
HC+
4.
C+ H3C
H3 C
CH3
1>3>2
CH3
CH3
CH3 CH3
C+
CH+
CH+
1>3>2 H3C
CH3 C+
5.
+
CH
CH3 H C 3
H2C
1=2>3
H3 C
CH3
H3 C
CH3
HC+
6.
H3 C
CH3 C+
D3 C
CD 3 T 3 C
D3 C
T 3C
C+
CT 3 C+
CH+
1>3>2
3>2>1
CH3
CD 3
CT 3
C+
C+
C+
7.
CH+2
8. CH3
1>2>3 CH+2
3>2>1 CH+2
CH+2
CH+2
9.
CH3
CN
1>2>3 H3C
CH+2
C+
CH3
HC+
CH3
CH3
H3C
CH+2
OH
CH+2
H3C
CH3
1>2>3
CH3
3>2>1 Ph
Br
CH+
Ph
Ph C+
3>2>1 CH+2
17.
CH+2
16.
1>2>3 CH+2
H3 C
14.
CH+2
CH+2
CH3
CH+2
Cl
15.
CH+2
CH+2
CH+2
2>3>1
NH2
CT 3
1>3>2
CH+2
CD 3
12.
NO 2
13.
CH+2
CH+2
1>2>3
CH+2
CH+2
11. CH3
CH+2
10. CH3
CH+2
CT 3
CD 3
NO 2
CN
1>2>3 CH+2
CH+2
CH+2
H3 C
CH+
18. 3>2>1
H3 C
CH3 C+
CH3
1.71
1.72
chapter one CH+2
CH+2
CH+2
19.
20.
CH+2
3>2>1
same stability CH3
CH+2
CH+2
CH+2
H3 C
21.
H3 C
C+
22.
CH3
1>2>3
CH3 H3 C
C+
H3 C
C+
CH3
2>1 CH3 H3 C
23.
CH3
C+
CH+
24.
H3C
CH+
H3C
H3C CH+
H3C
CH+ H3C
27.
CH+ NH O
NH O
HN HN
CH3
CH3 NH
NH
3>2>1 C+
C+
26.
O
C+ O
29.
CH+
HN
CH+2
CH+ NH
C+ CH+2
3>1>2
31.
H 3C
CH3
30.
C+ CH3
HN
CH+ NH
C+
CH3
CH3
H 3C
H 3C
CH3 H3C
CH+2 H C 3
C+
CH+ H 3C
CH3
3>1>2
CH+
32.
1>3>2
CH+
CH+
1>3>2
H3 C
33.
CH+
CH+ H3C
H 3C
CH+
CH+
C+
O
CH+2
28.
CH3
H 3C
H 3C CH H3C
CH+
CH+ O
H3C
2>3>1>4
H 3C
3
CH+
O
4>2>3>1
CH3
CH+
H 3C H 3C
O
O
4>2>3>1 H 3C
O
3>2>1
CH3
CH3
CH3
CH3
1>2>3
25.
C+
HC+
CH3 CH3
CH3
CH3 C+
CH3
CH+
3>2>1 O
O
34.
O
CH+
CH+
CH+
1>2>3
35.
C+
CH+ CH +
1>3>2
general organic chemistry
Exercise 3 Identify localised and delocalised 1p in the following examples 1.
2.
dl
..
H N
3.
l
..
..
l
N
N
..N
..
l
H2 N
4.
5.
l
.. ..
..
..N
N H
N N
..N
dl dl
l
..
N
8. dl
l HN
..
..
..
NH2
..
H2 N
10. l
dl
..
..
.. N
..
9.
l
.. N
..N
dl
H
12.
dl H N
l
.. O
..O
..N
dl
l
13.
14.
l
..O
l
dl
dl
.. ..O
15. dl
dl
H
dl
H
..N
..N
..N
l
l
..NH ..O 16.
..
dl
17.
l dl
..NH
HN
..
NH
dl
NH
HN
H2 N
dl
..
l
20.
..
N CH3
l
21.
..
..
NH
N N H
l
N
dl
..
..
H3 C
dl
..
..
18.
.. ..O
O
l
19.
l
..
dl
..NH
dl
.. NH
dl
l
..O
dl
..
dl
..N
H2 N
N
11.
..N
..N
H N
H
dl
N
dl
7.
6.
l
dl
dl dl
..NH
2
l
1.73
1.74
chapter one
dl
22.
..
HN
..
24. HB
l
23.
..O
..N
l
..
NH
..
HN
.. N
25.
l
..O
N H
l
dl
dl dl
dl
..
l
26.
NH
27.
dl
H N
..
..
NH
..
..NH2
H2 N
H
28.
l
dl
..
dl
dl
dl
..N
..N
dl
29.
NH2
dl
l
30.
..
..
..
NH
NH
HN
dl
..
NH2
l
H3 C
..
l
CH3
NH
..N 31. dl
dl
32.
..NH
..
..
l H N
dl
..
NH
HN
l
.. dl
..
O
l
N H
..NH
l
..NH
general organic chemistry
Exercise 4 Identify the site of electrophilic attack at benzene ring 1.
2.
O
3.
O
5.
O
6.
O
O
NH
9.
O
O
O
N
10.
O
11.
CH3
O
–
O
12.
CH3
CH3
CH3
CH3
H3 C
14.
CH3
CH3
H3 C
15.
CH3
+
H3 C
CH3
CH3
CH3
N
CH3
CH3 CH3 O
O
Note : Major attack represents b arrow ( )
CH3
16.
CH3
H3 C
8.
7.
O
O
NH CH3
H 3C
13.
O
O
NH
4.
O
17.
18.
1.75
1.76
chapter one
19.
20.
O
21.
CH3
H3 C
O O
CH3
H3 C
22.
23.
24.
CH3
CH3 CH3
H3 C
N O
O
O
HN
O
CH3
O CH3
25.
26.
CH3
O
28.
-
27.
CH2
30.
O
NH
N
29.
CH2 O
O
O S
NH
NH CH3 CH3
31.
32.
O
NH
O CH3 CH3 CH3
34.
H3 C H3 C
NH
33.
O
CH3
CH3
CH3
H2 N O
O
CH3
CH3
CH3
general organic chemistry
Exercise 5 Identify the correct order of resonance energy for the following pairs of compounds O
1.
4.
O
2.
3.
5.
6.
O
7.
8.
O
H N
O
O
CH–
CH+
CH–
CH+
S
9.
O
NH2
10.
CH+
13.
O
CH–
10. 11.
H N
S
12.
14. O
15.
16.
HN HN
S
18.
17.
19.
20. H2N
22.
S
CH+ O
NH2
NH2
O
O
CH+
21.
H B B H
23.
CH+
CH2+
24.
H B
H B
O
N H
CH+
CH2+
1.77
1.78
chapter one
25.
26.
27.
28.
29.
30.
31.
32. CH+
CH–
34.
33.
CH–
35.
37.
CH+
CH+2
CH – CH2–
36.
CH–
CH+
CH–2
CHAPTER
2
Isomerism Question Bank Level 1
1. How many stereocenters does latomoxef (an oxacephem antibiotic) have? O
HO N N N N
O
N
S O
O
NH O
OH
O OH
(a) 2
(b) 3
(c) 4
(d) 5
2. Which molecule is (R, Z)-7-methoxy-2, 7-dimethyl-4-propylnona-1, 4-diene? OCH3 H3CO (a)
H3CO (c)
(b)
OCH3 (d)
2.2
chapter two 3. Choose the correct order that has the following compounds correctly arranged with respect tothermodynamic stability. CH3 CH3 CH3 (iii) (i) (ii) H3C CH3 CH3
(a) ii < i < iii
(b) i < ii < ii
(c) i < iii < i
(d) iii < i < ii
4. Which of the structures below is a diastereomer of A? H H HO
CH3
(i)
(ii) OH HO H
H
CH3
(iv) H
(a) i
H
CH3
CH3
OH
(iii)
H
H
H
H
H OH
CH3
HO (v)
H
CH3
(b) iii
(c) ii and iv
5. The total number of structural isomers of C4H11N would be (a) 4 (b) 8 (c) 5
(d) iv (d) 10
6. Which of the following pair is the chain isomer? (a) ,
(b)
(c) ,
(d)
,
,
7. How many geminal dichloride with different formula are possible for C3H6Cl2? (a) only one (b) two (c) three (d) four 8. What is the relation between 3-ethylpentane and 3-methylhexane? (a) Chain isomers (b) Position isomers (c) Functional isomers (d) Metamers 9. How many isomers are possible for methyl anthracene? (a) 2 (b) 3 (c) 4
(d) 5
10. The compounds (CH3)3N and CH3CH2CH2NH2 represent (a) chain isomerism (b) position isomerism (c) functional isomerism (d) all of the above
isomerism 11. An isomer of ethanol is (a) methanol (c) diethyl ether
(b) acetone (d) dimethyl ether
12. The number of primary, secondary and tertiary amines possible with the molecular formula C3H9N respectively (a) 1, 2, 2 (b) 1, 2, 1 (c) 2, 1, 1 (d) 3, 0, 1 13. Examine the relation between the following pairs of compounds Cl (i) Cl
OH
Cl and
(ii)
Cl
OH
COOH and COOH
(a) All i, ii, iii are identical (b) All i, ii, iii are isomers (c) i, ii are identical, iii is isomer (d) i is identical and ii, iii are isomers Br
COOH Br
COOH and
14.
are Br
Br
HOOC
OH
OH
COOH (iii) HOOC
and
(a) Positional
(b) Chain
COOH
(c) Geometrical
(d) Functional
15. Given compound shows which type of isomerism? O
O
S–O
S–O
and
O (a) Chain isomerism (c) Metamerism
O (b) Positional isomerism (d) Functional group isomerism
COOH 16.
OCOH
and
Functional isomers
OEt
OMe
Et
Metamers
and Me
CH2 – CH2 – OH
CH2 – O – CH3 and
Metamers
2.3
2.4
chapter two Me – N – Me
CH2 – NH – CH3
and
(a) TFTF
(b) FTTF
Functional isomers
(c) TTFT
(d) TFFT
17. Which compound is not the isomer of 3-ethyl-2-methylpentane? | (b)
(a) (c)
| |
(d)
18. Which of the following is not the correct relationship? Me
Me
(i)
(ii) Me
Me
O – Me
OH Me (iii)
Me
Me (iv) O – Me
OH (a) ii and iv are metamers (c) i and iii are chain isomers
(b) i and ii are functional isomers (d) i and iv are positional isomers
19. What is the correct relationship between the following compounds? CH3 – CH2 – CH – CH2 – CH3, CH3 – CH2 – CH2 – CH2 – CH2
CH3
CH3 (a) Chain isomers (c) Functional isomers
(b) Position isomers (d) Identical
20. Which one of the compound is not isomer of others? (a)
(c)
(b)
(d)
21. CH3 – CH2 – NH – CHO; CH3 – CH – CHO
NH2 i ii Which type of isomerism is observed between i and ii? (a) Chain isomers (b) Position isomers (c) Functional isomers (d) Metamers
isomerism 22. The correct relationship among the following pairs of given compounds is O O O || O || (i) || (ii) O || O O O (a) Chain isomer (b) Positional isomer (c) Metamer (d) Functional isomer 23. Which of the following is a pair of metamers? O
(a) O (b)
O
O
O O
(c)
NH2
H2N Br
Cl I (d) Cl
Br
I 24. Which of the following can show tautomerism? (a) O
O
O (b) O O
O (c)
(d) O
O 25. Which of the following can show tautomerism? O H3C (a)
C C
CH3
O O (b)
O H C H C (c)
CH – CH2
C
CH – CH2
H
C H
(d) all of these
2.5
2.6
chapter two 26. Which of the following can show tautomerism? (a) (CH3)3CNO (b) (CH3)2NH (c) R3CNO2
(d) RCH2NO2
27. Which will not show tautomerism? (a) O
O
(b)
CH
NOH
O (c)
O
(d) O
O 28. Which will not show tautomerism? (a) CH3CH2CH2CH2NO2 (c) CH3CH–CH2CH3 | NO2
O
(b) (CH3)2CH–CH2NO2 (d) (CH3)3C–NO2
29. Which of the following compound show tautomerism?
C=O (a) (H3C)2CCl–CH=CH2 (b)
(c) (H3C)2C(NO2)–CH=CH–CHO
H (d) None of these
30. Which of the following will not show tautomerism? H3C (a) C = N H
OH
(H3C)3C C=C (c) (H3C)3C
(H3C)3C
(b)
N=O
H3C
H3C (d)
C(CH3)3
H
C=C
H3C C=C
31. Tautomerism will be exhibited by (a) (CH3)2NH
(b) (CH3)3CNO
(d) RCH2NO2
(c) R3CNO2
N=O CH3
C=N H
32. Which of the following is not an example of tautomeric equilibrium? H2C = CH – C = O (a)
+
CH2 – CH = C – O
H
H
–N = N – NH (b)
NH – N = N
> CH – N = O (c)
> C = N – OH
–NH – C = O (d)
– N = C – OH O
O 33. i
O
ii
iii
NO2
OH
isomerism
Among these compounds, which of following is the correct order of % enol content? (a) i > ii > iii (b) iii > ii > i (c) ii > iii > i (d) i > iii > ii
34. Which of the following will have highest percentage of enol content? O
O
O
C6H5 – C – CH2 – C – OC2H5 (a) O
CH3 – C – O – C2H5 (b)
O
O
CH3 – C – CH2 – C – OCH3 (c)
O
CH3 – C – CH2 – C – CH3 (d)
35. Which of the following compounds have less enol content?
i
(a) i (c) Both (a) and (b)
N | H
O
ii
N | H
O
(b) ii (d) None of these
36. Which of the following compounds have higher enol content? O O
i
ii OCH3
NO2
(a) i (c) i = ii
(b) ii (d) None of these
37. Geometrical isomers differ in (a) position of functional group (c) position of atoms
(b) spatial arrangement of atoms (d) length of carbon chain
38. Stereoisomers have different (a) Molecular formula (c) Configuration
(b) Structural formula (d) Molecular mass
H3C (a) H3C (c)
C
||
39. Which of the following compounds has restricted rotation? CH3
C
C (b)
H
CH3 C
C
CH3
(d) All of these
2.7
chapter two 40. Which of the following compounds does not have restricted rotation? CH3 (a)
CH3
(b) CH3 CH3
Br (c) C=C Cl
CH3 H
H C C H (d) Br
Br
41. Which compound can show geometrical isomerism? (a) CH3CH = C(CH3)2 (b) CH3CH = CH2 (c) CH3CH = CHCH3 (d) (CH3)2C = C(CH3)2 42. Which of the following will not show cis-trans isomerism? CH3 – CH – CH = CH – CH2 – CH3 CH3 – C = CH – CH2 – CH3 (a) (b)
CH3
CH3 (c) CH3 – CH = CH – CH3
(d) CH3 – CH2 – CH = CH – CH2 – CH3
43. Geometrical isomerism is shown by H (a) C = C H H3C (c) HC 3
I Br
(b)
H CH3
I Br
C=C
Cl
Cl H C = C Cl CH3 Br (d)
C=C
44. The “E”-isomer is H Br
F (a) C = C Cl H3C (c) H
C2H5 CH(CH3)2
C=C
(b)
H3C H
CH3 H
C=C
(d) none of the above
45. The compounds X and Y shown in the below reaction can be P+Q – H2O Ph – NH.NH2 + (X) + (Y) Organic products (a) CH3 – CH2 – C – CH3 + CH3 – C – Ph (b) Ph – C – CH3 + CH3CHO O
O
O
(c) CH2 = O + CH3CHO (d)
CH2 = O + CH3 – C – CH3
||
C
C
Cl F
C
C
CH3 C2H5
Cl
HOOC (d) C COOH H
||
CH3 (c) C2H5
(b)
||
O 46. The “Z”-isomer is Cl H (a) C C Br F ||
2.8
C
COOH H
isomerism 47. Which of the following compounds cannot show geometrical isomerism? Br (a) Cl
Br
CH3 |
(b)
CH3
Cl H3C (c) H3C
CH3
CH3
(d) CH3
H3C
CH3
48. The total number of geometrical isomers possible in following compound is Ph – HC = HC
(a) 2
(b) 1
CH = CH – CH3 (c) 6
(d) 8
49. The total number of geometrical isomers possible in following compound is CH = CH – CH = CH
(a) 4
(b) 6
(c) 3
(d) 2
50. The number of geometrical isomers in the following compound is CH3 – CH = CH – CH = CH – C2H5
(a) 4
(b) 3
(c) 2
(d) 5
51. The number of cis-trans isomer possible for the following compound is
(a) 2
(b) 4
(c) 6
(d) 8
52. What characteristic is the best common to both cis-2-butene and trans-2-butene? (a) B.P. (b) Dipole moment (c) Heat of hydrogenation (d) Product of hydrogenation 53. Number of chiral carbon atoms in the compound x, y and z respectively would be Me Me Me Me
Y
X
(a) 0, 2, 1
(b) 1, 0, 1
(c) 1, 2, 1
Z (d) 1, 2, 0
2.9
2.10
chapter two 54. Number of chiral carbon persent in the following compound is CH3 – CH – CH2 – CH – CH – CH3 OH
(a) 2
(b) 3
Br
C2H5
(c) 4
(d) 5
55. Which of the following have asymmetric carbon atom? Cl Br
H Cl
H – C – C – H (a)
(b) H – C – C – Cl
H H
H H
H Cl
H H
H – C – C – H (c)
(d) H – C – C – CH3
H H
Br OH
56. Meso‑tartaric acid and d‑tartaric acid are (a) positional isomers (b) enantiomers (c) diastereomers (d) racemic mixture 57. observe the following structures (i) to (iii) C2H5 – CH – C2H5 (ii) (CH3)2CH – CH – CH – CH3 (i) CH3
OH
CH3
(iii) CH3 – CH – CH – CH3 OH
CH3
Correct statement is (a) All three are chiral compounds (b) i and ii are chiral (c) Only ii is chiral (d) Only iii is chiral
58. The number of optically active compounds in the isomers of C4H9Br is (a) 1 (b) 2 (c) 3 (d) 4 59. Which of the following compound has “S” configuration? OH
CH3 (a) H
OH
H
Br CH3 Br (c)
CH3 OH
H
CH3
(b) Br
(d) HO
Br H
60. The number of optically active isomers observed in 2,3‑dichlorobutane is (a) 0 (b) 2 (c) 3 (d) 4
isomerism 61. The correct configuration assigned for compound (i) and (ii) respectively is CH3 COOH (i) H
CH3
(ii) HOOC
COOCH3
(a) R, R
C
(b) S, S
COOCH3
H
(c) S, R
(d) R, S
62. The R/S configurations of these compounds are respectively HO H CF3
H
NH2
H
HS
COOH (c) R, S, S
(b) R, S, R
(a) R, R, R
CH3
CHO
(d) S, S, S
63. Which of the following compound has plane of symmetry (Pos) but not centre of symmetry (Cos)? H Br CH3 H Cl H (a) (b) Cl H H CH3 H F Br F Cl H (c) H Br
Br H
(d)
H
F 64. The instrument which can be used to measure optical activity, i.e., specific rotation (a) Refractometer (b) Photometer (c) Voltmeter (d) Polarimeter 65. The two compounds given below are D
I (a) Enantiomer (c) Meso compound
H H
I D
Br Cl
H H
Cl
Br
(b) Identical (d) Diastereomers
66. Which of the following compounds do not possess a C2 axis of symmetry? D (a)
H3C (b) H3C
D
CH3 CH3
2.11
2.12
chapter two D
CH3 H3C (c)
H
CH3
(d) H3C
D
H
H CH3 H 67. How many stereoisomers can exist for the following acid? H
H – C(OH).CO2H H – C.CO2H H – C(OH).CO2H
(a) Two
(b) Four
(c) Eight
(d) Sixteen
68. CH3 – CH – CH – CH – CH3
Br Br Br Total number of stereoisomers in the above compound is (a) 6 (b) 4 (c) 8
(d) 16
69. Total number of stereoisomers of the compound is given below CH3 – CH – CH – CH3
(a) 2
(b) 4
OH Br (c) 6
(d) 8
70. How many stereoisomers of the following molecule are possible? HOOC.CH = C = CH.COOH
(a) two optical isomers (b) two geometrical isomers (c) two optical and two geometrical isomers (d) none
71. Total number of stereoisomer of compound is given below CH3 – CH = CH – CH – CH = CH – C2H5 Cl
(a) 2
(b) 4
(c) 6
(d) 8
72. CH3 – CH – CH – CH – CH3
Cl Br OH Total number of stereoisomers in the above compound is (a) 6 (b) 4 (c) 8
(d) 16
73. The enantiomeric excess and observed specific rotation of a mixture containing 6 g of (+)-2-butanol and 4 (g) of (–)-2-butanol are respectively (If the specific rotation of enantiomerically pure (+)-2-butanol is +13.5 units) (a) 80%, +2.7 unit (b) 20%, –27 unit (c) 20%, +2.7 unit (d) 80%, –27 unit
isomerism 74. Which of the following pair of isomers cannot be separated by fractional crystallisation or fractional distillation? (a) Maleic acid and fumaric acid (b) (+)-Tartaric acid and meso-tartaric acid (c) CH3 – CH – COOH and H2N – CH2 – CH2 – COOH
NH2 (d) (+)-lactic acid and (–)-lactic acid
75. Increasing order of stability among the three main conformation (i.e., eclipse, anti, gauche) of ethylene glycol is (a) Eclipse, gauche, anti (b) Gauche, eclipse, anti (c) Eclipse, anti, gauche (d) Anti, gauche, eclipse 76. Which of the following pairs of compound is/are identical? CH3 CH3 Cl H (a) H
Cl
CH3 CH3
Cl
H
I H (b) Cl
CH3
Cl Br (c) F Br
H
F
H H
F H
I
H
H3C
H
CH3
H
Cl
H
CH3
I H
H
H H H (d) I Br Br Cl
H
Br
F 77. The two structures (i) and (ii) represent CH3 H (i)
I
Br Cl I
H H
CH3
H H (ii) H H3C CH3
(a) Conformational isomers (c) Constitutional isomers
(b) Stereoisomers (d) Identical
78. In which of the following has minimum torsional strain and minimum Vander waal strain? CH3 CH3 CH H 3 H (i) CH3 H
(ii) H
CH CH3 3
CH3 CH3
CH3 CH3 (iii) H H
(a) i
CH3
CH3
H (iv)
CH3
H
CH3
(b) ii
CH3 (c) iii
CH3 (d) iv
2.13
2.14
chapter two 79. In the Newman projection formula of the least stable staggered form of n -butane, which of the following reasons is the causes of its unstability? (a) Van der Waal’s strain (b) Torsional strain (c) Combination of both (d) None of these 80. Which of the following represent the staggered conformation with dihedral angle f = 60? CH3 CH3 H
H (a) H
H
H
H
CH3
H
CH3 CH3
CH3 H
(c) H
CH3
H (b)
H
H
(d) H
H
H CH3
H
81. The dihedral angle between two methyl groups in partially eclipsed conformation of n-butane is (a) 180° (b) 120° (c) 90° (d) 109°28’ 82. Which of the following is an achiral molecule? CH3 H3C (a)
Br
Cl
H
(b)
Cl
H
CH3
Cl
H CH3
H CH3 H (c) H3C
OH
H (d)
H
H
CH3
COOH OH OH COOH
83. Which of the following is most stable? CHO
CHO NH2
H (a)
H
H
H
NH2 CHO H
CHO NH2 (c)
H H
H
H
H
H
(b)
H
H
(d) H H
H NH2
isomerism 84. Evaporation of an aqueous solution of ammonium cyanate gives urea. This reaction follows the class of (a) Polymerisation (b) Isomerisation (c) Association (d) Dissociation 85. The possible number of alkynes with the formula C5H8 is (a) 2 (b) 3 (c) 4
(d) 5
86. How many isomers of C5H11OH will be primary alcohols (a) 2 (b) 3 (c) 4
(d) 5
87. Number of isomeric forms of C7H9N having benzene ring will be (a) 7 (b) 6 (c) 5 (d) 4 88. Which of the following is an isomer of diethyl ether (a) (CH3)3COH (b) CH3CHO (c) C3H7OH (d) (C2H5)2CHOH 89. Total number of isomeric alcohols with the formula C4H10O is (a) 1 (b) 2 (c) 3
(d) 4
90. The molecular formula of a saturated compound is C2H4Cl2. The formula permits the existence of two (a) functional isomers (b) position isomers (c) optical isomers (d) cis-trans isomers 91. The type of isomerism found in urea molecule is (a) Chain (b) Position (c) Tautomerism (d) None of these 92. An alkane can show structural isomerism if it has ......... number of minimum carbon atoms (a) 1 (b) 2 (c) 3 (d) 4 93. How many chain isomers can be obtained from the alkane C6H14? (a) 4 (b) 5 (c) 6 (d) 7 94. Keto-enol tautomerism is observed in O
(a) C6H5
C
O H
(b) C6H5
O (c) C6H5
C
C6H5
(d) C6H5
C
CH3
O
CH3
C
C
C6H5
CH3 95. The number of geometrical isomers in case of a compound with the structure CH3–CH=CH–CH=CH–C2H5 is
(a) 4
(b) 3
(c) 2
(d) 5
2.15
2.16
chapter two 96. Which one of the following will show geometrical isomerism?
(a) CH2Cl H
(c) CH2
(b)
CH3
C
CH
CH
C
H
CH2Cl
C(CH3)2 CH2Cl CH
CH3
C
H CH
C(CH3)2
(d) CH3CH2CH=CHCH2CH3
CH2
97. In the reaction: CH3CHO + HCN ⎯→ CH3CH(OH)CN a chiral centre is produced. The number of stereoisomers of the product is (a) 3 (b) 2 (c) 4 (d) none of these 98. The molecule 3-penten-2-ol can exhibit (a) Optical isomerism (c) Metamerism The correct answer is (a) (a) and (b) (b) (a) and (c)
(b) Geometrical isomerism (d) Tautomerism (c) (b) and (c)
(d) (a) and (d)
99. Find the total number of isomers (including stereo isomers) in dimethyl cyclopropane and dimethyl cyclobutane (a) 6, 8 (b) 5, 6 (c) 4, 5 (d) 4, 6 Cl H5C2 100.
H H
H
H
has
C2H5 Cl
(a) plane of symmetry (c) C3 axis of symmetry
(b) centre of symmetry (d) C4 axis of symmetry
101. How many optically active cycloalkanones are possible with the molecular formula C5H8O? (a) 8 (b) 6 (c) 5 (d) 4 102.
H3C H
CH3
and
H
(a) Geometrical isomers (c) Chain isomers
H3C H
H
is/are
CH3
(b) Position isomers (d) Enantiomers
CH3 103. For the given compound which of the CH3 – C = CH – C – CH = C – CH3 following statement(s) are correct? D D D
(a) It has 4 stereoisomers (b) It has 3 stereoisomers (c) It has 2 chiral centres (d) The compound does not show G.I.
isomerism 104. Racemic mixture is formed by mixing two (a) Isomeric compounds (b) Chiral compounds (c) Meso compounds (d) Enantiomers 105. Which of the following does not show geometrical isomerism? (a) 1,2-dichloro-1-pentene (b) 1,3-dichloro-2-pentene (c) 1,1-dichloro-1-pentene (d) 1,4-dichloro-2-pentene 106. The general formula CnH2nO2 could be for open chain (a) Diketones (b) Carboxylic acids (c) Diols (d) Dialdehydes 107. Among the following four structures i to iv CH3 O CH3 | || | C2H5 – CH – C3H7 (ii) CH3 – C – CH – C2H5 (i) H CH3 | | H – C⊕ (iv) C2H5 – CH – C2H5 (iii) | H it is true that (a) All four are chiral compounds (b) Only i and ii are chiral compounds (c) Only iii is a chiral compound (d) Only ii and iv are chiral compounds 108. Amongst the following compounds, the optically active alkane having lowest molecular mass is CH3 | CH3 – CH2 – CH – CH3 (a) CH3–CH2–CH2–CH3 (b) H | CH3–C– (c) | C2H5
(d) CH3–CH2–C≡CH
109. Which of the following compounds is not chiral? (a) 1-chloropentane (b) 2-chloropentane (c) 1-chloro-2-methylpentane (d) 3-chloro-2-methylpentane 110. Which of the following molecules is expected to rotate the plane of polarised light? H2N
COOH
NH2
(a) H Ph
H
H2N (b)
Ph
H
CHO HO (c)
H CH2OH
(d) SH
H
2.17
2.18
chapter two 111. The correct decreasing order of priority for the functional groups of organic compounds in the IUPAC system of nomenclature is (a) –SO3H, –COOH, –CONH2, –CHO (b) –CHO, –COOH, –SO3H, –CONH2 (c) –CONH2, –CHO, –SO3H, –COOH (d) –COOH, –SO3H, –CONH2, –CHO HO2C 112. The absolute configuration of
OH HO H
(a) R, R
(b) R, S
CO2H is
H (c) S, R
(d) S, S
113. The alkene that exhibits geometrical isomerism is (a) 2-methyl propene (b) 2-butene (c) 2-methyl-2-butene (d) propene 114. The number of stereoisomers possible for a compound of the molecular formula CH3–CH=CH–CH(OH)–Me is (a) 2 (b) 4 (c) 6 (d) 3 115. Out of the following, the alkene that exhibits optical isomerism is (a) 3-methyl-2pentene (b) 4-methyl-1-pentene (c) 3-methyl-1-pentene (d) 2-methyl-2-pentene 116. Identify the compound that exhibits tautomerism (a) 2-butene (b) Lactic acid (c) 2-pentanone
(d) Phenol
isomerism
Level 2 Single and Multiple-choice Type 1. The value of equilibrium constant (K) for the following equilibria H H H3C e a H H C 3 C eH C CH 3 H3C a CH3 H C 3 C CH3 H3C CH3 Twist boat Chair
(a) K = 1 (c) K < 1
C
CH3
(b) K > 1 (d) Cannot relate
2. E/Z nomenclature of the following compound is H–C≡C
CH3 CH3 CH3
C C
C CH3 CH3 H2C = C
C – CH2
H H (a) E (c) Does not show geometrical isomerism
(b) Z (d) None
3. Correct order of stability of the following carbocations is ⊕
⊕
(i)
(ii)
⊕
CH2
CH2
(iii) CD3
CH3
⊕
CH2
CH2
(a) i > ii > iii > iv (c) ii > i > iv > iii
(iv)
H
CH3
CD3
(b) i > ii > iv > iii (d) i > iv > ii > ii
4. Which of the following compounds are chiral? O C–NH (i)
H3C–
–Cl C=C=C
(ii) NH–C O
Cl–
CH3 CH3
Cl
2.19
2.20
chapter two H
Cl Cl
Cl (iii)
(iv) H
H
O
CH3
(a) i, ii, iii, v
(v)
C O
O
(b) ii, iii, v
(c) i, ii, iii, v
CMe3 Me3C
Me
(b)
Me Et
Et Et (d) Me Et Me
Me3C (c)
6. Which of the following represent the meso compound? Cl H5C2 C2H5 H H5C2 (a) (b) H C2H5 H H
Cl Cl
(c) H
H
N
(d)
H3C Cl
7. Among the following pair of compounds functional isomer is
and
(a) N≡C
N≡C
Me Me
Me (b) O–NO
and N=O O
Me
NH
(d) i, iv, v
5. The conformation of the following compound is Et Me
Me3C (a)
O C
CMe3
CH3 Cl CH3 Cl
isomerism Me
Me (c)
and O
C – O – Ph
O – C – Ph
O
O – CH2 – CH3 (d)
CH2 – O – CH3
and
8. Identify equilibrium which has maximum K (equilibrium constant) Me (a)
K
Me OH (b)
K O
O
H O
Me Me K
(c) Me
Me OMe (d) O
K O
O O OMe
9. The most stable Newmann projection of the 2,3-dichlorobutane, whose Fischer projection is given below is CH3 – CH – CH – CH3 Cl CH3 Cl (a) H
Cl CH3
H
(b)
Cl
CH3
H H
Cl
CH3 H3C (c) H H
Cl
CH3
H Cl Cl
(d) H Cl
CH3 CH3 Cl
2.21
2.22
chapter two 10. The correct stereochemical descriptions for the structure given below are OH Me CH2 – CH2 – H D
(a) 1S, 4E
(b) 1R, 4E
(c) 1R, 4Z
(d) 1S, 4Z
11. The number of optical isomers possible for the compound is Cl HO
CH(OCOCH3)2
NC
(a) 2
(b) 4
(c) 8
(d) 6
12. Which one of the following compounds will not rotate the plane of plane p olarised light? HOOC
NO2
Cl Cl (b) C=C=C H H
(a) COOH
NO2
OH
H (c) H5C2
C
H C2H5
HOOC (d) H
H OH COOH
13. The correct Fischer projection formula of the Newman projection representation is H COOH
Me Ph H Ph (a) Me
OH H
OH COOH
H (b) HO Me
Ph COOH H
H H Ph (c) HOOC
H OH Me
(d)
HO HOOC
Ph Me
H H 14. Which one of the following statements regarding the projections shown below (i and ii) is correct? Cl Cl C H H 6 5 H (i) (ii) Cl C6H5 H C6H5 H5C6 H Cl (a) Both the projections represent the same configuration (b) Both (i) and (ii) are optically active (c) Only (i) is optically active (d) Only (ii) is optically active
isomerism 15. Among the following compounds which is used for resolution of racemic mixture? Me Me N Me Me (a) (b) Cl Cl Et Me Br Cl Me Cl (c) (d) H Cl I H 16. Identify specific rotation of a mixture have 5 g of (+)2-butanol and 7 g of (–)2-butanol (If specific rotation of 100% pure compound is 13.5°) (a) –2.25° (b) –1.6° (c) 12.2° (d) 4.45° 17. Identify compound having highest heat of combustion Me tBu Me tBu (a) (b) Me Me (d) Me
(c) Me
18. Identify R and S configurations of chiral centres in the following compound
HOOC
(a) (i)-R (ii)-S
(b) (i)-S (ii)-R
Cl (c) (i)-S (ii)-S
(d) (i)-R (ii)-S
19. What is the relationship between the two structures shown? Cl H3C CH3
Cl (a) Different drawings of the same conformation of the same compound (b) Stereoisomers (c) Constitutional isomers (d) Different conformations of the same compound
20. C8H12 has 3° of unsaturation. Thus, it can have the structure (a)
(b)
(c)
(d)
21. Calculate the total number of geometrical isomers for the following compound •
(a) 2
(b) 4
•
• (c) 8
(d) 16
2.23
2.24
chapter two 22. Identify the value of KC for the following equilibrium Me Me
Me
Et Me
Et (b) KC < 1
(a) KC > 1
Me
(c) KC = 1
Me (d) None of these
23. Identify the relationship between the following pairs of compound H
H
H
H
H
H
H
H H
(a) Positional isomers (c) Functional isomers
H
and
(b) Geometrical isomers (d) Identical compounds
24. Identify compounds that give geometrical isomerisation Me
Cl (a) H
•
(c)
H
(b)
(d)
25. Which conformation has a C3 axis of symmetry? (a) Boat (b) Twist boat (c) Chair
(d) Enveloped
26. Which of following represent (E)-3, 6-dibromo-6-methyl-3-heptene? Br (a) (b) Br Br Br Br Br Br (c) (d) Br 27. Which of the following represent a pair of enantiomers? Me Me H
HO (i) H
H Cl (ii) HO Cl H
Et
Et
Et
Me HO H (iv) H H H Cl
Cl (iii) HO Me
(a) i and ii
(b) iii and iv
Et (c) i and iv
(d) ii and iii
isomerism 28. Choose the total number of constitutional isomers with the formula C4H10O. (a) 9 (b) 7 (c) 5 (d) 3 29. Identify optically active molecules Cl Br • • (a)
(b) NH
•
•
• •
•
•
NH
•
• Cl
• •
Cl (c) Cl
Cl (d)
Br
• • Br
30. In which structure Gauche form has less potential energy than antiform CH3 – CH2 – CH2 – Cl (b) HO – CH2 – CH2 – F (a) CH2 — CH2 (c)
(d) HO – CH2 – CH2 – OH
Br Br 31. Which of the following molecule/s show the plane of symmetry as well as axis of symmetry? Me Br (a)
Me
Cl H
(b) Me
Br
H
Cl
D
D
Cl (c)
(d)
•
•
Cl Cl 32. The C3 axis of symmetry is present in which of the following compounds? H H (a)
N
B H
H
B N
(b)
B N H
H
2.25
2.26
chapter two Cl (c)
(d)
Cl
Cl
33. Which of the following compounds are chiral? Br
H
H
(a)
H
⊕
H
N
C2H5 – O – C (b)
C6H5
O
Br H
H C
(c) O
C (d)
C C
H
C
C
C
NO2
CH3
NO2
34. Which of the following molecule(s) has C3 axis of symmetry and plane of symmetry? Cl Me (b)
(a) Me
Me
Cl H
Me
H
(c)
(d)
Me
Me
H
B N
N B
N H
35. In which of the following case correct relationship is given? H3C
Br
Br
CH3
(a)
Enantiomers
H (b) Br H
Br
Br
H
Br
H
H Br
H
Br
Enantiomers
B
H
H
isomerism Br
I
Br
I
(c) OH CH3
Diastereomers
OH CH3
(d)
Cl
Cl Br
Enantiomers
Br
36. Which of the following is an optically active compound? CH3
H (a) C
C
H
(b)
H3C
H
H H5C2 C2H5 H C=C CH3 (c) C2H5 Br
Cl Cl (d)
37. Which of the following options is correct?
(a) pk1 Cis but-2-ene dioic acid < Trans but-2-ene dioic acid
(b) Dipole moment
NC C=C
Cl (c) Stability
C=C H H
(d) Basicity
C=C Cl
C=C
H
H
H
CH3
H
NC
Cl
H
H
Cl
NH2
H
H
Cl
Cl
C=C
H C=C
CH2 – NH2 H
38. Which of the following are optically active?
Me
Me (a)
(b)
Cl
Me H
Me (c) Me
Me
OH
(d) Cl
H 39. For the given compounds, correct statement is/are O O H3C – C – O – (i)
CH3
(ii)
O – C – OH (iii) H3C – O – C –
CH3
2.27
2.28
chapter two
(a) i and ii are positional isomers (b) ii and iii are functional group isomers (c) i and iii are metamers (d) i and iii are positional isomers
40. Among the following pair of compounds or conformers, identify pair(s) in which the Ist compound has more stability than the IInd HO
Me
(a) H
Me
H
H
and H
OH
OH O–H
Me (b)
tBu
Me
and tBu
H
H
(c)
tBu
OH
and H
HO
H
HO tBu
OH (d) tBu
and
Me
tBu
Me
41. Among the following pair of compounds identify metamers O
(a) Me
and
O–C–Me
O C–OMe
Me
O (b)
O and
CH2–C–OMe
CH2–CH3 (c) Me–N–CH2–CH3
and
CH2–CH2–C–OH
H–N
CH2–CH2–CH3 CH2–CH3
and CH3–NH–CH2–Ph
(d) CH3–CH2–NH
42. Which of the following pairs show functional group isomerism? O O (a) Cl and Cl
(b) CH3COOCOC6H5 and C6H5COOCOCH3
(c) HCOOCH3 and CH3COOH
(d) CH3COCH3 and
O
isomerism 43. Identify compound(s) in which gauche conformer is more stable than staggered
(a) Ethylene diamine (c) Ethylene glycol
(b) Succinic acid (d) n-butane
44. Identify the compound which has axial conformer more stable than equatorial
(a)
OH
O OH
Me OH (c)
(b) H
Me (d)
Me
H
H
Et
H
H
H
45. Among the following compounds, C3 axis is present in Cl (a)
Cl (d)
(b) PCl5 (c)
Cl
46. Identify among the following compounds having plane of symmetry, centre of symmetry and axis of symmetry Cl (a)
Cl Me
Cl
Cl
H Cl
Cl
(c) Cl H Me H
H
(d) Ph H H Ph
H
H
H (b)
H
Cl
47. Identify diastereo isomeric pairs COOH
COOH (a) and OH
OH (b)
and Cl
(c) HO
OH Cl
Me H
and
Cl Cl
Cl Cl (d)
Cl
and H
Me
OH
HO Cl
2.29
2.30
chapter two 48. Identify the optically active compound H
Cl
H Me (b) H H
H (a) Me
H
Ph
Cl
(c) Cl
H H
Br H Cl H
(d) Br Ph
H
OH
49. Which of the following statements is correct? H3C
NH2 (i) C H CH2–OCH3 C2H5
(ii)
C
O (iii)
C H OH
HO
CH2–OCH3
(a) i and ii have R-configuration (b) i and iii have R-configuration (c) Only iii has R-configuration (d) i and iii have S-configuration
50. Which of the following relationships are correctly matched? O (a) and Positional isomers O Br C2H5 Identical and (b) C2H5 CH2–OH (c)
Br OH Positional isomers
and CH3
(d)
Chain isomers
and
51. Which of the following molecules is/are optically active? H3C
H3C H
H (a) H
(b) H OH
OH CH3
H H
H
H
H H CH3
Br
isomerism H (c)
OH
(d) Br
H
Br
Me
Me
52. Identify compound(s) in which gauche conformer is more stable than staggered (a) 1, 2-difluoroethane (b) Chloropropane (c) Ethylene glycol (d) Succinic acid 53. Identify the structure of Erythro D
D CH3
H (a)
H
(b) H
D
H
D
CH3
D
Cl D (c)
CH3 CH3
H
CH3 Cl
D
Br
(d) H
CH3
D Br
54. Identify the structure of Erythro CH3 H OH (a) H OH CH3
D H (b)
CH3 CH3 H
D CH3CH3 (c)
HO H3C (d) T
Br Br
D D 55. Identify the structure of Threo
D OH CH3
CH3 H (a) HO
OH H CH3
H3C
CH3
(b) D Cl
T
D
2.31
2.32
chapter two CH3CH3 (c)
Br Br
(d)
H3C
HO D
T
OH CH3
D D
56. Identify the structure of meso compounds D CH3
H (a) H
D
(b)
CH3
H
CH3
D D
CH3
H
Cl H3C
CH3
D (c)
D (d) T H3C OH
Cl D
OH
Me
57. Identify the structure of meso compounds OH H (a) H3C
CH3 OH
D
CH3 H (b) CH3
CH3
D
CH3 H (c) HO
H
CH3CH3 OH
(d)
H
Br Br
CH3
D D
58. Identify the structure of optically inactive compounds D CH3
H (a) H
D
CH3
(b)
HO
OH
isomerism Cl CH3
D (c)
Cl D
HO
OH
HO (b)
OH
(d)
H
59. Identify the structure of Meso (a)
(c)
(d)
60. Identify the structure of identical compounds OH CH3 H (a) H
OH OH
(b)
CH3 CH3
H
CH3 HO CH3 CH3 (c) HO HO
H
HO H3C D (d) T OH CH3 H H
61. Identify the structure of identical compounds (a) Cl
Cl H
(b) Cl
Cl
H
(c) CI
CI
CH2
(d) Cl
Cl
2.33
2.34
chapter two 62. Identify the geometrical isomers CN H H CN CN H H (a) (b) H H CN H H H H H CN CN H CN H H (c) (d) H H H H H H H 63. Identify the pair of chain isomers Me H H H Me Me Me H (a) (b) H Me Me Me Me H H H H H H Me H H (c) (d) H H H H Cl COOH COOMe 64. Identify the pair of diastereoisomers (a) Cl
H H
H CN
Me Me
H
H
Me Me
Me Me
Cl
Cl
Cl
Cl
Cl
(b) Cl
Cl
Cl Cl
(c)
Cl
(d)
65. Identify the pair of diastereoisomers
(a)
(b)
O
O
O
O
Cl (c)
(d)
66. Identify the pair of diastereomers O
O
(a)
(b) O
O
Cl
isomerism Cl (c) Br
Cl
(d) Cl
Cl
Br
67. Identify the pair of diastereoisomers
(a)
(b)
(c)
Cl (d)
Cl
Cl
Cl
68. Identify the pair of enantiomers Cl (a)
(b) Cl Cl
(c) Cl
Cl
(d) Cl Cl
Cl
Br
Br
69. Identify the optically active shape
(a)
(c)
(b)
(planner)
(d)
(planner)
2.35
2.36
chapter two 70. Identify the structures having centre of symmetry (a)
(b)
(c)
(d)
71. Identify the pair of enantiomers (a)
(b)
HO
OH
HO
O
O
(c) OH OH
OH
Cl
Cl (d) Br
Br
72. Identify the structure of Erythro-butane-2, 3-diol OH
CH3 H (a) H
OH OH
CH3 CH3 CH3 (c) HO HO
CH3
(b) H
CH3 H
HO
HO H3C D C (d) C T OH CH3 D D
73. Identify the structure of Threobutane-2,3-diol CH3 H (a) HO
C
OH
C
H
CH3
H3C
(b)
C HO H
CH3 C H OH
isomerism CH3 CH3 (c)
Br Br
(d)
H3C
HO D
C
C
T
OH CH3
D D
74. Identify the structure of identical compounds (a) Cl
(b) Cl
Cl
H CI
Cl
H
(c)
CH2
H
(d) CI
CI H
CH2
CI
75. Identify the structure of identical compounds CH3 H (a)
(b)
H
Cl
Cl CH3 H
H
CI
H
(c)
(d)
CI
CI H
CI
76. Identify the structure of enantiomeric compounds H
H CI
H (a)
(b)
H
CI H
Cl
H Cl
(c) Cl
Cl (d) Cl
Cl
2.37
2.38
chapter two 77. Identify the structure of transdecaline H
H H
H
H (a)
H
H H
H H (b)
(c)
H H H
H H
H
H
H
H
H
(d)
78. Identify the compounds that give trans product on reaction with Zn dust and heat CI CH3 H (a) H
Cl Cl
(b)
H
CH3 CH3
CH3 Cl
(c)
CI CI
H
CI
CH3 CH3 (d)
H3C
D
T
Cl CH3
H H
79. Identify the compounds that give cis product on reaction with Zn dust and heat H CH3 H (a) Cl
Cl H
(b) CI
CH3 CH3
CH3
Cl
(c)
H CI
H
CI
CH3CH3 (d)
H3C
D
T
Cl CH3
H CI
80. Identify the compounds that give cis product on reaction with Zn dust and heat CH3
CH3 H (a) Cl
Cl H CH3
(b)
H
Cl
H
Cl CH3
isomerism CH3 Et (c) Et
CH3 Cl Cl
(d)
Et
Cl
H3C
Cl
CH3
Et
81. Identify the compounds that give cis product on reaction with Zn dust and heat Et CI (a)
H CH3 CH3
CI CH3 (b) CH3 Et
CI CI
CI CH3 CH3
H (c)
H
CI
CI
(d)
Ph
CH3 CH3 CI
H
Ph
82. Identify the compounds that give trans product on reaction with Zn dust and heat Cl H3C CH3 H3C Et (a) Et (b) Cl Cl H Cl H CH3 Cl H3C CH3 H3C D (c) (d) T Cl H Cl Cl H CH3 83. Identify the compounds that give trans product on reaction with Zn dust and heat CH3
CH3 CH3 (a) H CI
H CI
Et
Cl
Et
(b)
CH3 CH3
CH3 CH3
Cl
(c) CI CI
Cl
Et
(d) H H
Et
Cl CH3
2.39
2.40
chapter two 84. Identify the compounds that give trans product on reaction with alcoholic KOH and heat Et CH3 Et (a) H
Cl Et
(b)
CH3 CH3
H
CH3
Et
CI
CH3 CH3
Cl H3C (d) H T CH3 Et Et H
(c) Et CI
85. Identify the compounds that give trans product on reaction with alcoholic KOH and heat CH3
CH3 H (a) Cl
Ph Ph
(b)
Ph
Cl
H
Et CH3
CH3 CH3 Et (c) Et
CH3 Cl H
(d)
Et
H
H3C
Cl
CH3
Et
86. Identify the compounds that give trans product on reaction with alcoholic KOH and heat Ph Et CI (a)
CI CH3 (b) CH3
CH3 CH3
H
Et
H Et H (c)
H CH3 CH3
CI
Ph
Ph
(d)
Ph
CH3 CH3 CI
Ph
isomerism 87. Identify the compounds that give trans product on reaction with alcoholic KOH and heat Cl H3C (a) Et
H3C
Et
(b)
H
Ph H Cl Ph
CH3 H3C
CH3
(c)
CH3
H3C (d) Ph
Cl H Pr CH3
H Et Cl Ph
88. Identify the compounds that give trans product on reaction with alcoholic KOH and heat CH3 CH3CH3 Et Cl (a)
Pr Pr
(b) H
H CI
CH3 CH3
CH3CH3 (c)
CI Pr
Et
Cl
Et
Et
H
(d)
H Pr
CH3
Comprehension Type Passage 1 Different spatial arrangements of the atom that result from restricted rotation about a single bond are conformers. The general stability order of these conformer are as follows. Anti > Gauch > Partially eclipsed > Fully eclipsed Although anti is more stable than gauch but in some cases gauch is more stable than anti. 89. Which one of the following is the most stable conformer? CH3 CH3 HO H OH H (a) (b) H
OH
H
CH3
H
CH3 OH
H (c) H
OH
CH3
(d)
H
CH3 CH3
OH
CH3 OH
OH
2.41
2.42
chapter two 90. Number of possible stable conformers of butane is
(a) 2
(b) 4
(c) 6
(d) Infinite
91. Which of the following are more stable conformers? Cl Cl (a) H
H
H3C CH3 (b) CH3
H
Cl
Cl Cl
H (c) H CH3 H
Cl
(d) All of them
CH CH3 3
Passage 2 With few exceptions, enantiomers cannot be separated through physical means. When in racemic mixtures, they have the same physical properties. Enantiomers have similar chemical properties as well. The only chemical difference between a pair of enantiomers occurs in reactions with other chiral compounds. Thus resolution of a racemic mixture typically takes place through a reaction with another optically active reagent. Since living organisms usually produce only one of two possible enantiomers, many optically active reagents can be obtained from natural sources. For instance, (S)-(+)-lactic acid can be obtained from animal muscle tissue and (S)-(–)-2-methyl-1-butanol from yeast fermentation.
CO2H CO2H Cl Cl H H
CO–2 NH3 Cl H H CH3 +
Reaction 1
+ Racemic mixture of phenylchloroacetic
+ CO–2 NH3 Cl H H CH3
NH2 H CH3
(R)-phenylethylamine acid
salt HCl H
salt HCl
CO2H Cl
Cl
CO2H H
Separation of enantiomers In the resolution of a racemic acid, a solution of (R)-phenylethylamine is reacted with a racemic mixture of phenylchloroacetic acid to form the corresponding salts. The salts are then separated by careful fractional crystallisation. Hydrochloric acid is added to the separated salts, and the respective acids are precipitated from their solutions. Resolution of a racemic base can be accomplished in the same manner with tartaric acid. 92. Quinine, a natural antimalarial, is commonly used as an optically active reagent to resolve acidic enantiomers. How many chiral carbons exist in the quinine molecule drawn below? OCH3 N OH Quinine
(a) 5
(b) 2
(c) 3
(d) 4
isomerism 93. Which of the following compounds might be used to resolve a racemic mixture of acidic enantiomers? Cl Cl (a) C (b) CH3–CH2–CH3 C C C H H Et
(c) CH3–CH2–CH2–CH3
(d) Me – C – NH2 Ph
94. Which of the following amines could in principle be used as a resolving agent for a racemic carboxylic acid? CH3 CH3 CH3 – CH – NH – CH3 (a)
(±) C6H5 – CH – NH2 (b)
(c) (–) C6H5 – CH – NH2
(d) CH3NH2
CH3 Passage 3 Stereoisomers are compounds that have same sequence of covalent bonds but differ in the relative dispositions of their atoms in space. Geometrical and optical isomers are the two important types of configurational isomers. The compound with double bonds or ring structure has restricted rotation, so exists in two geometrical forms. The double bonds in larger rings can also cause geometrical isomerism. The optical isomers rotate the plane of plane-polarised light. A sp3-hybridised carbon atom bearing four different types of substituents is called an asymmetric centre of chiral centre. A chiral object or molecule cannot be superimposed on its mirror image. Stereoisomers that are mirror images of each other are called enantiomers. The stereoisomers that are not mirror images of each other are called diastereomers. Diastereomers have different physical properties. A racemic mixture is optically inactive and contains equal amounts of both the enantiomers. Resolution refers to method of separating a racemic mixture into two pure enantiomers. A meso compound is an optically inactive stereoisomer, which is achiral due to the presence of an internal plane of symmetry of centre of symmetry within the molecule. 95. The pair showing identical species is CH3
Br
CH3
CH3
H and
(a) H
Br
Br
Br
H
H
Me H (b) D
Br OH and Br
D H
Et OH
Et
Me H
COOH
H
(c)
HO
COOH
and
HOOC
OH OH
CH3
(d) None of these
H
COOH
H OH
2.43
2.44
chapter two 96. Which of the following pairs are diastereomers? Me
Me
Br H (b) Br
Cl Cl and Br H
H (a) H
OH
Br
H
HO
(d) All of them
and
H
H
CH3
H
CH3 97. The following two compounds are (i)
Br
OH OH
H3C (c)
and
Et
Et
Br
CH3
O
(ii)
O (a) Identical (c) Positional isomers
(b) Diastereomers (d) Enantiomers
Passage 4 Isomers that have the same skeletons (that is, with component atoms attached in the same sequence) but differ from each other with relative positions of some atoms in three-dimensional space by virtue of rotation about σ bonds are called conformational isomers or conformers. A quantitative description that relates relative atomic positions to the changes in potential energy during rotation about a σ bond describes the energetics of conformational interconversion, a process known as conformational analysis. Rotation about (C −σ C) bond in ethane can give various conformers: In structure A1 or B1, C–H flagpoles at C-1 completely overlap each other at C-2. This form is called eclipsed conformation. H H H
H
2
H (A1)
H
1
H
H H
(B1)
H
H
H
H
H H
H
2
H
1
H H
H
H (A2)
H
H
H (B2)
In structure A2 or B2, C—H flagpoles at C-1 is fixed at 60° dihedral angle so that it is exactly between two C–H flagpoles at C–2. This is called staggered conformation. • Various other structures in between eclipsed and staggered conformations are called skew conformation. • Structures B1 and B2 show the orientations of the hydrogens on the front carbon relative to those on the back carbon, these are called Newman projections. • Structures A1 and A2 are called Sawhorse projections. 98. Among the following conformers, which has highest potential energy for n -butane (along C2–C3 bond rotation)? (a) Skew (b) Fully eclipsed (c) Staggered (d) Partially eclipsed
isomerism 99. In the following chair conformer correct orientation of –OH groups is/are OH
6
CH2OH
4
HO
5 3
O
2
OH
1
OH
(a) OH groups at C1, C2 and C4 are axial (b) OH groups at C1 and C2 are axial (c) OH groups at C1 and C4 are axial (d) OH groups at C1, C2 and C4 are equatorial
100. In the following equilibrium, the value of “K” is CH3 H
K
CH3 H
(a) K < 1
(b) K > 1
(c) K = 1
(d) None of these
Passage 5 Consider the following pairs of compounds CH3
OH H
OH
and
(i)
H CH3
OH Me (ii)
OH
Me
and Me
Me
Me
Me
Me Me (iii)
and Me
Me
Me
Me Cl
(iv)
and Cl
Cl
Cl
2.45
2.46
chapter two
(v)
OH OH
HO
and
HO
101. Identical pair of compounds is/are
(a) i and ii
(b) ii and iii
(c) iv and v
(d) i and v
(b) 2nd pair
(c) 5th pair
(d) 4th pair
103. Diastereoisomeric pair is (a) 1st pair (b) 2nd pair
(c) 3rd pair
(d) 4th pair
102. Both compounds in above pair are meso
(a) 1st pair
Passage 6 Presence of chiral carbon in organic compound is neither a necessary nor a sufficient condition showing optical activity. The chirality, i.e., dissymmetry of a molecule as a whole is the necessary condition for optical activity. 104. Which of these compounds will NOT show optical activity? H5C6 (a) CH3–CHOH–CH2–CH3 (b) C=C=C H7C10 NO2 COOH H2N (c) (d) O2N H2N HOOC
C6H5 C10H7 H NH2
NO2
105. Which of the following pairs is correctly matched? (a) CH 3 − CH = C = CH 2; optically active allene
H3C (b) H3C
C
COOH H
Alkylidene
CH3 (c) H5C6
C=C=C allene
HOOC
C4H9
; optically active C7H15
NO2
(d) HOOC
; optically active
; optically active NO2
106. Which one of the following is an achiral molecule? COOH C6H5 CH2OH H – C – OH H – C – OH H – C – Br (a) (b) (c) H – C – OH HO – C – H H – C – Br C6H5
CH2OH
C6H13
C6H5 H – C – Br (d) H – C – Br C6H5
isomerism Passage 7 Observe the given molecule/s H
OH (i)
(ii)
H
OH
H
Br
(iii)
Br
OPh
H
Ph Br
Ph (iv) H
H
H
Ph Br
(v)
OH
H
H
HO
OH Br
(vi) H
Br Ph
Ph
Ph 107. Correct statement is (a) i and ii are enantiomers (c) i and iv are identical
(b) iii and v are diastereomers (d) i and vi are diastereomers
108. Diastereomeric pair is (a) i and ii (b) i and vi
(c) ii and v
(d) iii and vi
109. If Br is attatched in place of –OH group in structure “V” (with same s tereochemistry) then resultant structure is (a) Meso (b) Threo (c) Structure has odd degree of unstaturation (d) Structure is identical to (i) compound
Matrix Type Match the columns: 110. Column I H
Column II H
O
H
H (a) H
H H
O
(p) Compounds give positional isomerisation with 1,2-dichloro benzene.
H
Ph H
Cl (b) H
Cl Ph
(q) Degree of unsaturation in the given compound is even [excluding zero value]
2.47
2.48
chapter two Cl (c)
(r) Given compound or conformer has zero dipole moment.
Cl Cl
H
(d) H H
(s) Net dipole of one mole of compound is nonzero.
H Cl
(t) Compound has ketone functional group.
111. Column I (Compound) D (a) C=C H (b)
H OCH3
Column II (Isomerism) D
and
C=C
H O
O and
H (c) C=C Cl
H CH2CN CN
(d)
H
and
and
H
H
(p) Functional isomers
(q) Geometrical isomers
C=C CN
H
H CH2NC
(r) Position isomers (s) Chain isomers (t) Metamer
112. Column I (Structure) CH2CH3 H3C (a) C C H CH3 CHO (b) HO – C – H
Cl
CH2OH
Column II (Configuration)
(p) E
(q) Z
CH2OH Br F (c) C C Cl I CHO
(r) R
HO – C – CH2OH (d)
(s) S
H
113. Column I
(a)
(t) Plane of symmetry Column II
(p) Plane of symmetry absent
isomerism
Fe
(b)
(q) C6
(r) S6
Ferrocene (staggered)
(c)
COOH (d) Ph H
H
H Ph
(s) Ci/COS
H COOH
(t) C5
114. Column I (Compounds)
Column II (Type of isomerism) O
O
CH3–CH2–CH2–C–CH3 and CH3–CH2–C–CH2–CH3 (a) CH2–OH (b)
CH3 OH
and
CH3 (c)
(p) Positional (q) Conformational
CH3
CH3 and
(r) Metamerism
(s) Functional
CH3 Br (d) H
CH3
H
CH3 Br
Br
CH3
H
and Br
H CH3
(t) Optical isomerism
2.49
2.50
chapter two 115. Column I
Column II
Me S (a) O
S
O
(p) Optically inactive compound
(q) Optically active compound
S– O Cl Br
(b)
Cl Br
R P (c)
R R
(r) Meso compound
Cl
(s) Axis of symmetry present
P R F Br (d)
I
(t) Asymmetric compound
116. Column I
Column II CH3
Cl C
CH3
(a) Cl
C C
(p) Optically inactive compound
Cl CH3
I
Br F
Cl (b)
F Br
I
Cl
(q) Optically active compound
isomerism Cl
Cl
Br
Br
(c)
(r) Meso compound
F
F Cl
Cl Br
Cl
Cl
C
Br C
(d)
(s) Axis of symmetry present
C Br Cl
(t) Asymmetric compound
117. Column I
Column II
N
(a) H3C
N
OH
(c) Cl H3C
(p) Optically inactive compound
H3C O
(b) H3C
CH3
HO
CH3 O
(q) Optically active compound
CH3 Cl CH3
(r) Meso compound
2.51
2.52
chapter two Et
Et N N
(d)
O
O
N
N
MeO
OMe
N
N
(s) Axis of symmetry present
(t) Dissymmetric compound
118. Column I O
Column II Cl
CH
(a)
CH
(p) Optically inactive compound
CH3
HN O
O CH
(b)
C
CH
HNC H 3
HC
(q) Optically active compound
HC NH
CH3 C
(c)
(d)
(r) Meso compound
(s) Axis of symmetry present
(t) Asymmetric compound
119. Column I
(a)
Column II
(p) Optically inactive compound
isomerism Cl
CH3
I (b) Cl
(q) Optically active compound
CH3 I Cl
(c)
(r) Meso compound
Cl H3C CH3
(d) Cl
(s) Axis of symmetry present
Br
(t) Asymmetric compound
120. Column I
Column II
Cl (a)
Cl
(p) Optically inactive compound
Cl Br
(b) Cl
(q) Optically active compound
(r) Dissymmetric compound
(s) Axis of symmetry present
Br Cl I
(c) Cl
Br Cl I
(d) Cl
Br
F
(t) Asymmetric compound
2.53
2.54
chapter two 121. Column I
Column II
H3C
CH3
(a)
(p) Optically inactive compound
Br
Cl F
F (b)
Cl
(q) Optically active compound
Br F
F (c) H3C
CH3 Cl
(r) Degree of unsaturation is odd
(s) Axis of symmetry present
Br F
F (d) H3C
CH3
Cl Cl
(t) Asymmetric compound
122. Column I
Column II
(a)
(b) 3+ Cr
(c)
(p) Optically inactive compound
(q) Optically active compound
(r) Dissymmetric compound
isomerism Br Cl (d)
(s) Axis of symmetry present
Cl Br
(t) Asymmetric compound
123. Column I
Column II
(a)
(p) Optically inactive compound
N (b)
N
(c)
(d)
(q) Optically active compound
(r) Dissymmetric compound
(s) Axis of symmetry present
(t) Asymmetric compound
124. Column I
Column II
Cl (a)
Cl
(p) Optically inactive compound
(q) Optically active compound
Br
Br (b) Br Br
Br (c) C C C Cl
Br
Cl
(r) Dissymmetric compound
2.55
2.56
chapter two Br Cl (d)
(s) Axis of symmetry present
Cl
(t) Asymmetric compound
Br
125. Column I
Column II
(a)
OH
(p) Optically active molecules without chiral centres
NH2 O
(b)
O
(q) Optically active molecules with chiral centres.
O O
(c)
NH
(r) Compounds have even number of chiral centres
O Me (d) H
Me H
126. Column I
Column II
Me (a) Me (b)
(s) Optically inactive molecules
Me
(p) Optically active
(q) Optically inactive
(r) Compounds show geometrical isomerism
Me Me (c) H Me
Me H
(d)
Me
(s) Plane of symmetry
isomerism 127. Column I
Column II
H (a)
H
(p) Molecule has chiral centre
(q) Molecule is asymmetric
O N
Me (b) Me
O
COOH
Ph HOOC H (c)
Ph H
H Me (d) C=C=C H
(r) Molecule is dissymmetric
H n-butyl COOH
(s) Molecule is optically inactive
Integer Type 128. µ obs = ∑ µ i x i; where µi is the dipole moment of stable conformer and xi is the mole fraction of that conformer of Z–CH2–CH2–Z in Newmann’s projection. If µsolution or µnet = 1 D and mole fraction of antiform = 0.82, find µGauche. 129. Number of primary amine possible for C4H11N is 130. How many chiral centres are present in the following compound? CH3 Br Br CH3 131. How many chiral centres are present in the following compound? CH3 H3C H3C H3C HO
CH3
2.57
2.58
chapter two 132. How many stereoisomers are possible for the following compound? CH3 O OH H3C
O
O
O
O
O
OH
OH CH3
133. How many stereoisomers are possible for the following compound? CH3
CH3
NH
H3C
CH3 CH3
O
134. How many stereoisomers are possible for the following compound? OH H2C H2N
CH2
N H
O
O
CH2
N H
NH2
N H
O CH3 CH2
135. How many stereoisomers are possible for the following compound? O N N
HO
O
NH N
NH2
O HO
O
P OH
136. How many compounds are optically active? N (a)
N
N (b) N
N
Br
Br (d)
(c)
Br C
Br
isomerism COOH
NO2 Cl Cl
(e)
(f) Br Br
COOH (g)
O
(h) O
O2N
(i) F
(j)
(k)
(l) Br
I
Cl 137. How many stereocentres are possible for the following compound? CH3 H3C
O
H3C
O
CH2
CH3
H3C
138. How many compounds are optically inactive? (a) O
(b)
O (e) HN
(f)
(c)
O O (d)
(g) O (h) NH O O
O (i) O
(j)
Cl (n)
(m)
Cl Cl
(q)
(k)
O
Cl
(o)
(l)
HN
(p)
NH
2.59
2.60
chapter two 139. How many geometrical isomers are possible for the following compound? H3C
CH3
H3C
CH3
140. How many geometrical isomers are possible for the following compound? CH3 CH3
H3C H3C
CH3 CH3
141. How many geometrical isomers are possible for the following compound? Ph
COOH
HOOC
Ph
142. How many steroisomers are possible for the following compound? CH3 Cl Br Br
Cl H3C
CH3 Cl
Br Cl
Br CH3
isomerism
Answer Keys Level 1 1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
b
a
d
d
b
b
b
a
b
c
d
c
c
a
c
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
c
b
d
a
d
c
ac
ab
d
d
d
d
d
a
c
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
d
a
b
d
b
a
b
c
d
d
c
a
b
c
d
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
d
a
d
c
a
a
d
a
b
d
c
d
b
c
b
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
c
a
c
d
a
c
b
b
b
a
d
c
c
d
c
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
a
c
b
a
b
b
a
a
b
b
d
c
a
d
b
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
a
a
d
c
c
d
b
b
a
d
b
a
d
b
a
106
107
108
109
110
111
112
113
114
115
116
b
b
c
a
c
a
a
b
b
c
c
Level 2 1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
b
a
b
b
b
c
b
b
a
d
b
d
c
d
a
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
a
b
c
c
d
b
b
b
abd
c
b
b
b
bc
abd
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
bd
abcd
abc
acd
bcd
acd
abd
ad
bc
bd
ad
acd
abc
ab
abcd
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
ab
abcd
cd
a
abd
acd
abcd
abcd
abcd
ab
abc
bd
abd
abc
abc
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
cd
ac
a
a
cd
a
a
d
ab
bc
ad
ab
ab
bc
bc
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
ab
bc
abcd
abc
acd
ab
abd
cd
d
ac
d
acd
ad
b
a
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
b
d
d
c
d
ab
b
b
c
b
c
c
a
d
c
106
107
108
109
d
c
a
a
110(a) 110(b) 110(c) 110(d) 111(a) 111(b) 111(c) 111(d) 112(a) 112(b) 112(c) rst
qrs
pqr
s
p
rt
p
s
qt
s
pt
2.61
2.62
chapter two 112(d) 113(a) 113(b) 113(c) 113(d) 114(a) 114(b) 114(c) 114(d) 115(a) 115(b) 115(c) 115(d) 116(a) 116(b) r
rs
st
qrs
ps
pr
s
p
t
qs
pr
qs
qt
pr
pr
116(c) 116(d) 117(a) 117(b) 117(c) 117(d) 118(a) 118(b) 118(c) 118(d) 119(a) 119(b) 119(c) 119(d) 120(a) ps
qt
qst
qst
qst
pr
qt
qt
pr
prs
prs
pr
qs
qt
ps
120(b) 120(c) 120(d) 121(a) 121(b) 121(c) 121(d) 122(a) 122(b) 122(c) 122(d) 123(a) 123(b) 123(c) 123(d) ps
p
qt
qrt
qrt
qrt
pr
ps
ps
qrs
qrs
p
ps
qt
qt
124(a) 124(b) 124(c) 124(d) 125(a) 125(b) 125(c) 125(d) 126(a) 126(b) 126(c) 126(d) 127(a) 127(b) 127(c) qrs
qrs
ps
qrs
qr
qr
rs
p
qrs
qs
qsr
qrs
pr
pq
s
127(d)
128
129
130
131
132
133
134
135
136
137
138
139
140
141
q
5.55
5
2
8
64
1024
32
8
9
8
7
4
8
5
142 5
isomerism
Workbook Exercises Exercise 1 Identify molecules that show Geometrical Isomerism
1.
4.
7.
10.
2.
3.
5.
6.
8.
9.
11.
12.
15.
13.
14.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
34.
32.
35.
33.
36.
2.63
2.64
chapter two
37.
38.
39.
OH 40.
41.
N
42. NH
43.
N
N
NH
T
N
50.
53.
D
D
58.
45.
OH
47.
49.
55. T
OH
46.
52. HN
44.
48.
51. HN NH
N N
56. HN
54.
NH
N OH
59.
61. HN NH
62. O O
64.
65.
OH
N N
57. HN
NH
60.
63. N N
O
66.
O
OH N
HN
67.
N HO
N
68.
NH
69. N
isomerism
70.
Cl
OH N
O
71.
72. O
NH 73.
Cl F C C C C Br Cl F
76.
C C C C F
79.
Cl F C C C C Cl Cl
74.
75.
Cl F C C C C F F F
77. F
Cl
Cl C C C C CH2 F
C C C C
78. C C C C
Cl
Cl
Cl Cl Cl Cl C C C C CH 81. C C C C C F F F
80.
COOH Cl Cl F Cl 82. C C C C C CH 83. C C C C CH 84. F F COOH
85.
87.
N
N
N
86.
88. N
N
N
N
Cl 89.
Cl
N
Br
Br
Br
Br
COOH
Br
91.
Cl
90.
N Br
Cl
92.
COOH
2.65
2.66
chapter two Cl
Cl
Cl
93.
94.
Cl
Br Br
96.
Cl C C C C CH F
Br
97.
Br
C C C C CH F
F
F
F
F
95.
isomerism
Exercise 2 Identify molecules that show Geometrical Isomerism
1.
5.
9.
2.
3.
6.
10.
7.
17.
21.
25.
11.
12.
NH
16.
14.
15.
18.
19.
20.
23.
24.
27.
28.
22.
8.
O 13.
4.
26.
Cl
Cl
Br
29.
30.
31. Br
Br Cl 33.
34.
32.
Br HO
O
Cl
35.
39.
36.
F 37.
HO
38.
40.
O 41.
42.
F
43.
O
44.
O
2.67
2.68
chapter two
45.
NH
O
O 46.
47. O
HN
49.
50.
HO
HO 53.
48.
O
54.
52.
51.
55.
56.
OH 57.
61.
65.
58.
59.
60.
62.
63.
64.
66.
67.
Cl 68. Cl
Cl
71.
74.
69.
Br
72. O
Br 70. D
73.
75.
76.
79.
77.
78.
80.
81.
83.
84.
82.
85.
D
O
O O
O
isomerism
86.
87.
89.
92.
95.
98.
101.
90.
91.
93.
94.
96.
97.
99.
100.
102.
104.
105.
103.
106.
O
O 107.
88.
O
108.
O
O
109.
O 110.
113.
116.
119.
111.
114.
117.
120.
112.
115.
118.
121.
O
O
2.69
2.70
chapter two
122.
124.
123.
125.
126.
127.
128.
129.
130.
132.
134.
Cl
HO
131.
Cl
133.
Br F
Br
Br
Cl
Cl
isomerism
Exercise 3 Identify molecule give G.I.
1.
O
O
2.
O
4. HN
9.
11.
12. Cl
15.
Cl 14. Cl
16.
19.
22.
25.
27.
29.
17.
20.
23.
18.
21.
24.
26.
28.
N H
Cl 13. Cl
N H
8.
N H
N H
6.
H N
5.
10.
N H
NH
7.
O
3.
O
O
30.
Cl
2.71
2.72
chapter two
31.
32.
33.
C
35.
37.
34.
36.
38.
39.
41.
40.
43.
42.
45.
44.
46.
Identify stable conformer Me
Me
H
Cl
H
H
47. H
H
H
H
49.
H i
Cl ii
NMe+3
NMe+3 H
H
CHO H
H
H H i
H
H CHO ii
NMe+3 48.
50.
H
F
H
NMe+3 H
H
H
H
H
H i
F ii
NMe+3 H
I
H
NMe+3 H
H
H
H
H
H i
I ii
isomerism Me
Me H
: 51.
H
:
N H
N Me
Me
COOH
H
H
H
H i
53. H
Cl 55. H H i
H COOH ii
Cl
H
H
H
H
H
H
:
O
52. H
O Me
H i
Me
: ii
F
H
F
H
H
54. H
H
H
H
Cl
Cl ii
:
F H
H i
H
H
H ii
Me
:
NO2
NO2 H
Me
H i
F ii
NO2
NO2
H 56. H H i
OH
H
H
H
H H OH ii
H
2.73
2.74
chapter two
Exercise 4 Identify Isomeric Relationship between pair of Compounds CN
CN
1.
3.
5.
H
H
H
H H
H
CN
H
H
H
H
H
Me
H H
H
OMe H
H
H
H
H
H
H
H
CN
CN
H
H H NC
H
COOH Me H
H
H
H
H
H
O
H
H H H
H
H
H
OMe H
H
H
H
H
COOMe H
OH
Me
H
H
H
H
H
H
H H
H H
H H
H
H H
Me
H
OH
H
OMe
H
H
H
OMe H
Me
H
H
H H
H
H
H
H H H
H H H
H
H
H
H
Et Me
Me H
H
H
8.
Et
H NC
H
H
H
H
Et
H
H
H
H
H
H
H
H
H Me H
H
6.
H
Me Me
H H
13.
OEt
Me
Me H
H H H
H
H
12.
H
H
Me
H
Me
11.
Me
H
9.
10.
H
Me
H
Me
Me
H
H
H H
H
H
H
Me H H
H
H
Et
H H
H
H
Me
NC H 4. H H
H
H
2.
H
CN
H
Me 7.
CN
Me
H
H
H H
Me
H
H
H
H
Et Et
Me
Me
Et
Me
H Me
H
Me
Me H Me
Me
Me
isomerism Et 14.
15.
H H
H
OMe H H
H
H
H
H
H H
Me H
Me
OMe
H H
H
i-Pr
Me
Et
Me
Et
Me
Me
Me
Me
H
Me
H
Me
H
H H
H
Cl
H
H
H
H
Et OMe H
20.
Me
H
H COOMe
22.
H H
H
H
H
24.
Cl
H H
i-Pr
Et
CHO
COEt H
H
H
Me
H
H H
H
H
H
H
H H F
26.
H
Me Me ONO H H H Cl
Cl H
H
Me Me NO2
H
Bu H
H
Me H
H
i-Pr
Me
H
Me
Me
Cl
H
Me
H
H
Me
H COOH Cl
H
H
H
H
H
Me
H
H
H
Me Me
Me Me
H
Me Me
OH
Me
H
Me
H
Me
H
H
H
H H
27.
H H
H
H
25.
Me H
Me
H
23.
H
Et Me
Me
21.
Me
Me
OPr H
H
19.
OPr H
H H
18.
H
H H
Me
17.
H
H
H Et
16.
H H
H
H
H
F
Br H COMe H
Br
H H COEt H
H
H
H Et
H
H Me
2.75
2.76
chapter two
Exercise 5 Identify optically active compounds
1.
Cl
2.
Cl
Cl
4.
Br
5.
F
F
F
F
6.
Cl Br
Br Br
NO2
COOH
3.
7.
8.
9.
NO2
COOH CN 10.
11.
12.
13.
14.
15.
16.
N
N
NC
18.
N
17.
N
19.
N
N
N
20. N
N
21.
N N
NO2 Cl Cl 22.
Br Br O2N
23.
isomerism
24.
25.
26.
27.
28.
29.
30.
31.
33.
34.
36.
39.
51.
46.
41.
44.
47.
49.
52.
38.
43.
35.
40.
42.
48.
32.
37.
45.
50.
53.
2.77
2.78
chapter two
54.
55.
56.
Br 57.
Cl
58.
59.
Br Br
Cl Br
Cl Cl 60.
Cl
Cl
61. Cl
Cl
62. Cl
Cl
Br
Br
Cl
Cl 63.
64. Cl
Cl
Cl
65. Cl
Cl
Cl
Cl 66. O
Br Cl
67.
N
68.
Br Cl
F 69.
Br
70. Br
Br
I
71.
Br
Br
Cl Cl 72.
Br
Br
Cl
Cl
73.
Cl
O
74. O
Br Cl
75.
76. Cl
Br 78.
Br Br
Br Cl
Cl
Cl
77. Cl
Cl
isomerism
2.79
Solution for Workbook Exercises Exercise 1 Molecules that show Geometrical Isomerism 4, 6, 9, 11, 13, 16, 23, 24, 25, 26, 27, 30, 31, 33, 34, 35, 36, 38, 39, 40, 41, 44, 47, 50, 51, 52, 53, 54, 55, 56, 58, 59, 60, 61, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 76, 77, 82, 86, 89, 90, 92.
Exercise 2 Molecules that show Geometrical Isomerism 6, 9, 11, 12, 13, 14, 17, 18, 19, 20, 21, 22, 23, 25, 26, 28, 29, 30, 31, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 59, 61, 62, 63, 67, 68, 69, 70, 73, 78, 79, 83, 77, 86, 87, 90, 92, 93, 94, 95, 97, 98, 99, 100, 101, 102, 103, 106, 107, 109, 110, 111, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 134.
Exercise 3 Molecules that show Geometrical Isomerism 1, 3, 4, 5, 6, 7, 8, 9, 11, 12, 13, 14, 15, 17, 18, 19, 20, 21, 22, 23, 25, 27, 28, 29, 30, 31, 32, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 45, 46. Stable Conformer 47(I), 48(I), 49(I), 50(II), 51(II), 52(I = II), 53(I), 54(I), 55(II), 56(I).
Exercise 4 Isomeric Relationship between pair of compounds 1. Positional Isomers 2. Positional Isomers 3. Functional Isomers 4. Functional Isomers 5. Metamers Isomers 6. Chain Isomers 7. Chain Isomers 8. Chain Isomers 9. Chain Isomers 10. Functional Isomers 11. Functional Isomers 12. Not Isomers 13. Positional Isomers 14. Metamers Isomers 15. Chain Isomers 16. Metamers Isomers 17. Chain Isomers 18. Functional Isomers 19. Chain Isomers 20. Positional Isomers 21. Functional Isomers 22. Functional Isomers 23. Positional Isomers 24. Positional Isomers 25. Chain Isomers 26. Metamers Isomers 27. Functional Isomers
2.80
chapter two
Exercise 5 Optically active compounds 4, 7, 8, 10, 12, 14, 15, 22, 23, 24, 25, 27, 28, 30, 34, 36, 37, 38, 39, 41, 43, 44, 45, 46, 48, 49, 50, 51, 52, 53, 55, 56, 58, 59, 62, 63, 64, 65, 66, 67, 69, 73.
CHAPTER
3
Hydrocarbons Question Bank Level 1
1. When the trans-2-pentene is treated with Br2 in the presence of CCl4, then the number of stereoisomers formed is (a) 1 (b) 2 (c) 3 (d) 4 2. Which one of the following compounds will give Saytzeff product in E2 reaction? F Br CH3–CH2–CH–CH3 (a)
⊕
CH3–CH2–CH–CH3 (b)
CH3–CH2–CH–CH3 CH 3 − CH 2 − CH 2 − N(CH 3 )3 OH (d) (c) OCOCH3 3. Which compound is most reactive for E1CB reaction?
(a) CH3–CH2F (b)
(c)
CH2F
(d) C6H5–CH2–CH2F
CH2F
4. In the given reaction CH3 CH3 C=C +BrCl H H
The correct option about the product is (a) (+)-2-bromo-3-chlorobutane (c) (+)-threo-2-bromo-3-chlorobutane
CS2
(b) (±)-threo-2-bromo-3-chlorobutane (d) (–)-threo-2-bromo-3-chlorobutane
3.2
chapter three 5. In the given reaction D
(i) BH3/THF (ii) H2O2/OH
D
the product is
H
D H (b)
(a)
D OH
H D
D
D
D (c)
H
H (d)
D OH
OD H
6. o-xylene on ozonolysis may give CH3 – C = O O O CHO (a) (b) CH3 – C = O and CH3 – C – CHO CHO and CH3 – C – CHO3 CH3 – C=O CH3 – C=O CHO CHO O (c) (d) and and CH 3– C=O, CH3 – C – CHO CHO CH3 – C=O CHO 7. A hydrocarbon (C4H8) on reaction with m-chloro perbenzoic acid (MCPBA) gives (X). (X) on reaction with KOH (aq.) gives (Y), which on treatment with conc. H2SO4 forms 2-methyl propanal. The hydrocarbon is (a) CH2=C–CH3
(b) CH3–CH=CH–CH3 (c) CH3CH2CH=CH2 (d)
CH3 8. The final product of the following sequence is CHBr3 alc. A B t-BuO KOH OTs Br (a) (b)
OCMe3
Br (c)
(d)
9. Major product of reaction between cycloheptyne and H2O, H2SO4/HgSO4 is O O OH H C C–CH3 (b) CH3 (d) (a) (c) 3 OH
CH3 10. H2C=CH–C–COOH CH3 CH3
NaOH CaO/∆ X; X will be
(a) H3C–CH=C–CH3
CH3 (b) H2C=CH–C–CH3 H
CHBr2
O
hydrocarbons CH3
CH3
(c) (d) H2C=CH–C–COONa H3C–CH=C–CH2OH CH3 CH3 MCPBA 11. CH3–C=CH2 CH2Cl2 O
(a)
H
[X]
(i) H⊕
⊕ [Y] Conc. H [Z]; The major product (Z) can be
O18
(ii) H2
(b)
18
O
(c) 18 O
(d) O
H 12. An optically active organic compound has the molecular formula C7H10 (A). On reaction with H2 + Pt it forms an optically inactive compound (B). Then, compound (A) will be CH3
CH2 (a)
(b) H
H2C
CH
H2C
CH2
(c) CH3 CH
H3C
(d) None of these H
CH2
13. Identify end products A, B and C of the following (i) D⊕ CH3CH=CH2 A (ii) H2O CH3CH=CH2
(i) H⊕ B (ii) D2O
CH3CH=CH2
(i) D⊕ C (ii) D2O
(a) CH3CHCH3 in all case
(b) CH3CH(OH)CH2D, CH3CH(OD)CH3,CH3CH(OD)CH2D
OH (c) CH3CHCH3 in all cases (d) CH3CHCH2D in all cases OD 14.
OD
–CH=CH2
A B
–CH2CH2OH –CHCH3 OH
C
Schemes A, B and C are (a) simple acid catalysed hydration (b) hydroboronation, mercuration-demercuration, acid-catalysed hydration (c) acid-catalysed hydration, hydroboronation, mercuration-demercuration (d) mercuration-demercuration, acid-catalysed hydration, hydroboronation
15.
–C
C–C
C–
(a)
–CH2CH3 OH
(c) both are correct
Li/NH3
A; A is
(b) (d) none is correct
3.3
3.4
chapter three 16. Rate of dehydration when given compounds are treated with conc. H2SO4 is OH OH OH CH2OH CH CH3 3 (S) CH3 (R) (P) (Q)
(a) P > Q > R > S CH2OH
17.
(b) Q > P > R > S H2SO4 ∆
(c) R > Q > P > S NBS
P(Major)
(d) R > Q > S > P
Q(Major)
The structure of Q is Br (a)
Br Br (b) (c)
COOCH3
OSO4(1 eq)
18.
H2O/Acetone COOCH3 Identify “X”: COOCH3 OH (a) OH COOCH3 HO (c) HO
COOCH3 OH OH COOCH3
Br (d)
Br
X.
HO (b) HO
COOCH3 COOCH3
(d) reaction will not occur
19. 1-Penten-4-yne reacts with bromine at –80°C to produce (a) 4, 4, 5, 5-Tetrabromopentene (b) 1, 2-Dibromo-1, 4-pentadiene (c) 1, 1, 2, 2, 4, 5-hexabromopentane (d) 4, 5-dibromopentyne 20. Which of the following reagents cannot be used to locate the position of triple bond in CH3–C≡C–CH3? (a) Br2 (b) O3 (c) Cu22+ (d) KMnO4 21. An organic compound of molecular formula C4H6, (A) forms a precipitate with ammonical silver nitrate and ammonical cuprous chloride. “A” has an isomer “B”, one mole of which reacts with 1 mole of Br2 to form 1, 4-dibromo-2-butene. Another isomer of A is “C”, one mole of C reacts with only 1 mole of Br2 to give vicinal dibromide. A, B and C are
(a) CH3–CH2–C≡CH and CH2=CH–CH=CH2;
(b) CH3–C≡C–CH3 and CH3–CH=C=CH2; CH3–C≡C–CH3
CH2 (c) CH2
C=CH2
and
CH3–C–C≡CH3 and CH2 (d)
CH2–CH CH2–CH CH CH
; CH2=CH–CH=CH2 CH2; CH2=CH–CH=CH2
hydrocarbons CH3 Excess CH3I 22. CH3–CH–CH2–N–CH2–CH2–CH3 Moist Ag2O, ∆ CH3 Product mixture
O3/Zn-H2O
Final product mixture
The final product mixture contains: (a) CH3CHO + CH3COCH3 (c) CH3CHO + HCHO
(b) CH3CHO + CH3CH2CH3 + HCHO (d) CH3CHO + CH3COCH3 + HCHO
23. Choose the correct major product H3CO–
14
C=C Cl– 14
H3C–O– (a)
–C≡C–
OH (c) –C=CH–
H KNH2
[X] (major product)
Br OH –CH=C–
H3C–O– –Br (b)
14
H3CO– –Cl (d) –C≡ C–
–Cl
–Cl
24. Supposed you carried out the hydroboration of 1-methylcyclopentene: CH3 (i) BH3 (ii) H2O2, NaOH
?
Choose the correct answer for the products formed in the above reaction. H3C H (i) H OH
H3C H (ii) OH H
H CH3 (iv) H
H CH3 (v) OH H
OH
(a) An equal mixture of 1 and 5 (c) An equal mixture of 2 and 4
H3C OH (iii) H H
(b) An equal mixture of 1 and 2 (d) An equal mixture of 4 and 5
25. The ozonolysis of limonene (oil of lemons) give compound X plus formaldehyde. Choose the correct structure for X. CH3 (i) O3 (ii) (CH3)2 S H3C Limonene
X +
O H
H
3.5
3.6
chapter three O
O
O
O CH3 H
CH3 (b) H3C CH3
H (a) O O
O O
O CH3
H3C (c)
O H
O H CH3
H3C (d)
O
O
26. Choose the incorrect statement about the following catalytic hydrogenation. CH3
CH3
CH3
H2 – Pd/C
H H
CH3
H
+
CH3 H
CH3 major
minor
(a) The minor product occurs as the result of a catalyzed isomerization of the reactant. (b) The minor trans isomer is actually present as a racemic mixture. (c) The syn addition of hydrogen gives the cis isomer as the major product. (d) The catalyst (Pd/C) speeds up the reaction by stabilizing the major product of the reaction.
27. Choose the incorrect reaction. (b)
(c)
H2 / Pd (a) O
HgSO4 H2SO4
H3C C
(d)
Na / NH3 C CH3
Br H
HBr H Br
3 / CH 2 Cl 2 28. Product of the reaction CH 3 − CH = CH − CH 3 O → will be −78° C
(a) CH3–CHO
CH3–CH–CH–CH3 (c)
(b) CH3–COOH O (d) CH3–CH CH–CH3 O—O
OH OH 29. H2C–CH=CH2 OH
KHSO4 (i) OsO4 (B); compound (B) is (A) (ii) NaSO3H
(a) H2C=CH–CH2–OH (c) H2C=CH–CHO
(b) H2C=CH–COOH (d) H2C=C=CH2
3 / Al 2 O 3 30. CH3–CH2–CH2–CH3 CrO → [P]; Product is 600° C
hydrocarbons
(a) Mixture of 1-butene and 2-butene (c) 1,3-cyclobutadiene
(b) Cyclobutene (d) None of these
31. In the presence of peroxide, HCl and HI do not give Anti-Markovnikov’s additon to alkenes because (a) All the steps are endothermic in both the cases (b) One is oxidising and other is reducing (c) One of the steps is endothermic in both the cases (d) All the steps are exothermic in both the cases 32. Hydrogenolysis is a process of (a) Addition of H2 across C—C multiple bond (b) Elimination of H2 in CH–CH bonds (c) Cleavage of a single bond by H2 (d) Cleavage of C—C multiple bonds by H2 33. In the reaction with Tollen’s reagent actylene shows (a) Oxidising property (b) Reducing property (c) Basic property (d) Acidic property 34. Arrange the following halogenating agents in order of decreasing selectivity in free radical reactions (i) NBS (ii) NCS (iii) Cl2 (iv) F2 (a) iv > iii > ii > i (b) i > ii > iii > iv (c) ii > i > iii > iv (d) i > ii > iv > iii 35.
⊕
+ CHBr3 + t-BuOK
P1
Mg (i) Cl–CN P3 P dry ether 2 (ii) H3O+
The product P3 is (a)
COOH
(b)
CH2COOH
(c)
COOH
(d)
CH2COOH
36. A compound having the molecular formula C10H14 is hydrogenated with H2/Pd to O give 1-isopropyl-4-methyl cyclohexane and on reductive ozonolysis it gives H–C–H, CH3–C–C–CH2–C–H and CH3–C–CH2–C=O O O O H O The structure of the compound would be H3C
C
H3C
CH2
(a)
C
(b) CH3
H3C
CH2
C
CH3
(c) CH3
H3C
C
CH2
(d) CH2
CH3
3.7
3.8
chapter three 37. The product obtained during the following photochemical reaction is Me
hv
Me Me (a)
(b)
Me (c) Me
Me
Me
Me (d)
Me
Me
38. The major product formed on hydroboration oxidation of 1-methylcyclopentene is CH3 (a)
OH (b)
OH
CH3
CH3 (c) OH
CH3 (d)
O
H
39. Compound (A) on bromination gives (B), which gives (C) with alcoholic KOH. (C) decolouries 1% alkaline KMnO4 solution and on ozonolysis, it gives two molecules of smallest carbonyl compound. Compound (A) will be (a) C2H2 (b) C2H4 (c) C2H6 (d) C2H5Cl 40. CH2=CH–C≡CH on reaction with 1 mole of DBr gives (a) CH2=CH–CBr=CHD (b) CH2(Br)–CHDC≡CH (c) DCH –CHBrC≡CH (d) CH2=CH–CD=CHBr 2 41. In the given reaction, A and B respectively are CH3–CH2–C≡C–H
(A)
CH3–CH2–C–CH3
(B)
O
CH3–CH2–CH2–CHO
(a) (Sia)2BH/H2O2/HO– and H2O/HgSO4/H⊕ (b) H2O/HgSO4/H⊕ and (Sia)2BH/H2O2/HO– (c) H2O/HgSO4/H⊕ and Na, CH3–I (d) None
42. Identify the major product P obtained by the reaction OH 2 SO 4 H → P Heat
(a)
(b)
(c)
(d)
43. During the preparation of ethane by Kolb’s electrolytic method using inert electrode the pH of the electrolyte
hydrocarbons
(a) Decreases progressively as the reaction proceeds (b) Increases progressively as the reaction proceeds (c) Remains constant throughout the reaction (d) May decrease if concentration of the electrolytes is not very high
44. Major product obtained by the following reaction is + HCl ⎯→ (a)
(b) (c) Cl Cl Cl
45. In the reaction
Cl
(d)
Na/NH ( I )
( I ) Sia BH
3 2 CH ≡ CH → A DCI → B ( →(C) ( excess ) ii ) CH3 COOH
the product (C) is O
H
H
(a) D – C ≡ C – D (b) CH3 – C – H (c) C D
(d) C
C
D
H C
D
D
H
46. Identify structure of compound [A] Compound A
Hot (gas) + Compound B conc. KMnO4/∆ LAH
White ppt. with ammonical AgNO3
Compound C H⊕/∆ Compound D (i) Hg(OAc)2 (ii) NaBH4 Me–CH–CH3
(a) Me–C≡C–Me (c) Me–CH=CH–Me
OH (b) Me–CH2–C≡CH (d) Me–CH2–CH=CH2
47. The reaction of propene with HBr in the presence of ROOR (peroxide) proceeds through which of the following most stable intermediates? − CH 3 − CH 2 Br (a) CH 3 − CH (b) CH 3 − CH Br 2 CH3–CH–CH2 (c) (d) CH 3 − CH 2 − CH 48. The following transformation is carried out in three steps. What is the appropriate reagent for the first step? OH OH i ii iii H H
3.9
3.10
chapter three
(a) H2/Lindlar’s catalyst (c) NaNH2/NH3: EtBr
(b) C2H2/NaNH2/CH3I (d) H2/Pd/C
49. Compound A was treated with a large excess of CH3MgBr. The resulting product was exposed to POCl3/pyridine to give compound B, as one of many products. Which of the following compound can be A? B
O
O
O
O O H (b)
H (a)
O
O
O
O
O O
O (c)
(d)
O
O
O
O O
50. Which molecule will give the following dicarboxylic acid upon treatment with acidic solution of KMnO4/∆? O HOOC
CH2COOH
O
(a)
(b)
(c)
(d)
51. What is the product of the following sequence of reaction? NaNH2/NH3
H2/Pd/BaSO4
BH3/H2O2/NaOH
I HO (a)
HO (c)
HO
HO
OH
OH
HO (b)
OH
HO (d)
OH
HO
HO
OH
OH
hydrocarbons 52. Give the major product of the following sequence H⊕
(1) O3
HO
(2) (CH3)2S
(Major product) H (a)
OH O
O OH
(c) O H
O
O
OH
(b) H
O
(d) O O OH
53. Which of the following reactions involve a radical mechanism? HBr
(a)
Br
Br2, H2O
(b)
CH3 OH Br
(c)
HBr ROOR
(d) Br
O3 Zn, H2O
54. For the following multistep reaction, which set of reagents would be more likely to give the desired product in good yield? HO OH H
(i)
(ii)
(iii)
(a) (i) HBr, (ii) O3/Zn–H2O, (iii) Li/NH3 (b) (i) NaNH2/NH3/C2H5I, (ii) Lindlar’s catalyst/H2 (iii) OsO4 followed by NaHSO3 (c) (i) H2/Pd-C, (ii) NaNH2/NH3 followed by C2H5I, (iii) KMnO4/OH– (d) (i) HgSO4/H2SO4, (ii) Lindlar’s catalyst/H2, (iii) OsO4 followed by NaHSO3
55. In the following reaction, compound (B) is Br + Mg
(1eq.)
Dry ∆ A ether
B
Br (a)
Br
Br (b)
MgBr
(c)
(d)
Br
56. Here is a reaction Br2 H
H2O
C4H7BrO
Use your knowledge of mechanisms to choose the most likely product from among the following compounds. Br O Br OH (a) (b) (c) (d) OH Br OH
3.11
3.12
chapter three 57. Identify the reactant (X) on the given reaction O
O (X) (a)
(i) 1eq. O3/CH2Cl2
(b)
58. Compound (A) → Compound (A) can be CH2 (a) (b) dil . H2 SO 4
CH3
H
H
(ii) Me2S (c)
(d)
CH3 OH CH3 CH3 (c) CH3
CH3 (d) CH=CH2
59. Which of the following gives glyoxal as one of the product on ozonolysis? (a)
(c) H2C=CH–CH=CH2
CH2
(b) H2C=CH (d) Benzene
60. In which of the following reaction the rearrangment of carbocation is involved? Me Me dil. H2SO4 (a) (b) CH2 H–Cl CH2 Me Me (i) B2H6/THF Me Me Me dil. (c) (d) (ii) CH3COOH Me Alk. KMnO4 Me Me 61. The final product of the given reaction is Me H–Cl P1 Me
alc. KOH
P2
(i) m-CPBA (ii) CH3MgBr (iii) H2O
Me (a) Me
Me
Me
Me (b)
Me
Me Me
Me (d) Me
CH3 Aq. H+
62. H3C
A
H3PO4 B; Product B is H–C–OH O
H3C
Me OH Me
OH
H3C
Me
HO
Me Me (c) Me
Me
P3
CH3 CH3
hydrocarbons OH (a)
O
O
O
(b)
(c)
(d)
63. Choose the best reagent to carry out the following sequence of reaction HO Br
i
i
ii ii
OH
iii iii
(a) Acetylene/NaNH2/NH3 H2/Pd OsO4/NaHSO3 (b) Acetylene/NaNH2/NH3 H2/Lindlar’s catalyst BH3/NaOH/H2O2 (c) Pentyne/NaNH2/NH3 Li/NH3 MnO4 (d) Pentyne/NaNH2/NH3 H2/Lindlar’s catalyst OsO4/NaHSO3
64. When cyclohexadiene (A) reacts with Br2, a mixture of cis- and trans-1, 2-addition p roducts is formed (in addition to other products). However, when cyclohexene (B) reacts with Br2 under identical conditions, only trans product is observed. What is the best explanation for the observed difference in stereochemistry of the addition? Br Br2/CCl4
cis and trans
(A)
Br Br
Br
Br2/CCl4 (B)
only trans
(a) The cis and trans products are the result of aromaticity in the cyclic TS for reaction of A. In B there are only four electrons in TS, and cyclic TS is destabilised. (b) Reaction of A proceeds through an intermediate that has an sp3-hybridised carbocation, while the analogous intermediate in reaction of B has sp2-hybridised carbocation. (c) Both reactions occur through bromonium ions, but because of planarity enforced by neighbouring double bond, cis addition is not sterically hindered in A. (d) B reacts through a bromonium ion intermediate, while A does through an allyl cation. OH
H2SO4 2 / CCl 4 65. number of product (x) Br → number of products (y). Me Heat Me The (x) and (y) are respectively (a) ii, 4 (b) ii, 3 (c) iii, 6 (d) iii, 5 66. Final product in the given sequence is MeMgBr
I H2 CO H2 → [B] II Me–C≡CH → [C] Pd → [D] NH 4 Cl − BaSO 4 −[ A ] ↑
Me (a) H
H
Me (c) H
OH Me
OH
Me (b) H
Me OH
(d) None of these
3.13
3.14
chapter three 67. Identify “C” product in the given reaction Me
Me O3/Zn (i) Mg–Hg/ether H⊕ A B C Me (ii) H2O
Me (a) HO
O
(b)
O O O (c) (d)
OH
68. Consider the following reaction. Br + Br — Br
step-2
step-1 Br⊕
Br
Which one of the following statements is incorrect? (a) The Br2 addition occurs with anti-stereospecificity. (b) The final product will be a mixture of enantiomers. (c) In step 2 the Br- anion acts as a Lewis base. (d) In step 1 the Br2 molecule acts as a Lewis base. 69. Identify the product in the following sequence of reaction Br
dil. OH
i. CH3I(excess) ii. Moist Ag2O iii. ∆
A
CH2NH2
B
NMe2 (a)
(b)
CH2
(c) CH2NMe2
CH2
70. Which of the following is correctly matched? CH3
⊕ CH OH 3 N
(a)
(major)
H3C CH3
(b)
⊕ N
CH3
OH
∆
C2H5 CH3 H3C CH3 ⊕ (c) N
CH3
∆
N
CH2
C2H5 CH3 (major)
OH
∆
H3C
CH3 N
(major)
(d) All of these
(d) CH2
Br
hydrocarbons 71. The final product of the given reaction sequence is H D HO
CH3 SOCl2 t-BuO A H (CH ) N DMSO 3 3 CH 3
H
H CH3 (b) CH3
H (a)
HC D (c) 3 H CH3
B (major)
D (d) none of these CH3
H3C 72. Ph–CH=CH2 + BrCCl3 peroxide → Product is H
H (a) Ph
Ph CH2Br CH2CCl3 (b) Br
CCl3
Br
CCl3
(c) Ph
CH2CCl3 (d) Ph CH2Br H
H 73.
+ N
OH Me
The above compound readily undergoes elimination on heating to yield which of the following products? OH : Me (d) (a) + (b) (c) Me CH 2 N N CH2 N N Me Me Me Me Me Me Me Me 74. Select true statement(s) (a) Instead of radical substitution, cyclopropane undergoes electrophilic addition reactions in sun light. (b) In general, bromination is more selective than chlorination. (c) The 2, 4, 6-tri-tert,butylphenoxy radical is resistant to dimerisation. (d) The radical-catalysed chlorination, ArCH3 → ArCH2Cl, occurs faster when Ar = phenyl than when Ar = p-nitrophenyl. 75. Which reagent is the most useful for distinguishing compound i from the rest of the compounds? CH3CH2C≡CH CH3C≡CCH3 CH3CH2CH2CH3 CH3CH=CH2 (i)
(ii)
(a) alk. KMnO4 (c) Br2/CH3COOH
(iii) (b) Br2/CCl4 (d) Ammonical AgNO3
(iv)
3.15
3.16
chapter three CH3 (i) O3, CH2Cl2 (ii) Me2S
76.
(A) + HCHO
H3C (Limonene) ⊕
. OH (A) dil → products (mixture) ∆
For the given reaction, the products are O CH3 O C (a)
CH3
O
(b)
(c) C–CH3 O
CH2CHO
(d) O O
77. Which of the following reaction is correct regarding the formation of major product (alkene)? Me
H3C (a)
⊕
∆
N
OH
Me
CH2=CH2
CH3
H Me ⊕
(b) H3C
∆
N
OH
CH3–CH=CH2
CH3
H3C Me Me ⊕
(c) Ph
N
OH
∆
CH3
Me
Ph–CH=CH2
Me ⊕
(d)
N
H3C
OH
Cl
Me
CH3 C2H5
78. H3C – C – CH – CH – OH CH3
CH3
H⊕ ∆
∆
CH2=CH–Cl
Product mixture
the product’s mixture contains CH3
CH3
H3C–C– C H3C–CH – CH–CH–C2H5 (b) (a) CH3
OH
CH3 H3C–C– C (c)
C–H
CH3 C2H5 CH3 CH3
H
C–CH3 (d) H3C–C – CH–C=CH2
CH3 C2H5 CH3
CH3 C2H5
79. Which of the following reaction does/do not takes place by formation and rearrangement of carbocation?
hydrocarbons
R–CH–CH (a)
CH2
CH3 CH3–C (c)
(i) Hg (OAc)2, H2O (ii) NaBH4
R–CH–CH (b)
CH2
CH3
(i) BH3 (ii) H2O2
HBr (d) Peroxide OH NH2
CH2
CH3
HNO2 ∆
80. Which alkyl halide will form Wittig reagent with PPh3 and C6H5Li? CH3 (a) CH3–C–Br (b) CH3–CH–Br (c) CH3–Br CH3
(d) C6H5–Br
CH3
81. Alkyne can be converted into vic dicarbonyl compound by
(a) SeO2
(b) Baeyer’s reagent (c) KMnO4/H⊕
(d) K2Cr2O7
82. Which of these substrates will give rearranged product in hydration reaction? (b) CH 3 − S − CH 2 − CH = CH 2 CH3 Ph (d) C=CH–C–CH3 Ph CH3
(a) CH3–CH–CH=CH2 CH3
(c) CH3–CH=CH2
83. The reagent(s) of choice for conversion of propene to methylcyclopropane is/are (a) CH2N2/ether (b) CH2I2 (c) CH2I2/Zn (d) CH3I/NaOH 84. Anti-Markonikov addition is given by which of the following alkenes? ⊕
(a) CH 2 = CH − N(CH 3 )3
CH3–C=CH2 (d) C6H5–CH=CH2 (b) CH2=CH–CF3 (c) CH3
85. Which of the following gives allylic substitution product?
/hv (a) CH2=CH–CH3 NBS → product
2 → product (b) CH2=CH–CH3 SeO ∆
4 (c) CH2=CH–CH3 OsO → product
2 2 → product (d) CH2=CH–CH3 hv
SO Cl
86. In the given reaction, identify compound [A] HBr [A] CCl4 [B] CH3CH2CH3
(a) Compound [A] is
Br
(c) Reagent B is H2/Ni at 120°C
(b) Compound A is CH3CH2CH2Br (d) Reagent B is LiAlH4
87. In which of the following Hoffman’s elemination product is more? CH3 CH3 conc. H2SO4 CH3–C–CH–CH3 CH3–C–CH–CH3 (a) (b) H3C OH H3C Br
Potassium t-butoxide
3.17
3.18
chapter three CH3 (c) CH3–CH2–CH2–CH2–N ⊕
88. When formed would be
CH3 CH3
CH3 (i) AgOH (d) CH –C–CH –Cl 3 2 (ii) ∆ CH3
Alc. KOH
OH is treated with HCl then different carbocations and products ⊕
(a)
(b)
⊕ ⊕
(c)
CH2
(d) Cl +
+ Cl
CH2–Cl
89. Which of the following compounds can give bromination reaction with NBS/hv? CH3 CH3–CH–CH3 (d) C6H5–CH3 (a) CH3–C≡CH (b) (c) CH3 90. Which of the following alkynes show acidic character?
(a) H–C≡C–H
(b) CH3–C≡C–H (c)
C≡C–H
(d) CH3–C≡C–CH3
91. Aqueous solution of which of the following compounds is electrolysed, when acetylene gas is obtained? (a) Sodium fumerate (b) Sodium maleate (c) Sodium acetate (d) Calcium carbide 92. Which of the following acid will give isopentane on decarboxylation with soda lime? COOH COOH CH3–C–CH2–CH3 (a)
(b) CH3–CH–CH–CH3
CH3
CH3
COOH CH3–CH–CH2–COOH (c) CH2–CH–CH2–CH3 (d) CH3
CH3
93. Which of the following alkane cannot be synthesised by Wurtz reaction in good yield? (a) (CH3)2–CH–CH2–CH–(CH3)2 (b) (CH3)2CH–CH2–CH2–CH–(CH3)2 (c) CH3–CH2–C(CH3)2–CH2–CH3 (d) CH3–CH2–CH2–CH3 Br2/H2O
94.
major product of the reaction is
Me (a) (dl)
OH (b) Br
Me Br (c) (dl)
Br
Me
Me
OH
OH (d) (dl)
OH
(dl)
Br
hydrocarbons 95. Identify per cent yield of 2°-chlorination product of 2-methyl butane (Excluding stereo isomer), If propane on monochlorination gives 1-chloro and 2-chloro propane in 45% and 55% yield respectively and isobutane on monochlorination gives 1°-chloro and 3°-chloro product in 65% and 35% yield, respectively
(a) 40%
(b) 31.28%
(c) 54.3%
(d) 34.28%
96. Identify major product of reaction of (E)-3-methyl-2-pentene with D2/Ni Me
D
D
D D
(a) Me
Et (b)
(d) (a) and (c) both Et Me
D
Et
H
(c) Me Me
H
H
D
Me
97. Test for identification of But-2-ene and benzene is (a) Tollen’s Reagent test (b) 1% Alkaline KMnO4 (c) Iodoform test (d) Br2 + H2O test 98. In the given reaction, the possible structure of compound (X) is (X)
Me
conc. H2SO4
Me OH (b) OH
(a)
OH
OH (c)
Me
Me
(d)
99. Which of the following reactions will give an alkyne? Electrolysis
Zn dust
(a) Potassium fumarate →
(b) CH3CBr2CHBr2 →
. KOH/NaNH 2 / ∆ (c) CH3CH2CHBr2 alc →
2 /∆ (d) CH3CHBrCH2Br NaNH →
red hot 100. 4HC≡CH iron → “X”. “X” is tube
(a) Benzene
(b)
CH3
(c) H3C
CH3
H3C (d) H3C
CH3
CH3
CH3 CH3
3.19
3.20
chapter three
Level 2 Single and Multiple-choice Type OH
1. H2SO4 / heat
1.
Product
2. Br2 / CHCl3 CH3
(a)
Br (c) Br CH3 H Br
CH3 (b) Br
Br H
H
Br MCPBA
2.
O (b) O
HO
2. NaCN / DMF F
(a)
2. H2O2
O
(a) HO
(c) H
(a)
OH
(b)
O
H
OH O
O
conc. HBr
(b)
O
Product
H
(d)
CN O (c) (d)
OH
O
5.
CN
O
O
H
Product
(b)
1. Excess O3
4.
CH3
H O (c) H3C O O
H3C 1. TsCl, pyridine
3.
Br
CH3
Product
H (a) H
(d)
(d) HO
O OH
Product is?
(c)
Br
(d)
Br
hydrocarbons CH3 ? 6.
Br
H
H
Br CH3
(a) (i) Na/NH3 (l)
(ii) Br2/CHCl3
(b) (i) H2/Pd/CaCO3/pyridine
(ii) HBr
(c) (i) excess H2/Pd
(ii) Br2, uv light
(d) (i) H2/Pd/CaCO3/pyridine
(ii) Br2/CHCl3
7. ?
O
1. Br2 / hν 2. EtOH
OH Br (a)
8. ?
(b)
(c)
(d)
OH
aq. H2SO4 HO
(a)
9. ?
(b)
(c)
(d)
1. H2SO4, heat 2. O3 then Zn / CH3CO2H
CHO
OHC OH
(a)
10. ?
(b)
(c)
1. Excess NaNH2 then H2O work up
O only
2. HgSO4, H2SO4, MeOH
(a)
(b)
Br
OH (d)
(c)
Br
Br Br
(d) Br
11. ?
1. Tosyl chloride, Et3N 2. KOtBu / tBuOH / heat
3.21
3.22
chapter three OH (a)
(b)
(c)
(d)
Br
OH 12. ?
OH
1. O3 then H2O
CH3CH2CH2CO2CH3 only
2. Na2CO3 / CH3I / DMF
OH (a)
(b)
(c)
(d)
CH3 ?
13.
O
? Cl
(a) (i) H2O (b) (i) aq. H2SO4 (c) HBr/peroxides (d) (i) BH3 then NaOH/H2O2
(ii) NaOH (ii) Na (ii) NaI/acetonei
?
15.
Br (ii) NaOH (ii) NaBr (ii) HBr
(a) (i) Br2/CHCl3 (b) (i) NaOH (c) (i) BH3 then NaOH/H2O2 (d) Br2/H2O
14.
OH
(a) heat H2/Pd (b) (i) HCl (c) (i) SOCl2/Et3N (d) (i) Br2/hv
(ii) KOH/EtOH/heat (ii) KOH/EtOH/heat (ii) KOH/EtOH/heat
16. Identify the correct reaction sequence (A)
CH3
CH3
OH
Br
(B) BH3/THF H2O2/NaOH
Br2/CCl4
Br
CH3 Hg(OAc)2 (C)
CH3
Br2/H2O
OH
NaBH4
CH3
(D) OH
Br
hydrocarbons 17. Which of the following is most reactive towards aqueous HBr? (a) 1-Phenyl-2-propanol (b) 1-Phenyl-1-propanol (c) 3-Phenyl-1-propanol (d) 2-Phenyl-1-propanol 18. Ethylbenzene when treated with chlorine in the presence of light mainly gives (a) β-phenylethyl chloride (b) α-phenylethyl chloride (c) o-chloroethyl benzene (d) o- and p-chloroethylbenzene 19. When the following alcohol is treated with conc. H2SO4, the major product obtained is C6H5
OH
. H2 SO 4 conc → ( − H2 O )
H C6H5 (a)
C6H5 (b) H
H H
(c) C6H5
(d) All the three will be formed in equal amounts
( i ) B 2 H6 ( → X. The compound X is ii ) H2 O 2 , OH −
20.
CH3 (a) H
OH
CH3
CH3 (b) H
H OH
H
(c) HO
H
(d) Both (b) and (c)
H
21. Give the nature of A and B in the given reaction −
KMnO 4 4 / OH B ← (CH 3 )3 COH KMnO →A H+
(a) A and B both are (CH3)2C = CH2 (b) A and B both are (CH3)2CO + CH2O (c) A is (CH3)3COH, while B is (CH3)2C = CH2 or (CH3)2CO (d) A and B both are (CH3)3COH, i.e., there is no reaction
22. Which of the following is liable to be oxidised by periodic acid? O OH O (a) (b) (c) (d) All the three OH
O
OH
23. From the given set of reaction O i ) NaOI A ( →[B] heat → ( ii ) H+
starting compound A corresponds to (a)
O CH2COOH
O (b) CH2COOH
3.23
3.24
chapter three
(c)
O
O
(d) COCH3
COCH3 24. Methanoic acid is heated with conc. H2SO4 to form (a) CO (b) CO2 (c) CH4
(d) (COOH)2
25. When ethane-1,2-dioic acid is heated with conc. H2SO4, it gives (a) CO + HCOOH (b) CO2 + HCOOH (c) CO + CO2 + HCOOH (d) CO + CO2 + H2O 26. When sodium fumrate is heated with soda lime, we get (a) CH4 (b) Ethyne (c) Sodium oxalate (d) No action 27. Sodium formate is heated at 360ºC to gives (a) CO (b) CO2 (c) Sodium oxalate (d) No action 28. When cyclohexanone is treated with Na2CO3 solution, we get O (a)
O
O OH (c)
OH (b)
(d)
COOH COOH
OH ( i ) BH 3 29. In the given reaction, CH3–CH2–C≡C–H ( → [X], [X] will be ii ) H O /OH − 2
(a) Butanal
(b) Butanone
2
(c) 2-butanol
(d) 1-butanol
2 / Ni 2 B/∆ 30. In the given reaction, CH3–C≡C–CH3 H → [X], [X] will be
(a) 1-butene
(b) trans-2-butene
(c) cis-2-butene
(d) 1-butyne
/NH3 ( l ) 31. In the given reaction, C6H5–C≡C–CH3 Na → [X], [X] will be
(a) 1-phenyl propane (c) trans-1-phenyl propene
(b) 1-phenyl propene (d) cis-1-phenyl propene ⊕
++
/H/Hg 32. In the given reaction, CH3–CH2–C≡C–CH3 + HOH HOH → [X], [X] will be (a) 2-pentanone (b) 3-pentanone (c) Pentanol (d) Mixture of 2-pentanone and 3-pentanone CH3 80° C 33. In the given reaction, C=CH–CH=CH2 + Br2 − → [X], [X] will be CH3 Br Br | CH3–C–CHBr–CH=CH2 (b) (a) | Br CH3
Br CH3 CH3 C=CH–CH=CH–Br (c) C=C–CH=CH2 (d) CH3 CH3
hydrocarbons 34. In the given reaction, CH3–C≡CH HOBr → [X], [X] will be O O O OH || || || | CH3–C–CH2Br (b) CH3–C–CBr2 (c) CH3–C–CHBr2 (d) CH3–C=CHBr (a) 35. 8 mL of a gaseous hydrocarbon needs 40 mL of oxygen for its complete combustion. The hydrocarbon is (a) CH4 (b) C3H4 (c) C3H8 (d) C3H6 36. 0.34 g of a hydrocarbon when heated with methyl magnesium bromide gives 112 mL of CH4 at STP. Possible structure of the hydrocarbon is
(a) CH3CH2CH2C≡CH
(b) CH3CH2C≡C–CH3
CH3CH2–CH–C≡CH (c) | CH3
(d) CH3CH2CH2CH2C≡CH
37. Which of the following structures are chiral? CH3 (i) H3C
(a) i and iii
(ii) CH3
(iii)
(b) All of the three
38. The lowest boiling point is expected for (a) Isooctane (b) n-octane (c)
CH3
Cl
H3C (c) i and ii
(d) ii and iii
2,2,3, trimethyl butane
(d) n-heptane
CH3 | 39. CH3–C–CH3 + D2O ⎯→ X. “X” is | MgBr CH3 CH3 CH3 CH3 | | | | (a) CH3–C–CH3 (b) CH3–C–CH3 (c) CH3–C–CH3 (d) CH3–C–CH3 | | | | D OH H OD 40. Acetic acid, when reacts with excess of HI in the presence of red phosphorus gives (a) Ethanol (b) Ethane (c) Acetaldehyde (d) Acetone 41. Sodium adipate, on electrolysis gives (a) Cyclobutane (b) Cyclopropane
(c) But-2-ene
(d) But-2-yne
42. Clemensen reduction cannot be used in which of the following? O O O COCH3 || (a) COOH (b) NO2 (c) CH3–C–H (d) 43. Wolff Kishner reduction cannot be used in which of the following? O CHO O O NH 2 (a) SO3H (b) (c) (d)
3.25
3.26
chapter three CH3 CH3 2 / Ni /∆ D → ?, product will be?
44. In the given reaction, H CH3
CH3 H (a)
H
D
CH3
CH3 (b)
H
H
H
D
D
H
H
H
H
D CH3
45. In the given reaction,
CH3 CH3 (a) COH–CH3 CH3
(c) Both (d) 70% (a) and 30% (b)
( i ) BH3 → [X], [X] will be C =CH2 ( ii ) NaOH/H2 O 2
CH3 (c) C=CHOH CH3
CH3 (b)
CH3
CH–CH2OH
HOCH2 (d) C=CH2 CH3
. H2 SO 4 46. In the given reaction, CH3–CH=CHD Conc → [X], [X] will be
OH | CH3–CH–CH2D (a)
OSO3H | (b) CH3–CH–CH2D
OSO3H | (c) CH3–CH–CH3
OSO3D | (d) CH3–CH–CH2D
47. Arrange the following compounds in decreasing order of their heat of hydrogenation CH3
(i) CH3–CH=CH2
CH3 (iii) C=CH–CH3 CH3
Select the correct answer (a) i, iv, ii, iii (b) i, iv, iii, ii
(ii)
CH3
C =CH2
(iv) CH3–CH=CH–CH3
(c) iii, ii, iv, i
(d) iii, ii, i, iv
48. Arrange stability of the given compounds in decreasing order (i) CH2=C=CH2 (ii) CH2=CH–CH=CH2 (iii) CH2=CH–CH2–CH2–CH=CH2 (iv) C6H6 Select the correct anwer (a) ii, iv, i, iii (b) iv, ii, iii, i (c) iv, ii, i, iii (d) ii, iv, iii, i 49. 2C2H5Cl + Zn ⎯→ CH3CH2CH2CH3 + ZnCl2. The reaction is known as (a) Frankland reaction (b) Wurtz reaction (c) Fittig reaction (d) Wurtz-Fittig reaction
hydrocarbons 50. When isobutane is chlorinated in the presence of diffused sunlight, then the product formed is
(a) tertiary butyl chloride in major amount
(b) isobutyl chloride in major amount
(c) both 50% each
(d) n-butyl chloride, isobutyl chloride and sec-butyl chloride are formed
51. By which of the following methods, alkanes containing odd number and even number of carbon atoms can be prepared with good yield?
(a) Wurtz reaction
(b) Frankland reaction
(c) Riemer Tiemann reaction
(d) Groove’s process
52. During the halogenation of n-pentane, assuming no regeoselectively, the ratio in which 1-chloropentane, 2-chloropentane and 3-chloropentane are formed is
(a) 1:2:3 respectively
(b) 3:2:1 respectively
(c) 9:4:1 respectively
(d) 1:1:2 respectively
53. When isobutane is brominated in the presence of diffused sunlight then the product formed is
(a) exclusively tertiary butyl bromide
(b) exclusively isobutyl bromide
(c) exclusively n-butyl bromide
(d) s-butyl bromide
54. Which of the following statements is correct?
(a) Chlorination of CD4 is about 12 times faster than the chlorination of CH4.
(b) Chlorination of CH4 is about 12 times faster than the chlorination of CD4.
(c) Chlorination of CH4 and CD4 takes place at the same step.
(d) C–H and C–D bond energies are the same.
55. When 2-butyne is brominated, A is formed. When 2-butyne is reacted with HgSO4 + H2SO4, then B is formed which then gives C. Hence OH | Me Me C=C (a) A is and B is Me–C=CH–Me Br Br OH | Me Br (b) A is and B is Me–C=CH–Me C=C Br Me O || (c) B is Me–C=CH–Me and C is Me–C–CH2–CH3 | OH
O OH || | (d) B is Me–C–CH2–Me and C is Me–C–CH2–CH3 | OH
3.27
3.28
chapter three
is reacted with
CH3 CH3 H C–C H CH3 CH3 B – H
followed by treatment with H2O2/ C–H CH3 Me H H C CH3 OH–, then the different products formed at different stages are
56. When
H (a)
H
Me
B
Me (b) H
H
(c)
B
Me
H
H
OH
H (d) Me
H OH
is treated with Br2 (1-equivalent), it would give
57. When Br (a)
(b) Br
Br (c) Br
Br (d) Br
Br
Br 3 Li 58. (H − C ≡ CLi + Br − (CH 2 )8 − Br) ⎯→ A CH →C → B A
In this reaction, sequences (a) A is H–C≡C–(CH2)8–Br (b) B is H–C≡C–H and C is Li C≡C–(CH2)8–Br (c) B is Li C≡C–(CH2)8–Br and C is CH2 — C C — CH2 — CH2 | | CH2 – CH2 – CH2 – CH2 – CH2
(d) B is Li C≡C–(CH)8–Br and C is Br (CH2)8 C≡C (CH2)8 Br
59. When CH2=CH–Br is reacted with HBr then the product formed is A and when CH2=CH– COOH is treated with HBr then the product formed is C. Hence here Br (b) A is CH3 – CH (a) A is CH2 – CH2 | | Br Br Br
(c) C is CH3–CH–COOH | Br
(d) C is CH2 – CH2 – COOH | Br
60. Which of the following will give cis diol? Et (a) Me
Et Me
Me ( i ) KMnO 4 ( → (b) ii ) H2 O /OH − Et
Et Me H
Me
35% H2 O 2 HCOOH → 25° C
OsO 4 25° C Na 2 SO 3
→ (d)
(c)
( i ) OsO 4 ( → ii ) Na 2 SO 3
H
Et 61. Which of the following reactions will give alkyne? (a) CH3CH2CH–CH2 | | Cl Cl
2 NaNH → H2 O
. KOH (b) CH3CH2CHBr2 alc → ∆
hydrocarbons Br Br | | CH3 – C – C – CH3 (c) | | Br Br
(d) Potassium maleate Electrolysis →
/alcohol Zn →
62. Which of the following reactins are correct?
(a)
Br
H
Br2 CCl → 4
i ) C6 H5 COOH + CH2 Cl 2 (b) ( → ( ii ) OH − /H O
H
H
OH
2
Br
H
OH
Me (c)
OH
+
/H 2 O H →
Me
Me
+
(d) Me
OH
/H 2 O H →
Me
H
H
Me
Me
Me
63. In the conversion given below a b CH3–CH2–C≡CH
c d
CH3–CH2–C–CH3 O CH3–CH2–C≡CD Br CH3–CH2–C=C–CH3 Br CH3–CH2–CH2–C–H O
(a) H2O/Hg2+/H+
(b) (i) one equivalent of LDA, (ii) D2O
(c) Br2/CCl4
(d) (i) (Sia)2BH, (ii) H2O2/OH–
64. Which of the following reactions are correctly represented?
(a) R–CH=CH2 + HCl ⎯→ R–CH–CH3 | Cl
(b) R–CH=CH2 + HI Peroxide → R–CH2–CH2–I
→ R–CH2–CH2–Br (c) R–CH=CH2 + HBr Peroxide
(d) R–CH=CH2 + HI Peroxide → R–CH–CH3 | I
65. The iodo lactisation of HI. The different intermeidates are
CO2H
with I2 gives the compound
O I
O
+
3.29
3.30
chapter three O
I⊕
(a) C HO
H
O (b)
C
O
⊕O
(c)
O (d) ⊕I
I
I
O 66.
+
H /H 2 O → B. Here LiAlH 4 → A
O
(a) A is
+
+
Li
(b) A is
H O Li
H
OH
OH
(c) B may be
(d) B may be
HO
OH
67. The reaction of propane with nitric acid in vapour phase gives (a) 1-nitropropane (b) 2-nitropropane (c) Nitromethane (d) Nitroethane 68. n-hexane reacts with Pt at 770 K to give (a) Cyclohexane (b) Benzene (c) Isohexane
(d) Neohexane
69. Iodination of methane can be carried out in the presence of (a) HI (b) HIO3 (c) HNO3 70. Cracking of alkanes involves (a) Homolytic fission (c) Heterolytic fission
(d) NaOH
(b) Free radical (d) Carbocation
71. Arrange reactivity of the given compounds in decreasing order for electrophilic a ddition reaction (i) C6H5–CH=CH2 (ii) C6H5–C=CH–CH3 | CH3 (iii) C6H5–C=CH–CH3 | C6H5
Select the correct answer (a) iv, i, ii, iii (b) iii, ii, i, iv
(iv) CH2=CH–NO2
(c) ii, iii, i, iv
(d) ii, iii, iv, i
72. Which among the following compounds will give electrophilic addition reaction? (i) CH2=CH2 (ii) CH3–C≡CH NO2
NO2
(iii) CH2=CH–CH=CH2
Select the correct answer (a) i, ii and iii (b) i and ii
(iv)
C= C NO2
(c) i, ii and iv
NO2 (d) i, ii, iii and iv
hydrocarbons 73. In which compound addition reaction will take place according to anti-Morkonikov’s rule? (i) CH2=CH–NO2 (ii) CH2=CH–CHO (iii) CH2=CH–CN (iv) CH3–CH=CH2 Select the correct anwer (a) i, ii and iii (b) i, ii and iv (c) i and ii (d) i and iii 74. For electrophilic addition with HCl, which pair is correctly matched? (i) CH3–CH=CH2, alkyl carbocation (ii) CH3–CH≡CH, vinyl carbocation (iii) CH2=CH–CH=CH2, allyl carbocation CH3 (iv) C6H5–CH=C
, alkyl carbocation
CH3 Select the correct answer (a) i, iii and iv (b) ii, iii and iv
(c) i, ii and iii
(d) i, ii and iv
75. Consider the following statements (i) Alkene is more reactive than alkyne for electrophilic addition reaction. (ii) Alkyne gives nucleophilic as well as electrophilic addition reaction. (iii) Alkyne is more reactive than alkene for nucleophilic addition reaction. (iv) For electrophilic addition reaction, RI of alkyne is alkyl carbocation. Of these, the correct statements are (a) Only i (b) i and ii (c) i, ii and iv (d) i, ii and iii 76. Consider the following statements (i) Conjugated diene gives direct as well as conjugate addition. (ii) Conjugated diene gives only direct addition. (iii) Conjugated diene gives only conjugate addition. (iv) Thermodynamically controlled product is obtained by less stable reaction intermediate. Of these, the correct statements are (a) Only i (b) i and iv (c) ii and iii (d) Only iii 77. Consider the following statements (i) Conjugated diene gives i, 2 and i, 4 adduct. (ii) Conjugated diene gives kinetically and thermodynamically controlled product. (iii) Formation of kinetically controlled product takes place by formation of stable RI. (iv) Formation of thermodynamically controlled product takes place by the formation of stable RI. Of these, the correct statements are (a) i, ii and iii (b) i, ii and iv (c) Only i (d) Only iv 78. Which among the following reagents give syn addition with alkenes? (i) Br2 (ii) dil. KMnO4/OH– (iii) OsO4/NaSO3H/HOH (iv) H2/Ni/∆
3.31
3.32
chapter three
Select the correct answer (a) Only i (b) ii and iii
(c) ii, iii and iv
(d) Only iv
79. Match List i (reaction) with List ii (reagent) and select the correct answer from the codes given below
List I (a) CH3–CH=CH2 ⎯→ CH3–CH2–CH2–OH
OH | (b) CH3–CH=CH2 ⎯→ CH3–CH–CH3 (c) CH3–C≡C–CH3 ⎯→ trans-2-butene (d) CH3–C≡C–CH3 ⎯→ cis-2-butene
List II (i) Na/NH3(l)
(ii) (i) BH3 (ii) H2O2/ OH (iii) Ni2B (iv) (i) Conc. H2SO4 (ii) HOH
a b c d a b c d (a) iv ii i iii (b) iv ii iii i (c) ii iv i iii (d) ii iv iii i 80. Match List I (substrate/reagent) with List II (product) and select the correct answer
List I CH3 CH3 (a) C =C + Br2 H H H CH3 (b) C =C + Br2 CH H 3
List II (i) (±) 2,3-dibromobutane
(ii) (±) 2,3-butanediol
CH3 CH3 (c) C =C + Baeyer reagent (iii) Meso-2,3-dibromobutane H H CH3 (d) C =C H
H + Baeyer reagent (iv) Meso-2,3-butanediol CH3
a b c d a b c d (a) iii i iv ii (b) i iii iv ii (c) i iii ii iv (d) iii i ii iv 81. Match List I (substrate/reagent) with List II (RI of the reaction) and select the correct answer
List I (a) C6H5–CH=CH–CH3/HCl
List II ⊕ (i) CH3–CH2–CH–CH=CH2
CH3 (b) C=CH2/HOH CH3
(ii) CH3–CH–CH2–CH=CH2
(iii) C6H5–CH–CH2–CH3
(c) CH3–C≡CH/HCl
⊕
⊕
hydrocarbons
⊕
(iv) C6H5–C=CH2
(d) CH3–CH=CH–CH=CH2/HCl
CH3 ⊕ (v) C–CH3 CH3
a b c d a b c d (a) iii v iv i (b) iii v iv ii (c) v iii iv i (d) v iii i iv 82. Which of the following reagent reacts in different ways with CH3CHO, HCHO and C6H5CHO? (a) Fehling solution (b) C6H5NHNH2 (c) Ammonia (d) HCl 83. The reaction
−
OH →
O
CHO (a) Oxidation reaction (c) both OH O || | 84. C6H5CH – C – C6H5
is an example of (b) Reduction (d) aldol condensation
Zn/Hg
→ P. Here, P should be HCl
OHOH | | C6H5CHCHC6H5 (a)
O
(c) C6H5CH2CH2C6H5
Cl | C6H5CHCH2C6H5 (b) (d) C6H5CH = CHC6H5
85. Nitrobenzene can be reduced to aniline by (i) H2/Ni (ii) Sn/HCl (iii) Zn/NaOH (a) i, ii and iii (b) i and ii (c) i, ii and iv
(iv) LiAlH4 (d) only ii
86. 1-methylcyclopentene can be converted into 2-methylcyclohexanol by (a) acid-catalysed hydration (b) hydroboration oxidation (c) epoxide formation followed by reduction with LiAlH4 (d) oxymercuration-demercuration 87. 2-methylpropanol-2 can be obtained by the acid-catalysed hydration of (a) CH3CH2CH=CH2 (b) CH3CH=CHCH3 (c) (CH3)2C=CHCH3 (d) either of the three 2 /inert solvent 88. Predict the nature of P in the following reaction: CH3C ≡ CCH3 NaNH →P heat (a) CH2=CHCH=CH2 (b) CH2=C=CH–CH3 (c) CH3CH2C≡CH (d) No reaction
89. Arrange the following alcohols in order of increasing ease of dehydration CH3CH2OH C6H5CH2OH Cl3CCH2OH F3CCH2OH
3.33
3.34
chapter three
i (a) ii < i < iv < iii
ii (b) iv < iii < ii < i
iii iv (c) iv < iii < i < ii
(d) ii < i < iii < iv
90. Which of the following statements are true? (i) Structural isomers are compounds with the same molecular formula, but are different in the connectivity (order of attachment) of their atoms. (ii) Stereoisomers are compounds with the same molecular formula and same order of attachment of their atoms, but are different in the orientation of their atoms or groups in space. (iii) Enantiomers are stereoisomers whose molecules are mirror images of each other. (iv) Diastereomers are stereoisomers whose molecules are not mirror images of each other. (v) A molecule with two chiral centres designated as (R,R) will have an enantiomer with two chiral centres designated as (S,R). (vi) Cis-1,2-dichlorocyclopentane and trans-1,2-dichlorocyclopentane are enantiomer to each other. (a) i, ii, iv, vi (b) i, ii, iii, iv (c) i, ii, iii, iv, vi (d) ii, iii, iv, vi 91. Which of the following are chiral molecules? OH (i)
(ii)
(iii) OH
NH2 (iv)
CH3
(v)
OH
H3C
(a) ii
(b) i, ii, iv
(c) ii, v
(d) ii, iv, v
92. How many stereoisomers are possible for the following compound? OH
(a) 2
(b) 3
(c) 4
(d) 8
93. What is the name of the following compound?
(a) (2R,3S)-2,3-dimethylhexane (c) (S)-2,3-dimethylhexane
(b) (R)-2,3-dimethylhexane (d) (2S,3R)-2,3-dimethylhexane
94. What is the role of H3O+ in this reaction? + H2O
(a) Base
(b) Nucleophile
H3O+ OH (c) Catalyst
(d) Leaving group
hydrocarbons 95. Which statements are true for SN2 reaction of alkyl halides? i: Both of the alkyl halide and nucleophile are involved in the transition state. ii: Reaction proceeds with inversion of configuration at the substitution centre. iii: Reaction proceeds with retention of configuration at the substitution centre. iv: The order of reactivity is 3º > 2º > 1º. v: The nucleophile must have an unshared electron pair and bears a negative charge. vi: The greater the nucleophilicity of the nucleophile, the greater the rate of reaction. (a) i, ii, iv, v (b) i, ii, v, vi (c) i, iii, v, vi (d) i, ii, vi
Comprehension Type Passage 1 In the given reactions CH3
H
(i)
(i) CF3CO3H Product (X + Y) (i) OH/H2O
CH3 (ii)
H
(i) CF3CO3H (i) OH/H2O
Product (P + Q)
CH3 H
dil. alk Product (A + B) KMnO4
(iii) CH3 (iv)
H
dil. alk Product (M + N) KMnO4
96. For the given reaction (i), X and Y are (a) Meso compound (c) Identical
(b) Diastereomers (d) Enantiomers
97. For the given reaction (iv), products M and N are (a) Enantiomers (b) Diastereomers (c) Identical (d) Meso compound 98. Which of the following is a correct statement? (a) Products A and B are Diastereo Isomers (b) Products P and Q are enantiomers (c) Products A and B are identical (d) Products P and Q are identical Passage 2 The reaction of 1, 3-butadiene with HBr is shown below. At 40°C the major product is the 1, 4-addition product; however, at –80°C the major product is the 1, 2-addition product. Br + HBr
+ 1, 2-addition
Br 1, 4-addition
3.35
chapter three 99. Thermodynamically controlled product is (a) 1, 2-addition product (b) 1, 4-addition product (c) The products have same stability (d) cannot be determined 100. Why are two products formed? (a) The carbocation intermediate allows delocalisation of the second double bond. (b) There are two double bonds present. (c) The fact that the carbocation is planar allows attack from both sides of the plane. (d) There are 2 moles of HBr. 101. Which of the two products has a lower activation energy for formation? (a) 1, 4-addition product. (b) 1, 2-addition product. (c) The products have same activation energy. (d) The relative activation energy cannot be determined. Passage 3 Karl Ziegler reported that alkenes react with N-bromosuccinimide (NBS) in the presence of light to give products resulting from substitution of hydrogen by bromine at the allylic position, i.e., the position next to the double bond. Let us consider the halogenation of cyclohexene Br → NBS Light
+
Br
Br
+
Energy level diagram for allylic, vinylic and alkylic free radicals is given C (Vinylic free radical)
C
R
Energy
3.36
R–C (Alkyl free radical) R C
C
C (Allylic free radical)
Answer the following questions 102. In the treatment of cyclohexene with NBS, which of the following products will be formed? Br Br (a) (b)
(c)
Br
103. Consider the three types of C—H bonds in cyclohexene H H
C
B
H
A
(d) cannot be predicted
hydrocarbons
104.
Which of the following is/are correctly matched? (a) A-Vinylic C–H bond (b) B-Allylic C–H bond (c) C-Alkylic C–H bond (d) All of these CH3 CH3 (4, 4-dimethyl cyclohexene)
Above compound on treatment with NBS gives allylic bromides. How many product(s) will be obtained in this reaction (neglecting stereoisomers)? (a) One (b) Two (c) Three (d) Four
Passage 4 Hydroboration is a reaction in which boron hydride acts as an electrophile. R2BH adds to a carbon–carbon double bond which acts as a nucleophile i.e.,
+ R2BH
H–C–C–BR2 Organoborane compound
The organoborane compound then is oxidised by treatment with hydrogen peroxide in aqueous medium to form alcohol. The OH-group enters the carbon atom from the same side where the boron atom was present. R R
R B H C=C + R2BH
R R
B C
H C
R
C =C
R O.....OH R
B C
B C
H C
O –O–H H C
R B OH C
H H2O C
O C
R
H C
Hence this reaction is highly regioselective and the boron atom attaches to that carbon atom which is less stearically hindered.
105.
Me H Me
(i) B2H6 (ii) H2O2/OH
A; Hence, compound A is
3.37
3.38
chapter three H
HO
H
(a) OH Me H
(b) H
Me
HO
Me H H
(c)
Me
H
H Me H (d) H Me
Me
OH H H Me
106. R–CH=CH2 NOCl → X; Hence, X is R–CH–Cl (b) R–CH–CH2–Cl (a) NO NO
(c) R–CHO + CH2Cl2 (d) R–CH–CH2–NO Cl
Co2 ( CO )8 ] 107. R–CH = CH2 + CO + H2 [ → A; Hence, A is
(a) R–CH2CH2CHO
(c) R–CH=CH–CHO
R–CH–CH3 (b) CHO (d) Both (a) and (b)
Passage 5 Compound having atleast one π-bond gives addition reaction. Alkene behaves as a nucleophile and hence it gives an electrophilic addition reaction. Electrophilic addition reaction in most of the cases takes place by formation of carbocation as reaction intermediate. 108. Which one of the following is NOT correct for electrophilic addition of alkenes? (a) In the first step, alkene reacts with electrophile to form a π-complex. (b) π-complex converts into carbocation and the step is a rate-determining step. (c) Product formation takes place by formation of most stable reaction intermediate. (d) Rearrange product is not formed in addition reaction with HBr. 109. Consider the following statements (i) Unsymmetrical alkene gives addition product according to Markovnikov’s rule. (ii) Addition reaction is a regioselective reaction. (iii) Rearranged product is formed in addition reaction. (iv) Alkene gives mixed addition product with NaCl/HOH/H+. Which one is/are correct? (a) i, ii, iii and iv (b) ii, iii and iv (c) i, iii and iv (d) i, ii and iv 110. In the given reaction H3C
CH=CH2
+ HBr
(a)
CH3 CHBr–CH3
(b)
CH3 CH2–CH2Br
Product (s)
hydrocarbons
(c) Mixture of (A) and (B) Br CH 3 and CHBr–CH3
(d) Mixture of
CH3 CH3
Passage 6 NaOI
(–)ve iodoform test
ZnCl2
I
Immediate turbidity
HCl
dil H2SO4 Compound A C4H8 Hot conc. KMnO4 (i) EtMgCl (ii) H⊕
NaOI F
H⊕
(i)
(ii) NaOH/CaO
D + E (yellow)
Cl2/hv R
G
C
(i) NaOH (ii) Electrolysis
B + gas
H
CH–CH3 111. Compound B
PPh3
( 1) B2 H6 − THF X-compound ( → Y-compound 2 ) NaOH/H2 O 2
Identify structure of compound Y (a)
OH
(b)
OH
(c)
(d)
OH Ag/∆
OH
/BaSO 4 2 4 → Comp. 1 → → Comp. 2 Pb → Comp. 3 ( 112. (Compound E) 2 ) NaHSO3 H2 ( 2 ) 2 eq . CH3 l (Aqueous) Comp. 4 ( 1) 2 eq . NaNH
( 1) OsO
Identify stereochemistry compound 4 OH H (a) H
OH Me Me
OH
(b) OH
3.39
3.40
chapter three OH (c)
(d) (B) and (C) both
OH Passage 7 A terpene that is contained in the oil of citronella is α-farnesene. Refer to the structure of α-farnesene to answer the following questions. 2 3 1
4
113. What reaction conditions could be used to produce acetone from α-farnesene?
(a) H2SO4 and heat
(b) HBr
(c) O3 and (CH3)2S
(d) dil. acid and cold conditions
114. If α-farnesene is reacted with an excess HBr, what would be the product? Br
Br (a) Br
Br
Br
Br
Br Br Br
Br
Br
Br
(c) Br
(b)
(d)
Br
Br
Br Br
115. In the reaction of α-farnesene with excess HBr, which double bond would be slowest to react?
(a) The bond labelled 1
(b) The bond labelled 2
(c) The bond labelled 3
(d) The bond labelled 4
Passage 8 Hydrogenation of alkenes and alkynes takes place in the presence of certain catalysts. In S abatier Senderen’s reaction, the addition of hydrogen takes place in the presence of Raney nickel catalyst. Platinum and palladium can also be used as catalysts in these reactions. These are heterogeneous catalysts and used in finely divided state. Experimentally, it is observed that less crowded alkenes adsorb H2 with faster rate. Controlled hydrogenation of alkyne in the presence of Lindlar’s catalyst yields cis product, i.e., “cis” alkene. Thus, in the presence of Lindlar’s catalyst “syn” addition takes place. The relative rate of hydrogenation follows the order —C≡C— > >C=C < > >C=O > C6H6
hydrocarbons Non-terminal alkynes are reduced in the presence of Na or Li metal dissolved in liquid ammonia. In this reaction, anti addition of hydrogen results into the trans-product. 116. The product of the following reaction is O + H2
Pd/CaCO3 Boiling quinoline
O
O
(a)
(b)
OH
OH
(c)
117.
A
C
CH
(d)
(i) NaNH2, NH3 (ii) CH3Br
C C–CH3 (a)
(A)
H2 Lindlar’s catalyst
(B); Product (B) is
H (b)
C
C–CH3 H
H –C–H (d) C–H CH
(c)
C
C
H H
3
Pd/CaCO 3 118. CH3–C≡C–CH3 + H2 Boiling → (A); The product (A) will be quinoline
(a) CH3CH2CH2CH3
CH3 C=C (c) H
H CH3
(b) H CH3
C=C
H CH3
(d) CH3–CH2–CH=CH2
Passage 9 The structure of alkyne is linear. Terminal alkyne is acidic in character. It reacts with base to give acid–base reaction. Alkyne is nucleophile and gives electrophilic as well as nucleophilic addition reaction. 119. Which one of the following compounds forms carbonyl production reaction with 1% HgSO4 + dil.H2SO4? (a) CH2 = CH2 (b) CH3 – C ≡ C – C6H5 (c) CH3 – C ≡ C – CH3 (d) Cyclohexene 120. Terminal alkyne will react with which of the following? (a) Tollen’s reagent (b) Sia2BH/THE (c) H2O/HgSO4/H2SO4 (d) All of these 121. Which one of the following will react with NaNH2? (a) CH3 – CH3 (b) CH2 = CH2 (c) CH3 – C ≡ CH
(d) CH3 – C ≡ C – CH3
3.41
chapter three Passage 10
–150
Mono Di substituted substituted
Ethylene
–100
(kcal/mol)
Following figure is given to test analytical ability. Based on it, answer the questions at the end of it. Heat of hydrogenation (kJ/mol)
Tri Tetra substituted substituted
–23.9
–50
–11.95
0
0 A plot of heat of hydrogenation versus substitution pattern for alkenes
Catalytic hydrogenation is usually a stereospecific reaction called syn addition. • The C≡C bond is reduced more readily than C=C but other unsaturated groups (except nitro and acid chlorides) are reduced less readily. Catalytic hydrogenation can, therefore, be used for the selective reduction of C=C in the presence of aromatic rings and carbonyl groups, whether or not the unsaturated functions are conjugated. O Ph
O Ph
H2–Pt
Ph
Ph
The rate of hydrogenation of olefinic bonds under standard state is –CH=CH2 > –CH=CH– or a ring double bond 122. Base on the data of heat of hydrogenation, which has maximum stability? Me (a) Me
Me
Me
Me (c)
(b) Me
Me
Me
Me
Me
30.3 kcal 27.6 kcal
Reaction coordinate From this, it is clear that
Me
(d)
123. Consider following graph
Energy
3.42
H
H
hydrocarbons
(a) cis-2-butene is more stable than 1-butene by 2.7 kcal (b) trans-2-butene is more stable than 1-butene by 2.7 kcal (c) trans-2-butene is more stable than cis-2-butene by 11 kJ (d) trans-2-butene is more stable than 1-butene by 11 kJ
124. Bond energies (in kcal mol–1) of different types of bonds have been given as >C=C< (π bond=40); H–H=(104) and >C–H=(87). –C–C–
–C=C– + H–H
H H Heat of hydrogenation of the above reaction is
(a) 57 kcal mol–1 (b) –57 kcal mol–1
(c) –30 kcal mol–1
(d) 30 kcal mol–1
Passage 11 Strictly speaking, then, dehydration is not an E1 reaction of the protonated alcohol. In a true E1 elimination, the rate of reaction depends only upon heterolysis step, since every carbocation formed goes rapidly on to the product, that is, loss of a proton is much faster than regeneration of substrate. Here that is not the case for carbocations are formed reversibly from the protonated alcohol, and every so often one looses a proton to yield an alkene. Where the structure of alkyl group permits, rearrangement takes place. The initially formed c arbocation rearranges to a more stable carbocation. The alkenes obtained are those formed by a loss of proton from this rearranged carbocation as well as from the original one. When more than one alkene can be formed the preferred product is the more stable one. Another factor comes in here. Since dehydration is reversible, the composition of the product does not necessarily reflect which alkene is formed faster but depending upon how nearly reaction approaches equilibrium which alkene is more stable. 125. When neopentyl alcohol, (CH3)3C CH2OH is heated with an acid, it is slowly converted to a 85:15 mixture of two alkenes of formula C5H10. The 85% of these alkene is CH3–C=CH2 (a)
CH3–C–CH=CH2 (b) CH3
CH3 CH3–C=CH–CH3 (c)
CH2=C–CH2–CH3 (d)
CH3
CH3
Conc.H2SO4 (A) ∆
126.
OH The product (A) is (a)
CH3 CH3
(b)
CH3
CH3
CH2OH 127. CH2OH
∆ (B); Conc.H2SO4
CH3 (c)
CH3 (d) None
3.43
3.44
chapter three The product (B) is CH3 (a) (b) (c)
CH2 (d) None
CH2 Passage 12 An organic compound A(C5H11Cl) is optically active and on treatment with ethanolic KOH solution yields B(C5H10) as a major product, which does not show stereoisomerism. Also A on treatment with (CH3)2CuLi yields C(C6H14), which is optically inactive. Deduce structures of A to C. 128. Identify structure of “A” compound Cl (a)
(b)
Cl
Cl (c)
(d)
Cl
CH3 129. Identify structure of “B” compound CH3 (a)
CH3CH=C–CH3 (c) (b)
(d)
130. Identify structure of “C” compound (a)
(b)
(c)
(d)
Passage 13 An organic compound A(C13H23Cl) exists as distereomers and decolourise bromine water. A on treatment with ethanolic solution of KOH produces isomeric B and C with their molecular formula C13H22. Treatment of either B or C with Rany Nickel produces 4-isopropyl-1-tertiarybutyl cyclohexane. A on oxidative ozonolysis gives acetone as one product. Identify A, B and C considering C to be enantiomeric. 131. According to the information given in the above paragraph compound (A) will be Cl
Cl (a)
(b)
Cl
Cl (c)
(d)
132. According to the information given in the above paragraph compound (B) will be (a)
(b)
(c)
(d)
133. According to the information given in the above paragraph compound (C) will be
(a)
(b)
(c)
(d)
hydrocarbons Passage 14 An optically active hydrocarbon A has molecular formula C8H18. A on monochlorination gives five alkyl halide B to F with their molecular formula C8H17Cl. B does not undergo dehydrohalogenation on treatment with alcoholic solution of KOH. Treatment of either C or D with alcoholic KOH yields same alkene G(C8H16), which on ozonolysis followed by work-up with Zn-dimethyl sulphide gives an optically inactive compound C6H12O and ethanal. Also C is enantiomeric, whereas D is distereomeric. E on dehydrohalogenation yields an alkene, which on reductive ozonolysis yields H(C7H14O), which is optically inactive. H on treatment with LiAlH4 yields I(C7H16O) which can be resolved into enantiomers. F on dehydrohalogenation yields an alkene (C8H16), which on reductive ozonolysis yields J(C7H14O), which is optically active and has same configuration as that of A. Identify A to J explaining the reactions involved. 134. Identify structure of “A” compound (a)
(b)
(c)
(d)
135. Identify structure of “H” compound (a)
(b)
(c)
O
(d)
O
O
O
136. Identify structure of “J” compound (a)
O
(b)
(c)
(d) O
O
Passage 15 D2/Ni (Major) C Br2 E CCl4 H3PO4 B O H 150° – –C O t E (i) i) H 2 Mg (i CH3–CH2–CH2–Br dry ether A Me–C≡C–H Me–I F –(C3H8) D
J
(i) Pd/BaSO4 Br2 H CCl4 (ii) H2 O3/Zn I
137. Identify “Z” compound X
Mg–Hg H2O
Y
H⊕
Z
G
CHO
3.45
3.46
chapter three where X is a functional isomer of “W” which is next higher homologue of “I” Me Me
O
O Me Me (c) Et–C–C Me
Me–C–C (a) Me – C – C – Et (b) OH OH
OH Et Et (d) Et
138. In the above reaction sequence “B” compound is (a) OH
OH
(b)
OH
(c)
(d)
OH
139. In the above reaction sequence “J” compound is Me
Me
Me Br Br (c) H H
Br (b) H Br Br
H (a) H
Me
Me
H (d) both (b) and (c) Br Me
Passage 16 Based on the potential energy diagram for the following reaction
HCl
H3C — CH=CH2
ii
H | H3C — C — CH3 | Cl
iv
Potential energy A
iii
B
i C
v Reaction coordinate
140. Is this an endothermic or exothermic reaction? (a) endothermic (b) exothermic (c) There is not enough information to determine. (d) This reaction can be either exothermic or endothermic. 141. What is B representing in this potential energy diagram? (a) heat of reaction: the energy required for the reaction to occur (b) heat of reaction: the overall energy change for this reaction (c) activation energy: the energy required for the reaction to occur (d) activation energy: the overall energy change for this reaction
OH
hydrocarbons 142. What is C representing in this potential energy diagram? (a) heat of reaction: the energy required for the reaction to occur (b) heat of reaction: the overall energy change for this reaction (d) activation energy: the energy required for the reaction to occur (d) activation energy: the overall energy change for this reaction 143. What is ii representing in this potential energy diagram? (a) transition state (b) intermediate (c) activation energy (d) heat of reaction 144. What is iii representing in this potential energy diagram? (a) transition state (b) intermediate (c) activation energy (d) heat of reaction 145. Which step is the rate-determining (rate-limiting) step? (a) from i to v (b) from i to iii (c) from ii to iii
(d) from iii to v
Matrix Type 146. Column I (Reaction)
Column II (Type of reaction) alc. KOH
Br
(a) Ph
(p) E1
Ph
O OCCH3
(b) CH3 CH3 (c) Ph
Br CH3
CH3
CH3O − Ph DMSO
C2H5OH Ph ∆
(d)
∆
OTs 147. Column I (a) (CH3)3C—Br
Ph
(q) E2 CH3 CH2
(r) E1CB
CH3 (s) Ei
Column II (Type of reaction) (p) E1 CB
Cl CH3–CH–CH3 (b)
(q) First-order kinetics
Br CH3–CH2–CH–CH3 (c)
(r) E1
C6H5–CH2–CH–CH3 (d)
(s) E2
F
3.47
3.48
chapter three 148. Column I
Column II
(a) CH2=CH–COOH + HBr
(b) cis CH3–CH=CH–C2H5 + KMnO4(cold alk.)
(q) Trans addition
(c) cis CH3–CH=CH–CH3 + X2 →
(r) Primary carbocation
(p) Nonregioselective CS 2
Me (d) H
HCl
(s) Optically active
149. Column I Column II (Reaction) (Reagent)
(a) (CH3)3C–CH=CH2 ⎯→ (H3C)2C–CH(CH3)2 (p) B2H6/H2O2/OH– OH
(b) (CH3)3C–CH=CH2 ⎯→ (CH3)3C–CH–CH3
(q) H2O/H+/MnO2
OH
(c) H5C6–CH=CH2 ⎯→ C6H5–CHO
(r) Hg(OAc)2/H2O/NaBH4
(d) C6H5–C≡CH ⎯→ C6H5–CH2–CHO
(s) H2O/H+
150. Column I
Column II
(a) HC≡CH ⎯→
(p) O3/H2O N •• (b) H5C2–C≡C–C2H5 ⎯→ H5C2–C–CH2–C2H5 (q) CH2N2 (cold ether solution) O
CH–CH
(c) HC≡CH ⎯→ CH N
NH (d) H5C2–C≡C–C2H5 ⎯→ 2H5C2–COOH
(r) HCN (Red hot Fe)
151. Column I
Column II H
H3C (a)
(s) H2O/H2SO4/HgSO4
Br H
H
Alc. (p) KOH
Et H (b)
CH3
H ⊕
Et
NMe3
Alc. KOH
(q) E2
H H3C (c) H–C O
H
Et
⊕
⊕
Bu O K
(r)
Br F
(s) E1CB
hydrocarbons 152. Column I (a) R–CH2–X
Column II (p) Corey-house reaction
R (b) R–C–X R
(q) Kolbe electrolysis
(c) CH2=CH–X (d) R–COO– Na⊕
153.
Column I (a) But-1-yne (b) But-2-yne (c) Benzene (d) CH3C≡CNa
(r) Wurtz reaction (s) Frankland reaction Column II (p) Reacts with KMnO4/KOH to give acetic acid (q) With Hg2+/H2SO4 gives butan-2-one (r) Reacts with CH3Cl to form but-2-yne (s) Reacts with O3/Zn/H2O to give glyoxal
154. Column I (a) Oxidative ozonolysis of alkene
Column II (p) R–CHO (R–C≡C–R)
(b) Oxidative ozonolysis of alkyne
(q) R–COOH (R–CH=CH–R) O
(c) Reductive ozonolysis of alkene
(r) R – C – R (R–C≡C–R) O O
(d) Reductive ozonolysis of alkyne
(s) (R–C–C–R) (R – CH =C – R) R
155. Column I Column II Na Br2 (a) Me − C ≡ C − Me liq → P1 CCl → Final product (p) Final product of reaction is . NH3 4 racemic mixture. Na D2 (b) Et − C ≡ C − Et liq → P → Final product (q) Final product of reaction is 1 Ni . NH3 meso. Cl H2 H (c) (r) Net optical rotation of final Final product Pd/BaSO4 product is zero. (d)
Me OMe
Li/liq. metal Final product P NH3 1 1eq.O3
156. Column I
(s) Net optical rotation of final product is nonzero. (t) Final product has one asymmetric carbon atom. Column II
(a)
(p) NaBD4/EtOH
OH
(q) LiAlD4/dil. HCl
O (b)
3.49
3.50
chapter three O
OH
(c)
H
O
HO D D OH
O
(d)
D H
(s) NaNH2/liq. NH3/CH3–I
OH
D
O
(r) C2H5MgBr/CO2/H3O+
(t) CH3MgBr/CH3–I
157. Column I (Substrate for elimination reaction)
Column II (Type of elimination)
High temp.
Me–CH–CH2–CH3 (a) Me–C–O
(p) E1
O OH ⊕ (b) CH3–C–CH2–CH3 H /∆
(q) E2
CH3 Br (c) CH3–CH2–CH–CH3
Alc. KOH
(r) Ei/Pyrolysis
Alc. KOH
(s) Saytzeff elimination
F (d) CH3–CH2–CH–CH3
(t) Hoffmann elimination
158. Column I (reaction)
Column II (type of reaction: Major) OH
Ph
KOH
⊕ O Na + Me
(b) Me (c) Ph
CHO
CHO
(a)
CH3
OTs
Me
Br
O
(q) E2
Me CH3
C2H5OH Ph
(p) E1
Ph
CH3O Ph DMSO
Br
(d)
Ph
(r) E1CB
(s) S N2
Integer Type 159. Number of hydrocarbons formed when C2H5Br and CH3–CH2–CH2–Br are treated with Na in the presence of dry ether is:
hydrocarbons 160. How many number of moles of H2 is used for the complete hydrogenation of the given compound in the presence of a metal catalyst? Me
CN
Me
CN
161. Number of different products formed by the ozonolysis of 1-4-butadiene is 162. Consider the following reaction scheme Br2/CCl4
D
A
NaNH2 Δ
B
HgSO4/H2SO4
NaOD/D2O C (excess)
How many deutrium are present in the compound D? 163. What volume of ethane (NTP; 1 bar, 273 K) is formed from 38 g of sodium propionate by fusion with sode lime? 164. (CH3)2C=CH CH3
Catalyst Optical isomers H2
165. Degree of unsaturation in
is
166. Minimum number of C-atoms in alkynes to show optical isomerism is 167. Number of products obtained on ozonolysis of 1, 2-dimethyl benzene is 168. 1 mole
O3/H2O2 [A] – + [B] ∆ (gas) LAH [D]
H⊕/∆ [C]
If X = Number of moles of CO2 Y = Number of α–H in “D” compound X+Y=Z Identify value of “Z”. 169. An optically active compound A has the molecular formula C6H10. The compound gives a precipitate when treated with Ag(NH3)2OH. On catalytic hydrogenation, A yields B(C6H14), which is optically inactive. Identify total number of “α” “H” in product formed by treatment of A with O3/H2O2 then LAH and then H⊕/∆. 170. Consider the following reactions Cl2/hv.
Cl2
Total number of monochlorinated product = X (Excluding stereoisomers) Total number of monochlorinated product = X (Excluding stereoisomers)
Identify value of X + Y.
3.51
3.52
chapter three
Answer Keys Level 1 1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
b
a
b
b
c
d
a
c
d
ab
a
c
b
b
b
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
c
c
b
d
a
a
d
d
c
b
d
cd
d
c
a
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
c
b
d
b
c
d
c
a
c
a
b
b
b
c
c
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
b
b
c
b
d
c
bd
c
b
c
d
b
acd
acd
ab
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
b
d
d
d
c
d
b
d
c
c
d
ac
b
abc
d
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
abcd
abcd
bd
abc
bc
a
a
ac
ab
abd
bc
bc
abcd
ad
abc
91
92
93
94
95
96
97
98
99
100
ab
abc
ac
a
d
d
bd
abc
abcd
b
Level 2 1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
b
ac
c
d
d
d
a
ab
b
cd
ab
ab
d
d
d
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
abd
b
b
b
b
c
d
c
a
d
b
a
c
a
c
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
c
d
b
b
b
a
a
c
b
b
a
b
a
d
b
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
b
a
b
a
b
b
b
a
b
bc
c
ab
acd
bd
c
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
acd
ac
abd
ac
ac
bcd
abcd
b
bc
ab
b
a
a
c
d
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
a
a
c
c
b
a
a
d
b
b
b
c
c
c
b
hydrocarbons 91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
c
c
c
c
b
d
b
a
b
a
b
a
d
c
c
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
d
a
d
a
d
d
a
c
b
d
a
c
b
bc
d
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
c
a
b
b
c
a
a
c
b
d
b
c
d
b
a
136
137
138
139
140
141
142
143
144
145
d
b
b
d
b
c
b
a
b
b
146(a) 146(b) 146(c) 146(d) 147(a) r
s
q
p
qrs
147(b) 147(c) 147(d) 148(a) 148(b) 148(c) 148(d) 149(a) 149(b) 149(c) 149(d) 150(a) 150(b) 150(c) 150(d) qrs
qrs
p
r
ps
pqs
s
s
r
q
p
r
s
q
p
151(a) 151(b) 151(c) 152(a) 152(b) 152(c) 152(d) 153(a) 153(b) 153(c) 153(d) 154(a) 154(b) 154(c) 154(d) pq
qr
s
prs
ps
pr
q
p
pq
s
pr
q
p
s
r
155(a) 155(b) 155(c) 155(d) 156(a) 156(b) 156(c) 156(d) 157(a) 157(b) 157(c) 157(d) 158(a) 158(b) 158(c) qrt
prt
st
r
s
r
pq
q
rt
ps
qs
qt
r
158(d)
159
160
161
162
163
164
165
166
167
168
169
170
p
7
7
2
4
10
0
6
6
3
11
9
8
s
q
3.53
3.54
chapter three
Workbook Exercises Exercise 1
1.
HC CH2
CH
3.
1eq HCl CCl4
2. HC
CH2
Excess HCl CCl4
CH2
1eq HCl
4. H2C
CCl4
CH3
1eq HCl CCl4
H3C Ph
1eq HCl
5.
CCl4
1eq HCl CCl4
6. Ph
CH2
1eq HCl
7.
CCl4 H3C
8. H3C
CH3
Excess HCl CCl4
CH3 CH
9.
11.
H3C
H3C
CH
Excess HCl CCl4
CH2
1eq HCl Aq. NaOH A CCl4
Excess HCl CCl4
10.
B
conc. H2SO4 ∆
C
CH3 12. H3C H3C
CCl4 CH2 1eq HCl A Aq. NaOH
B
∆ conc. H2SO4
C
B
conc. H2SO4 ∆
C
CH3 13. CH2
1eq HCl Aq. NaOH A CCl4
A
Excess NaOH B CCl4
hydrocarbons
14.
CH2
1eq HCl Aq. NaOH A CCl4
B
conc. H2SO4 ∆
D
15. H3C
16.
17. H3C
CH
Excess HCl CCl4
NBS
CH2
A
NBS
A
Aq. NaOH
Aq. NaOH
A
B
Aq. NaOH
CH3
H2/Pd/BaSO4 A
Br2 CCl4
O3/Zn
dil. H2SO4
B
(1) MeMgCl/D.E (2) H2O
conc. H2SO4 C ∆
B
conc. H2SO4 C ∆
D
18. H3C
C
B
HCl/CCl4 50 °C
C
3.55
3.56
chapter three
Exercise 2
Z
Na liq.NH3
Me2CuLi I
J
K
O3/ H2O
Excess HCl
2Br2/ CCl4
mcpba
P
H3O+ NaNH2(1Eq.) C MeI
Dry
Q
Ag2O HOBr
R
at He
CH
HC
Con. NaOCl O
X+Y
NaNH2(1Eq.)
A
MeI
HgSO4
B
D Dil. H2SO4
KMnO 4
/
Ag
B(Sia)3H
E H2O2/OH–
Gas
U
AD
th
yE
N AE
H
r a/D
er
O .K
W
Cl2/hv
co
LAH
T
F
Al
Ac2O
S
Lime Water
H3O+
EtMgCl
OH–
PhOH
Ni/H2
V
L
HgSO4
O
H
Pd BaSO4/H2
G
OsO4
AB
AA
∆
Aq.KOH
D2/Ni
N
MeMgCl
OH–
AF
AC
Dil. H2SO4
Br2 CCl4
M
hydrocarbons
Solution for Workbook Exercises Exercise 1
CH2
2. HC
3.
CCl4
CH2
CH
Excess HCl CCl4
CH2 1eq HCl
4. H2C
CH3
H3C
Cl Cl Cl
1eq HCl CCl4
Cl
1eq HCl
1. HC
Cl Cl
Cl
CCl4 KCP
TCP
H
1eq HCl
5.
CCl4 Ph
6.
+ Cl
Cl
1eq HCl
Ph
CCl4
Ph
Ph
+ Cl TCP
CH2
1eq HCl
7.
CCl4 Cl H3C
8.
H3C
CH3 Excess HCl CH3
CCl4
Ph
Cl Cl
Cl KCP
Ph
3.57
3.58
chapter three
9. H3C CH CH
10.
Cl
Excess HCl CCl4
ClCl
12.
CH2
H3C H3C
CH2
Cl Aq. NaOH
1eq HCl
CCl4
O
OH
conc. H2SO4
CCl4 1eq HCl CCl4
CH3
OH
Cl
1eq HCl CH2 CCl4
CH2 1eq HCl
conc. H2SO4
Aq. NaOH
CH3 13.
Ph
Excess NaOH
Ph
Excess HCl CCl4
11. H3C
Cl
Cl Aq. NaOH
Cl
Aq. NaOH
OH
HO
conc. H2SO4
conc. H2SO4
O3/Zn
CCl4
14.
O
O
H
OH dil. H2SO4
15. H3C
16.
CH
Excess HCl
(2) H2O conc. H2SO4
Aq. NaOH Br
CH2
(1) MeMgCl/D.E
CCl4
NBS
H3C
O
Cl Cl Aq. NaOH
∆
OH
NBS
conc. H2SO4
Aq. NaOH Br
∆
OH
17. HCl/CCl4 Cl
18.
H3 C
H2 /Pd/BaSO4 CH3
Br2 CCl4
50 °C
Me H Br
Br H Me (I)
OH
hydrocarbons
Exercise 2 OH Me Br Br
O
D2/Ni
D D
Me COOH Na liq.NH3
Me Me OH OH Me
O3/ H2O
Excess HCl
2Br2/ CCl4
mcpba H3O+ NaNH2(1Eq.) Dry
O
MeI
Me C C Me
Ag2O HOBr
t
HC
Con.
Ag
Me
NaOCl O
CH
NaNH2(1Eq.) HC
C
MeI
Dil H2SO4
O
B(Sia)3H
C H
H2O2/OH–
CO2
MeCOO + CHCl3
O
HgSO4
Me C CH
KMnO4
OH Br
ea
Me H (±) H
./H
OH
EtCOOH
Lime Water
a/D
N
OH
r
he
Et
OH .K
Ac2 O
Cl
co
COOH
Milkg [CaCO3]
Al
OAc
Cl2/hv
ry
LAH
COOH
H3O
EtMgCl
OH
PhOH
Ni/H2 +
(±)
Br Br HgSO4
OsO4
Pd BaSO4 /H 2
OH H
H H
O
Cl Cl
Me
(±)
Me2CuLi
Br Br
Me H HO
MeMgCl
dil. H 2SO4
Me
(±)
O
CCl4
Me (±) H D
OH−
Aq.KOH
H H
O
Br2
3.59
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Alkyl Halides, Alcohols and Ethers
CHAPTER
4
Question Bank Level 1 Br 1. H
CH3 + Cl H
DMF
A, A is
CH3 CH3 Cl H (a) (b) H H Cl H (c) Both are correct (d) None is correct 2. Arrange the following in the order of their reactivity of SN2 reaction (i) –CH2Cl (ii) –CH=CH–CH2Cl
(iii) CH2=CH–CH2Cl (a) iv > iii > i > ii (c) i > ii > iv > iii
(iv) CH3CH2CH2Cl (b) ii > i > iii > iv (d) iii > ii > i > iv
3. Identify the product of the following reaction Ph H–Br NaI Ph–CH3 Acetone Br CH2 H (b) CH–C Ph Ph CH3 I (d) CH–CH Ph I
H (a) Ph
CH3 Ph
Ph (c) H
CH3 Ph
4.2
chapter four 4. The conversion of ethanol to propanenitrite is best done by
∆ → (a) CH3–CH2–OH + KCN ( i ) TsCl/P yridine → (c) CH3–CH2–OH ( ii ) KCN
∆
→ (b) CH3–CH2–OH + HCN ∆ → (d) CH3–CH2–OH + CH3CN
5. Major product of the following reaction is O18
14
CH2
⊕
Major product
CH2 CH2 + CH3ONa
Cl 18
OCH3
O
(a) CH2–CH–CH2 14
CH2–CH–CH2 (b) OH
Cl
OCH3
18
O18
O18
(c) CH2–CH–CH2
(d) CH2–CH–CH2 14
OCH3
OH
6. The final product of the following reaction is + NBS
A
Alc. KOH
(b)
B
CH3MgBr
C
Br
CH3
CH3 (a)
hυ
(c)
(d) None of these
7. Arrange the following compounds in order of decreasing rate of hydrolysis for S N 1reaction (i) –CH2–Br (ii) –CH2–Br H3C– (iii) CH3–CH2–
CH3 –CH2–Br (iv) CH– CH3
(a) iii > iv > ii > i (c) ii > iii > iv > i
–CH2–Br
(b) iv > iii > ii > i (d) i > ii > iii > iv
8. For the given reaction major product will be – OH
O2N–
H5C2O (a)
CH3 NHCOCH3
(i) NaOH Major product (ii) CH3CH2Br (iii) LiAlH4; H2O (iv) (CH3CO2)O/pyridine H5C2O (b) NHCOCH3
alkyl halides, alcohols and ethers NO2
NO2
(d) CH2CH3 OC–CH3 OEt O 9. The product/s formed is/are (c)
CH2
CH2
(a)
OTs CH ONa 3 ? CH2 CH 3OH (14)
14 OCH3 OCH3 CH2 (b) CH2 CH2
14
CH2
(c)
14
CH2
(d) Both (a) and (b)
O 10. In the following reaction, compound (b) is Dry Br + Mg A (1 eq.) ether
∆ B
Br
Br
(a)
Br (b)
MgBr Me 11. H C Br Et
(c)
(d)
Br + NaN3 DMF → Product
The correct representation of the product is Me
Me (a) H
N3 (b) N3 Et
N3
N3 Me H (d)
H (c) Et Me
Et
Et H
12. Arrange the following in the order of their reactivity with alcoholic AgCN to yield the substitution product CH3 CH3 (i) CH3–CH2Br (ii) (iii) CH3–C–Br CH3–CH–Br CH3
(a) i > ii > iii (b) (iii) > ii > i
(c) ii > i > iii
13. The final product is D H D
Br H CH3
NaN3 DMF
(i) LiAlH [A] (ii) H O 4 [B] 2
(d) i > iii > ii
4.3
4.4
chapter four D
D
H (a) D
D HN NO2 (c) 2 H D
H D (b) H D CH3
CH3
H (d) None of these H CH3
14. An aromatic compound (A), C7H6Cl2, gives AgCl on boiling with alcoholic AgNO3 solution and yields C7H7OCl on treatment with sodium hydroxide. (a) on oxidation gives a monochlorobenzoic acid which affords only one mononitroderivative. The c ompound (a) is Cl (a)
Cl (b)
Cl
Cl (c) Cl (d)
Cl
Cl
Cl
15. Which will give white ppt. with AgNO3 + NH4OH? (a)
Cl
Cl (c)
(b)
CH2Cl
(d) Both (a) and (c)
16. Consider the S N 1 solvolysis of the following halides in aqueous formic acid Br
Br CH3 (i) CH–CH–CH3 CH3
CH3
(ii)
C6H5–CH–C6H5 (iii) (iv) Br
Br
Which one of the following is correct sequence of the halide given above in the decreasing order of their reactivity? (a) iii > iv > ii > i (b) ii > iv > i > iii (c) i > ii > iii > iv (d) iii > i > ii > iv
17. For which leaving group X would you predict the SN2 reaction shown below to take place most rapidly? O X
NaSH +
(a) X = –OH
H3C
S
CH3
SH + NaX
25 °C
(b) X = –Cl
(c) X = –Br
(d) X = –I
18. Which of the following order is correct for dipole moment? (a) CH3F > CH3Cl > CH3Br > CH3I (b) CH3Cl > CH3Br > CH3F > CH3I
(c) CH3Br > CH3Cl > CH3I > CH3F
(d) CH3Cl > CH3F > CH3Br > CH3I
19. Choose the correct statement(s) concerning reactions of the two stereoisomers of 3-tert-butyl-5-methylbromocyclohexane. Br
(H3C)3C
Br
(H3C)3C (ii)
(i) CH3
CH3
alkyl halides, alcohols and ethers
(i) 1 will undergo SN1 reactions faster than 2 (ii) 1 will undergo E1 reactions faster than 2 (iii) 1 and 2 undergo SN1 reactions at some rate (a) i (b) ii (c) iii
(d) i & ii
20. Under identical conditions, solvolysis of which of the following substrates would lead to maximum racemization? OCH3 NO2 CH3 H (a)
Cl (b) H
H Cl (c)
Cl (d) H CH3
CH3
CH3
D
Cl
21. Consider the following chlorides (i)
CH2Cl
(ii) CH3
CH2Cl
CH2Cl (iv) O2N
(iii) CH3O
CH2Cl
The order of reactivity of (i), (ii), (iii) and (iv) towards hydrolysis by S N 1 mechanism is
(a) i < ii < iii < iv (c) iv < i < ii < iii
(b) iv < iii < ii < i (d) iii < ii < i < iv
22. Which of the following would be the best synthesis of the acid shown below? H3C O CH3–C–C–OH H3C
O (a) CH3CH2–C–H
CH3MgBr Et2O
O CH3CH2–C–H (b) O (c) CH3–C–CH3 O CH3–C–CH3 (d)
CH3MgBr Et2O
CH3MgBr Et2O CH3MgBr Et2O
H3O⊕ H3O⊕ H3O⊕
SOBr2
SOBr2 SOBr2
H3O⊕ SOBr2
Mg Et2O
CO2
KCN
H3O⊕ Heat
Mg Et2O KCN
CO2
H3O⊕
H3O⊕
H3O⊕ Heat
23. Rank the groups in order of decreasing leaving group ability O –O–S (i) O
O Me (ii) –O–C–CH3 O
(iii) –O–S–CF3 –OMe (iv) O
4.5
4.6
chapter four
(a) ii > i > iv > iii (c) iv > i > iii > ii
(b) i > ii > iv > iii (d) iv > i > ii > iii
24. In the given reaction
C6H5–O–CH2–CH3 HI/∆ → [X] + [Y] [X] and [Y] will respectively be (a) C6H5I and CH3–CH2–I (c) C6H5I and CH3–CH2OH
(b) C6H5–OH and CH3–CH2–I (d) C6H5OH and CH2=CH2
25. 1-Propanol can be prepared from propene by (a) HOH/H⊕ (b) Hg(OAc)2/H2O and NaBH4 – (c) B2H6–THF and H2O2/OH (d) All of these 26.
OH (aq.)AgNO3 ; Major product will be CH2Br OH
(a)
O
(b)
NO2
(c)
(d)
OH CH3
27. The decreasing order of reactivity of methyl alcohol (i), isopropyl alcohol (ii), tertiary butyl alcohol (iii) and ethyl alcohol (iv) for esterification will be (a) i > ii > iii > iv (b) iv > iii > ii > i (c) i > iv > ii > iii (d) i > iv > iii > ii 28. The product of the reaction is CH CH2
O
CH2
(a) CH2=CH–CH2OH (c) CH2=CH–CH2–CH2CHO
CH
CH2
(~200°C)
(b) CH3CHO (d) CH3–CH=CH–CH2CHO
29. Which of the following is correctly matched? CH3 (a) CH3–CH2–O–C–CH3
HOH/H⊕
CH3 CH3–CH–CH2 (c)
CH3O/CH3OH
CH3 SN1 (b) CH3–C–CH2 O
HOH/H⊕
SN2 (d) All of these
O 30. Which of the following ether does not give peroxide formation? (a)
(c)
O
O
(b)
O
(d) –O–
SN1
alkyl halides, alcohols and ethers 31. Correct order of the reactivity of the given alcohols towards the substitution with (NaBr + H2SO4) (i) –CH2OH (ii) H3C– –CH2OH (iii) O2N–
–CH2OH (iv) Me2N– –CH2OH
(a) i > ii > iii > iv (c) iii > i > ii > iv
(b) iv > ii > i > iii (d) iv > iii > ii > i
32. Which of the following is a stable hydrate? OH (b) Cl3C–CH OH
(a) OH OH O (c)
C
OH OH
(d) all of these
O 33. The products of the given reactions Me O O
H3O⊕
A + B (C2H4O)
OH CH3
4 (B) HIO → products (a) CH3CH2COOH (b) HCHO
(c) HCOOH
(d) Both (a) and (b)
34. For the following reactions, the product C is HOOC
Dil.
OH
A
PhMgBr
B
H2O
C
Br (a)
(b) (c) OH Ph OH Ph OH Ph CH3 OH
(d) none of these
35. Compound [X], whose MF is C4H8O gives positive haloform test but gives no 2, 4-DNP derivative is OH (a) CH2=CH–CH–CH3
(b) CH3–CH2–CH2–CHO
O (c) CH3–CH2–C–CH3
(d)
OH
4.7
4.8
chapter four 36. When HI is added in excess to the unsymmetrical ether Ph–O–CH2–CH2
37. CH3–CH–CH–COOR
NO2
it results in (a) PhCH2OH (c) HOCH2CH2Ph-NO2
(b) PhI (d) ICH2CH2PhNO2
(i) 1mol HIO4 (ii) H3O
Products
OH NH2 The product mixture will contain (a) CH3CHO + OHC–NH2 + CO2 (c) CH3CHO + OHC–COOR + NH3
(b) CH3COOH only (d) CH3COOH + NH2COOR + HCOOH
38. Williamson’s synthesis is applied to prepare ether. Identify the ether from the following which cannot be prepared by it? (a) (CH3)3C–O–CH2CH2CH3 (b) PhOCH3 (c) CH2=CH–CH2–O–CH3 (d) CH3–CH=CH–O–CH=CH2 39. Which of the following predictions regarding the solubility of each pair of c ompounds in water are correct? (i) CH2Cl2 is more soluble than CH3OH in water O (ii) H3C
CH3
in water
CH3
H3C
(iii) CH3CH2Cl is more soluble than NaCl in water (iv) CH3CH2CH2SH is more soluble than CH3CH2CH2OH in water
O (v)
CH2
is more soluble than
is less soluble than
(a) iii, iv, v
OH
in water
(b) i, ii, iv
(c) ii, iv, v
(d) ii, v
40. What is the role of H3O+ in this reaction? +
H3O+
H2O
OH
(a) Nucleophile
(b) Catalyst
(c) Leaving group
(d) Base
41. Arrange the yields (high to low) for the products of the following reaction and judge the possible mechanism.
Cl
Et3N (weak base) MeOH
+ (i)
+ (ii)
+ (iii)
(iv)
alkyl halides, alcohols and ethers
(a) ii > iii > i > iv via E1 mechanism (b) ii > iv > iii > i via E2 mechanism (c) ii > iii > iv > i via E1 mechanism (d) iv > i > ii > iii via E2 mechanism
42. What reagent can be used to convert 1-isopropylcyclopentene to 1-isopropyl-cyclopentanol? (a) HBr (b) H2O, diluted H2SO4 (c) H2/Pd (d) H2O, neutral 43. Which statements are true for SN2 reaction of alkyl halides? (i) Both of the alkyl halide and nucleophile are involved in the transition state. (ii) Reaction proceeds with inversion of configuration at the substitution centre. (iii) Reaction proceeds with retention of configuration at the substitution centre. (iv) The order of reactivity is 3° > 2° > 1°. (v) The nucleophile must have an unshared electron pair and bear a negative charge. (vi) The greater the nucleophilicity of the nucleophile, the greater the rate of reaction. (a) i, ii, v, vi (b) i, iii, v, vi (c) i, ii, iv, v (d) i, ii, vi 44. What reactions will likely occur through SN1 mechanism? (i)
Nal Acetone
Cl
Cl (ii)
Cl
Nal Acetone
I Cl MeO
Cl (iii) Cl
(iv)
I
Cl
NaOMe MeOH
Cl
Nal MeOH I
(a) ii, iii, iv
(b) i, iv
(c) iii, iv
(d) ii, iii
45. What is the reagent(s) needed for the following reaction? Reagent Room termperature
(a) HCl
(b) NaBr
(c) HBr
Br (d) Br2
46. Which are secondary alkyl halides? (i)
(ii) Br
(iii) OH OH
4.9
4.10
chapter four
(iv)
(vi)
(v) (viii)
(vii) (a) i, vii
(ix) CH3OH
(x) CH3I
OH
F
Cl
Br
(b) vii
(c) v, x
(d) i, v, vi, x
47. What reagent can be used for the following transformation? Reagent? 25°C
OH
(a) HCl
(b) Na2Cr2O7
+ H2O Cl (c) Cl2
(d) NaCl
48. What could be the product(s) for the following SN1 reaction? Cl
(i)
SCH2CH3
Na+ SCH2CH3 SN1
Product(s) + Cl
SCH2CH3 (ii)
SCH2CH3 (iii) (iv)
(a) i, ii
(b) i, iii
(c) iii, iv
(d) ii, iii
49. What could be the major product for the following E2 reaction? Cl Na+OCH2CH3 E2 OCH2CH3 (i)
OCH2CH3 (ii)
(b) ii
(a) i
Major product + NaCl + CH3CH2OH
(iii)
(iv)
(c) iii
(d) iv
50. What could be the major product for the following reaction? H+, H2O Room temperature OH (i)
(a) i
Major product OH
HO (ii) (b) ii
(iii) (c) iii
(iv) (d) iv
alkyl halides, alcohols and ethers 51. The last step in the synthesis of Valium® is treatment of the following aromatic compound with NH3. Choose the correct structure of Valium®. Cl H3C O N O NH3
Valium (C16H13CIN2O)
Cl NH2 O
O
H3C N
HN
O
(a)
(b)
Cl
Cl O N
CH3
N
N
O CH3
(c)
N N (d)
CH3
Cl
Cl 52. Choose the reaction that is not correctly shown.
(a)
CO2H
+ SOCl2
Cl
+ SO2 + HCl
O (b)
(1) LiAlH4 ⊕ CO2H (2) H3O
CH2OH
(1) NaBH4
(c) CO2H (d) MgBr
(2) H3O⊕ (1) CO2 (2) H3O⊕
CH2OH
COOH
53. Choose those reactions that would give the following amine. OH
NH2
4.11
4.12
chapter four PBr3
N3
(i) LiAlH4
PCC
NH3
H2– Pd/C
(ii) H2O 1
2
PBr3
C
(i) LiAlH4
N
(ii) H2O 3
(a) 1 + 2 + 3
(b) 1 + 2
(c) 2 + 3
(d) 1 + 3
54. Bromobenzene reacts with potassium amide to form aniline. Identify the most important intermediate. Br
H2N H Br (a)
H2N
KNH2 NH3 H2N H
Br (b)
⊕
H2N (c) Br
(d)
55. Here are three possible syntheses of phenylpropylether. Which one would work? (i)
OH
KNH2
Br
O
Br (ii) OH
O
NaOH Br
(iii) OH
(a) i only
O
NaH
(b) iii only
(c) ii or iii
(d) i or iii
56. Identify correct reactivity order for SN1 reaction Br
Br
Br
(i) (ii) (iii)
(a) i > ii > iii (c) i > iii > ii
(b) ii > iii > i (d) iii > i > ii
alkyl halides, alcohols and ethers 57. Identify correct reactivity order for SN1 reaction Cl
Br
I
(i) O (ii) O (iii) O
(a) i > ii > iii (b) ii > iii > i
(c) i > iii > ii
(d) iii > i > ii
58. Identify correct reactivity order for SN1 reaction.
CH2
Cl
C
Cl
C
Cl
H
(a) i > ii > iii (b) ii > iii > i
(c) i > iii > ii
(d) iii > i > ii
59. Identify correct reactivity order for SN1 reaction OTs (i)
OTs
OTs
(ii)
(a) i > ii > iii (b) ii > iii > i
(iii)
(c) i > iii > ii
(d) iii > i > ii
60. Identify correct reactivity order for SN1 reaction Cl (i)
Cl
Cl
(iii) (ii)
(a) i > ii > iii
(b) ii > iii > i
(c) i > iii > ii
61. Identify correct reactivity order for SN1 reaction Cl Cl (i)
Cl
(ii) (iii) B H
N H
O
(d) iii > ii > i
(a) i > ii > iii
(b) ii > iii > i
(c) i > iii > ii
(d) ii > i > iii
62. Identify correct reactivity order for SN1 reaction Cl
(i)
(a) i > ii > iii
Cl
Cl
(ii) Me
(b) ii > iii > i
(iii) Me
(c) i > iii > ii
(d) iii > i > ii
4.13
4.14
chapter four 63. Identify correct reactivity order for SN1 reaction Cl Cl (ii) (i) (iii) Cl
(a) i > ii > iii
(b) ii > iii > i
(c) i > iii > ii
(d) ii > i > iii
64. Identify correct reactivity order for SN1 reaction Cl (i)
Cl
Cl
(ii) (iii)
(a) i > ii > iii
(b) iii > ii > i
(c) i > iii > ii
(d) iii > i > ii
65. Identify correct reactivity order for SN1 reaction Cl (ii) (iii) Cl
(i) Cl
(a) i > ii > iii
(b) ii > iii > i
(c) i > iii > ii
(d) iii > i > ii
66. Identify correct reactivity order for SN1 reaction Me (i)
Me
Me
OTs (ii)
OTs (iii)
Me
Me
Me (a) i > ii > iii
OTs
(b) ii > iii > i
(c) i > iii > ii
(d) iii > i > ii
67. Identify correct reactivity order for SN1 reaction OTs (i)
OTs (ii)
(a) i > ii > iii
(b) iii > ii > i
OTs (iii) (c) i > iii > ii
(d) iii > i > ii
68. Identify correct reactivity order for SN1 reaction Br (i)
Br Br (iii) (ii)
(a) i > ii > iii
(b) ii > i > iii
(c) i > iii > ii
(d) iii > i > ii
69. Identify correct reactivity order for SN1 reaction
(i) Ph—CH2—Br
(a) i > ii > iii
(ii) Ph—Br (b) ii > iii > i
(iii) (c) i > iii > ii
Br (d) iii > i > ii
alkyl halides, alcohols and ethers 70. Identify correct reactivity order for SN1 reaction O F O S F (ii) (i) Cl (iii)
(a) i > ii > iii
O F (b) ii > iii > i
(c) i > iii > ii
O O S O
Br (d) iii > i > ii
71. Identify correct reactivity order for SN1 reaction (i) Br
(ii) (iii) Br
(a) i > ii > iii
(b) ii > iii > i
(c) i > iii > ii
Br
(d) iii > i > ii
72. Identify correct reactivity order for SN1 reaction
O (iii)
(ii)
(i) Cl (a) i > ii > iii
Cl (b) iii > ii > i
(c) i > iii > ii
NH
Cl (d) iii > i > ii
73. Identify correct reactivity order for SN1 reaction Cl (i)
NH
Cl
Cl
(ii) O O O (iii)
(a) i > ii > iii
(b) ii > iii > i
(c) i > iii > ii
(d) iii > i > ii
74. Identify correct reactivity order for SN1 reaction Cl (i) HN
Cl
Cl
NH (ii) O O (iii)
(a) i > ii > iii
(b) ii > iii > i
(c) i > iii > ii
(d) iii > i > ii
75. Identify correct reactivity order for SN2 reaction (i)
Cl Cl (iii) Cl (ii)
(a) iii > ii > i
(b) ii > iii > i
(c) i > iii > ii
(d) iii > i > ii
4.15
4.16
chapter four 76. Identify correct reactivity order for SN2 reaction Cl
Cl
(i)
Cl
(ii) (iii)
(a) i > ii > iii
(b) ii > iii > i
(c) i > iii > ii
(d) iii > i > ii
77. Identify correct reactivity order for SN2 reaction (ii) (iii)
(i)
Cl
Cl
Cl
(a) i > ii > iii
(b) ii > iii > i
(c) i > iii > ii
(d) iii > i > ii
78. Identify correct reactivity order for SN2 reaction O (i)
Cl
(a) i > ii > iii
(ii) Cl (b) ii > iii > i
iii H3C—CH2—Cl
(c) i > iii > ii
(d) iii > i > ii
79. Identify correct reactivity order for SN2 reaction Cl
Cl
(iii) (ii)
(i) NO2
Cl
OMe
(a) i > ii > iii
(b) ii > iii > i
(c) i > iii > ii
(d) iii > i > ii
80. Identify correct reactivity order for SN2 reaction Cl (iii) Cl (i) Cl (ii) N (a) i > ii > iii (b) ii > iii > i (c) i > iii > ii (d) iii > ii > i 81. Identify correct reactivity order for SN2 reaction Cl
(i) tBu
(a) i > ii > iii
tBu (ii)
Cl (iii) tBu
(b) ii > iii > i
(c) i > iii > ii
Me
Cl
(d) iii > i > ii
82. Identify correct reactivity order for SN2 reaction Cl (i)
Cl
Cl (ii) (iii)
(a) i > ii > iii
(b) ii > iii > i
(c) i > iii > ii
(d) iii > ii > i
alkyl halides, alcohols and ethers 83. Identify correct reactivity order for SN2 reaction Cl
Cl
Cl
(i) (iii) O S O O (ii) S S
(a) iii > ii > i
(b) ii > iii > i
(c) i > iii > ii
(d) iii > i > ii
84. Identify correct reactivity order for E2 reaction with alcoholic KOH (i) Ph
Cl
Cl (iii) (ii) Cl Ph
(a) i > ii > iii
(b) ii > iii > i
(c) i > iii > ii
(d) iii > i > ii
85. Identify correct reactivity order for E2 reaction with alcoholic KOH Cl Cl (i)
(ii)
(iii)
Cl
(a) i > ii > iii
(b) ii > iii > i
(c) i > iii > ii
(d) iii > i > ii
86. Identify correct reactivity order for E2 reaction with alcoholic KOH Cl (iii)
Cl (ii)
(i)
Cl
(a) i > ii > iii
(b) ii > i > iii
(c) i > iii > ii
(d) iii > i > ii
87. Identify correct reactivity order for E2 reaction with alcoholic KOH D3C
T3C
(i) Cl (ii) Cl (iii) Cl T3C D3C CT3 CD3
(a) i > ii > iii
(b) ii > iii > i
(c) i > iii > ii
(d) iii > i > ii
88. Identify correct reactivity order for E2 reaction with alcoholic KOH Cl (i)
Cl Cl D T D (ii) (iii) D D T
(a) i > ii > iii
(b) ii > iii > i
(c) i > iii > ii
T T
(d) iii > i > ii
89. Identify correct reactivity order for E2 reaction with alcoholic KOH Me H (i)
H
Me
Cl
(a) i > ii > iii
Me H (iii) Me H (ii) Me H (b) ii > iii > i
H
Cl (c) i > iii > ii
Cl
(d) iii > i > ii
4.17
4.18
chapter four 90. Identify correct reactivity order for E2 reaction with alcoholic KOH Me D (i)
H
Me
Cl
Me
Me H H (ii) Me
Me
Me T H (iii) Me
Cl
(a) i > ii > iii (c) i > iii > ii
Me
Cl
(b) ii > i > iii (d) iii > i > ii
91. Identify correct reactivity order for E2 reaction with alcoholic KOH
(i)
(ii) (iii) Cl
Cl
Cl
(a) i > ii > iii (c) i > iii > ii
(b) ii > iii > i (d) iii > ii > i
92. Identify rate of sololysis or hydrolysis S
S
S
(i)
(ii)
(iii) Cl
Cl
(a) i > ii > iii (c) i > iii > ii
Cl
(b) ii > iii > i (d) iii > i > ii
93. Identify rate of sololysis or hydrolysis OTs (i)
(ii) OTs
OTs
(iii)
(a) i > ii > iii (c) i > iii > ii
(b) ii > iii > i (d) iii > ii > i
94. Identify rate of sololysis or hydrolysis OTs
OTs (i)
(ii)
(a) i > ii > iii (c) i > iii > ii
OTs (iii)
(b) ii > iii > i (d) iii > i > ii
alkyl halides, alcohols and ethers 95. Identify rate of sololysis or hydrolysis Cl (i)
Cl (ii)
(iii) Cl
(a) i > ii > iii
(b) ii > iii > i
(c) ii > i > iii
(d) iii > i > ii
96. Identify rate of sololysis or hydrolysis Cl (i)
Cl
Cl (iii)
(ii)
Cl
(a) iii > ii > i
(b) ii > iii > i
(c) i > iii > ii
(d) iii > i > ii
97. Which statements are true for SN1 reaction of alkyl halides?
(i) Both of the alkyl halide and nucleophile are involved in the transition state. (ii) Reaction proceeds with inversion of configuration at the substitution centre. (iii) Reaction proceeds via the formation of carbocation intermediate. (iv) The order of reactivity is 3° > 2° > 1°. (v) The nucleophile must have an unshared electron pair and bear a negative charge. (vi) Protic solvents favour SN1 reaction.
(a) iii, iv, vi
(b) ii, iv, v
(c) i, ii, vi
(d) i, ii, v, vi
98. What could be the product for the following reaction? O OH
(1) SOCl2 (2) CH3CH2NH2 Pyridine
O
NH (a)
CH3
(b)
NHCH2CH3 O
O (c)
Product?
OCH2CH3 (d) Cl
99. What could be the product for the following reaction? O (i)
N
Br
O (ii)
H+,
H2O, Heat
Product?
4.19
4.20
chapter four
Br
NH2
(a)
(b)
Br
Me
(c) O
N
Major product is
(ii) HCl, H2O
O
N H
(d)
Br (i) NaOH, H2O
100.
O
N
Me
(a) Me – C ≡ C – COOH
(b)
N
O
N Me
Br
(c) N
Me
N H Br
COOH
N N
Base ∆
101.
(a)
(d)
OH
Br
COOH
O
Major Product?
(b) Br
(c)
COOH
O 102. Ph
COOH
(d) COOH
∆
Major product
Ph Ph (a) Ph
COOH
Ph (b) Ph
O
Ph
C
H (c) Ph
OH
O
Ph H (d) Ph C O
C
O
alkyl halides, alcohols and ethers O
O Ph
103.
H+
Major product
OH OH
O
O
(a)
Ph (b) OH
O
O
O Ph
(c)
(d)
O
OH (i) TSCl
104. HO
O
O O H C (a) (c) HO O
(ii) K2CO3, MeOH
Major product
O O (b) H C O
O
O
OH
(d) COOMe O
(i) 1 eq. Me MgCl (ii) H2O
Major product HO
(a)
(c)
HO
OH
(d)
COOEt CN
(i) NaOEt (ii)
Me
O
(b)
Me
O
N
OH
O
105.
106.
Ph
Major product
O Br
HO
OH
4.21
4.22
chapter four HO
O
EtOOC COOEt
(a)
CN
(b)
CN
N
N COOH
EtOOC (c)
(d) N
O
N
Conc. H2SO4
107. O (a)
COOH
HOOC
Major product O
OH
O
(b) (c) O (d)
OH
O
108.
∆ H+
+NH2 — OH
Major product
O O NH (a)
(b) N
NH O
109. O
HO (c) HO
HO
Ph
CN O CN
Ph
O O
Major product
(ii) NaCN/DMSO O
OH (d) N H
(i) NaOH/H2O
Ph
OH
(a) O
O
(c)
HO
O (b) CN HO HO
O (d) OH HO
Ph
Ph
alkyl halides, alcohols and ethers 110. Four of the five reactions shown below should proceed as shown to give good yields. One of reaction has problems and will not proceed as indicated. Identify this one reaction which will not proceed as shown. O (a)
O Cl
HO Pyridine
O
O O (b)
Cl O (c)
O
O Pyridine
Pyridine
O (d)
O O
H2N O
O
NH O
HO
NH
O O
111. Which of the following synthetic schemes would be the best for the synthesis of the compound, 2-bromo-1-chloro-4-nitrobenzene? Cl Br
NO2 2-bromo-1-chloro-4-nitrobenzene (a)
Br2 FeBr3
HNO3 H2SO4
Cl2 AlCl3
(b)
Br2 FeBr3
Cl2 AlCl3
HNO3 H2SO4
(c)
Cl2 AlCl3
HNO3 H2SO4
Br2 FeBr3
(d)
Cl2 AlCl3
Br2 FeBr3
HNO3 H2SO4
112. Which reaction is faster (i) or (ii) and what is its mechanism? DMF OCH3 + Br– (i) Br + CH3O–Na+ DMF (ii) Br + CH3S–Na+ SCH3 + Br–
(a) reaction i, SN1 (c) reaction ii, SN1
(b) reaction ii, SN2 (d) reaction i, SN2
4.23
4.24
chapter four 113. Which reaction is faster (i) or (ii) and what is its mechanism? O CH3CO2H
(i)
+ HBr
O
Br
O (ii)
Cl
CH3CO2H
+ HCl
O
(a) reaction ii, SN1 (c) reaction i, SN1
(b) reaction ii, SN2 (d) reaction i, SN2
114. Which reaction is faster (i) or (ii) and what is its mechanism? (i) (ii)
Cl
Cl
Et–O|/CH3CH2OH
+ Cl–
Et–O|/CH3CH2OH
(a) reaction ii, E2 (c) reaction i, E1
+ Cl– (b) reaction i, E2 (d) reaction ii, E1
115. Which reaction is faster (i) or (ii) and what is its mechanism? (i)
Cl
80 per cent H2O/CH3CH2OH
+ HCl
80 per cent H2O/CH3CH2OH
(ii)
+ HCl
Cl
(a) reaction ii, E1 (c) reaction ii, E2
(b) reaction i, E2 (d) reaction i, E1
116. Predict the major product of the following reaction. H2SO4 OH
(a)
(b)
(c)
(d)
117. Which ONE of the following reactions is NOT correct? (a)
OH
Br2
O
Br
+ Enantiomer
alkyl halides, alcohols and ethers OH H2SO4
(b) Cl (c)
H2O Cl
HCl
+ Enantiomer Cl
(d)
(i) BH3
OH
OH
(ii) H2O2/NaOH
118. Consider the following reaction. H BH3
B H
Step 1
Step 1
H H
B H
H2O2/NaOH
H
Step 1
OH
Which ONE of the following statements is INCORRECT?
(a) In step 1, the boron atom acts as a Lewis base. (b) In step 2, the boron atom is oxidized by hydrogen peroxide. (c) The borane addition occurs with syn-stereospecificity. (d) In step 1, a hydride is added at carbon 2.
119. Which one of the following five SN2 reactions will take place most rapidly? O O
(a) CH3CH2OH +
S O
O (b) F +
O
S O
(c) Cl +
O
O S O
(d) I +
O
O S O
Ethanol
Ethanol
O
25ºC F
25ºC
Ethanol
Cl
25ºC
Ethanol 25ºC
I
4.25
4.26
chapter four 120. Which of the following changes will increase the rate of elimination reaction in the following reaction? Cl
O Ethanol 50°C
+
(i) using 100°C instead of 50°C
(ii) using water instead of ethanol I
(iii) adding ethoxide to the ethanol
(a) i and ii
instead of
(iv) using
(b) ii and iii
Cl
(c) i, iii and iv
(d) iii and iv
121. Which one of the following is the major product of the reaction below? Br NaH/diethylether HO HO (a)
(b) O
HO (c)
(d) O
?
122. Which one of the sequences below is the best synthesis of (E)-3-hexene? (a)
O H
(d) C
OC(CH3)3
HOC(CH3)3 (i) NaH (ii)
O
HBr
(ii) H2O Br
(b) C (c)
⊕
CH2Li
(i)
Br
⊕ CH2Li
(i)
Na/NH3
HBr
Me (ii) H2O Br
OCH2CH3
HOCH2CH3 (i) NaH
Na/NH3
(ii) CH3Br Me
123. Which reactions will provide the following diol as the major product H H
OH ? OH Me
alkyl halides, alcohols and ethers
(1) OsO4 (i) (2) NaHSO3
(1) RCO3H (ii) (2) H3O+
(1) OsO4 (iii) (2) NaHSO3
(1) RCO3H (iv) (2) H3O+
(a) i
(b) iii
(c) ii and iii
(d) i and iv
124. Which is the best synthesis of the following alcohol? OH
?
(1) Hg(OAc)2 (a) (2) BH4
(1) Hg(OAc)2 (b) (2) BH4
(1) BH3 (c) (2) H2O2/HO
H⊕ (d) H2O
125. Which is the best synthesis of the following cyclopropane? H CH2I2 (a)
OH
H
Br
H2/Linear
CH I (b) 2 2 Zn/Cu CH2I2 (c) Zn/Cu
OC(CH ) 3 3
CH2I2 (d) Zn/Cu
OH
Br
Br
126. Which is the correct product of the following reaction? O H
H
NaH Diethyl ether
HS OH
OH (a)
H S
(b) H S
OH H H
(c) S
H OH H
(d) S
4.27
4.28
chapter four 127. Arrange the indicated C––H bonds in order of increasing reactivity towards chlorination. H H H H H H H H H H H H (i) C C C C H
H (ii) H
H
H
H (iii) C C C C
C C C C H
H
H
H
H
(ii) < (i) < (iii) (i) < (ii) < (iii) (ii) < (iii) < (i) Increasing Increasing (a) (b) (c) Increasing reactivity reactivity reactivity
H
(i) < (iii) < (ii) Increasing (d) reactivity
128. Choose those reaction(s) that is (are) the propagation step(s) in the following free radical chain reaction.
(i) · +
H + n-Bu3Sn—Br
·
(ii) n-Bu3Sn· +
Br
n-Bu3Sn—Br +
(iii) n-Bu3Sn —H + ·ln
·ln
Br
n-Bu3Sn—H +
(a) i
n-Bu3Sn ·+ H—ln
(b) ii
(c) iii
(d) i and ii
129. Choose the answer that is correct for the ∆H°(kJ/mole) of the following step in the bromination of propane. H
H H
C C C H
H
H H
+ · Br
Light
H
H
(a) Exothermic
H H
(b) Endothermic
H · C C C H
(c) Reversible
H
+ H—Br
H (d) Irreversible
O 130.
+
HO
OH
H+
(A)
Me2SO4
(B)
OH N OH
O O (a)
O (b)
O
OMe O O (c)
O (d)
O
‘B’ product is
alkyl halides, alcohols and ethers
Level 2 Single and Multiple-choice Type 1. Which of the following shows greater reactivity towards S N 2 reaction than CH3—CH2Br with sodium methoxide? (a) CH3–O–CH2Br (b) CH3Br (c) CH2=CH–Br (d) CH2=CH–CH2Br 2. Consider the S N 1solvolysis of the following halides in aqueous formic acid? Br Br CH3 H3C (i) CH–CH–CH3 (ii) H3C Br C6H5–CH–C6H5 (iv) (iii) Br Which one of the following is correct sequence of the halides, given above, in the decreasing order of their reactivity?
(a) iii > iv > ii > i (c) i > ii > iii > iv
(b) ii > iv > i > iii (d) iii > i > ii > iv
3. The correct statement for the given reaction is CH3 Br–H CF3CO3H NaI A B Br–H Acetone CH3
(a) B is optically inactive due to external compensation (b) B is optically inactive due to internal compensation (c) A is predominantely cis-alkene (d) B does not have chiral centres
(i) Dil. OH 4. CH3–CH2SH Product, product is (ii) Ethylene oxide (iii) H2O
(a) CH3–CH2–S–CH2–CH2–OH
(b) CH3–CH2O–
(c) CH3–CH2–O–CH2–CH2–OH (d) CH3–CH2–S
⊕
CH–OH CH2
5. Which of the following statements are correct?
(a) The S N 1 reaction obeys the Ist order kinetics (b) The solvolysis of ethylbromide in ethanoic solution is first order kinetics (c) R configuration of a compound may result in R and S configurations in an S N 2 reaction (d) 1-Bromo-1-phenylethane shows greater reactivity towards S N 1 and S N 2 reaction compared to isopropyl bromide
4.29
4.30
chapter four 6. Which of the following reactions will proceed with retention of configuration only (no inversion) at the chiral carbon?
O
H (a) H3C
H3C H2O H (b) C–CH2–S–CH3 Ag⊕ I
C C O
Br H
CH3
H2O Ag⊕
CH3–C–Br (c) C2H5
(d) C6H5–C–Br C2H5
H2O Ag⊕
H2O Ag⊕
7. Correct statements is (a) Nucleophilicity of SH is greater than OH in dimethyl formamide (b) Hydrazine is a better nucleophile than NH3 (c) Phenoxide ion is more basic than acetate ion
CH 3 is a better nucleophile than OH in a non-polar solvent (d) O
O NO 8. 2
H NaOH → A , A can be CH2Cl O
CH–CHO
NO2 (a)
CHO
NO2 (b)
O O
O NO2 CHO (c)
NO2 (c) O
CHO OH
9. Identify the compounds that will undergo substitution reaction faster than C2H5Br with OH–/DMSO.
(a) CH3CH2–S–CH2CH2Br
CH3–CH–CH3 (d)
CH3–CH–C=O (c) Br
O
(b) CH3–CH2CH2Br
Br
10. In which of the following cases, the configuration of chiral C is retained in product? Et * OH (a) H D C2H5 * OH (c) H D
Et
(i) Na (ii) CH3–Br
(i) SOCl2/ (ii) CH3
N – O Na+
* OH (b) H D C2H5 (d) * OH H D
(i) TsCl (ii) CH3ONa
(i) BF3 (ii) CH2N2
alkyl halides, alcohols and ethers (excess) Cl EtMgBr
11.
O+
H3
O
(A)
H2SO4 (B) ∆
(i) Br2/H2O/NaOH (ii) H3O+ HO
(a)
(b)
(C) ; Products B and C are HO
OH
(c)
(d)
OH
12. Which statement is/are correct in the following statements?
(a) Allyl bromide gives S N 1 reaction but vinyl chloride does not. (b) Primary alkyl halides can give S N 1 or S N 2 reaction. This depends on the structure of the substrate and nature of solvent. (c) CH3–CH=CH–CH2Cl reacts with KCN to give mixture of two isomeric products. (d) CH3–CH2–O–CH2Br is less reactive than tert. butyl bromide for S N 1 reaction.
13. Identify reaction that follows S N 2 path ⊕ (a) ONa +
(b) NaI/Acetone +
I
Cl
I DMSO (d) NaN3 +
NaSH + (c)
I
DMF
14. Which of the reactions give the correct product?
(a)
Cl + C2H5OH
OC2H5 +
∆
OC2H5 (possible product) OCOCH3
(b)
I
OCOCH3
+ CH3COOH
(c)
MeOH
(d) Cl Cl
OEt
OC2H5
I + C H OH 2 5
(possible product)
+
(possible product)
+
(major product)
Cl OMe
15. Which of the following alcohol gives the white turbidity immediately with HCl + ZnCl2 (anhy.)? Ph (a) CH3–C–OC2H5 OH (c) Ph–CH–CH=CH2 OH
(b) Ph–CH–CH3 OH (d) CH3–CH2CH2OH
4.31
4.32
chapter four 4 16. A HIO → CH3CHO + 2HCOOH + CH3COOH. The structure of A is
CH3
CH3
CH3–CH–OH
CH3–C–OH
CH–OH
(a) CH–OH (b)
C=O
CH–OH
C=O (c) CH–OH (d) none of these CH–OH
CHO
CHO
CH2OH
17. Which of the following gives turbidity immediately with Lucas-reagent (anhy. ZnCl2 + HCl)? CH3
CH3 CH3–C–OH (b) Ph–CH–OH (c) (a) Me– CH3
–C–OH (d) CH3CH2OH CH3
CH3
18. The possible structure of the alcohol is 2 SO 4 ROH (alcohol) H → Heat
CH2OH (a)
OH
(b)
(c)
CH2OH
=CH2
(d) OH
19. Identify correct reactivity order for S N 2 reaction (a)
>
Cl
Cl
Cl
NO2
Cl >
Cl
Cl (c)
O
(b)
Cl >
(d)
Cl >
OMe
CH3
CI
20. Identify correct reactivity order for S N 2 reaction Cl (a)
Cl
Cl
(b)
>
CN
>
CN
CI Cl
Br
CN
Br
Br
Cl (c)
>
(d) >
NO2
NO2
alkyl halides, alcohols and ethers 21. Identify correct reactivity order for ArSN reaction Br
Cl
Cl
Cl O2N
(a)
(b)
>
NO2
NO2
NO2
NO2
Cl
Cl
NO2
O2N
O2N (c)
>
> NO2
NO2
(d) (a) and (b) are correct
22. Identify correct reactivity order for ArSN reaction Cl
Cl O2N
O2N
NO2
(ii)
(i) NO2
Cl (iii) NO2
NO2
(a) i > ii > iii (c) i > iii > ii
(b) ii > i > iii (d) iii > i > ii
23. Identify correct reactivity order for ArSN reaction Cl
(i)
O2N (ii)
O2N
Cl
Cl
(iii) NO2
(a) i > ii > iii (c) i > iii > ii
NO2
(b) ii > iii > i (d) iii > i > ii
24. Identify correct reactivity order for ArSN reaction F
(i)
Cl
(ii) (iii) NO2
Br
(a) i > ii > iii (c) i > iii > ii
NO2
NO2 (b) ii > iii > i (d) iii > i > ii
4.33
4.34
chapter four 25. Identify correct reactivity order for ArSN reaction F O2N
Cl H3C
H3C (ii)
(i)
(iii)
(a) i > ii > iii
NO2
CH3
NO2
Br
(b) ii > iii > i
(c) i > iii > ii
(d) iii > i > ii
26. Identify correct reactivity order for ArSN reaction F O2N
Cl O2N
O2N (ii)
(i)
(iii) NO2
NO2
NO2
Br
(a) i > ii > iii (c) i > iii > ii
(b) ii > iii > i (d) iii > i > ii
27. Identify correct reactivity order for ArSN reaction F O2N
Cl
(i) NO2
Br
H3C (ii)
(a) i > ii > iii (c) i > iii > ii
(iii) O2N
CH3
NO2
(b) ii > iii > i (d) iii > i > ii
28. Identify correct nucleophilicity order
(i)
(ii) (iii) N N
N
(a) i > ii > iii (c) i > iii > ii
(b) ii > iii > i (d) iii > i > ii
29. Identify correct nucleophilicity order N
N (ii)
(i)
(a) i > ii > iii (c) i > iii > ii
(iii) (b) ii > iii > i (d) iii > i > ii
N
alkyl halides, alcohols and ethers 30. Identify correct nucleophilicity order CH3
NO2
(i)
N (a) i > ii > iii (c) i > iii > ii
CN
(ii) (iii) N
N (b) ii > iii > i (d) iii > i > ii
31. Identify correct nucleophilicity order H H N N (ii) (iii)
N
(i)
(a) i > ii > iii (c) i > iii > ii
(b) ii > iii > i (d) iii > i > ii
32. Identify correct nucleophilicity order
(i) H2O (a) i > ii > iii (c) i > iii > ii
(ii) H2S
(b) ii > iii > i (d) iii > ii > i
(iii) H2Se
33. Identify correct nucleophilicity order
(i) PH3 (a) i > ii > iii (c) i > iii > ii
(ii) NH3
(b) ii > iii > i (d) iii > i > ii
(iii) AsH3
34. Identify correct nucleophilicity order S
O
Se
(ii) (iii)
(i)
(a) i > ii > iii (c) i > iii > ii
(b) ii > iii > i (d) iii > ii > i
35. Identify correct reactivity order for S N 1 reaction (a) Cl (c) NO2
O
(b)
Cl >
Cl >
Cl Cl
>
Cl (d)
CH3
Cl
OMe
Cl > CI
4.35
4.36
chapter four 36. Identify ccorrect reactivity order for S N 1 reaction (a) Cl >
(b)
Cl >
(d)
OMe
>
Cl
Cl
Cl
(c)
Cl
Cl
Cl >
OMe
CH3
CI
37. Identify final product in following sequence H3C Ph
NH2
Br
NaNH2
CH2
X
Y
mcpba
Z
H3C
Product
Ph
(a)
(b) NH
CH3
NH
HO
NH CH3
O
H3C
CH3 CH3 (d)
(c)
NH HN
CH3
CH3 CH3
38. Identify final product of following reaction O
O
CH3 +
H3C
H3C (a) O
O
O
O O
CH3
O +
H3C (b) O O
K2CO3/∆
O
alkyl halides, alcohols and ethers O
O H3C
(c) H3C
CH3
CH3 (d) O
O
39. Identify final product of following reaction O
O
O O
H3C
CH3
+ H2C
NaH /∆
O
CH3 O (a)
OH
O
CH3 (b)
H3C
H3C
CH3 OH
CH3 CH3 O
O
HO OMe (d)
(c) HO
OMe
H3C
CH3
OMe OH
40. Identify final product of following reaction O
H+/∆
2
H3C
CH3
A
NaOEt / EtOH
O
OEt O
H3O+/∆
O
O EtO
O (a)
B
O
(b) CH3
O (c) H3C
CH3
O
O
CH3
O
(d) H3C
CH3
41. Select all of the following statements about the aldol experiment that are true (a) The ketone was added to a solution containing the aldehyde and base. (b) The reaction can be catalysed by acid (c) The electrophile is the enolate ion (d) The aldehyde is used in excess
4.37
4.38
chapter four 42. Which of the following structures is the product from the self-condensation of two molecules of pentan-3-one? O O (a)
(b)
O
O (c)
H
O 43.
(d)
i. HO–(CH2)2–OH, H+ O
OMe
ii. Excess MeMgBr, then H3O+
O (a)
(b) MeO
44.
C
(a)
(c)
C
CH3
H
Br
C
C
H
H
H
H
C
C
Br
H
O
(i) Na, NH3 (ii) HBr
OH
OH
O (d)
(c)
Me
H
Product is Br
CH3 (b)
Br CH3 (d)
O Br
45. O
(i) Mg, Ether (ii) EtOH (iii) Catalytic H+, H2O
H
OEt (b) O
(a) O O O (c)
OH
H OH (d) O
OEt
OH
O
alkyl halides, alcohols and ethers
46. CH3CO2H
(i) SOCl2 (ii) 3-Methylaniline (iii) LiAlH4, then H3O+ H3C
NH2
H3C
NH2
CH3 (b)
(a)
CH3
O (c) H3C
47.
N H
OH H3C NH (d)
CH3
(i) O3, then Zn in H2O
HO
(ii) NaBH4 (iii) Excess PBr3 (iv) Excess KCN (v) H+, H2O and heat
OH O
CH3 (a)
O
CH3
CH3
CH2
(b) (c) (d)
H3C 48.
CH3
(i) HO–CH2CH2–OH, catalytic H+
OH O
O+
(ii) Mg, THF then H2C=O, then H3 (iii) H3O+, heat O
(a)
Br CH3
(b)
H O
Br H (c)
Br (d)
O
O
Br 49.
(i) Ph3P, then n-BuLi (ii) Cyclohexanone (iii) CH2I2, Zn–Cu OH
(a)
O
Br
NH2
(b) (c) (d)
4.39
4.40
chapter four OH 50.
BrMg–(CH2)4–MgBr then H3O+ O
O (a)
(b) O
(c) OEt
O CH2CH3
51.
Br2
H
Br
H
Br
O
(d) O
O
CH2CH3 +
Br
H
Br
H
CH3
CH3
(50:50 of these enantiomers) (a)
(b)
52. O
(i) LDA
(d)
(ii) CH3I (iii) NaBH4/MeOH O
OH C (a) 3
53.
(c)
(b)
OH
OH (c)
(d)
(i) HBr (dark, N2) (ii) PH3P, then nBuLi O (iii)
(a)
(b)
(c)
(d) OH
alkyl halides, alcohols and ethers (i) (CH3CO)2O/AlCl3
54.
(ii) Zn/Hg, HCl (iii) CH3Cl/AlCl3
(a)
O
(b)
(c)
(d)
O 55. H
(i) HOCH2CH2OH/H+/heat
CO2CH2CH3 O
(a) HO
H
OH (c)
(ii) LiAlH4, then H3O+ (iii) H3O+/heat OH OH (b) OH
O
OH
(d) OH3C
56. Identify major product for the following reaction Cl 1 eq. NaI/Acetone
Cl Cl
Cl (a)
(b)
(c)
(d) Cl
I
I
I
I
Cl
57. Identify major product for the following reaction I OMe
O2N OH (a) O2N
OMe
OH O2N (b)
OMe
Aqueous/Acetone
4.41
4.42
chapter four HO (c) O2N
OMe
OH OMe
O2N (d)
58. Identify major product for the following reaction Cl
O
(i) Excess MeMgCl (ii) H3O+
Major product is?
HO (a)
H3C (c)
OH OH H3C CH3 CH3 (d)
HO (b)
O
59. Identify major product for the following reaction I
I
N
HO I
Major product is?
H
H
(a)
H
(b) N
HO H
N
HO H
I
(c) HO
(i) NaH (ii) H3O+
I
(d) N
HO
N
60. Identify major product for the following reaction OR NR2
Major product is?
alkyl halides, alcohols and ethers NR2 (a)
(b) NR2 NR2
(c)
(d) NR2
61. Identify major product for the following reaction I NaSH HO
Major product is?
OMe
SH
SH
(a)
(b) OMe
HO
HO
OMe SH
SH (c)
(d) HO
OMe
HO
OMe
62. Choose the major product of the following reaction.
OH
(a)
(b)
Cl
H — Cl
Cl OH (d)
OH (c) Cl
63. Identify major product of the following reaction CH3
BH3/THF H2O2/NaOH
CH3 (a)
(b) CN
A
TsCl/Py
B
NaCN/DMF
CH3
CN CH3 (c)
CN (d)
CN
C
CH3
4.43
4.44
chapter four 64. Identify best reagent for the following conversion Reagent?
OH
(a) ZnCl2/HCl
(b) PCl5
Cl
(c) PCl3
(d) SOCl2
65. Identify best reagent for the following conversion Reagent?
OH
(a) ZnCl2/HCl
(b) PCl5
Cl
(c) PCl3
(d) SOCl2
66. Identify best reagent for the following conversion HO
Cl Reagent?
(a) ZnCl2/HCl
(b) PCl5
(c) PCl3
67. Identify reactions that correctly match with their products HO
Cl
(a)
F (b)
SOCl2
Alcoholic KOH ∆
(c) + N
(d)
Alcoholic KOH ∆
N
+
Alcoholic KOH ∆
N
(d) SOCl2
alkyl halides, alcohols and ethers 68. Identify reactions that correctly match with their products (a) N+
(b)
Alcoholic KOH ∆
Alcoholic KOH ∆
N+
(c) N+
N
N
Alcoholic KOH ∆
N
Alcoholic KOH ∆
(d) ⊕ Me3N
69. Identify reactions that correctly match with their products Alcoholic KOH ∆
(a) F
(b)
N+
N Alcoholic KOH ∆
D
Alcoholic KOH ∆
(c) H ⊕
D
NMe3 Alcoholic KOH ∆
(d) ⊕ Me3N
70. Identify reactions that correctly match with their products Alcoholic KOH ∆
(a) F
HO Alcoholic KOH ∆
O (b) CHO
CHO
4.45
4.46
chapter four Alcoholic KOH ∆
(c) Br
Alcoholic KOH ∆
(d) ⊕NMe 3
71. Identify reactions that correctly match with their products Alcoholic KOH ∆
(a) Br
(b)
Alcoholic KOH ∆
Br
(c)
Alcoholic KOH ∆
F
(d)
Alcoholic KOH ∆
Cl
72. Identify reactions that correctly match with their products? Cl Cl
Cl
Cl
(a) Cl
Cl
Cl +
EtOH O
EtO
O
EtO
O
Monosubstituted product Cl
Cl
(b) Cl
EtOH EtO Monosubstituted product Br
(c) EtO
EtO EtOH
EtO
alkyl halides, alcohols and ethers
Alcoholic KOH ∆
(d) Cl
73. Identify major product for the following reaction Cl
Cl
Ph
Aqueous NaOH
Ph
HO (b) Ph Ph
OH
Cl
HO (a) Ph
Major product is?
(c) Ph Ph
O
(d) Ph Ph
74. Identify major product for the following reaction Cl
Cl Cl
Cl
HO Cl (a)
Major product is?
HO (b) HO
Cl
HO (c)
Cl
Cl
Cl
OH
HO
HO
Aqueous NaOH
Cl
Cl
Cl
Cl
Cl
Cl
Cl
Cl (d)
OH
Cl
Cl
O
Cl
75. Identify major product for the following reaction Cl Cl NaOMe/MeOH O2N
Major product is?
NO2 Cl
OMe
MeO (b)
MeO (a) NO2
O2N
O2N
Cl
OMe
MeO (c) O2N
NH2
Cl (d) NO2
O2N
NO2
O H
4.47
4.48
chapter four 76. Identify SN2 reaction which is favourable in a polar protic medium
(a) NaOH + CH3 – I ⎯→ HO–CH3 + NaI ⊕
(b) OH– + Me
N
Me Me
OH–Me + NMe3
Me Me ⊕
NH3 + Me (c)
H2N – Me + SMe2
S Me
(d) NH3 + Me–I ⎯→ H2N – Me + H–I O
77.
(i) LAH
O
(ii) Conc. KMnO4/∆ (iii) ∆
O
Possible products
O O
O O
(a)
(b) O
O
O O
O O
O
O (d) O
(c) O
78.
O
O
O
(i) Aq. NaOH (ii) H+/∆
O
Major product?
O
(a) C
O
O
O (b)
O
H
O O (c)
O
O
(d)
O C O
H
alkyl halides, alcohols and ethers
Comprehension Type Passage 1 Suppose, a sample of an initially pure single enantiomer of tartaric acid [α]D20 = +12.4° (H2O) underwent a chemical isomerization reaction which yielded 10 per cent of the other enantiomer and 20 per cent of the meso isomer, in addition to 70 per cent of the unchanged starting compound. 79. What is the enantiomeric excess (ee.) of the major enantiomer relative to the minor enantiomer?
(a) 70 per cent (c) 75 per cent
(b) 700 per cent (d) 87.5 per cent
80. If 1.0 g of the total mixture (including the meso isomer) was dissolved in 1 mL water and the rotation measured in a 1 dm cell, what value of αD would one expect to observe?
(a) +9.92
(b) +7.44 C
(c) +12.4
(d) +8.68
81. From the total mixture, chromatographic separation on silica gel (a commonly used achiral solid adsorbent) might be expected to yield one of the three components in a pure state. Which one?
(a) the minor enantiomer (b) the meso isomer (c) the major enantiomer (d) the 1:1 racemic form of tartaric acid
Passage 2
(a) When 1-chloro-2-pentene is reacted with concentrated solution of sodium ethoxide, the rate of reaction depends on the concentration of both allylhalide and ethoxide ion. The product of reaction is exclusively CH3–CH2–CH=CH–CH2OC2H5
(b) In dilute solution of sodium ethoxide, the reaction rate is dependent only on the concentration of allylhalide. (c) In the presence of traces of water, 1-chloro-2-pentene is slowly converted to a mixture of 1-chloro-2-pentene and 3-chloro-1-pentene
82. In case (a) the mechanism exclusively followed by reaction is S N 1 (b) S N 2 (a) (c) E1
(d) E2
83. The intermediate formed in case (c) is ⊕
⊕
CH 3 − CH 2 − CH − CH = CH 2 (b) CH 3 − CH 2 − CH = CH − CH 2 (a)
(c) both (a) and (b)
(d) none
84. Correct statement is
(a) The solvolysis of 1-chloro-2-pentene is greater than 1-chloropentane in water (b) The solvolysis of 1-chloro-2-pentene is lesser than 1-chloropentane in water (c) The solvolysis of 1-chloro-2-pentene and 1-chloropentane is equal in water (d) The solvolysis of 1-chloro-2-pentene and 1-chloropentane do not take place in water
4.49
4.50
chapter four Passage 3 Williamson’s ether synthesis is one of the best method to prepare ether. In this method ethers can be prepared by the reaction of alkoxides with alkyl halide. The reaction takes place by S N 2 mechanism. The more basic alkoxide ion displaces the halide or other leaving group to produce ether. While going for Williamson’s ether synthesis one should be aware of competitive reactions. The mechanism take palces as
R–O + R'–X
SN2
R – O – R' + X
85. Which combination will be better to prepare anisole Br
ONa (a)
+ CH3F
(b)
+ CH3ONa
ONa (c)
+ CH3OSO2OCH3
(d) Both (a) and (c) can be used
86. The ether that cannot be synthesized by the above method is CH3 (a) CH3–O–C–CH3
(b)
OCH2CH2CH3
CH3
(c) (CH3)3C–O–C(CH3)3
(d) All can be prepared
87. Which one of the following will give most effective yield of ether?
–
(a) CH3CH2O + CH3CH2CH2CH2Br (b) CH3CH2O + CH3–CH–CH2Br
CH3 CH3 CH3CH2O + CH3–C–Br (d) (c) PhO– + CH3–CH–Br CH3 CH3 Passage 4 The specific rotation of (2R, 3R) – (+) – tartaric acid is +12.4º (c = 2, H2O). The optical rotation of a solution made up from 10 g of a mixture B and C in 20 ml of water was measured in a 10 cm cell. The observed rotation was –3.1º. CO2H H (a) H
OH OH CO2H
CO2H (b) CO2H
(c) H
OH
alkyl halides, alcohols and ethers COOH
CO2H
OH H
(d) HO
(e)
HO
H
H
OH
COOH
H
CO2H
88. What is the specific rotation of A?
(a) +12.4º (c) –12.4º
(b) 0º (d) None of these
89. What is the specific rotation of the mixture?
(a) –3.1°
(b) –6.2°
(c) –0.62°
(d) +12.4°
90. What is the relative ratio of B:C in the mixture?
(a) 0:100
(b) 50:50
(c) 25:75
(d) 75:25
Passage 5 Based on the potential energy diagram for the following reaction CH3 C
H3C ii
CH3 CH3
CH3OH
H3C
C
CH2
Cl iv
Potential energy
B A
iii v
C
i Reaction coordinate 91. Is this an endothermic or exothermic reaction?
(a) exothermic (b) There is not enough information to determine. (c) endothermic (d) This reaction can be either exothermic or endothermic.
92. What potential energy difference represents the heat of reaction?
(a) A (c) C
(b) B (d) Both A and B
93. Which of the following indicates the location of intermediate?
(a) i
(b) ii
(c) iii
(d) iv
94. According to the potential energy diagram, what is the possible mechanism for the reaction? (a) E1 (b) E2 (c) SN1 (d) SN2
4.51
4.52
chapter four Passage 6 Based on the following five structures (i–v) shown below, answer questions 99 to 106. H2C–OH
HO
H
HO
(i) HO
OH (ii)
H OH (iii) H OH
H H
HO
OH
OH
H2C–OH
4
CH2OH CH2OH H OH OH
H HO
HO
CH2OH
(iv) H
OH
HO–CH2
OH
HO
HO (v)
OH HO
H 95. What type of isomers are (i) and (iv)? (a) diastereomers (c) identical
(b) conformational (d) enantiomers
96. What type of isomers are (i) and (iii)? (a) diastereomers (c) identical
(b) conformational (d) enantiomers
97. If the specific rotation of i is –60.0º, what is the specific rotation of iii, if 1.0 g of iii is dissolved in 10 mL of methanol and placed in a 1 dm tube? (a) +60º (b) 0º (c) 6º (d) –60º 98. If the specific rotation of i is –60.0º, what is the specific rotation of iv, if 1.0 g of iv is d issolved in 10 mL of methanol and placed in a 1 dm tube? (a) +60º (b) 0º (c) 6º (d) –60º 99. If the specific rotation of (i) is –60.0º, what is the observed rotation of a sample made up of a mixture of 1 g of (i) and 0.5 g of (v) when dissolved in water (10 mL) and placed in a 10 cm cell? (a) 60º (b) 0º (c) 6º (d) –60º 100. If the specific rotation of i is –60.0º, what is the optical purity of a sample of made up of a mixture of 1 g of (i) and 0.5 g of (v) when dissolved in water (10 mL)?
(a) 50 per cent
(b) 33 per cent
(c) 100 per cent
(d) 66 per cent
101. Assign the absolute configuration to carbon atoms 2 and 4 in compound (ii).
(a) 2R, 4S
(b) 2S, 4S
(c) 2S, 4R
(d) 2R, 4R
102. If the melting point of pure iv is 152ºC, what is the melting point of pure (v)?
(a) –152ºC (c) lower than 152ºC
(b) 152ºC (d) higher than 152ºC
alkyl halides, alcohols and ethers
Matrix Type Match the reaction mechanism in Column I with their reaction conditions in Column II 103. Column I
Column II
OCH3 (a) OCH3
HI (excess)
(p) More than 4 moles of HI will be consumed
OCH3 OCH3 (b) OCH3 HI (excess)
(q) Product will react with Na
OCH3 OPh (c) OPh
HI (excess)
(r) Product formed contains 2° halide
OPh CH2–OH (d) CH–OH
HI (excess)
(s) CH3I is one of the product
CH2–OH 104. Column I S N 1 (a) S N 2 (b) (c) E1 (d) E2
Column II (p) 3° alkyl halides > 2° alkyl halides > 1° alkyl halides (q) 1° alkyl halides > 2° alkyl halides > 3° alkyl halides (r) High concentration of strong base (s) Favourable medium is polar protic solvent
105.
Column I (a) Walden inversion (b) Racemic mixture ’s (c) Alkene Bayer → reagent
Column II (p) Syn-addition (q) Anti-addition (r) S N 1 reaction
2 (d) Alkene Br →
(s) S N 2 reaction
106. Column I (reaction) Column II (comment on major product and intermediate) Me SOCl2 Ph (a) (p) Optically active compound OH D
Ph (b) Me (c)
OH HCl
SOCl2 Et3N
(q) Inversion of configuration
(r) Retention of configuration
Me Ph (d)
Me (i) NaH
(ii) CH3Br OH
(s) Optically inactive compound (t) Carbocation intermediate
4.53
4.54
chapter four 107. Column I Cl
Column II CN NaCN DMSO
(a)
(p) Carbocation intermediate is formed
(q) SN1
NO2
NO2 Cl
OH H2O
(b)
Cl (c)
(r) SN2
AlCo KOH / ∆ Br
HBr
(d)
CCl4 H
108. Column I
(s) Addition reaction (t) Elimination reaction Column II Me
Cl (a)
NaI Acetone
Me H (p) H
I H
Cl
Me
H
H (b) H
Me
NaI Acetone
(q) I
H Et
Me H (c)
Cl
H
OMe
Et Me
OMe
NaI Acetone
Me (d) Cl
H
NaI Acetone
(r) I
I (s)
Et
H (t) H
H
I Me Me
alkyl halides, alcohols and ethers 109. Column I
Column II
(a) NaOH + H3C
Cl
(b) NH3 + H3C
Cl Me
(c) NH3 +
S
HO H2N
⊕
Me
CH3 + NaCl
Me
H2N Cl
Cl (d)
(p) Rate of reaction increases in polar protic solvent
CH3 + HCl
(q) Rate of reaction increases in polar aprotic solvent
Me + SMe2 OMe
(r) SN2 mechanism
+ MeOH + 110. Column I (energy profile)
(s) SN1 mechanism (t) TS has positive charge [non-zwitter ion]
Column II (chain propagation of halogenation)
(a)
(p) Iodination
(b)
(q) Fluorination
(c)
(r) Chlorination
(d)
(s) Bromination
111. Column I (RDS of halogenation)
(a) R – H + F• ⎯⎯→ R• + H – F
Column II (energy profile)
(p)
4.55
4.56
chapter four
(b) R – H + Cl• ⎯⎯→ R• + H – Cl
(q)
(c) R – H + Br• ⎯⎯→ R• + H – Br
(r)
(d) R – H + I• ⎯⎯→ R• + H – I
(s)
112. Column I
Column II Ts
Cl H2O (a) OH
E
R (p)
OH
P Reaction co-ordinate
+
I (b)
NaCN OMSO
CN
E (q)
Int.
R
P Reaction co-ordinate
E
OH (c)
Conc.
(r)
R P
H2SO4 /∆ Reaction co-ordinate OH (d) +
Conc. H2SO4 / ∆ +
E
R (s) Reaction co-ordinate
alkyl halides, alcohols and ethers 113. Column I (compounds) (a)
Column II (rate of solvolsis)
(p) 0.07
(b) Cl
(q) 0.12
(c) Cl
(r) 2100
(d) Cl
(s) 130000
114. Column I (compound)
Column II (rate of reaction with NaI acetone)
(p) 0.02
Cl
(a) Me–Cl O
(b)
(c)
Cl
(q) 100000
Cl
(r) 200
(d) Cl
(s) 79
Integer Type 115. Minimum number of steps involved in conversion of Br
D OHC–CH–CH2–CH2–CH2–CHO
116. When (S)-2-chloropentane reacts with NaOH in 75 per cent EtOH and 25 per cent acetone follows rate law: Cl H Cl –5 –6 Rate = 2.35 × 10 .[OH] + 5.30 × 10 Then, calculate percentage of S N1 product when concentration of [OH] = 1.5 molar. If percentage of S N 1 product = X, then calculate value of Y if: Y= X – 5. 117. Identify total number of SN1 reactions Cl Cl (i)
NaCN (ii) H2O DMSO
4.57
4.58
chapter four Me NaOMe EtOH (iv) DMF
(iii) Cl
Cl
Cl Me
Me (v)
Me H OH NaSMe (vi) NaI DMA H OH Acetone Me
Cl Ph (vii) Ph
Ph
MeOH (viii)
OTs
Ph O Me Conc. (ix) Ph HI
Ph
O Me Conc. HI
118. Identify total number of ‘β’-elimination reactions Cl
Zn. dust Alco. (ii) ∆ KOH/∆ Cl
Cl (i) Me H (iii) H
Cl Cl
OH NaI Acetone/∆ (iv) Al2O3 ∆
Me Cl (v)
Cl NaNH 2 ∆ D
Cl (vii) H
H Me
(vi)
Cl
OH NaI (viii) Acetone
Aqueous KOH
Conc. H3PO4/∆
D
Cl
Mg/Dry ether
(ix) Cl
119. Calculate percentage of SN1 product if (R) -2-chloro butane on reaction with NaOH/H2O and acetone gives 98 per cent inverted product. 120. Calculate total number of alkene products when 2-chloro-2-cyclobutyl hexane react with alcoholic KOH and heat. 121. Calculate total number of α-H present in alkene formed when 2, 3-dimethyl butanol react with concentrated H2SO4/∆.
alkyl halides, alcohols and ethers
Answer Keys Level 1 1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
b
b
c
c
a
d
c
b
d
c
a
b
c
a
d
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
a
d
d
d
d
c
c
d
b
c
b
c
d
d
d
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
b
d
d
b
a
d
c
d
d
b
a
b
a
c
c
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
b
a
a
d
a
d
c
b
d
a
c
a
b
a
d
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
d
a
d
b
a
a
b
b
d
c
b
b
b
a
a
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
c
b
a
c
d
d
d
a
a
a
b
a
a
a
b
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
d
a
d
b
c
a
a
b
b
a
b
b
b
d
b
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
b
d
a
c
d
c
d
c
a
d
c
cd
a
d
c
121
122
123
124
125
126
127
128
129
130
d
b
d
a
b
b
c
b
bc
d
Level 2 1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
bd
a
a
a
d
ab
bcd
a
ac
acd
ad
abc
bcd
abc
bc
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
d
abc
ab
ac
a
abd
b
b
a
c
a
c
a
a
c
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
d
d
d
d
abd
cd
b
a
c
c
abd
b
c
c
d
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
d
b
a
c
c
d
d
a
c
a
b
d
d
a
b
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
a
a
a
bc
d
bc
acd
ab
abcd
abd
bc
ad
c
d
c
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
4.59
4.60
chapter four d
ab
a
c
a
d
b
c
a
c
c
a
91
92
93
94
95
96
97
98
99
100
101
102
c
c
c
a
d
a
b
a
d
c
ac
b
bcd
b
d
103(a) 103(b) 103(c) qs
pqrs
pqr
103(d) 104(a) 104(b) 104(c) 104(d) 105(a) 105(b) 105(c) 105(d) 106(a) 106(b) 106(c) 106(d) 107(a) 107(b) pqr
ps
qr
ps
pr
s
r
p
q
prt
pq
st
pr
r
pq
107(c) 107(d) 108(a) 108(b) 108(c) 108(d) 109(a) 109(b) 109(c) 109(d) 110(a) 110(b) 110(c) 110(d) 111(a) t
ps
ps
ps
r
s
qr
prt
qrt
pst
q
s
r
p
p
111(b) 111(c) 111(d) 112(a) 112(b) 112(c) 112(d) 113(a) 113(b) 113(c) 113(d) 114(a) 114(b) 114(c) 114(d) r
q
s
r
p
q
s
115
116
117
118
119
120
121
5
8.233
5
6
4
4
12
s
r
p
q
r
q
s
p
alkyl halides, alcohols and ethers
Workbook Exercises Exercise 1 Conversion
Reagents CHO
i
CH
ii
(B) H3O+
O
iii
(C) HgSO4/aq. H2SO4 CH3
viii
(A) BH3/THF, then NaOH, H2O2, H2O
(D) CH3I (E) Excess HBr
Br
Br
(F) CH3CH2I CH3
(G) Br2/CCl4 (H) NaOH
CH3
(I) H2/Pd iv v
(J) Br2/H2O CH3
(K) H2/Pd/CaCO3/Pb (L) HBr/UV light (M) NaNH2/NH3 (i)
vii
CH3
OH CH3 CH3
vi Br
(N) Na/NH3 (i)
4.61
4.62
chapter four
Exercise 2 Conversion
Reagents CH3 O
O CH3 i ii
O iii
CH
CH3 CH3
iv CN CH2
v vi CH3 CN
H3C F
vii
viii
(A) HgSO4, aq. H2SO4 (B) (i) NaNH2 then add MeI (ii) HgSO4, aq. H2SO4 (C) (i) NaNH2, then add MeI (ii) BH3, then H2O2, NaOH, H2O (D) (i) BH3, then H2O2, NaOH, H2O (ii) Na then MeI (E) (i) H2/Lindlar’s catalyst (ii) BH3, then H2O2, NaOH, H2O (iii) MeOH (F) (i) H2/Lindlar’s catalyst (ii) BH3, then H2O2, NaOH, H2O (iii) Na then MeI (G) (i) H2/Lindlar’s catalyst (ii) aq. H2SO4 (iii) MeOH (H) (i) H2/Lindlar’s catalyst (ii) aq. H2SO4 (iii) Na, then MeI (ii) Na, then MeI (I) (i) aq. H2SO4 (J) Na in NH3 (1) (K) H2/Lindlar’s catalyst (L) H2/Pd (M) HCN (ii) NaCH/DMSO (N) (i) H2/Pd (ii) NaCN/DMSO (O) (i) aq. H2SO4 (ii) NaCN/DMSO (P) (i) HBr, H2SO2 (Q) HF/Pyridine (ii) NaF/DMSO (R) (i) H2/Pd or Ni (ii) NaF/DMSO (S) (i) HBr, H2O2 (T) (i) HBr (dark, N2) (ii) NaF/EtOH (U) (i) HBr (dark, N2) (ii) NaF/DMSO (ii) H2S (V) (i) HBr H2O2 (W) (i) HBr, (dark, N2) (ii) H2S (X) H2S/EtOH (Y) (i) HBr (dark, N2) (ii) NaCN/DMSO
alkyl halides, alcohols and ethers
4.63
Exercise 3 There are 18 alkene isomers with the molecular formula C6H12, and they are all drawn (A-R) in the box at the bottom of this page. You are presented with five flasks (1 to 5), each one containing a single pure sample of one of these alkenes. In a very long and excruciating lab class one afternoon, you run two separate reactions on each sample (i) ozonolysis (O3 followered by Me2S) and (ii) bromination (Br2/CCl4). For the ozonolysis reactions, you analyse what kind of stereoisomers (if any) are formed in each reaction. The results of the two reactions for each flask are summarized below that flask. Using your knowledge of alkene reactions, identify each sample (1 to 5) as as ONE of the alkenes drawn below (A-R) by writing that letter in the small box below: Key 1
2
3
4
5
Number of unique ozonolysis (O3) products
One
One
One
Two
Two
Reaction with Br2 in CCl4 gives
Ach
Rac
Meso
Ach
Dia
Racemic mixture (Rac) Diastereoisomers (Dia) Achiral meso compound Achiral, non-meso compound (Ach)
IDENTITY OF SAMPLE Note: For one of the samples, there are two correct answers, but you only need to indicate one of them. A
G M
B
H
N
C
D
E
J
I
K
O
P
Q
F
L
R
4.64
chapter four
Exercise 4 Match alkanes with their products. Total Number of Mono-chloro Products
Total Number of Mono-chloro Fractions After Distillation
(A) 6
(a) 2
(B) 12
(b) 3
(iii)
(C) 14
(c) 4
(iv)
(D) 16
(d) 5
(E) 8
(e) 6
(F) 4
(f) 7
(G) 5
(g) 8
(H) 10
(h) 9
(I) 8
(i) 10
(J) 16
(j) 11
(K) 7
(k) 12
(L) 5
(l) 13
(M) 13
(m) 14
(N) 3
(n) 16
Alkanes (i) (ii)
(v)
(vi) Me Me
(vii)
Me (viii) Me
CH3 (ix)
H C Cl CH2 CH3 CH3
(x)
H C OMe CH2 CH3
alkyl halides, alcohols and ethers
Solution for Workbook Exercises Exercise 1
Conversion
Reagents A
CHO
CH
(B) H3O+
C
(C) HgSO4/aq. H2SO4
O CH3
E
M, D
Br
Br CH3
(D) CH3I (E) Excess HBr (F) CH3CH2I (G) Br2/CCl4 (H) NaOH (I) H2/Pd (J) Br2/H2O
CH3
(K) H2/Pd/CaCO3 (L) HBr/uv light (M) NaNH2/NH3 (l)
K CH3
I N
CH3
OH CH3 CH3
(A) BH3/THF then NaOH, H2O2, H2O
J Br
(N) Na/NH3 (l)
4.65
4.66
chapter four
Exercise 2
Conversion
Reagents
CH3 O
O CH3
1= K,D 2=B
O
3=H
CH
CH3 CH3
4=K CN CH2
5=P 6=Y CH3 CN 7=Q, U H3C
8=W
Br F
CH3
(A) HgSO4, aq. H2SO4 (B) (i) NaNH2 then add MeI. ( ii) HgSO4, aq. H2SO4 (C) (i) NaNH2 then add MeI. ( ii) BH3, then H2O2, NaOH, H2O (D) (i) BH3, then H2O2, NaOH, H2O (ii) Na then MeI (E) (i) H2 / Lindlar catalyst. (ii) BH3, then H2O2, NaOH, H2O (iii) MeOH (F) (i) H2 / Lindlar catalyst. (ii) BH3, then H2O2, NaOH, H2O (iii) Na then MeI (G) (i) H2 / Lindlar catalyst. (ii) aq. H2SO4 (iii) MeOH (H) (i) H2 / Lindlar catalyst. (ii) aq. H2SO4 (iii) Na then MeI (I) (i) aq. H2SO4 (ii) Na then MeI (J) Na in NH3 (l) (K) H2 / Lindlar catalyst. (L) H2 / Pd (M) HCN (N) (i) H2 / Pd. (ii) NaCN / DMSO (O) (i) aq. H2SO4 (ii) NaCN / DMSO (P) (i) HBr, H2O2 (ii) NaCN / DMSO (Q) HF / Pyridine (R) (i) H2 / Pd or Ni. (ii) NaF / DMSO (S) (i) HBr, H2O2 (ii) NaF / DMSO (T) (i) HBr (dark, N2) (ii) NaF / EtOH (U) (i) HBr (dark, N2) (ii) NaF / DMSO (V) (i) HBr, H2O2 (ii) H2S (W) (i) HBr (dark, N2) (ii) H2S (X) H2S / EtOH (Y) (i) HBr (dark, N2) (ii) NaCN / DMSO
alkyl halides, alcohols and ethers
4.67
Exercise 3 There are 18 alkene isomers with the molecular formula C6H12, and they are all drawn (A-R) in the box at the bottom of this page. You are presented with five flasks (1 to 5), each one containing a single pure sample of one of these alkenes. In a very long and excruciating lab class one afternoon, you run two separate reactions on each sample (i) ozonolysis (O3 followered by Me2S), and (ii) bromination (Br2/CCl4). For the ozonolysis reactions, you analyse what kind of stereoisomers (if any) are formed in each reaction. The results of the two reactions for each flask are summarized below that flask. Using your knowledge of alkene reactions, identify each sample (1 to 5) as ONE of the alkenes drawn below (A-R) by writing that letter in the small box below:
Note: For one of the samples, there are two correct answers, but you only need to indicate one of them. D A B C E F
G M
H
N
J
I
O
P
K
Q
L
R
4.68
chapter four
Exercise 4 Alkanes (i)
--A,c
(ii)
--E,d
(iii)
Total Number of Mono-chloro Products
Total Number of Monochloro Fractions After Distillation
(A) 6
(a) 2
(B) 12
(b) 3
(C) 14
(c) 4
(D) 16
(d) 5
(E) 8
(e) 6
(F) 4
(f) 7
(G) 5
(g) 8
(H) 10
(h) 9
(I) 8
(i) 10
(J) 16
(j) 11
(K) 7
(k) 12
(L) 5
(l) 13
(M) 13
(m) 14
(N) 2
(n) 16
--N,a
(iv)
--H,e
(v) --B,f
(vi) --C,g Me (vii)
Me --C,f
Me (viii)
--K,d Me
(ix)
CH3 H C Cl CH2
--L,d
CH3 CH3 (x) H C OMe CH2
CH3
--K,e
CHAPTER
5
Carbonyl Compounds and Acid Derivatives Question Bank Level 1
1. When phenyl ethanoate is alkylated with chloroethane/AlCl3, the para product is the major product. This is because (a) Alkylation usually occurs at the para position. (b) The -Cl group is a weakly deactivating and an ortho/para director. (c) The -OCOMe group is an activator and an ortho/para director. (d) The -Et group is weakly activating and an ortho/para director. 2. Terminal alkynes react with 9-borabicyclononane (9-BBN) and then aq. alkaline hydrogen peroxide to give aldehydes because (a) Acid catalysed electrophilic addition of water follows Markovnikov’s rule. (b) Acid catalysed electrophilic addition of water is anti-Markovnikov. (c) The radical addition is anti-Markovnikov. (d) Steric and electronic effects cause the boron to the terminal carbon. 3. In general, ketones are more reactive towards nucleophiles than esters because (a) The α-protons of a ketone are more acidic than those of an ester. (b) The alkyl group in a ketone is an electron donating group due to hyperconjugation. (c) Alkoxy (RO-) groups are sterically larger than the related alkyl group. (d) Alkoxy (RO-) groups are stronger electron donating than alkyl groups via resonance.
5.2
chapter five 4. When 2-methylcyclohexanone reacts with a base and is then treated with an electrophile such as methyl iodide the product depends on the reaction conditions, see below. At high temperature, the major product is the geminal dimethyl compound. This is because O–
O CH3I
O–
O Et3N heat
LDA 0ºC
O CH3I
(a) Alkyl groups are weak electron donors due to inductive effects and hyperconjugation. (b) The enolate formed at high temperature is more stable. (c) diisopropyl amide (LDA) is a much stronger base than Et3N. (d) Lithium diisopropyl amide (LDA) promotes an anti-Markovnikov type addition.
5. The reaction of a Grignard reagent with a carboxylic acid does not give a secondary alcohol. This is because (a) Grignard reagents only react with the aldehydes, ketones, esters and epoxides. (b) The carboxylic acid is too sterically hindered to react. (c) The carboxylic acid is not electrophilic enough to react. (d) The Grignard reagent is a base, so an acid–base reaction occurs. 6. When 1-phenylpropyne reacts with H2O/HgSO4/H2SO4, the major product is propiophenone shown below. This is because O
(a) Alkyl groups are weak electron donors due to inductive effects and hyperconjugation. (b) Carbonyl groups are electron withdrawing groups due to resonance. (c) Phenyl groups can stabilise positive charge by resonance. (d) The reaction is controlled by steric factors.
7. When methyl benzoate is nitrated with HNO3/H2SO4, the meta product is the major product. This is because (a) The -CO2CH3 group is a meta director. (b) The -OCH3 is a meta director. (c) The -NO2 group is deactivating and a meta director. (d) Nitration usually occurs at the meta position. 8. A chemist attempted to reduce the compound shown below with NaBH4, but could not isolate the desired product 4-hydroxybutanoic acid. This is because O O
HO H
carbonyl compounds and acid derivatives
(a) NaBH4 reduced both the carboxylic acid and the aldehyde. (b) NaBH4 is not reactive enough to reduce the carboxylic acid or the aldehyde. (c) An intermediate was formed that reacted to give a cyclic acetal. (d) An intermediate was formed that reacted to give a cyclic ester.
9. ?
(i) LDA then methyl iodide (ii) LiAlH4 then H3O+ (iii) TsOH, propanone, heat
O
(a)
O Identify reactant O O
(b)
(c) O
O
10. ?
O
O
Br
(b)
(i) CH3CO3H (ii) H+, H2O
C
HO
N+
(c)
CH2CH3 H3C C
Identify reactant
O
Br
11. ?
O
(i) NaCN (ii) H+, H2O, heat (iii) SOCl2, Et3N (iv) Benzl alcohol, pyridine
(a)
O
O (d)
OH
HO +
H
H
N
N+ N
(d)
CH2CH3 C CH3 C
OH
Identify reactant
CH3
CH3
(50:50 of these enantiomers) OH (a)
(b)
(c)
(d)
O 12. NaOEt, EtOH, heat
Identify reactant
O
O O
(a)
O
O (c)
O
(b)
O (d)
O
5.3
5.4
chapter five
13. ?
(i) KOH, heat
OH
(ii) H+, H2O
CH2CH3 Br
(a)
Br
OH
(b)
OH
(c)
(d)
OH
OH
(i) BH3 14. ?
Identify reactant
+
(ii) NaOH, H2O2
Identify reactant
(50:50 of these enantiomers) (a)
(b)
(c)
(d)
15. Appropriate reagent for the following conversion is O Br
Br
–
(a) NH2NH2; EtOH/OH (b) Red P + I2 (c) Zn–Hg/HCl (d) All of them
16. In the given reaction Me
O
Me–C–CHO +
–C–H
50% NaOH
A + B; A and B are
Me
–
(a) Me3C–CH2OH + Ph–COO
–
(b) Me3C–COO + Ph–CH2OH
Me O CH3 O (c) Me–CH–C–Me + Ph–CH2OH (d) Me–CH2–C–Me + Ph–CH–OH 17. Which of the following gives glyoxal as one of the product on ozonolysis (a)
(c) H3C=CH–CH=CH2
(b)
CH2 H2C=CH
(d) Both (a) and (c)
18. The correct statement is (a) chloral forms stable hydrate (b) methanal is more reactive than ethanal towards nucleophilic addition (c) protonated carbonyl group is more reactive towards KCN (d) all of them
carbonyl compounds and acid derivatives 19. In the given reaction sequence, the B is CHO
CH2–OH CH2–OH
–CH3
A
dry HCl
(i) H2N–NH2 (ii) KOH/C2H5OH (iii) H3O⊕
B
O –CH3
O (b)
(a) CH3
–CHO (d) none of these
(c)
CH3
CH3
20. The maximum reactive towards the nucleophilic attack is Cl
H3C (a)
H3C CH3 (c)
H3C (b) O
O
H3C OCH3 (d)
NH2 O
O
21. Match column I (reaction) with column II (name of the reaction) and select the correct answer using the codes given.
Column I
Column II
20% NaOH → NaOH (b) C6H5CHO + HCHO 20% →
(ii) Self-Cannizzaro reaction
(c) 2C6H5CHO
(iii) Cross Cannizzaro reaction
(a) 2C6H5CHO
(i) Benzoin condensation
→ KCN/(alc.)
3 COONa (d) C"6 H 5 CHO + (CH 3 CO)2 O CH → ∆
(iv) Perkin reaction
(b) a - ii, b - iii, c - i, d - iv (d) a - ii, b - iii, c - iv, d - i
(a) a - i, b - ii, c - iii, d - iv (c) a - i, b - iii, c - iv, d - ii
22. In the reaction
O CH3–C–CH3+
C2H5ONa Product C2H5OH ∆
the product is CH3 (a)
–C–
OH
CH3
(b) CH3–C–
(c) CH3–C–C HO OH
CH3
CH3
(d)
23. The product of the given reaction is (i) Ph3P CH3–CH–Cl (ii) BuLi CH3 (iii) O
CH3–C (a) CH3
OCH3 CH3 CH3
[X] OCH3 CH3 CH3
(b) CH3–CH CH3
OCH3 CH3 CH3
CH3 CH3
C
5.5
5.6
chapter five
(c) CH3–CH CH3
OCH3 CH3 CH3
OCH3 CH3 CH3
(d) CH2=C CH3
24. Which of the following gives positive Fehling’s solution test (a) Ph–CHO (b) CH3CHO (c) CCl3CHO (d) All of them 25. In the given reaction H3C O
(i) Conc. NaOH Product is (ii) H3O⊕
CH3–C–C–CHO CH3 CH3 (a) CH3–C–CHOH–CH2OH CH3
CH3 (b) CH3–C–CHOH–COOH CH3 H3C O
H3C O (c) CH3–C–C–COOH
(d) CH3–C–C–CH2OH CH3
CH3 26. In the given reaction, (P) will be O
(i) (CH3)2CuLi (ii) H3O⊕
(P)
CH3 (a) H3C–
CH3
(b) CH3–
OH
–CH3
O (c) H3C–
–CH3
(d) CH3
27. In the given reaction O
O (i) C2H5ONa/C2H5OH (ii) R
(R) would be (a) HCHO
CH3
(b) CH3CHO
CHO
(c) HCOOC2H5
(d) (COOC2H5)2
28. Aldehydes and ketones react with α-bromo esters and zinc in ether or benzene medium to yield (a) α-keto ester (b) β-hydroxy ester (c) γ-keto acids (d) β-keto ester 29. In the given reaction sequence, compound (B) is
(i) OH (ii) C6H5CHO/∆ O
NH2NH2/OH (A) (B) ∆
carbonyl compounds and acid derivatives
(a)
CH–C6H5
(b) CH–C6H5
(c)
–CH2–C6H5
(d) CH2–C6H5
30. In the given reaction sequence
(i) O3 (ii) Zn/H2O
(A) OH/Δ
(B)
compound (B) is (a)
CHO
(b)
–CHO (c)
–CHO (d)
CHO –OH
31. Two isomeric ketones, 3-pentanone and 2-pentanone can be distinguished by (a) I2/NaOH (b) NaHSO3 (c) NaCN/HCl (d) 2,4-DNP 32. Silver mirror test with Tollen’s reagent is given by
(a) C6H5CHO
(b) Ph–OH
(c) C6H5–CH2–C–CH2OH
(d) CH3CHO
O 33. Which of the following is a correct conversion? OH OH
O O
(a) Br (b) Br Br (c) N H
(i) Mg, ether (ii) HCOH HOH2C (iii) H3O⊕
(i) Mg, ether
–OC2H5
(ii) C2H5OH CH2OH (i) Mg, ether
O (i) Zn–Hg, HCl
(d)
(ii) HCOH (iii) H3O⊕
N H
H3C
Br
(ii) Mg, ether (iii) H3O⊕
34. For the given reaction, the product is 18
O
O
Cl
C
OOH
+ Cl (a) Cl–
O
Cl 18
Product Cl
–C–O–
O Cl (b) Cl– –C–O–
CH3
5.7
5.8
chapter five Cl –C–O–
Cl– (c)
O
Cl– –O–C– (d)
Cl
18
O
18
35. Which one of the following does not respond positive to iodoform test even on heating? O
Br
(a) CH3–C–CH2–C–OPh
(b) CH3–C–CH3
(c) CH3NO2
(d) Both (a) and (b)
Br
O
36. The rate of reduction of the following carbonyl compounds by NaBH4 C2H5 O
CH3 O (i)
H
(ii)
C2H5
CH3
C2H5
CH3 CH3 H3C O (iii)
O CH3
(iv)
H
O2N
CH3
(a) iv > i > ii > iii
(b) i > ii > iv > iii
(c) iii > ii > i > iv
(d) ii > i > iii > iv
18
37.
O –C–
CF3CO3H
A ; product (A) is 18
18
O
O
(a)
–CH
O
(b)
–
O O (c)
18
O
–C
(d) None of these
CHO 38.
Alc. KCN
A
(i) LiAlH4 , Et 2 O → Products (ii) H2 O
The number of possible stereoisomers in the product mixture is (a) 1 (b) 2 (c) 3 (d) 4 O 39.
O R
O
* OH A ; The product (A) is
CH3 O (a) O
O CH3 (b)
O*
O * O
(c) CH3
O
(d) CH3
O CH3
carbonyl compounds and acid derivatives 40. The incorrect statement amongest the following is (a) The order of reduction reaction by LiAlH4 and that of the reduction by NaBH4 each is two (b) Al–H bond is more ionic than B–H bond and hence LiAlH4 can produce larger concentration of hydride ion than that of NaBH4 (c) LiAlH4 cannot reduce –NO2 group (d) Inspite of very small rate constant of reduction of any carbonyl function other than aldehydes and ketones, the rate of reduction with LiAlH4 becomes appreciable due to large concentration of hydride ion 41. Which of the following ketones has the largest equilibrium constant for addition of water? O (a)
O
(b)
O
O
(c)
(d)
O 42. Ethyl acetoacetate react with CH3–C–H in the presence of base/∆ followed by acidic hydrolysis and subjected to heat, product formed is H3C H3C O O –C–OH –C–OH O (a) (b) O CH3
CH3 COOH
O
(c) O
–C–OH
(d) O CH3
43. Identify the product (C) of the given sequence of reaction Ph
COCl Ph
anhy. AlCl3
(A)
H2N–NH2
(B)
KOH/Δ (C) HOCH2CH2OH
Ph Ph (a)
–CH3
(b)
Ph (c)
–Ph Ph
(d)
–Ph Ph
Ph
44. Which of the following gives positive Fehling’s solution test
(a) HCOOH
(b) HOOC–CHO
HC–CH –CHO (d) O O
(c)
45. Which of the following geminal diol is most unstable? F3C (a) C F3C
OH OH
(b)
H3C H3C
C
OH OH
5.9
5.10
chapter five ClCH2 (c) C ClCH2
OH OH
Cl C (d) 3 C H
OH OH
46. In the given reactions, sequence O HCN H3C
A
H SO + NaNO2 (i) LiAlH4 B 2 4 C (ii) H2O
The compound C is O
O (a)
–NH2
H3C
(b) H3C NH2
O (c) H3C
(d)
O
H3C -
47. What will be the pH of an acetate-acetic acid solution when the ratio of [CH3CO2 ]/ [CH3CO2H] is 10? (A table of pKa data is given below.) Some useful pKa values (a) 5.76 CH3CO2H 4.76 (b) 4.76 H3PO4 2.2 (c) 3.76 H2PO|4 7.2 – (d) 1.76 HPO42 12.4 48. If the internal pH of a muscle cell is 6.8. Which one of the following statements about the – – – concentrations of PO43 , HPO42 , H2PO41 , and H3PO4 is true? (Hint: use the table of pKas given in the previous question.)
(a) The species with the highest concentration is H3PO4. – (b) The species with the highest concentration is H2PO41 . – (c) The species with the highest concentration is PO43 . – (d) The species with the highest concentration is HPO42 .
49. Choose the incorrect statement about the following acid/base reactions involving propyne and its anion propynide. pK a H3C
(i) H3C
C
CH + OH
(ii) H3C
C
CH + NH2
C
16
H2O CH NH3
25 34
H3C
C
C
H3C
C
C
+ H2O + NH3
(a) The equilibrium in equation (i) lies to the left. (b) The equilibrium in equation (ii) lies to the right. (c) In reaction (ii) ammonia, NH3, acts as a base. (d) Propyne, CH3C ≡ CH, is a stronger acid than ammonia, NH3.
carbonyl compounds and acid derivatives 50. Choose among the following reactions those that will give a racemic mixture of two enantiomers as the products. O (i)
(i) CH3Li (ii) H2O
OCH3 (iii)
O
(ii)
O H
(i) CH3Li (ii) H2O
(i) NaBH4 (ii) H2O
(a) i
(b) ii
(c) iii
(d) ii + iii
51. Choose the order that has the following carbonyl groups correctly arranged with respect to increasing reactivity with NaBH4. (i)
O
O
C
(ii) C
H3C
H
F3C
O (iii) C H3C
H
(a) i < iii < ii
(b) i < ii < iii
(c) ii < i < iii
increasing acidity
increasing acidity
increasing acidity
(d)
CH3 iii < i < ii increasing acidity
52. Which of the following is the correct order for hydrate formation of the given compounds? O O O O (i)
(ii)
(iii)
(iv)
O2N
Cl
HO
(a) i > ii > iii > iv
(b) iv > i > ii > iii
(c) iii > ii > i > iv
(d) iii > i > iv > ii
OH (i) O3 (i) dil. OH/∆ [Z] [Y] Δ (ii) Me2S (ii) (CH3)2 CuLi (iii) H2O In the above sequence, compoud [Z] is OH O O Me Me (d) (a) (b) (c) H2SO4
53.
[X]
Me OH PCC P1
O 54. P2
Me
(i) NaBH4 (ii) H⊕, Δ
P4
Final compound P4 is
Me
I2 P + P3 (Yellow ppt.) NaOH 2
HO
Me Me
5.11
5.12
chapter five O
(a)
⊕
(i) HO(CH2)2OH/HCl NaOEt P1 (ii) LiAlH4 H–C–OEt (iii) H3O⊕ O
55.
(a)
CH2 (b)
O CH2
O
O
O O
O
O (d)
O (c)
O (b)
∆
P2
P3 ; Compound P3 is
(c)
O
CHO (d)
CH3
56. Product “P” obtained by the reaction O OMe
PhMgBr (excess) (A) Et2O
Ph (a)
(B)
H⊕ heat
Product
OH
Ph Ph (b)
Ph (c)
Ph
Ph (d)
Ph
O
CN 57. CH2
H2O
+ Ph – C – H
NaOEt ∆
major products
NO2 NC
NC
NC
OEt
OH
(a) C = CH – Ph (b) (c) C=C C=C O2N O2N O2N Ph Ph
(d) None of these
58. Aldehydes and ketones having α-hydrogen convert into carbanion in the presence of base as follows O O – OH CH –C–R CH – C – R 3
2
This carbanion is stable because of (a) Presence of -I group (–CO–) (b) Delocalisation of negative charge by pi bond (c) Presence of +I group (i.e., R) on –CO– (d) Both (a) and (b) 59.
COOPh Br
(i) Zn/Et2O (ii) CH2O (iii) H3O+;
COOH (a)
OH
A, A is
COOH (b)
OH (c)
COOH OH (d)
COOH OH
carbonyl compounds and acid derivatives 60. Choose the reaction that would not be successful for the preparation of the following alcohol. OH (a)
(c)
(i) CH3MgBr (ii) NH4Cl, H2O
O
O
(b)
(i) CH3CH2MgBr
(d)
O
(i) CH3MgBr
O
(ii) NH4Cl, H2O
O
(i) CH3CH2MgBr (2 eq) (ii) NH4Cl, H2O
O
61. Choose the major product of the following reaction sequence. O
(i) CH3CH2Li (excess) (ii) NH4Cl, H2O
O
HO (a)
(b)
O
O
OH (c)
OH
(d)
O
OH
62. The compounds A, B and C in the reaction sequence
CH3 CH3
Ag dil. H2 SO 4 I2 O Alkali → A → B →C ∆ Hg +2
C
(ppt)
are given by the set
(a) Iodoform, ethylene, ethyl alcohol
(b) Iodoform, acetylene, acetaldehyde
(c) Iodoform, propyne, acetone
(d) Iodoform, 2-propanol, propanone CHO
OHC i) Conc. NaOH
63. Any one of the product formed is by
ii) H+, Δ CHO
COOH
HOOC
(a)
COOH
OHC CH2OH
CH2OH
CH2OH
CH2OH
(b)
HOOC
O CH2OH
COOH
(c)
O (d)
COOH
CH2OH
O O
5.13
5.14
chapter five 64. A compound “A” formula of C3H6Cl2 on reaction with alkali can give “B” of formula C3H6O or “C” of formula C3H4. “B” on oxidation gave a compound of the formula C3H6O2. “C” with dilute H2SO4 containing Hg2+ ion gave “D” of formula C3H6O, which with bromine and alkali gave the sodium salt of C2H4O2. Then “A” is
(a) CH3CH2CHCl2
(b) CH3CCl2CH3
(c) CH2ClCH2CH2Cl (d) CH3CHClCH2Cl
65. Identify compound [X] in the given reaction HgSO 4 P.C.C Me–C≡C–H 1% →[P1] ← compound [X] dil. H SO 2
O (a)
4
OH (b) OH (c) (d) O OH
66. What is the major product obtained from the following reaction O + one mole HO–CH2–CH2–OH HCl gas OH O–CH2–CH2–OH
(a) (c)
O
(b)
O
O–CH=CH2
(d)
67. Give the product from the following reaction sequence O Ethyleneglycol H⊕ OH O
HO (a)
H⊕ H2O
EtMgBr
Collin’s reagent
O
O
(b)
(d)
(c) H
OH
O
HO
68. Predict the major organic product from the following reaction H3C
O O
NaBH4
A LiAlH4
B
O OH (a) A
OH
O
(c) A
B
OH
OH
OH O
OH
O
OH
OH B
OH
OH
OH
OH O (b) A B OH
OH
OH
O
OH O (d) B A O
OH
carbonyl compounds and acid derivatives O
O
69.
Me dil. OH ∆
[X]
(i) H2N–NH2 (ii) KOH/C2H5OH
[Y]
(i) O3 (ii) H2O–Zn
[Z].
The product (Z) is O
O (a)
O
CHO (c) CHO
Me (b)
O O
(d) O
H
70. The final product (Y) of the following reaction sequence is O + HN
(i) CH3Br CH3 dil. H⊕ Y+Z X C2H5 (ii) H3O+ KOH
Z + Hinsberg reagent
(No dissolution/solid residue) Me
O
(a) –CHO (b)
O
(d)
C2H5
CH3
71. In the given reaction O
(c)
–N Et CH3
O 50% NaOH –C–H A + B (A and B are cross Cannizaro product);
H–C–H + Me– A and B are –
–CH2OH
(b) CH3OH + Me–
–COO
–
–COO
(d) CH3OH + Me–
–CH2OH
(a) HCOO + Me–
(c) HCOO + Me–
72. Choose the major product of the following reaction. O
O
CH3 (i) LiAlD4 ⊕
(ii) H3O D
O (a)
H N 73.
O
D
(b)
CH3CHO NH2 (1 Eq.)
D (c)
A
Sn+HCl
B. B is
H
H H (d)
O
D D
5.15
5.16
chapter five H (a)
C2H5
N
N
(b)
NH2
NH2
H (c)
CH3
N
N (d) NHC2H5
NHCH3
74. An organic compound A(C6H12O) neither decolourise bromine water nor changes the colour of acidic dichromate solution. A on heating with H2SO4 produces an alkene which on oxidative ozonolysis gives B(C6H10O3), which gives an yellow precipitate with NaOH/I2. The most probable structure of A is (a)
75. H H
OMe (b) HIO4.2H2O
A
OH
NaOH/∆
OH
(c)
B
(i) Me2CuLi (ii) H2O
OH
(d)
(C).
HO OH Identify “(C)” product O
O (b)
(a)
O
O H (c)
H (d)
H
Me 76. In the given reaction CH3–CH2–COOH
Br2/PBr3
(a) would be O
O
(a) CH3–CH2–C–Br (b) CH3–CH–C–OH NH2 O 77. H C 3
Ph O
18
NH3 (A) (alc.)
CH3
H2O/H⊕
O
(c) CH3–CH–COOH (d) CH3–CH–C–NH2 Br NH2
A (an acid) + B
CH3
where A and B are, respectively Ph O H C H3C 3 (a) and Me–C–OH (b) OH Me 18
H3C (c)
O OH
Ph 18 H3C and Me–C–OH (d) Me
O
18
OH O
18
OH
Ph
18
and Me–C–OH Me Ph
18
and Me–C–OH Me
carbonyl compounds and acid derivatives NH2
NH2
78. CH3–CH–COOH can be converted into CH3–CH–CH2OH by the use of
(a) H2/Pd
(b) LiAIH4
(c) NaBH4
(d) CH3MgBr
79. Arrange in increasing order of reactivity towards nucleophile O
O
O
O
H3C–C–NH2 (ii) CH3–C–Cl (iii) CH3–C–OAc (iv) H3C–C–OCH3 (i)
(a) ii > iv > i > iii (c) iii > ii > i > iv
(b) ii > iii > iv > i (d) iii > iv > ii > i
80. What is the name of the following compound? C2H5 NH O
(a) trans-N-ethyl-3-pentenamide (c) trans-N-ethyl-4-pentenamide
(b) trans-1-ethyl-3-pentenamide (d) trans-1-ethyl-4-pentenamide
81. What is the name of the following compound? CH2CN C H
H3C
CH2CH2CH3
(a) (R)-3-methylhexaneamine (c) (R)-3-methylhexanenitrile
(b) (S)-3-methylhexaneamine (d) (S)-3-methylhexanenitrile
82. What is the name of the following compound? H O
OH
(a) (R)-3-hydroxybutanal (c) (R)-3-hydroxybutanol
(b) (S)-3-hydroxybutanal (d) (S)-3-hydroxybutanol
83. What is not the name of the following compound? CH3 H3C
(a) acetone
(b) dimethyl ketone
C
O (c) 2-oxoketone
(d) propanone
84. Which of the following compound has the highest boiling point?
(a) CH3CH2CH3 (b) CH3CO2H
(c) CH3COCH3
(d) CH3CH2OH
5.17
5.18
chapter five 85. Valproic acid found clinical use as an anticonvulsant and mood-stabilizing drug that has proven useful in the treatment of epilepsy, bipolar disorder, and other problems. Choose the constitutional isomer(s) of valproic acid. H O
H
O
O
(i)
O
O
O
(ii)
O
(iii)
H
O
H
valproic acid
(a) i
(b) ii
(c) iii
(d) i and ii
86. What is the name of the following compound? O O O
(a) ethyl 4-oxopentanoate (c) ethyl 4-ketonepentanoate
(b) ethyl ester methyl ketone (d) ethyl 4-ketone pentyl ester
87. What is the structure of 2,4-hexanedione? O (a)
O
O (b) H
(c) O
O
O
O
(d) O
88. What is the name of the following compound? O CHO
(a) (R)-2-ketocyclohexane carbaldehyde
(b) (R)-2-aldehydecyclohexanone
(c) (S)-2-formylcyclohexanone
(d) (S)-2-aldehydecyclohexanone
89. If only one equivalent of NH3 (one mole of NH3 reacts with one mole of cyclohexyl chloride) was used, the reaction may not go to completion. Why? (a) NH3 is not a strong nucleophile. Therefore, more NH3 is needed.
(b) Cl is not a good leaving. Therefore, more NH3 is needed. (c) Cyclohexyl group presents large steric hindrance. Therefore, more NH3 is needed. (d) NH3 will be protonated by HCl as reaction proceeds. Therefore, the reaction will be incomplete.
90. What could be the best reagents for the following reaction? O
Reagents
NCH2CH3
carbonyl compounds and acid derivatives
(a) H2NEt and CH3CO2H
(b) H2NEt and HCl
(c) H2NEt and NaOH
(d) H2NEt and Na+–OCH3
91. What could be the product for the following reaction? OH
O
HCl
OH
(a)
Cl
Product
OH (b)
O
O
OH
Cl
Cl
O
(c) O
(d)
O
92. What is the order of increasing boiling points (from the lowest to highest) for the following compounds? O (i)
O
(ii) NH2
O
(iii) Cl
OH
(a) ii, i, iii (b) ii, iii, i (c) i, iii, ii (d) iii, i, ii (i) CH3CO3H (ii) CH3MgBr then H3O+
93.
product is OH
HO (a)
(b)
(c)
(d)
OH (i) BH3 94.
(ii) aq. NaOH/H2O2 (iii) PCC/CH2Cl2 O
(a)
H
(b) H
O
O
(i) Excess LiAlH4, then H3O+
O
OMe
(ii) Catalytic H+, ethanal, heat
O (a)
O
(b)
O
O (c)
(d)
OMe
(d)
O
O 95.
OH
(c)
OH
5.19
5.20
chapter five O
(i) 1, 3-butadiene, heat 96. ?
(ii) Hg(OAC)2, H2O (iii) NaBH4 (iv) PCC
(a)
97.
(b)
O
O
(a) O
O H N
(c) (d)
Aqueous NH3 O H2N (b)
O
NH2 O O
O H2N (c)
(d) H2N
OH O
98.
O Br
H3C
O–
(i) Mg, Ether (ii) Methyl ethanote, then H3O+
?
(excess) HO
OH (a)
OH (b)
(c)
(d) HO
(i) O3, then H2O2
99.
(ii) NaBH4 (iii) Catalytic H+ HO
(a)
?
O (b)
O
O (c)
HO
100.
(a)
O HO
(d) HO
(i) Br2/UV light (ii) Ph3P, then CH3CH2CH2CH2Li (iii) O
(b)
(c)
(d)
OH
carbonyl compounds and acid derivatives O
O (i) MgBr
101.
MgBr
O+
(ii) H3 (iii) PCC
(a)
(b)
102.
C
(a)
(c)
C
O
O
O
CH3
H
Br
C
C
H
H
H
H
C
C
Br
H
(c)
O
(i) Na, NH3 (ii) HBr
(d)
O
OH
product is Br
CH3
(b)
CH3
(d)
Br
O 103.
(i) Mg, Ether (ii) EtOH
Br
O
(iii) Catalytic H+, H2O H
OH OEt
(a) O
H
O OH (d) O
O (c)
104. CH3CO2H
H3C
OEt
(b) O
(i) SOCl2 (ii) 3-methylaniline (iii) LiAlH4, then H3O+ H3C
NH2
(a)
CH3
(b)
CH3
O (c) H3C
N H
NH2
OH (d)
H3C
NH
CH3
O
5.21
5.22
chapter five
Level 2 Single and Multiple-choice Type 1. The product is
O Conc. OH –C O H C=O
O
(b)
(a) O O O 2.
H3O⊕
Product
OH OH –C–COOH (d) O –C–CHO (c) O H O H
(i) O3 (A) dil. OH Products ∆ (ii) Me2S
In the above sequence the final products of the reaction is/are O O O CHO CHO (d) (a) (b) (c) O H 3.
F (i) H2N–NH2 Product (A) (ii) OH/ROH Zn–Hg Product (B) HCl NaBH4 Product (C)
Correct option is CH2OH
A = B = H3C– (a)
–CH2CH2F; C = F
(b) A = H3C – (c) C = HOCH2– (d) B = H3C – 4. (A)
–CH COOH OH
(i) Ph3P (ii) BuLi (iii) (B)
–CH=CH2; B = H3C –
–CH2CH2F
–CH2CH2F –CH2CH2F; C = HOCH2 –
– CH2CH3
CH–CH3
In the above reaction, (A) and (B) will respectively be
CHO CHO
carbonyl compounds and acid derivatives (a)
Cl and CH3CHO
(b) CH3CH2Cl and
(c)
Cl and HCHO CH3
(d) Cl
O and CH3CHO
5. Which of the following pairs will form the same product with phenyl hydrazine/H⊕? (a) CH2OH–CO–CH3 and CHO–CHOH–CH3 (b) Glucose and mannose (c) Glucose and fructose (d) Glucose and sucrose 6. Which is/are untrue statement(s)? (a) Protonation increases electrophilic nature of carbonyl group – – (b) CF3SO3 is a better leaving group than CH3SO3 (c) Benzyl carbonium ion is stabilised by resonance OH
(d) CCl3CH
OH
is unstable
7. Identify the product in the following reaction O
O
A+B
+ Br2 + KOH A and B are
O
⊕
C–OK
(a) CHBr3 (b)
⊕
O (c)
(d)
C–OK
O ⊕ C–OK
H Br
Br O
O
8. In the following reaction O
⊕ Br C H ONa (i)H3O⊕ 2 5 B A C2H5OH (ii) Soda lime/∆
Product A and B are
O OC2H5 (a)
O (b)
+ (CH3CO)2O
9.
CHO O Product (C) is/are
C
OC2H5
CH3COONa ∆
(c)
A
SOCl2
O (a)
CHO
(b) O
O
(d)
B
H2-Pd (BaSO4) Quinoline
C;
O (c)
O
(d)
–C–O–C–CH3 O
O
CHO
5.23
5.24
chapter five 10.
O + H2N–OH
⊕ H O, 260°C (polymer [X]). A H B 2 H2SO4
pH = 4.5
Correct statements about [X] are (a) the polymer is bakelite (b) the polymer is Nylon-6 (c) the polymer contains six carbon atoms in the repeating units (d) it is condensation polymer(s) CH3
Br
C=N
11.
OH H⊕
Product; The product formed is
NO2 NO2
Br
CH3
(a)
(b)
N
Br
NHCOCH3
CONHCH3
(c)
(d) None of these
O NO2
NO2
NO2
12. Select the correct reactions O (a) H3C
O C2H5
O
(i) C2H5ONa (ii) H⊕
H3C
O
C2H5 + C2H5OH
O CH3
(b)
(i) dil. NaOH H3C
CHO
(ii) ∆
O
O (c) Ph
H
H3C OH
CH3
(i) SeO2 (ii) Conc. NaOH
ONa
Ph O
O
(d) PhCHO + (CH3CH2CO)2O (i) CH3CH2COONa Ph (ii) H ⊕
OH CH3
13. Choose the alkene(s) that would give the two products of the following ozonolysis reaction. O O H (1) O3 H + alkene (2) Me2S H H O O (i)
(a) i
(ii) (b) ii
(iii) (c) ii and iii
(iv) (d) iii and iv
carbonyl compounds and acid derivatives 14. Choose the major product of the following reaction O OCH3
+
Pd base
CuLi
Major product?
2 O
O (a)
OCH3
(b)
OMe
O (c)
OCH3
(d)
O OCH3
15. Which of the following is correct for the final product of the given sequence of reaction MgBr CH2 – OH HIO (i) (i) PCC 4 P1 P2 P (Final product) (ii) CH3MgBr 3 CH2 – OH (ii) H2O (iii) H2O
(a) Compound P3 on oxidation with (CrO3 + H2SO4) gives a compound which gives 2, 4 DNP test (b) Compound P3 on reaction with I2 + NaOH gives yellow ppt (c) Compound P3 on reaction with cerric ammonium nitrate gives red colouration (d) Compound P3 on reaction with MnO2 gives carboxylic acid
16. Identify correct method of preparation of acetaldehyde from reaction of cyanide
(a) Me – C ≡ N
(i) DIBAL (ii) H3O+
(c) Me – C ≡ N
(i) Conc. H2SO4 (ii) dill. NaOH
(b) Me – C ≡ N
(i) SnCl2 + HCl (ii) H3O+
(d) Me – C ≡ N
(i) Pd/BaSo4 / H2 (ii) H3O⊕
17. Identify compounds that give iodoform test O
(a) (b) Me – C – OPh
O
OH
(c)
O (d) O
18. Identify compounds which give PPT with Tollen’s reagent (a) ⊕ ClNH3 – NH
OH
NO2
(c) Me – C ≡ C – H
NO2
(b) O
(d)
O Me – C – H
5.25
5.26
chapter five I 19. H – C ≡ C – H l eq. NaNH2 P1
P2
1% HgSO4 dil. H2SO4
P3
Identify the correct statement for the above reaction sequence?
(a) P3 – Product gives +ve iodoform test
(b) P2 – Product on reaction with HB(Sia)2 and H2O2/OH gives
2 3 2 6 (c) P3 – Product → X (ii) → NaOH/H2 O 2
(d) P3 – Product gives Tollen’s test
O –CH2–C–H
CH = PPH
20.
–O–O–H
H⊕
Products is/are O
O (a)
OH
(i) B H -THF
O (b) H
H C=O H (d) C=O
O–H (c)
H O
O
21. Ph – C – CH3 + CH2 – C – O – C2H5
NaNH2
Br O O (a) Ph–C–CH2–CH2–C–NH2
A
KOH/H2O B ; Products A and B are H+/∆ O
O (b) Ph–C–CH–C–OC2H5 CH3
O
O (c) Ph–CH2–C–CH3
(d) Ph–CH–C–H
CH3 22.
dil. H2SO4
O
P1 + P2
P1 and P2 products are identified by
(a) Tollen’s reagent O
23. Benzene
(b) Iodoform test (c) Br2 + H2O test
Et–C–Cl NH2–NH2/OH Cl /hν ; Regent “R” is P1 P3 P2 2 ∆ AlCl3 Aq. NaOH R
(d) 1% alkaline KMnO4
(a) MnO2/∆
(b) P.C.C.
P4 (c) Br2 + H2O
(d) LAH
carbonyl compounds and acid derivatives 24. Among the following reactions identify lactonisation reactions O O (1) CrO3.H2O (a) Me–C–H (2) EtOH/H⊕ O
OH
H⊕/∆
P
C–H
(b)
(i) Conc. NaOH (ii) H⊕/∆
C–H O
P
COOH
(c) C–OH
P
∆
(d) COOH
O 25. The compound which gives lactone on heating or in the presence of Conc. H⊕ medium OH (a)
COOH
COOH (d)
COOH (c)
(b) OH
OH
COOH COOH
26. The products Y and X are CH3–CH2COOH
Br2 Red P
NH3 [X] (alc.) O
CH3 (a)
C
CH2–NH2
H⊕ [Y] ∆ NH
(b) CH3– NH
–CH3 O
O O (c) C2H5–C–NH2 O 2MeO
O
(d)
CH3–CH–NH2 COOH
O CHO
OMe +
27.
(i) 4. eq. NaOMe /∆ (ii) NaOH /∆
Identify product
CHO COOH COOH
O
O (a)
(b) O
O
HOOC COOH
O (c) HOOC
COOH
COOH (d)
O
O HOOC
O
5.27
5.28
chapter five O
H3C CHO
28.
+ H2C
(i) NaOMe /∆ Identify product CH3
H3C O
O
O (a)
(b)
(c)
(d) H3C
CH3
CH3
Cl HC
O
29.
NaOD / D2O Dioxane
S
Identify product
CH2 O
(a)
CH2 O
(b)
S
(c)
(d)
CH2 O
D
CH3 CH2
30. H3C
KH 18-Crown-6 / THF
Identify product
CH2 HO CH3
(a)
CH3 (b)
H3C
H3C O OH
HO (c)
(d) OH
D
O
carbonyl compounds and acid derivatives OH
Conc. H2SO4 Identify product
31. OH
CH3 (a)
(b)
O
O CH3 (d)
(c) H3C
O
O
CH3
32. H C 3
Conc. H2SO4
Identify product
O CH3
(a)
CH3
(b) O
CH3
O
CH3
(c)
CH3
H3C
(d)
O
H3C
H3C
CH3
O
CH3 CH3
O
33.
Conc. H2SO4
Identify product
CH3 H3C
CH3
(a) H3C
CH3
CH3
(b) CH3
H3C
CH3
H3C
CH3 CH3
CH3
CH3
(d)
(c) H3C
CH3
5.29
5.30
chapter five CH3 Ph
CH3
34.
H2C
Ph
P
Ph
Identify product
RLi /∆ O
O
CH3 CH3
(a)
CH3
O
O
CH3
(b)
O
CH2
CH3
CH3 CH3
(c)
CH3
(d)
H2C
H2C
(i) CH2N2 (ii) NaH
35.
(iii) MeI
Identify product
O
(b)
(a) MeO
OMe
OMe H3C
(c)
(d)
MeO O
36. H3C
H3C
O
(i) MeMgCl (ii) HClO4 (aq.) (iii) NaOH (aq.) CH3
Identify product
OMe
carbonyl compounds and acid derivatives OH
OH (a)
(b)
OH
OH
HO
(c)
(d) H3C
OH
O
AcO
CH3
H3C
O
Aq. NaOH /∆
O
37.
CH3
Identify product
CH3 CH3
H3C
O (a)
O (b)
H3C
O
(c) H3C
CH3 O Ac2O
38. H3C
Identify product
CH3
(a)
OH
CH3
(b) CH3
CH3
CH3
OAc
OAc
(c)
(d) CH3 CH3
CH3
O OH NaOH
39. H C 3 O 2N
Identify product
(d)
5.31
5.32
chapter five COOH
O
COOH
COOH
O
(a) H3C
(b)
(c)
(d)
H3C
COOH NO2
O2N
OH
40.
(a)
NO2
NO2
Conc. H2SO4 /∆ Identify product
(b)
(d)
(c)
O
41.
Conc. H2SO4 /∆
Identify product
OH (a)
O
(b)
O
(c)
(d)
HO Conc. H2SO4 /∆
42.
Identify major product
OH O
O (a) O
(b)
H
(c)
H
OH Conc. H2SO4 /∆
43. OH
Identify major product
(d)
carbonyl compounds and acid derivatives
(a)
O
(b)
O
OH
(c)
(d) H3C
Conc. H2SO4 /∆
44. O
Identify product
OH (a)
CH3
OH
(b) H3C
OH
OH
HO
CH3
(c)
(d) OH
CH3
H3C
O Conc. H2SO4 /∆
45.
Identify product
OH (a)
O (b)
Conc. H2SO4 EtOH
46. O (a)
OEt OH
47.
(c) O
Conc. HCl
O
O
Identify product
(b) O
(d)
(c)
(d) EtO
Identify product
HO
5.33
5.34
chapter five OH
(a)
OH
O
(b)
(c)
Cl
Cl
(d)
Cl OH
48.
Conc. H2SO4 /∆
Identify product
O
(a)
OH
(b) O
O OH
(d) O
(c)
O O OH 49. H3C
(a)
C
C
Dil. H2SO4
CH2
HO
OH CH2 C
C
CH2
O
(b)
(a)
(c)
(d)
O
Conc. H2SO4 /∆
50.
Identify product
Identify product
(b) HO
(c)
(d)
O O
51.
COOH
Product is?
O O
O HO
HO (a)
O O
O HO (c)
(b)
O
(d) O
O
COOH
carbonyl compounds and acid derivatives
Comprehension Type Passage 1 If we take an alcohol solution of an aldehyde (or ketone) and pass into it a small amount of gaseous HCl the hemiacetal forms, and hemiacetal reacts with a second molar equivalent of the alcohol to produce an acetal (or ketal). R H
R C = O + R'OH HCl(g) H
OH
C
OR'
R'OH R HCl(g) H
OR'
C
+ H2O
OR'
All the steps in the formation of an acetal from an aldehyde (or ketone) are reversible. With excess of alcohol, equilibrium favours forward (acetal formation) direction. Although acetals are hydrolysed to aldehydes and ketones in aqueous acid, they are stable in basic solution. Because of this property, it is a convenient method for protecting aldehyde and ketone from a series reaching in basic solution. R
H
HO – CH2
C=O+
R
HCl(g) –H2O
HO – CH2
C
H
O – CH2
OH H2O
O – CH2
No reaction
Similarily, thioacetal (ketal) formation takes place. R
C=O+
R'
O
C
52.
HS – CH2 HS – CH2
O OC2H5
HOCH2CH2OH HCl(g)
BF3 or HCl(g)
R R'
CH3MgBr (excess)
The final product of the reaction is CH3 OH CH3
OH (a) H3C O (c)
CH2
C
S – CH2 H⊕/H2O
HO
(b) O
OH CH3
(d)
O
HS(CH2)2.SH BF3
Raney Ni H2
CH3 O
X + Y + NiS ↓
Correct statement for the given reaction is (a) X and Y are structural isomers (b) both X and Y gives only one monochlorinated product (c) X on oxidative ozonolysis gives gluteric acid (d) X and Y on reaction with H2N – OH gives oxime
Product
C2H5 C2H5
O
CH3 53.
S – CH2
C
5.35
5.36
chapter five O 54. H–C–
O –CH2–C–
HO(CH2)2OH HCl (g)
H2N–NH2
HOCH2CH2OH KOH
H3O⊕
[Y]
The product (Y) is (a) H3C–
–CH2–CH2–
H3C– (c)
–CH2
C=O
O (b) H–C–
–CH2–CH2–
HOCH2 –
–CH2
(d)
C=O
Passage 2 In organic chemistry various reactions take palce by rearrangements. These rearrangements can be classified on the basis of migratory group and its nature. One of the well-known rearrangement is the formation of N-substituted amides by rearrangement of aldoximes or ketoximes. This is known as Beckmann rearrangement. It is catalysed by various acidic reagents. The mechanism of this reaction is given as ⊕
R R'
C=N
H⊕ R R' OH
C=N
⊕
⊕
R'–C=N–R
H2O
OH2 R'–C=N–R
OH R'–C=N–R
OH2 O R'–C–NHR
CH3 OH C=N H⊕ Product; The product formed is
55. Br
CH3 (a)
N O
NHCOCH3 (b)
Br
56.
CONHCH3 (c)
Br
(d) none of these Br
H C=N CH=CH OH P O Product; The final product is 2 5
(a)
(c)
CH=CH–CN
(b)
CH=CH–CH2NH2
(d)
OH CH=CH–N=C–H
N
carbonyl compounds and acid derivatives 6 H5 SO 2 Cl 2 O/H 57. (CH3)(C2H5)C=NOH C → (A) H → CH3NH2 + C2H5COOH
⊕
The formation of final product suggest the migration of
(a) –CH3 group
(b) –C2H5 group
(c) C6H5–SO2–group
(d) cannot predicated without structure
Passage 3 Aldehydes and ketones show nucleophilic addition reactions. The α-hydrogens in aldehydes and ketones are acidic. Therefore, aldehydes and ketones having at least one α-H undergo aldol condensation in the presence of a base such as NaOH. Aldehydes having no α-hydrogen undergo Cannizzaro reaction in the presence of concentrated alkali. The carbonyl group of aldehydes and ketones can be reduced to methylene group by Clemmensen or Wolf Kishner reduction. Aldehydes are easily oxidised to carboxylic acids by Tollen’s reagent and Fehling’s solution. Functional derivatives of carboxylic acids undergo nucleophilic acyl substitution with nucleophiles. 58. In the reaction given hereunder, correct statement (s) about A and B are O
R O+ H
H2N
⊕
NH
dil. H A –H2O B
H2N
(i) A is optically active and dextrorotatory
(ii) A is racemic mixture and optically inactive R
(iii) B is
R N
H
NH
O
(a) i and iii
(iv) B is
H
N NH
O NH2
NH2 (b) ii and iv
(c) ii and iii
(d) i and iv
59. To convert CH2=CH–CH2CHO to CH2=CH–CH2COOH, the best reagent will be
(a) KMnO4 (b) P.C.C. (c) [Ag(NH3)2]OH (d) HIO4
60. The reactivity order of the following toward nucleophilic substitution will be O O O O O (i) (ii) (iii) (iv) R–C–NH2 R–C–OR' R–C–Cl R–C–O–C–R
(a) i > iii > iv > ii
(b) ii > iii > i > iv
(c) iii > iv > i > ii
(d) iii > i > iv > ii
5.37
5.38
chapter five Passage 4 Identify the missing products in the following sequence of reactions. O
(i) aq. NaOH (ii)
O
(A)
H⊕
HCCl3 NaOH
(B)
PhNH2
(C) + (D)
61. Which statements about compound A are correct? (i) Compound A is used in the formation of phenolphthalein (ii) Compound A is used in the formation of aspirin (iii) Compound A gives colour with FeCl3
(a) i and iii
(b) i and ii
(c) ii and iii
(d) i, ii and iii
62. Compound B will be OH (a)
O CHO
(b)
OH
H O
OH
O (c)
O (d)
CHCl2
H 63. Compounds C and D are
(a) Identical
(b) Geometrical isomers
(c) Functional isomers
(d) Optical isomers
Passage 5 Given hereunder is the mechanism of Beckmann rearrangement.
CH3
C=N
H⊕ C=N (ii) OH (i) CH3 ⊕O–H H
CH3–C=N–
(iv)
⊕
H2O (iii)
CH3–C=N–
O CH3–C=NH–Ph
OH 64. Rate-determing step in Beckmann rearrangement is
(a) i
(b) ii
(c) iii
(d) iv
CH 65. 3 C=N Ph
OH On treatment with H2SO4 followed by hydrolysis in acidic medium, the above compound gives
(a) CH3–CO2H, Ph–NH2
(b) Ph–CO2H + CH3–CO2H
(c) Ph–CH2–NH2 + Ph–CO2H
(d) CH3–NH2, Ph–CO2H
carbonyl compounds and acid derivatives
66.
C=N
OH PCl 5 ∆
(A); Product (A) of the reaction is
CH3 O (a)
C–NH–
O
(b)
–C–NH–
CH3 O –C–NH–
(c) CH3–
–CH3
(d)
–CH3
O CH3–
–C–NH–
Passage 6 Ethanal is heated with a base in two separate testtubes. In one testtube nothing except the two mentioned reactants were present. In another testtube, malonic ester, CH2(COOR)2 was also added. The final products of both testtubes add easily 1, 3-butadiene molecule. The product obtained in the first test tube can be converted into second product identical in all respects with that obtained in the second testtube. 67. The respective reaction involved in the two testtubes are
(a) Aldol condensation and Cannizaro reaction
(b) Aldol condensation and Perkin reaction
(c) Aldol condensation and Knoevenagel reaction
(d) Aldol reaction and Claisen condensation
68. Which feature is common in the products of both reactions?
(a) presence of an acidic group
(b) presence of an aldehydic group
(c) presence of α, β unsaturation
(d) presence of a ketonic group
69. What would have been the final product when ethanal of the first testtube is replaced by propanal?
(a) CH3CH2CH=CHCH2CHO
(b)
(c)
(d)
CH3 CH3CH2CH=CCHO CH3 CH3CH2C=CH–CHO CH3 CH3CH=CH–CHCHO
5.39
5.40
chapter five Passage 7 Aldehydes and ketones react with phosphorous ylides to yield alkenes and triphenylphosphine oxide. (An ylide is a neutral molecule having a negative carbon adjacent to appositive heteroatom). Phosphorous ylides are also called phosphoranes. R R'
⊕
C=O + (C6H5)3P–C Phosphorous ylide or phosphorane
R R" + Ph3P=O C=C R' R"' Alkene– [(E) and (Z) isomers]
R" R"'
Through reaction, known as the Witting reaction, phosphorus ylides are easily prepared from triphenylphosphine and alkyl halides. Their preparation involves two reactions: CH3
⊕
(C6H5)3P–CH
Reaction 1: Ph3P + CH3 – CH–X C2H5 Reaction 2:
⊕ (C6H5)3P +
CH3 C–H + : Base (B) C2H5
X
C2H5
⊕
Ph3P – C :
CH3
+H–B C2H5
Specific example: Ph3P + CH3Br
C6H6
[Ph3P –CH3] Br [Methyl triphenyl phosphorium bromide]
⊕
⊕
[Ph3P–CH3]Br + C6H5Li
Ph3P –CH2C6H6 + Li Br ylide
Mechanism of Witting reaction R' R" R–C=O + : C–R"' PPh3
R' R"
R' R"
R–C–C–R"'
R–C–C–R"'
O⊕PPh 3
Betaine [may not be formed]
R' C=C
O– PPh3 Oxophosphetane
R
R" + O = PPh3 R"'
(Alkene + diastreomer)
The mechanism suggested that the ylide, acting as a carbonion, attacks the carbonyl carbons of the aldehydes or ketone to form an unstable intermediate with separated change called a betaine. In the next step, betaine forms oxaphosphetane, which spontaneously loses triphenylphosphine oxide to become an alkene. 70. H CO– 3
O –C–CH3 + H3C–O–CH=PPh3
A
H3O⊕ H2O
Product (B)
In the given sequence of reaction, the product (B) is (a) H3CO–
O –C–CHO
(b)
H3CO–
CH3 –C=CH2
carbonyl compounds and acid derivatives H3CO– (c)
–C=O CH3
CH3 (d) HO– –CH–CHO
71. Which of the following cannot be used in the preparation of ylide?
(a) CH3CH2Br H5C2
72.
(b) (CH3)3C–I (c)
Ph C=PPh3 C=O + H5C2
CH3–CH–Br CH3
(d) Both (b) and (c)
Alkene + Ph3P = O (X)
In the given reaction, the correct statement for alkene (X) is
(a) X on reaction with Br2/CCl4 forms an optically inactive mixture
(b) X on reaction with alk. KMnO4 forms an optically inactive mixture
(c) X on reaction with alk. KMnO4 forms an optically active mixture
(d) Both (a) and (b)
Passage 8 Active methylene compounds are of great importance in synthetic chemistry. When –CH2 (methylene) group is flanked between two electron withdrawing groups, then its hydrogen becomes acidic and can be replaced easily. The acidity of methylene hydrogen depends upon the strength of electron withdrawing group. Acetoacetic ester, malonic ester, etc. are the examples of active methylene compound. In synthetic application acidic hydrogen is trapped by a strong base to get resonance stabilised anion which reacts accordingly to give the desired product.
H2C
73. CH3COCH2COOEt
COOEt OEt COOEt
COOEt COOEt Resonance stabilised CH
(i) dil. HCl (i) NaOEt A Products; Products are (ii) Heat (ii) CH3CH2Br not in excess
(a) CH3COCH3 + CO2 + EtOH
(b) 2 mol of CH3COCH2CH2CH3 + CO2
(c) CH3COCH2CH2CH3 + 2EtOH
(d) CH3COCH2CH2CH3 + EtOH + CO2
74. Which one of the following is most effective as an active methylene compound? O (a)
O
O (b) CH3COCH2COOEt (c)
(d) O
O
O
5.41
5.42
chapter five O
O
C–OC2H5 Base (i) H3O⊕ A Product C–OC2H5 ∆ (ii) ∆ O
75. Ph–CH + CH2
The final product is
O
(a) Ph–COOH
(b) Ph–Ph–C–CH=CH–COOH
(c) Ph–CH=CH–COOH
(d) Ph–CH=CH–CHO
Passage 9 O3 Zn/H2O
Compound A (C11H22)
B (C6H12O) + C (C5H10O)
[O]
LiAlH4
NaOCl
E (C6H14O)
CHCl3 + sodium salt of compound (D)
H⊕/∆
G (C2H4O) + H (C4H8O) NaOI
O3 Zn/H2O
F (C6H12)
+ve Test
76. D(C5H12O2)
SOCl2
⊕
x CH2=N=N y; product y is H2O/Ag2O
OH
(a) O (c)
O
O
(d)
OH
OH
(b)
NH2
77. Compound A is (a)
(b)
(c)
(d)
78.
Br
PH3P Bu+O–K+
W + H(C4H8O)
T; Product T is
(a)
(b)
(c)
(d)
D (C5H10O2)
carbonyl compounds and acid derivatives Passage 10 MeMgBr Na
(evolves H2 gas)
A(C11H16O) optically active
gives of colourless gas
Conc. H2SO4 B (C11H14) HBr ∆ (No stereoisomerism
C(C11H15Br) (Resolvable)
is exhibited) O3 ZnH2O F + E (C3H6O) (C8H8O)
H–Br peroxide
D(Isomer of C)
O
Cl C6H6 AlCl3 (anhydrous)
NaOH/I2 Give Yellow ppt 79. Compound (C) is Br
(a)
Mg–Hg H2O
O CH3 –C–C–CH3
(a)
O
CH3 (c) CH 3 Br
(b)
CH3
80. Compound (E)
H3C
(b)
(a)
(c)
O
–
CH3
H2CrO4 NaOI . Compound (S) and (T) respec(R) (S) + (T) Acetone (aq.) Yellow ppt.
+
C–ONa + CHI3
CH3 CH3
O CH3 –O–C–C–CH3
(d) CH3 – O – C – C – Ph
CH3
CH3
O Ph
(c) CH3–C–O–C–Ph
tively are
Br CH 3 (d)
(i) H⊕ (Y); compound (Y) is O (ii) F3C–C–OOH
(X)
Ph
81. Compound (A)
H3C
(b)
CH3 O – + C – ONa + CHI3 CH3 O
O – + C – ONa + AgI (d)
–
+
CH2–CH–C–ONa + CHI3 CH3
5.43
5.44
chapter five
Matrix Type 82. Match the reactions in column I with their reagents in column II.
Column I
Column II
(a) CH3–CH2=CH–CHO → CH3CH=CHCOOH
(p) LiAIH4
(b) CH3–CH=CH–CHO → CH3CH=CH–CH2OH
(q) NaBH4
(c) Ph–CH=CH–CHO → Ph–CH2–CH2–CHO
(r) Pd–C/H2
(d) CH2=CH–CH2CHO → CH2=CH–CH2CH2OH
(s) Ag(NH3)2⊕
83. Match the columns. Column I Column II (In the given sequence) O (a) (p) Formation of six memNaNO LiAIH4 HCN (A) (B) HCl 2 (C) ber ring takes place traces of KOH O
(b)
(c)
(d)
NH2OH
(A)
O
H⊕ O
CH3–C–CH2–CH2–CH2–C–H Ph H{ CH3 OH OH
(B)
(q) Final product is ketone
HO|
(A)
(r) Final product formed will give positive Tollen’s test
(A) (s) Final product formed will react with 2,4-DNP. (2, 4-di-nitrophenyl hydrazine)
84. Match the chemical compounds in Column I with the reagents used to test them in Column II.
Column I
Column II
(a) Ethanol
(p) [Ag(NH3)2]OH
(b) Glucose
(q) Fehling’s solution
(c) Glyoxal
(r) H2N
(d) Acetone
(s) I2/NaOH
⊕
Ph–NHSOOH Ph–NHSOOH SO3H
C
85. Match the columns. Column I (Reaction) Column II (Reducing reagent) O O A (a) –CH2C–OPh HO– –CH2C–OPh (p) Zn + Hg/HCl O
(b) O
–CH2–CH–Ph B Br
HO–
–CH2CH2Ph (q) LiAIH4
carbonyl compounds and acid derivatives C
(c) O
–CH=CH–Ph
(d) O
–CH2–C–Ph D
–CH2CH2Ph (r) NaBH4
HO–
–CH2CH2Ph
O
(s) Red P + HI (t) Ni/H2
86. Match the columns.
Column I
Column II Br
(a) PCC (Pyridiniumchlorochromate)
(p)
(b) NBS (N-Bromosuccinimide)
(q) MeC ≡ CMe —→ OH
Me H
C=C
OH
OH
(c) AlPO4
(r)
(d) Li/Liquid NH3
(s) CH3COOH —→ CH2 = C = O
87. Match column I with column II.
Column I
Column II
O (a) Me Me
(p) 2, 4-DNP test
O (b) OH H
(q) Tollen’s reagent test
(c) Cl–
O –C–H
(r) I2 + NaOH (Iodoform test)
(s) Fehling’s solution test
O (d)
88. Match column I with column II.
Column I (conversion)
(a)
(b)
Column II (reagents)
O
O
O
(p) HCN; H2/Ni; HNO2 (q) CH2N2
H Me O
5.45
5.46
chapter five
O
O
(c)
(r) m-CPBA (Meta-chloroperbenzoic acid)
O
(d)
CH2 (s)
O
–P
CH2
89. Match Column I with Column II.
Column I
Column II
(a) Aldol condensation
(p) Hydride ion transfer
(b) Cannizzaro reaction
(q) Zinc enolate
(c) Reformatsky reaction
(r) CN as catalyst
(d) Benzoin condensation
(s) Enolate ion
90. Match the coloumns.
Column I CN CN CN CN
(a)
H3O⊕ ∆
Product
Column II (p) Anhydride
O MCPBA
(b)
Product
(q) Carboxylic acid
O | –NO2 OH (c) Product (r) Alkene { H Ph (s) Optical active compound O (t) Ester 91. Match the columns. Column I (compound) (a)
–C
O (b) CH3–C–
O H
O (c) CH3–C–H (d) H3C
O
CH3
Column II (Tests) (p) 2, 4-DNP test
(q) Yellow ppt. with NaOH + I2
(r) Red ppt. with Fehling’s solution (s) Silver mirror with Tollen’s reagent
carbonyl compounds and acid derivatives 92. Match the columns.
Column I (Reagents)
Column II
(a) Tollen’s reagent give white ppt. with
(p) Me –CH=CH–Me
(b) Br2 + H2O test given by
(q) Me–C≡C–H
(c) Product of reaction of acetylene with 1% (r) Cl N H 3 − NH 2
⊕
HgSO4 and dil. H2SO4
O
(d) Pd/H2 reacts with
(s) Me–C–H O
(r) Me–C–Me 93. Match column I with column II.
Column I
(a) CH3CHO + CH3CH2CHO
(b) PhCHO + CH3–C–CH3
dil. OH ∆
Column II (p) CH3–CH2CH=CH–CHO
O
(c) PhCHO + HCHO
(d)
OH ∆
(q) CH3–C=CH–CH3 CHO
OH ∆
OH + CHCl3
–
(r) HCOO
O OH (s) Ph–CH=CH–C–Me ∆
(t)
–OH CHO
94. Match the column I with column II.
Column I
(a) Schimdt reaction
(b) Curtius reaction
Column II NaOH/CaO RH ∆ Red P/X2 (q) R–CH2COOH ∆ (p) RCOOH
(c) Decarboxylation
(r) RCOCl
(d) HVZ reaction
(s) RCOOH
(i) NaN3 ∆ (ii) H3O N3H ∆
RNH2
RNH2
R–CH–COOH X
5.47
5.48
chapter five
Integer Type 95. How many products are possible when ethanal and phenyl ethanal (mixture) is treated with dil. NaOH at about 10°C. 96. For the given sequence of reaction CH +
Me – C
(i) O3; CH2Cl2 [q] (ii) (CH3)2S
dil. OH ∆
Products
gas
MgBr
[x] Me
H2SO4 [p] Heat
I
[y] dil. H2SO4 HgSO4
LiAlH4 [z] H2O
How many products are obtained finally? 97. Identify the total number of compounds that give positive test with Tollen’s reagent O H3C
O
O
H3C
H
H
CH3
H OH
CH3
H3C
OMe
CH3 OH
OH O
O
O
O
CH2
OH
O
OH
98. Identify the total number of compounds that give positive iodoform test O CH3
O
O CH3 H3C
H3C
C
B
A O
O
F OH CH3 L
CH3 H3C CH3
H
G
CH3 E
D HO
CH3
OH
CH3 H3C
O HO
H3C
O
I
H3C J
CH3 H3C
CH3 OH M
H3C OH N
OH
HO
CH3
CH3 K
carbonyl compounds and acid derivatives 99. Identify the total number of compounds that give diastereomeric product on reaction with MeMgCl O
O
O
O CH3
CH3 H3C
HO A O
O
H3C
O
CH3 G
F O CH3
H3C
CH3
H3C
H
CH3
I
J
K
CH3
H3C
CH3
O
O
CH3 H3C
H3C
O M
L
E
D
CH3
O
CH3
H3C
C
B
OH
CH3
O N
100. Identify that compounds that give Cannizaro reaction O
H H O
O D
H
H3C
O
O G
F O H H3C
CH3
CH3 L
CH3
H3C
CHO
O
O OHC CHO
H CH3
O M
E
D
O
H3C
CHO
H3C
C
B
A
O CH3
J
CH3
H3C
CH3
O N
CH3
H3C
I
K
5.49
5.50
chapter five
Answer Keys Level 1 1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
c
d
d
b
d
c
a
d
c
bd
b
a
a
c
c
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
ab
d
d
c
a
b
d
a
bc
b
d
c
b
a
b
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
ab
abcd
d
d
c
a
d
c
b
c
a
b
c
abd
b
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
b
a
b
c
d
d
c
b
b
c
a
a
d
c
bc
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
b
b
c
a
c
b
d
b
c
b
a
d
c
b
d
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
b
a
b
b
a
c
b
c
b
b
a
c
a
d
b
91
92
93
94
95
96
97
98
99
100
101
102
103
104
d
d
a
b
a
a
d
d
b
a
d
c
d
d
11
12
Level 2 1
2
3
4
5
6
7
8
9
10
13
14
15
c
ac
bc
ab
abc
d
ab
bd
bd
bcd
b
bcd
a
b
abc
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
abd
bcd
ac
abc
abc
bd
ab
ab
bc
ab
bd
a
c
d
b
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
a
a
b
b
b
d
a
c
b
a
a
b
c
a
b
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
a
b
d
b
a
a
c
b
b
b
a
a
b
c
b
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
d
a
b
b
d
b
c
c
b
d
b
d
d
a
c
76
77
78
79
80
81
82(a)
82(b)
82(c)
82(d)
83(a)
83(b)
83(c)
83(d)
84(a)
a
c
b
b
c
b
s
p
r
pq
pqs
p
pqs
pqs
s
84(b)
84(c)
84(d)
85(a)
85(b)
85(c)
85(d)
86(a)
86(b)
86(c)
86(d)
87(a)
87(b)
87(c)
87(d)
pq
pqr
s
r
qr
t
ps
r
pr
s
q
pr
qs
pq
p
88(a)
88(b)
88(c)
88(d)
89(a)
89(b)
89(c)
89(d)
90(a)
90(b)
90(c)
91(a)
91(b)
91(c)
91(d)
r
pq
r
s
s
p
q
r
pr
st
qs
ps
pq
pqrs
pq
92(a)
92(b)
92(c)
92(d)
93(a)
93(b)
93(c)
93(d)
94(a)
94(b)
94(c)
94(d)
95
96
97
qr
pq
s
pqst
pq
s
r
t
s
r
p
q
12
11
6
98
99
100
6
2
6
carbonyl compounds and acid derivatives
Workbook Exercises Exercise 1 Identify reagents (1 to 10) used in the following conversion from reagent present in second Column II (A to P).
Column I (Conversion)
O
Conversion O O
O OEt
i
Reagent
OEt
ii
O
v
A. CH3CH2CH2CH2Li / THF
Br
Br OSiEt3
B. CH3CH2CH2Br
iii OSiEt3
C. Et3SiCl / Et3N D. Et3SiH / pyridine
OH
iv
E. CH3CHO
Br
PPh3Br
Br
vi OSiEt3
OSiEt3 PPh3Br
vii
viii
F. CH3CH2CHO G. PDC H. PPH3 I. CH2 = CHCH2Br
OH
J. H3O+ / ∆ K. Conc. H2SO4 / ∆
O H+ O
Column II (Reagent)
O
ix
OH x HO
O
L. NaOEt then Br(CH2)3Br M. Et3N N. NaBH4 then H3O+ O. Bu4NF then H2O P. KMnO4 / aq. NaOH / 0ºC
5.51
5.52
chapter five
Exercise 2 Identify reagents (1 to 10) used in the following conversion from reagent present in second Column II (A to T).
Column I (Conversion)
Column II (Reagent) (A) NaBH4 then NH4Cl
O i
CO2H ii
CO2Et
CO2H
CO2Et
+ COOEt (B) LiAlH4 then H3O (C) O3 then Zn / CH3CO2H
iii
(D) O3 then H2O2
iv Bn
O
OH
(E) NaOH (F) Na dissolved in EtOH (G) AC. H3O+
O
vi
v
CO2Et
CO2Et
CO2Et
vii O
Bn
O
OH
Bn
Bn Br
viii CO2Et
ix CO2Et
O
(H) BH3 then NaOH / H2O2 (I) Na then add PhBr (J) Na then add PhCH2Br (K) Pyridinium chlorochromate
O
(L) Na2Cr2O7 / H3O+ (M) NaBr / acetone (N) PBr3 (O) Br2 / hv
NOTE: Bn = Benzyl group, PhCH2
–
(P) LDA / THF / –78ºC (Q) Mg / Et2O (R) EtOH / H+ / heat (S) CH2=CH–CH2MgBr (T) NaOEt then CH2=CH–CH2Br
carbonyl compounds and acid derivatives
Exercise 3 Identify reagents (1 to 10) used in the following conversion from reagent present in second Column II (A to P).
Column I (Conversion) O
O
i
O
OEt
OH OH
O
ii
iii
O
OEt O
iv
Column II (Reagent)
v
(A) NaH (B) Na / THF then MeOH (C) H2 / Pd (D) NaOH /Cl2 (E) HCl / Cl2
Cl Cl
OH viii
Cl
O
O vii
OH
vi O
O
(G) 1 mol. eq. LiAlH4 then H3O+ (H) Pyridinium chlorochromate COOEt (I) H2O2 (J) H3O+ / ∆ (K) Conc. H2SO4 / ∆
ix
(L) EtOH / H+ / ∆ (M) NaOEt / EtOH (N) LiNiPr2 / THF
S EtOOC
(F) PCl3
COOEt
S || H2NCNH2
HN
NH
O
NaOEt
Spirothiobarbital
O
(O) Aq. NaOH / ∆ (P) NaOEt / EtOH / CH2(CO2Et)2
5.53
5.54
chapter five
Exercise 4 Identify reagents (1 to 10) used in the following conversion from reagent present in second Column II (A to O).
Column I (Conversion)
Column II (Reagent) Br
OH
i
O ii
iii
COOH
iv
(A) 1 eq NaBH4 then H3O+ (B) 1 eq LiAlH4 then H3O+
v O
vii
Li O–
OTs
OH
vi
(C) Ph3PCH2 (D) NaTs / DMSO (E) MCPBA
OTs
(F) Br2 /hν (G) PBr3
O
(H) Pyridinium chlorochromate
O viii
O
ix
HO
O
(I) Mg then CO2 then H3O+ (J) Conc. H2SO4 /∆
HO
(K) TsCl / pyridine (L) NaOEt / EtOH (M) LiNiPr2 / THF (N) LiCl / DMF Multistriatin
O O
(O) NaOH then CrO3 / pyridine
carbonyl compounds and acid derivatives
5.55
Exercise 5 Identify the intermediate product in the following conversion O (ii) PhCH2Br
H (i) NaH/THF
OH
(x) Aq. NH4Cl
(iii) PhLi/THF (iv) Aq. NH4Cl
(ix) (CH3)2CHCH2MgBr
(viii) PDC/CH2Cl2
(xii) CH3CH2CH2Br
(xi) NaH/THF
(xx) Ph3P=CH2, ether
(xiii) 5% HCl, 3 h, RT
(xix) PCC/CH2Cl2
(v) PCC/CH2Cl2
(vii) H2/Pt
(vi) XsCH3OH, Cat H+
(xv) (CH2OH)2, Cat. H+
(xiv) Br2 /Fe
(xviii) Aq. NH4Cl
(xvii) H2C=O
(xvi) 2 Li, THF
(xxi) m-CPBA, (xxii) (CH3)2CHMgBr, (xxiii) aq. NH4Cl (xxiv) PCC, (xxv) Br2, H2O, THF (xxvi) NaOCH3, CH2Cl2
Ether
(xxvii) CH3CH2CH2MgBr, Eether
CH2Cl2
(quench)
CH3OH
(xxx) CH3Br
(xxviii) aq. NH4Cl (xxix) NaH, THF (quench)
(xxxi) CH2I2, Zn, THF
(xxxiii) LDA, THF, –78ºC
(xxxii) 5% HCl, 3 h, RT
PPh3 H3C
(xxxiv) CH3CH2Br
(xxxv)
Br
CH3
THF
OMe CH3 O
H3C CH3
H3C
CH3
(xxxvii) HBr
(xxxvi) dil. H2SO4
5.56
chapter five
Exercise 6 Identify the intermediate product in the following conversion (i) CH3COCl, AlCl3 (x) PDC, CH2Cl2
(ii) Br2, Fe
(iii) HOCH2CH2OH, Cat. TsOH (iv) Mg, ether
(ix) aq. NH4Cl (viii) (CH3)2CHLi, THF (quench)
(xi) PhMgBr, THF
(xii) aq. NH4Cl (quench)
(xiii) NaH, ether
(xx) PhMgBr, Ether
(xix) m-CPBA, CH2Cl2
(xviii) NaOCH3, CH3OH
(xxi) aq. NH4Cl (quench)
Product
(v) H2C=O, Ether
(vii) PCC, CH2Cl2
(vi) aq. NH4Cl (quench)
(xiv) PhCH2Br, ether
(xv) 5% HCl, 3 h, RT
(xvii) HBr
(xvi) NaBH4, CH3OH
carbonyl compounds and acid derivatives
Exercise 7 Identify the intermediate product in the following conversion
H3C
OH
(i) Na2Cr2O7, (ii) xs CH3OH, (iii) NaOCH3, (iv) aq. NH4Cl (v) NaOCH3, THF H2SO4 Cat. H2SO4 CH3OH (vii) NaOH, (x) LDA, ) (ix) 180°C (–CO aq. THF 2 (viii) dil. HCl THF, –78°C
(xi) PhCH2Br
Product
(vi) CH3CH2Br
5.57
5.58
chapter five
Exercise 8 Identify the final product in the following reaction sequence
O
(a)
OEt
EtO
OH
(b)
(iv) PhCH2Br (v) NaOH, aq. THF (vi) dilute HCl (quench) (vii) 180°C (–CO2)
(i) Na2Cr2O7, H2SO4 (ii) xs CH3OH, Cat. HCl (iii) NaOCH3, CH3OH (iv) dilute HCl (quench) (v) NaOH, aq. THF (vi) dilute HCl (quench)
CH3
(i) NaOEt, EtOH (ii) dilute HCl (quench) (iii) NaOCH3, THF
O
(c)
O
(i) PhLi, THF, 0°C (ii) H3O+ (quench) Product (iii) H3PO4, heat (iv) OsO4, H2O2, NaOH
O
(d)
(i) NaOH, CH3OH, ∆ (ii) (CH3)2CuLi, THF (iii) aq. NH4Cl (quench)
Product
Product
Product
carbonyl compounds and acid derivatives
Solution for Workbook Exercises Exercise 1 Conversion O
O
O
Reagent
O
1=L OEt
OEt
2=J
O Br
Br
OSiEt3
5=H
3=N OSiEt3
PPh3 Br
4=C
OH
Br
Br
6=A OSiEt3
7=F
OSiEt3
8 = O OH
PPh3Br 9=G
O H+ O
O
OH
HO
10 = P O
(A) CH3CH2CH2CH2Li / THF (B) CH3CH2CH2Br (C) Et 3SiCl / Et3N (D) Et 3SiH / pyridine (E) CH3CHO (F) CH 3CH2CHO (G) PDC (H) PPh 3 (I) CH 2= CHCH2Br (J) H 3O+ / (K) Conc. H 2SO4 / (L) NaOEt then Br(CH2)3Br (M) Et 3N (N) NaBH4 then H3O+ (O) Bu 4NF then H2O (P) KMnO 4 / aq NaOH / 0ºC
5.59
5.60
chapter five
Exercise 2 O CO2 H 2 = R CO2 H
1=D
COOEt
CO2 Et 3 = P CO2 Et
4=T Bn
O
OH
O
6=J CO2 Et
5=A
CO2 Et
CO2Et
7= H O
Bn OH
O
Bn
Bn
Br 9=Q
8=N CO2 Et
CO2Et –
NOTE: Bn = Benzyl group, PhCH2
O
O
(A) NaBH4 then H3O+ (B) LiAlH4 then H3O+ (C) O3 then Zn / CH3CO2H (D) O3 then H2O2 (E) NaOH (F) Na dissolved in EtOH (G) AC. H3O+ (H) BH3 then NaOH / H2O2 (I) Na then add PhBr (J) Na then add PhCH2Br (K) Pyridinium chlorochromate (L) Na2Cr2O7 / H3O+ (M) NaBr / acetone (N) PBr3 (O) Br2 / hv (P) LDA / THF / –78ºC (Q) Mg / Et2O (R) EtOH / H+ / heat (S) CH2=CH–CH2MgBr (T) NaOEt then CH2=CH–CH2Br
carbonyl compounds and acid derivatives
5.61
Exercise 3 O
O
1=L
3=H
O
O
OEt
OH OH
2=M
O
OEt O
4=E
5=M Cl
Cl
OH
O
O 7=G
8=F
6=J COOEt
Cl
OH
O
O
9=P EtOOC
S || COOEt H2 NCNH 2
S HN O
NH O
NaOEt
SPIROTHIOBARBITAL
(A) NaH (B) Na / THF then MeOH (C) H2 /Pd (D) NaOH /Cl2 (E) HCl / Cl2 (F) PCl3 (G) 1 mol. eq. LiAlH4 then H3O+ (H) Pyridinium chlorochromate (I) H2O2 (J) H3O+ / Conc. H2SO4 / L EtOH / H+ / NaOEt / EtOH (N) Li NiPr2 / THF (O) Aq. NaOH / P NaOEt / EtOH / CH2(CO2Et)2
5.62
chapter five
Exercise 4 OH 1 = H
Br O 2=C
COOH
4=I
3=F
(A) 1 eq NaBH4 then H3O+
5=F O
7=M
Li O–
OTs
6=B
OH
(B) 1 eq LiAlH4 then H3O+ (C) Ph 3PCH2 (D) NaOH / DMSO/ H2O
OTs
(E) MCPBA (F) Br 2 /h (G) PBr3
O
O
8=E
O
(H) Pyridinium chlorochromate
9=D
HO O
(I) Mg then CO2 then H3O+ BC. H3O+ (J) Conc. H2SO4 /
HO
(K) TsCl / pyridine (L) NaOEt / EtOH (M) Li NiPr 2 / THF (N) LiCl / DMF (O) NaOH then CrO3 / pyridine
MULTISTRIATIN
O O
carbonyl compounds and acid derivatives
Exercise 5 O H 2.
1.
OLi
O
ONa
H 3. OCH2Ph
OCH2Ph OH
H3 CO OCH3
O
5.
4.
6.
OCH2Ph
OCH2Ph
H3 CO OCH3
H3 CO OCH3
7.
OCH2Ph
8. OH
H3 CO OCH3
9. OMgBr
O H3 CO OCH3
H3 CO OCH3
10.
11.
H3 CO OCH3
12. ONa
OH
O
O
O
O
Br
13.
14. O
O
16.
O Li
O
OLi H
O
O H 20.
19.
O
H 18.
O
O
O
O
OH H
H
O
O
CH2
O
H 21. O
Br
O
17.
O
O
15. O
O
O
O
O
O H
5.63
5.64
22.
chapter five
O
OMgBr
O
H
23.
O
O
O
OH H
24.
O
O
O O
O
Br
25.
O
O
O 26.
O
O
O
29.
O
O
30.
OMgBr
O
O
O
OLi
32.
33.
OMe
OMe
O
OMe
O
O
O
34.
35.
OMe
OMe O
O
Br
37.
OMe O
O OMe
O
O
O
ONa
O
O
O
O
OH
31.
O 27.
O
O
28.
O
OH
36.
OMe O
carbonyl compounds and acid derivatives
Exercise 6 O
O
1.
2.
O
3.
O
5.
O
6. H
OLi
H
O
H
OH O
O
10. H
O
H
O
O
13.
O
ONa
OMgBr
Ph
O
O
OCH2 Ph
OCH2 Ph OH Ph OCH2 Ph
Ph
O
OH OH
16. Ph
OCH2 Ph
Ph
19. OCH2 Ph
Ph
20. Ph
OCH2 Ph OMgBr
O
18.
Ph
O
15. Ph
17.
21.
O
OLi
12.
Br
Ph
H
O
Ph
14. Ph
O
O
O
O
8.
11.
OH
O
O
7. H
9.
MgBr
Br O
O
4.
Br O
O
O
OCH2 Ph
Ph
OCH2 Ph
5.65
5.66
chapter five
Exercise 7
H3 C
(i) Na 2Cr2O7, H2SO4
OH
O
(ii) xs CH3OH, cat. H2SO4 COOH
(v) CH3CH2Br
MeOOC
(vii) NaOH, aq. THF
O–
(iii) NaOCH3, CH3OH COOMe
(v) NaOCH3, THF
O
(viii) dil. HCl
COOMe
(iv) aq. NH4Cl
MeOOC
MeOOC
O
O
O–
(ix) 180oC (–CO2)
O
HOOC
OOC
Ph O
O (xi) PhCH2Br
Product
(x) LDA, THF, –78 oC
carbonyl compounds and acid derivatives
Exercise 8 O
O
OEt
(A) EtO
(i) NaOEt, EtOH (ii) dilute HCl (quench) (iii) NaOCH3, THF
O Ph
(iv) PhCH2Br (v) NaOH, aq. THF (vi) dilute HCl (quench) (vii) 180oC (–CO2)
(B)
OH
(i) Na2Cr2O7, H2SO4 (ii) xs CH3OH, cat. HCl (iii) NaOCH3, CH3OH
O HO
Ph
(iv) dilute HCl (quench) (v) NaOH, aq. THF (vi) dilute HCl (quench) (i) PhLi, THF, 0oC (ii) H3O+ (quench)
(C)
(iii) H3PO4, heat (iv) OsO 4, H2O2, NaOH
(D)
(i) NaOH, CH3OH, (ii) (CH3)2CuLi, THF (iii) aq. NH4Cl (quench)
Ph
OH OH Ph
O
O
O
O
5.67
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ESR Amines and Phenols
CHAPTER
6
Question Bank
Level 1
NH2
⊕
Cl 2 3 2 3O → A AlCl → B H → C the — CH3 Pyridine 3 ( CH CO ) O
1. In the given reaction H2N — product (C) will be NH2
HNCl
NH2
Cl
(a)
(b)
(c)
(d)
Cl CH3
CH3
CH2Cl
CH2Cl
2. Rank the following compounds in order of decreasing reactivity for nitration. O
(i) H–C–
H3C – O – – C – CH3 (ii)
– OCH3
O
(iii) Br –
H3C – NH – C – CH3 N– – COCH3 (iv) ON O
Select the correct answer from the following: (a) iv > ii > i > iii (b) ii > iv > iii > i (c) ii > iv > i > iii (d) i > ii > iii > iv
6.2
chapter six 3. In the given reaction major product (P) will be CH3
H OC – H
O
CH3 + F – C – H CH3
BF3
CH3
CH3
F– (a)
O HC – (c)
– CH2CH3 – OCH2 – CH3 (b) H3C C–H CH3 O O CH3 CH3 H–C – OCH2CH3 (d) – OCH2CH3 CH3 CH3
4. The major product [X] of the given reaction is – OCH3 + CH3 – Cl
–
O2N –
AlCl3 [X] ∆
CH3
(a)
O2N –
CH3 – OCH3
CH3
(c) O2N –
– OCH3
(b) H3CO –
– NO2
H3C (d)
5. In the given reaction sequence, identify (B) C6H6 + Cl – CH2 – (excess)
(a) – CH2 –
(c) C6H5 – CH2 –
– CH2 – Cl
– CH2 – Br – CH – C6H5
anhy.AlCl3
Br (b)
(d) Br –
(A)
(B) Br
– CH2 – – CH2 –
6. The final product of the given reaction is CH3
KMnO4 Br2 [Y] [X] + H Fe (small quantity)
NBS/hv
– CH2 – – CH2 –
– Br
esr amines and phenols CH3 – Cl
(a)
COOH
COOH
COCl
(b)
(c)
Br
Br
(d) Cl
Br
NO2 HNO3 H2SO4
7.
(i)
NO2
+
(ii)
Which statement is correct? (a) i form in large quantity (c) i, ii form in equal quantity
(b) ii form in large quantity (d) naphthalene does not show nitration
OCH3 (CH3)2C = CH2/H⊕
8.
Major product is
CH3 OCH3 C(CH3)3 (a)
OCH3
(b)
C(CH3)3 CH3
CH3
CH3
OCH2 – CH(CH3)2 (c)
O – C – CH3
CH3
(d)
CH3
CH3 O
9. Nitration of the compound CH3 —
gives
—N
H3CO O CH3 — (a)
—N
H3CO
H3CO
—N
H3CO NO2 O
(c) CH3 —
NO2 (b) CH3 —
O
—N
NO2
(d) CH3 — H3CO
O —N
NO2
6.3
6.4
chapter six OH
10. CHO
Br2 CCl4
A; A can be
H3C OH
OH H3C (a)
Br (b)
CHO
CHO H3C
Br OBr
OH Br (c)
Br
CHO
(d) CHO
Br
Br
11. The major product of the following reaction is CH3 – O – H + HO – C – CH3 CH3
20 per cent H2SO4 80°C CH3
CH3
(a) – O – C – CH3
(b) HO – C – CH2 –
CH3
CH3
CH3 H3C – C –– (c)
H CH3 – C – CH2 – – OH (d)
– OH
CH3
CH3
O HNO3
12.
H⊕
Major product is NO2
NO2
(a)
(b) O
(c)
— NO2
(d) NO2
O
O
esr amines and phenols CH3 NH2
13.
— CH2 —
— CH3
Br2/CCl4
Major product is
Br
NH2
Br CH3 (a) CH2 (b)
CH3
CH3
CH3
NH2
NH2
CH3 (c) Br
CH2
CH2
CH3 (d) Br
CH2 NH2
14. The product of the following reaction is H3C – C – NH
O
+
O
BF3 H2O O
⊕
O – BF3
(a)
NH – C – CH3
(b) H3C – C – NH
O
O O (d) H3C – C – NH HO
(c) O H3C – C – NH
CH3 HO
15. Which has equal carbon–carbon bond length? O−
O
(a) O2N
— O (b)
O
O
Ph (c)
−
— O (d)
Ph
16. Product of the reaction is
Cl
C – O – OH
H⊕ H2O
Product
CH3 HO (a)
Cl +
C
CH3 (b) H3C
OH +
O (c)
OH + CH3
C O
C
Cl
O Cl (d) OH + Cl
C O
CH3
6.5
6.6
chapter six 17. For the following reaction, correct options are
O
CH2OH
PhMgBr (1Eq.)
A+B (salt)
O A+
O
AlCl3
i. SOCl2 C ii. AlCl3
O
(a)
O
B (salt) + H3O⊕
OH Ph
B (salt) + H3O⊕ (b)
CH2OH Me
CH2OH
O
O⊕
B (salt) + H3 (c)
(d) C is
CH2OH 18. Consider the following ions
H3C (i) N – H3C
⊕
–N
⊕
⊕
–N
(iii) O – H3C
⊕
–N O2N – (ii) N N
N
–N
(iv)
N
The reactivities of these ions in azo-coupling reactions (under similar conditions) will be such that (a) i < iv < ii < iii (b) i < iii < iv < ii (c) iii < i < ii < iv (d) iii < i < iv < ii OH O
19.
CH3
H⊕
CH3 OH
OH
[A]; [A] is
OH
CH (a) (b) 3 (c)
O
(d)
–C–
CH3
20. Which of the following is/are more reactive towards nitration than benzene? (a)
CH3
(b)
(c)
(d) All of these
esr amines and phenols CH(CH3)2 21.
is; where the reagent ‘X’ is
Reag.'X' (major product)
(a) CH2 = CH—CH3/HF
(b) CH3CH2CH2Cl/Anh. AlCl3
CH3–CHCH3/Anh. AlCl3 (c)
(d) All of these
Cl 22. In the given reaction sequence I /NaOH /∆ C6H5OCOCH3 AlCl → (B) + CHI3, (B) is → (A) 2
3
OH
OH
(a) C6H5COONa (b) C6H5COOH
(c)
COCH3
(d)
COONa
23. The major product formed in the reaction is O –C–O–
Conc. HNO /Conc. H SO
3 2 4 → ( mononitration )
O
O
–C–O–
(a)
(b) O2N –
–C–O–
O2N O (c)
–C–O–
O (d) –C–O–
– NO2
O2N NO2 24.
Fe/HCl
(a)
(A)
HNO3 H2SO4
(B). The major product (b) is
N=O
(b) NO2
– NH2
NH2 (c)
(d)
–N–N– H
H
NO2 25. Arrange the following in the order of their nucleophilic substitution reaction Cl Cl NO2 (i) (ii) (iii) (iv) N Cl N NO2 NO2
(a) ii > iv > i > iii (b) i > iv > ii > iii
(c) iv > i > ii > iii
Cl
(d) iv > ii > i > iii
6.7
6.8
chapter six 26. For the following reaction NO2
NO2 (i)
CH3NH2 NaHCO3
(ii)
F
NO2 NHCH3
NO2
NO2
NO2
(iii) NO2
CH3NH2 NaHCO3
Correct order of reactivity
(a) i = ii = iii
NO2
CH3NH2 NaHCO3
Cl
(b) i > ii > iii
(c) i < ii < iii
(d) ii > iii > i
27. What is correct order of rate of nitration of the following compounds? (i) C6H5CH3 (ii) C6H6 (iii) C6H5Br ⊕
C6 H 5NR 3 (iv)
(v) C6H5NMe2
(a) iv > iii > ii > i > v (b) v > iii > ii > i > iv (c) v > i > ii > iii > iv (d) v > iv > ii > i > iii HNO3 H2SO4, ∆
28. Identify the product N NO2
(a)
NO2
(b)
N
N
NO2 (c)
(d) N
N
NO2
NO2 29. Which centre (s) more reactive towards EAS in the given molecule? (c)
(a) (b)
(f) (d)
(a) a
(b) d
NO2 NHCH3
NO2 NHCH3
I
NO2
NO2
(e) (c) c
(d) e
esr amines and phenols
(i)
SH SH (ii) BuLi O (iii) H2O
O 30. H
O
Product is?
(iv) Raney Ni + H2 (v) TSCl/Py (vi) LiBr/Acetone (vii) AlBr3
O
(a)
BF3
(b)
O
O O (c)
(d)
OH O 31.
H⊕
CH3
[A]; [A] is
Cl OMe OH
OH
OH
O CH (a) (b) 3 (c) (d) –C– OMe
32. H3C
Concn. HI
O
Products?
Br Me (a)
I
(b) I
Br Me (c)
OH Me
(d) No Reaction
6.9
6.10
chapter six CH3
33.
NaNH2/NH3 ( )
Product.
Br Product is (a)
CH3
CH3
NH2
(b) NH2
CH3
(c)
(d) Mixture of (a) and (b)
H2N 34. Which compound on oxidation with acidified KMnO4 solution gives benzoic acid? (a) – CH
Me Me
(b)
(c) –C –– C – CH3
– CH3
(d) All of these
35. In the given reaction O
O
H–C–
– CH2 – CH2 – CH2 – C – Cl
AlCl3
(X)
Zn – Hg/HCl
(Y) is (a) HC O
(b) H3C
O
O
CH3 (c)
(d) HC
36. Based on the following reaction, the major product would be Cl Cl
NO2 (i) HO /∆ (ii) H⊕ P (major)
(Y); The final product
esr amines and phenols OH
Cl
Cl
OH (a)
(b) NO2
NO2
(c) Both in equal proportions
(d) None of these
37. Give the major product from the following reaction sequence Br2 FeBr3
Br
SO3 H2SO4
H⊕ H2O
AlCl3
Major product
Br
Br
(a)
(b) SO3H Br
Br
(c)
(d) SO3H
38. Which one of the following compounds will be most readily hydrolyzed in aqueous alkali? Cl Cl (a) NO2 (b) NO2
Cl
Cl
(c) O2N
NO2
(d)
NO2
NO2
39. Which of the following is most reactive towards the reaction with NaOMe? F (a) NO2
Br
Cl (b) NO2
NO2
NO2
F NO2 (d)
(c) NO2
NO2
NO2
40. An aromatic compound ‘A’ C7H6Cl2, gives AgCl on boiling with alcoholic AgNO3 solution and yields C7H7OCl on treatment with NaOH. ‘A’ on oxidation gives monochloro benzoic acid which affords only one mononitro derivative. The compound ‘A’ is CH2 – Cl CH2Cl CHCl2 CH2 – Cl Cl (a) (b) (c) (d) Cl
Cl
6.11
6.12
chapter six H3C O 41.
Cl
– NH – C –
AlCl3
[A]
H3O⊕
[B]
N CH3
NaNO2/HCl [C] NH4Cl/H2O 0°−5°C
[D]
Product [D] is H3C (a) H3C
–N=N–
– NH2
H3C (b) H3C
–N=N–
–N
(c) – N = N –
–N
CH3 CH3
CH3 CH3
(d) 42. Identify B, X and R respectively in the following sequence of reactions +
ClCN 3O C2H5MgBr → A H → B, I2 → X Ag → Y CH3COCH3 NaOH
2 C6H5NH2 NaNO P HCl →
+ 4H CuCN → Q → R
(a) C2H5COOH, CHI3, C6H5CH2NH2
(b) C2H5COOH, CH3I, C6H5COOH
(c) C2H5CH2NH2, CH3I, C6H5COOH
(d) C2H5COOH, C2H5I, C6H5CONH2
43. p-nitrotoluene on further nitration gives CH3 (a)
NO2
CH3 (b)
CH2OH NO2 (d) (c) NO2
NO2
NO2
CH3 NO2
O2N
NO2
44. Which of the following structures correspond to the product expected, when excess of toluene reacts with CH2Cl2 in presence of anhydrous AlCl3? CH3 CH3 H3C– –CHCl2 (b)
(a) –CH– Cl
Cl
(c) H3C–
–CH3 (d) H3C–
–C– Cl
–CH2–
–CH3
45. In the sulphonation, acetylation and formylation of benzene the group of effective electrophiles would be ⊕
⊕
⊕
⊕
SO ⊕3 , CH 3 C ≡ O , HCO (a)
(b) SO3, CH3C ≡ O , HCO
(d) HSO3, CH3CO, HCO
(c) SO3, CH3CHO, CO + HCl
esr amines and phenols 46. When benzene is heated with acetic anhydride in the presence of anhydrous aluminium chloride at 80°C, the product formed is? (a) Benzoic acid (b) Benzophenone (c) Acetophenone (d) Ethyl phenyl ketone 47. Which of the following is not the structural formulae of benzene? (a)
(b) (c)
(d) None of these
48. Most reactive towards nitration is D
O
OMe
D (a) D
D
(b)
Me (c)
D O 49. MeO MeO
HO (a) HO MeO (c) MeO
CH
CH
Br
Br
OMe
H2O
D
O
D Me (d) D D
C
CH
Br
Br
O OMe (b) MeO MeO
O CH
CH
OH
OH
OMe (d) MeO
CH
CH
OH
OH
CH
MeO
(a) (b) (c) (d)
Reagent B
CO2H
reagent A: CH3COCl/AlCl3; reagent B: Sn, HCl, heat reagent A: CH3CH2Cl/AlCl3; reagent B: KMnO4, heat reagent A: CH3COCl/AlCl3; reagent B: H2NNH2, KOH, H2O, heat reagent A: HNO3, H2SO4; reagent B: Sn, HCl, heat
51. What could be the product for the following reaction? O Cl
(i) AlCl3 (ii) H2O
OMe
O
50. What reagents (conditions) are needed for the following reaction? Reagent A
D
Major Products is?
(10 min.)
O CH
OMe
Products?
CH
OMe
6.13
6.14
chapter six O (a)
(b)
O (c)
OH
(d)
52. What could be the product for the following reaction? CH3 N NH2
CH3
NaNO2, HCl CH3 (a)
Br
N (b) N N
CH3
CH3 N CH3
Br (c)
N
Br
(d)
N
N
53. What could be the product for the following reaction? NH2
NaNO2, HCl
CuBr CH3
(a)
Br
N
(b)
N
N H3C
Br (c)
N
Br
(d) N N
N
CH3
CH3
esr amines and phenols 54. What could be the product for the following reaction
Ph
NH Me
H
NaNO2 HCl
?
N2+ NCH3 (b)
(a) NO NO (c)
H
NCH3
N+
(d)
NO
CH3 55. What could be the major product for the following reaction? OMe
H2NNH2
O
KOH, H2O Heating
Cl AlCl3
. Major product?
OMe O (a)
(b) OMe
(c)
(d) OMe
OMe
O
56. What could be the product for the following reaction? O Zn(Hg) HCl, heating
. Major product?
OH OH (a)
(b) OH
OH
(c) Cl
O (d) Cl
6.15
6.16
chapter six 57. For the following compound, which nitrogen is most apt to be protonated? N
c
b
N N H
N
a
d
(a) Nitrogen indicated by arrow ‘a’ (c) Nitrogen indicated by arrow ‘c’
(b) Nitrogen indicated by arrow ‘b’ (d) Nitrogen indicated by arrow ‘d’
58. What could be the product for the following reaction? (i) AlCl3
O OCH3
(ii) H2O
O
+
O OCH3 OCH3 O (a)
(b) O
O
O O O
(c)
O O
O OH
(d) O
MeO
OCH3
59. What is the correct order of decreasing basicity for the following anions (from the most to the least)? CH3
OCH3 (i)
(ii)
Br (iii)
(iv)
O
CH3
(v)
O O
O
(a) i > ii > iii > iv > v (c) i > ii > iv > iii > v
O (b) i > ii > iii > v > iv (d) v > iv > iii > ii > i
O
esr amines and phenols 60. What is the correct order of decreasing acidity for the following phenol and phenol derivatives (from the most to the least)?
(i)
CH3
O
OCH3 (ii)
NO2 (iv)
(iii)
CH3
Br (v)
(vi) OH
OH
OH
OH
OH
(a) i > ii > iii > iv > v > vi (c) iii > ii > iv > vi > v > i
OH
(b) ii > iii > iv > vi > v > i (d) ii > iii > iv > vi > i > v
61. What is the correct order of decreasing reactivity (fastest to slowest) toward nucleophilic aromatic substitution for the following compounds? Cl Cl (i)
(ii) NO2 NO2
Cl (iii) O2N
Cl
(iv) NO2
(a) i > ii > iii > iv
NO2
O2N
(b) ii > iii > iv > i
(c) iii > ii > iv > i
(d) iv > iii > ii > i
62. What could be the product for the following reaction? N(CH3)2 NaNO2, HCl
(a)
Cl
(b)
Product? N2+
CH3
N(CH3)2
(d) N+
(c) NO
NO
CH3
63. What is the correct order of decreasing reactivity (fastest to slowest) toward electrophilic aromatic substitution for the following compounds? (i)
CO2H
(ii)
CH3
(iii)
OCH3
(iv)
(a) i > ii > iii > iv (c) iii > ii > iv > i
(b) ii > i > iv > iii (d) iv > iii > ii > i
6.17
6.18
chapter six 64. What could be the reagent for the following reaction? NaNH2 Cl
Reagent
NH3(liq)
O
O (a) (b) (c) (d) 65. What could be the product for the following reaction? (i) NH3, heat
Cl O2N
(ii) OH|/H2O
Product?
NO2
NH2 (a)
OH (b)
O2N
O2N
NO2
NO2 NH2
Cl (c)
(d)
O2N
NH2
O2N
NO2
66. Which could be the major product of the following reaction? CF3
Cl2, FeCl3
Product? CF3
CF3
(a)
(b)
Cl
Cl CF3
Cl Cl
CF (d) 3
(c)
Cl Cl 67. Which could be the major product of the following reaction? Cl
Br2 (1 equivalence) FeCl3
NO2
K2Cr2O7 H2SO4 Heating
Major Product
esr amines and phenols CO2H
Br
(i)
Br
(ii)
NO2
NO2 CO2H
(iii)
Br
Br
(iv)
NO2
NO2
(a) i
(b) ii
(c) iii
(d) iv
HO dil H2SO4
68.
∆
Products are?
HO
HO
(a)
(b)
OH
HO (c)
(d)
69. Choose the order that has the following compounds correctly arranged with respect to increasing basicity. NH2
NH2
NH2
NH2
(a)
NO2
increasing basicity NH2
NO2
NH2 NO2
NO2 increasing basicity
NO2
increasing basicity NH2
(c)
NH2
(b)
NO2
NO2
NH2
NH2
NH2
NH2
(d) NO2
NO2 increasing basicity
6.19
6.20
chapter six 70. What could be the reagent and reaction condition for the following transformation? O OEt
EtO ?
(a) ethanol, NaOH (c) methanol, NaOH
(b) ethanol, H+ (d) methanol, H+
71. What could be the product for the following reaction? H
K2Cr2O7 H2SO4 Heat
(a)
CO2H
Product
OH (c)
OH
(b) O
OH
(d)
H
72. What could be the reagent to complete the following reaction? O H
OH Reagent
(a) HCrO4
(b) K2Cr2O7
(c) PCC in dried CH2Cl2
73. What could be the product for the following reaction? (i) Cl2, AlCl3 (ii) Mg, Et2O (iii) H2C = O then H2O (iv) PCC
Product OH
H (a)
O
OH (c)
O
(b) O
(d) H
(d) OsO4
esr amines and phenols 74. What could be the reagent for the following reaction? O CH3
Reagent Cat. acid
O
CH3
Removal of H2O
(a) CH3OH (c) CH3COCH3
O
(b) CH3CH2OH (d) HOCH2CH2OH
75. What is the expected product for the following reaction? Cl2(1 equiv.) FeCl3 Cl Cl
(a)
(b)
Cl
Cl (c)
CH3
Cl
(d)
76. What could be the product for the following reaction? CO2H
P2O5
Product
CO2H O
CH2OH
(a)
(b)
CH2OH
O O O
(c)
CO2H
(d)
O OH
77. What is the name of the following compound? CH3 OH CH3
(a) 2,6-Dimethylphenol (c) 2,6-Dimethylanisole
(b) 1,5-Dimethylphenol (d) 1,5-Dimethylanisole
6.21
6.22
chapter six 78. What is the name of the following compound? NO2
(a) p-aminotoluene (c) p-nitrostyrene
(b) p-nitrotoluene (d) 3-aminostyrene
79. What should be the major product for the following reaction? Cl AlCl3
(a)
(b)
O (c)
(d)
80. What is the name of the following compound? OCH3
CH3
(a) p-methylphenol (c) o-methylanisole
(b) m-methylphenol (d) m-methylanisole
81. What is the name of the following compound? O H
(a) benzylcarbonyl (c) phenylaldehyde
(b) benzaldehyde (d) phenylketone
82. What is the name of the following compound? O O
esr amines and phenols
(a) benzyl phenoate (c) benzyl benzoate
(b) phenyl benzoate (d) phenyl phenoate
83. What could be the product for the following reaction? O (i) SOCl2 OH
(ii) CH3CH2OH, H+
O
OCH2CH3
(a)
OCH2CH3
(b)
O
OCH2CH3
(c)
OCH2CH3 (d)
84. Which of the following structures is benzoic acid? (a)
(c)
CO2H
O2CH
OCOH
(b)
(d)
O2HC
85. Which of the following reaction sequences would be the best for synthesizing the compound, 1-bromo-3-propylbenzene? Br
1-Bromo-3-propylbenzene O Br2
(a)
Zn (Hg)
Cl
FeBr3
AlCl3
HCl
Br2
Zn (Hg)
FeBr3
HCl
O (b)
Cl AlCl3 O
(c)
(d)
Cl AlCl3 Br2 FeBr3
Zn (Hg)
Br2
HCl
FeBr3
Cl AlCl3
6.23
6.24
chapter six 86. What is the expected product for the following reaction? O Cl AlCl3 O (a)
(b)
(c)
(d)
O
87. What is the expected product for the following reaction? Cl2(1 equi.) FeCl3
Cl
Cl
Cl (a)
(b)
(c)
Cl (d)
Cl 88. What could be the product for the following reaction? CH3 Br
NaNH2 Liquid NH3
Product?
CH3 CH3
CH3
NH2 CH3
NH2 (a) CH3
(b) CH3
CH3
(c)
(d) CH3
89. What could be the product for the following reaction? O Zn(Hg)HCl, heating
CH3
esr amines and phenols OH (a)
(b)
O (c)
(d) OH
OCH3 90.
O || (i) CH3CH2CCl/AlCl3 (ii) LiAlH4/THF (iii) H3O+
OCH3
O (a)
(b)
O
OH OH
OCH3 (c)
(d) O O OH
(i) H2SO4, heat
91.
?
(ii) CH3CO3H (iii) CH3MgBr, then H3O+
OH
OH (a)
(b)
OH (c)
92.
OH
(d)
1. Benzyl bromide 2. Hg2+, H3O+ O
O (a) H3C
O
(b) H3C Cl
O H – C –– C Cl (c) (d)
6.25
6.26
chapter six H3C
CH3 (i) Excess MeMgBr, then H3O+
O
93.
O (a)
?
(ii) Catalytic H+, heat O O (b)
H
O (c)
CO2CH3 O
(d) CO2CH3
COOH
O (i) O3
94.
(ii) Zn, H2O (iii) Toluene-4-sulphonic (TOSIC) acid, heat OH
O
OH
O
(a) (b) (c) (d)
O 95. ?
(i) CuCN (ii) Vinyl lithium, then H3O+, heat Br
(a)
Br
(b)
(c)
N+
O
N (d)
NO2
(i) CH3I, K2CO3
96. HO
(ii) H2SO4, HNO3
NO2
NO2
H3C (a) HO
(b) HO
NO2
CH3
NO2
esr amines and phenols NO2 NO2 O2N
O2N
HO (c)
(d) MeO
CH3
97.
OH
(i) Na2CO3, CH3Br (ii) CH3I, AlCl3
possible products?
OCH3
OCH3 (a)
(b)
OH (c)
OH (d)
O 98.
OH
(i) Ethanoyl chloride, pyridine (ii) Excess NH3 (iii) LiAlH4, then H3O+
NH2 (a)
NH2
H2N
(b)
HO HO
NH2 (c)
(d) HO
NH2
6.27
6.28
chapter six
Level 2 Single and Multiple-choice Type 1. What should be the major product for the following reaction? Cl Major product?
AlCl3
O (a)
(b)
(c)
(d)
2. Which of the following is not the resonance structure of intermediate from the listed electrophilic aromatic substitution? OMe
OMe
Br2 FeCl3
Br (i) ⊕
⊕ OCH3
OCH3 (ii)
Br ⊕ OCH3 (iii) Br
Br Br (iv)
OCH3
Br (v)
⊕
OCH3
⊕
(a) v
(b) ii
(c) iii
(d) iv
3. What could be the product for the following reaction? Br
NaNH2 Liquid NH3
Product?
NH2 NH2 (a) (b)
Br (c)
(d)
esr amines and phenols 4. What could be the product for the following reaction? O (i)
N
Br
O
Product?
(ii) H+, H2O, heat
NH2
Br (a)
(c) O
(b)
O (d)
N
5. Which of the following compounds are aromatic compounds? H H O N S N (i) (ii) (iii) (iv) N H N N O O (v) (vi) (vii) (viii) N N N N N H OH O H N (ix)
N (x) N
H N
(xi)
(xii)
N OH
O
(a) i, ii, iii, iv, v, vi, viii, x, xii (c) i, ii, iii, vi, viii, x, xi, xii
(b) i, ii, iii, v, vii, viii, ix, x, xii (d) i, ii, iii, iv, v, vi, vii, x, xii
6. What could be the product for the following reaction? NH2
NaNO2, HCl
Product? ⊕ N2
Br (a)
CuBr
(b) Br
Br (c)
N
CuBr Br
(d)
6.29
6.30
chapter six 7. Which one of the following compounds is antiaromatic? N (a) (b) (c) (d) O⊕ N
8. What is the expected product for the following reaction? Cl2 (1 equivalent) FeCl3 Cl
Cl (a)
Product is ?
(b)
(c)
Cl
(d)
9. What could be the product for the following reaction? O H OH/∆
+
Product? + H2O
O
O
O
(a)
O H3CO OH (b)
OH
O (c)
O
(d)
10. What could be the product for the following reaction? (i) Cl2 / FeCl3 (ii) Na2Cr2O7 / heat / H+ (iii) PCl3
Product?
(iv) CH3OH O
O (a)
OCH3 Cl
OCH3
(b) Cl
esr amines and phenols OCH3
O OCH3
(c)
Cl
(d)
11. What could be the product for the following reaction? (i) Cl2, AlCl3 (ii) Mg, Et2O (iii)
O Product?
(iv) H+/∆ OH (a)
(b) O
(c)
CH2Cl
(d)
OH
12. What could be the product for the following reaction? O Cl
(i) AlCl3 (ii) H2O
Product? O
(a)
O
(b) O
O (c)
Cl
(d)
13. What could be the product for the following reaction? (i) Cl2, AlCl3 (ii) Mg, Et2O (iii) O then H2O (iv) K2Cr2O7, H+ room temp
Product?
OH
6.31
6.32
chapter six
H (a)
OH (b)
O
O
OH
(c)
O
(d)
OH
14. What could be the reagent for the following reaction?
O
O
Reagent O
(a) PhCO2H
(b) PhCO3H
(c) OsO4
(d) Na2Cr2O7
15. Which of the indicated compounds would be the major product in the following Friedel Crafts reaction? CH3 O O Cl AlCl3
NO2
?
CH3
CH3 O
O (a)
O
NO2 (b)
NO2
O CH3 O
CH3
O
O O (c)
NO2 (d)
NO2
16. The following reaction yields compound T predominately. O �OH O H + H3C CH3 Predict the main product T. (a) O
O H
(b)
O (c)
T
O H
(d)
esr amines and phenols 17. The compound isopentylnitrite is a source of NO+ ions and will react with an amine to generate a diazonium cation. Predict the product of the following reaction sequence. O
N O O isopentyl nitrite
OH
O heat
NH2 O
O
O (a)
O
(b)
O NH
(c)
(d) N H
O
O
18. What could be the major product for the following Reaction? O Cl
CH3 AlCl3
OMe O (a)
CH3
CH3
(b)
O
MeO
MeO CH3 (c)
CH3
(d) MeO
OMe
19. The following reaction gives two main products. Identify the products. CH3 NaNH2 NH3 Br CH3 (a)
NH2
+
NH2
NH2
CH3
+
CH3 NH2
(b) + NH2
CH3 (c)
CH3
CH3
NH2
CH3 (d) + NH2 NH2
CH3 NH2
6.33
6.34
chapter six 20. What could be the product for the following reaction? CH3 Mg, Et2O
D2O
Product?
Br (a) H3C
(b) OH
H3C D
(c)
(d) H3C
CH3
MgBr
21. The following reaction gives two main products. Identify the products. CH3 NaNH2 NH3 Br CH3
CH3
CH3
CH3 NH2
NH2 (a)
(b) +
+
NH2
NH2
CH3 (c)
CH3
NH2
CH3
+ NH2
NH2
CH3 NH2
(d) + NH2
22. What could be the product for the following reaction? OH CH3
(i) PCC (ii) CH3CH2OH, H+
Product?
Removal of water O (a)
H3CH2CO
OCH2CH3
(b) CH3
CH3
esr amines and phenols OCH2CH3
O (c)
OCH2CH3 (d) CH3
23. What could be the product for the following reaction? O CH3
(i) Na2Cr2O7, H+, heat
Product?
(ii) CH3CH2OH, H+ removal of water H3CH2CO
O (a)
CH3
(b)
CH3
OCH2CH3
O (c)
OCH2CH3
OCH2CH3
(d) CH3
24. What could be the product for the following reaction? OH
(i) MnO2 (ii) CH3MgBr (iii) H+ / H2O
OH (a)
Product?
OH (b)
O
O (c)
(d)
25. What could be the product for the following reaction? OH CH3 (i) (COCl)2, Me2S = O; Et3N
Product?
(ii) Ph3P = CH2 O (a)
CH3
(b)
O (c)
CH3 O
OCH3
(d)
Cl
6.35
6.36
chapter six 26. What could be the product for the following reaction? NH2
O
O2N H+ Removal of water
HN (b) O2N
N
(a) O2N
Product?
O O2N (c)
HN (d) O2N
27. What could be the major product for the following reaction? HN
O
H+ Removal of water
(a)
(c)
N
N
Major product?
N
(b)
N (d)
28. What could be the product for the following reaction? OH
O OH H+ Removal of water
Product?
esr amines and phenols
O (a)
O
(b)
O
O
HO
OH
O
O
(c)
OH
O
O
(d)
O
29. What could be the product for the following reaction? O Cl2 (excess)
Product + CHCl3
HO–, H2O O
Cl (b) HO
(a) HO
O O
O
(c) Cl
(d)
O
30. Predict the product of the following reaction sequence. O Cl AlCl3
(a)
NO2
Zn(Hg) HCl
HNO3 H2SO4
(b) NO2
(c)
NO2 (d) NO2
31. What could be the product for the following reaction? CH3 Br
(i) Mg, Et2O (ii) CD2O (iii) H2O
Product?
6.37
6.38
chapter six CH2OD (a)
CH3
(b)
CH3
H
CH3 (c)
(d)
OH
D D
CH3
D 32. For the given reaction: CH3 – C – CH3 (R) will be
(R)
CH3 CH3
CH3
(b) CH3–C–OH/H⊕
(a) CH3–C–Br/AlBr3 CH3
CH3
/H⊕
(c) CH3–C=CH2
Cl (d) CH3–CH–CH–Ph
CH3
CH3
33. Which of the following compound will not give Friedel-Crafts reaction? CHO (a) O2N–
(c)
–NO2 (b) ⊕ NR3 O (d) C5H5N –C OH
34. In the given reaction, electrophilic substitution will take place readily at the carbon?
Br H3C
1'
1 2
2' 3'
(a) 1’
3
NO2 H3C
(b) 1
(c) 3
(d) 3’
35. In the given reaction O H–C– options.
O – CH2 – CH2 – CH2 – C – Cl
AlCl3
(X)
Zn–Hg/HCl
(Y); Choose the correct
esr amines and phenols
(a) (X) is HC
(b) (Y) is H3C
O
O CH3
(c) (X) is
O
(d) (Y) is HC
36. The type of substitution reactions of benzenoid hydrocarbons are (a) elimination (b) electrophilic (c) nucleophilic (d) free radical 37. Among the following compounds, which liberates F– on reaction with MeO–? F
F (a)
(b)
OMe
NO2
F
F NO2
(c)
(d) Me
NO2
38. Among the following reactions, which form salicylic acid (after acidification)? OH (a)
OH (b) + CCl4 + NaOH
+ CHCl3 + NaOH
COOH
OH
(c)
+ CO2 + NaOH Me
39. Me –
– C – O – OH
H3O⊕
(d)
P1 + P2; (P2 + FeCl3
+ NaOH
Violet colour)
P1 + NaOI → P3 ↓ + P4 Yellow
Correct statement for the above sequence is (a) P3 on reaction with Ag gives acetylene (b) P4 on reaction with sodalime gives toluene (c) P4 on reaction with sodalime gives benzene (d) P1on reaction with 2,4-DNP gives yellow compound
6.39
6.40
chapter six 40. Identify compounds which are unstable at room temperature. O (a) (b) (c) (d) N 41. Identify reactions which give aromatic product. O (a)
O (c)
O O (b) + H2N – NH2
+ H+ O
+ H2N – OH
H+
(d)
+ H+
H+
− H2
42. Identify reactions which are not feasible.
(a)
NO2
NH2
NH2
Me–C– Cl (b) AlCl3
Me–Cl AlCl3 Me
NO2 (c)
NO2
O
F
F
NO2 Fe
Me
O
Cl2
(d)
Cl2
C
Fe
Cl
Cl
43. Identify reactions that give tribromo substituted product. OH
OH (a)
Br2
COOH
(b)
H2O
NaOH OH
OH (c)
Br2
Br2 CS2
Br2
(d)
H2O SO3H
44. Identify coupling reactions. (a)
⊕
N2Cl
Phenol + NaOH T < 5°C
N2Cl (b) Me
(c)
N2Cl
T < 5°C
(d)
OH OH
Me–Cl AlCl3
H3PO2 H2O
esr amines and phenols 45. Identify reactions which give phenol product. Cl Fused
(a)
FeSO4 H2O2
(b)
NaOH V2O5
(c)
500°C
(1) O2/hν
(d)
(2) Conc. H2SO4
46. Identify correctly matched reactions with their products. CH3
COOH Conc.
(a)
KMnO4 /
OH
OH (1) K2S2O8
(b)
H
OH CH3 Ac2O
Ph–NH2 (c)
H2C
Cl
SO2Cl2
Ph–NH–Ac (d)
hν
47. Identify method of prepration of benzene. OH (a) 3CH
CH
Red hot Fe tube
Zn dust ∆
(b)
CH3 (c)
NBS
(d)
Cr2O3 ∆
48. Identify correctly matched reactions with their products. NH2 (1) Ac2O (2)
(a)
Cl (3) Aq. NaOH
NH2
NO2
AlCl3
NH4SH
(b) NO2
NH2 (c)
NO2 CF3COOH
NH2
N
NH2 (d)
NO2
H2SO5
O
6.41
6.42
chapter six 49. Identify correctly matched reactions with their products. Cl ⊕ SbCl5 (a) + 2SbCl6 ⊕ Cl
(b)
2Na
Cl 2Na
(c)
Dry ether
Cl COONa
Electrolysis
(d) COONa
50. Identify correctly matched reaction with their products. Me
Me
(a)
Na/Liq. NH3
NO2
NO2
(b)
Na/Liq. NH3 NO2
NO2
(c)
Na/Liq. Me
NH3
Me
Me
Me
(d)
Na/Liq. Me
NH3
Me
51. Identify reactions that give aromatic products. (a) O O (c)
(NH4)2CO3 ∆
O
Conc. H2SO4 ∆
CHO (b)
NH2NH2 H+/∆
CHO (d)
HCl CCl4
esr amines and phenols 52. Annealation takes place in which of the following compounds? (a)
(b)
(c)
(d)
53. Which of the following is an anti-aromatic compound? H H H ⊕ ⊕ (a) (b) (c) N B (d)
54. Which compound does not give SN′/solvolysis reaction? O I O (a) (b) (c) Cl (d) Cl Cl
Comprehension Type Passage 1 The conversion of an amide into an amine with one carbon atom less by the action of alkaline hydrohalite is known as Hofmann bromamide rearrangement: Br /KOH
2 → R—NH2 RCONH2
The most important feature of the reaction is the rearrangement of N–bromamide anion to isocyanate: O O O H Br OH R – C – N – Br R–N C O R – C – NH2 2 R – C – N Br OH Step 1 Step 2 Step 3 H2O
OH
R – NH2 + CO23−
55. The product of the reaction H C6H5
CONH2
Br2/KOH
Product
CH3
Product amine will be (a) S-amine (c) 50:50 mixture of (+) and (–) amine
(b) R-amine (d) 30:70 mixture of (+) and (–) amine
6.43
6.44
chapter six 56. Predit the product in the following reaction * CONH2
CONH2
KOBr
+ D NH2
NH2 (ii)
(i)
* * NH2 NH2 (iii) (iv)
D
D
(a) i and ii
(b) i and iii
(c) ii and iii
(d) i and iv
57. Which of the following can undergo Hofmann bromamide reaction most easily? CONH2 (a)
CONH2
CONH2 (b)
(c)
CONH2 (d) NO2
OCH3
CH3 Passage 2
A general equation for a Friedel-Crafts alkylation reaction is the following R AlCl3 +HX +R – X Alkyl halides by themselves are insufficiently electrophilic to react with benzene. F urther, AlCl3 serves as a Lewis acid catalyst to enhance the electrophilicity of the alkylating agent. The mechanism for the reaction is shown in the following steps Mechanism for the reaction: Cl Step I
H3C
CH – Cl +
H3C
Cl
⊕
+ HC
Step II
Al Cl
CH – Cl+ ––Al – Cl
H3C
Cl
⊕
CH3
CH3 H
CH3
H3C ⊕ CH + AlCl4 H3C
CH3
Other canonical forms
Cl
⊕
Step III H
Cl
H3C
CH3 + CH3
CH3 + HCl + AlCl3 CH3
Cl – Al – Cl Cl
With R–X is a primary halide, the carbon halogen bond is nearly broken and one in which the carbon atom has a considerable +ve charge.
δ+ R–CH2
Cl
δ– AlCl3
esr amines and phenols this complex acts as the electrophile. The Friedel-Crafts acylation reaction is an effective means of introducing an acyl group into an aromatic ring. The reaction is often carried out by treating the aromatic compound with an acyl halide. O CH2 – CH3 O + HCl AlCl3 + H3C Cl 58. Consider the following statements for the given reaction
(i) The Friedel-Crafts reaction is an electrophilic aromatic substitution. (ii) First step of the reaction is the rate-determining step. (iii) Second step of the reaction is the rate-determining step. (iv) Third step is an acid–base reaction. Now, of these statements (a) i and ii are correct (b) i, ii and iii are correct (c) i, iii and iv are correct (d) i, ii, iii and iv are correct
59.
CH3 – Cl
(CH3)2CHCl AlCl3
;
AlCl3
What is the reason for trisubstituted product in the second case? (a) less positive inductive effect (b) more steric effect (c) less hyperconjugation (d) more mesomeric effect
60. Ph3C COCl + AlCl3 + COC(Ph)3 (a)
∆ (strong heating)
The major product is Ph
CPh3 (b)
Cl
(c) Ph
(d) Ph
Passage 3 Nitration of benzene or any aromatic system is done by treating it with a mixture of Conc. HNO3 and Conc. H2SO4 (called nitrating mixture). These two acids react together according to the equation given below, to form nitronium ion which act as an electrophile: ⊕
⊕
2H2SO4 + HNO3 ⎯→ 2HSO4– + H 3 O + NO 2 ⊕
NO 2 ion, an electrophile then attacks benzene or any aromatic system to accomplish nitration in the following two steps with arenium ion as the reaction intermediate: ⊕
+ NO2
H Step I
⊕
NO2 ⊕ HSO4 Step II
NO2 + H2SO4
The direct nitration of aniline or phenol with nitrating mixture gives very poor yield of nitro product because benzene ring attached to –NH2 or –OH group is very sensitive to oxidation and major part of aniline or phenol is oxidized to give a black tar mass that contains mainly
6.45
6.46
chapter six benzoquinone, O
O. Although –NH2 group is o/p-orienting, m-nitro derivative is also
formed. The ring is protected from oxidation by acetylating –NH2 group before subjecting it to nitration. After nitration, product is hydrolyzed to get deacetylated product (o- and p-nitro derivatives). Nitration of phenol is carried out by Dil. HNO3. It is believed that nitrous acid (present as an impurity) interacts with HNO3 to give nitrosonium ion, an electrophile which reacts with phenol to give o- and p-nitrosophenol, the latter being the principal product, according to the same mechanism as that of nitration mentioned above. Nitrosophenol is then oxidized by HNO3 to nitrophenol while HNO3 is itself reduced to HNO2. 61. Regarding the nitration of phenol with Dil. HNO3 as described above, the incorrect statement is (a) HNO3 acts as an acid and also as an oxidant. (b) Nitrous acid acts as a base. (c) The reaction intermediate is an arenium ion. (d) Amount of HNO2 goes on decreasing with the progress of nitration. 62. Correct statement is/are
CH3
NO2
(a) Rate of nitration is in the order:
(b) Rate of nitration of benzene and that of hexa deuterated benzene occur almost at the same rate (c) By increasing the concentration of acids (HNO3 + H2SO4), the rate of nitration increases (d) All of the above
H2SO4
63. NH
N
O
HNO3
>
>
Major product is:
NO2
NO2
(a)
(c)
(b) N
NH
O
N
NH
O
NO2
Passage 4
NH
N
N
O
(d) G
It is very well known that when a compound
reacts with an electrophile then we either get
G ortho- or para-substituted product, i.e., G i.e.,
N
G E
+
or we get a meta-substituted product, E
. E
esr amines and phenols This depends on the electron-releasing or electron-withdrawing power of the group, i.e., +R/–R or +M/–M effect of group G. There is another theory that is the electrophile attacks the ring carbon where the substituent G is a already attached. G +E⊕
i.e.,
E G ⊕
–E⊕
E –G⊕
This is called ipso substitution reaction. 64. The factor which is expected to promote ipso substitution is
(a) The group G should be a strong electron withdrawing group (b) A group which is highly electron withdrawing should be attached at ortho or para position with respect to the group G (c) The group G should leave as G+ easily, i.e., G+ should be highly stable (d) The group G should leave easily, i.e., G+ should be highly unstable Me
CH
Me HNO3 + H2SO4
65. In the reaction Me
CH
A + B.
Me
A and B are respectively Me
CH
NO2
(a) Me Me
Me
Me +
O2N
CH
NO2 CH
CH
NO2
Me
Me
Me
Me
NO2
(c)
Me
CH
CH
Me
Me
Me
+ CH Me Me
CH
Me
Me
CH
Me NO2
+
(b)
Me
NO2 C – NO2 Me Me
Me
NO2 CH
CH
Me
Me
Me
Me
CH
CH
Me Me
+
(d) NO2
NO2 CH Me Me
66. In which of the following can you expect ipso addition? OH OH OH CH3 COOH H SO 3 (i) (ii) (iii)
(a) i only
(b) ii only
(c) i and ii only
(d) i, ii, and iii
Passage 5 When a second substituent is introduced in benzene ring, it is directed by group already present on benzene ring. Electron-releasing groups are activating, therefore o and p-directing, whereas electron-withdrawing groups are deactivating, therefore m-directing. H alogens, although they are electron withdrawing due to –I effect but still o- and p-directing due to +R effect. –N=O
6.47
6.48
chapter six group is also deactivating but o- and p-directing due to presence of long pair of electrons like halogens it shows +R effect. When a third substituent is introduced into a disubstituted product, the o-isomer gives two, the m-isomer gives three while p-isomer gives only one product. This method is called Korner’s method. The major product is formed such that it has minimum steric hindrance. 67. Which of the following is not formed at all? Cl Cl Cl (a)
+ HNO3 conc.
Conc. H2SO4 Cl
Cl
(b) O2N Cl
NO2 Cl
Cl
NO2 Cl
(c)
(d) Cl
O2N
CH3 + H2SO4 Heat 'A.' 'A' is: Conc.
68. NO2
CH3 (a)
CH3 SO3H
NO2
(b) SO3H NO2
CH3
CH3
(c)
HO S (d) 3
SO3H NO2
NHOH CH3 69.
CH3 (o-xylene) on mononitration gives
(a) two products (b) three products
(c) one product
(d) four products
Passage 6 When a mono substituted benzene derivative, C6H5Y, undergoes further electrophilic substitution, e.g., nitration, the incoming substituent may be incorporated at the o-, m- or p- position and the overall rate at which substitution takes place may be faster or slower than with benzene itself. It has been observed that substitution occurs so as to yield either predominantly the m-isomer or a mixture of o- and p-isomers, in the former case the overall rate of attack is always
esr amines and phenols slower than on benzene itself, in the latter case the overall rate of attack is usually faster than on benzene itself. This is due to electronic effects that Y can exert. Substituent, Y is thus classified as m- or o-/p-directing; if the substituent induces faster overall attack than on benzene itself then the substituent is said to be activating, if slower then deactivating. NH
O
Ph
70.
O
NH
on mononitration gives the major product
NH
O Ph
(a)
O Ph
(b) NO2
NH Ph NO2 (d)
NH
O (c)
NO2
NO2
OH ⊕
+ PhN2
71.
pH = 9 – 10
Ph
X (major product). X will be
NH2 OH (a)
OH
OH N2Ph
(b)
N2Ph
(c)
NH2
NH2
N2Ph (d)
N2Ph
NH2
72. Which among the following will give highest yield of p-isomer during nitration? Br F Cl I (a) (b) (c) (d)
Passage 7 Me CH – Me
Sn + HCl
– NO2
(X)
HCl + NaNO2 0−5°C
(Y)
p-nitro cummene
H2O/∆
(Y)
CuCN HCN H3PO2
(P) (Q)
(i) SnCl2 + HCl (T) (ii) H3O⊕
(R) (S) OH
For the given reaction sequence, answer the following
6.49
6.50
chapter six N3 H 4 4 /H → Final product; final product is 73. (Y) HBF → KMnO → H ∆ 2 SO 4 ∆ ⊕
(a) F –
O
–C
NH2
Me (c) CH – Me 74. (R)
(b) F– – NH2
Me N– – NH2 (d) Me
(i) CH3COCl/AlCl3 (A) + (B) (ii) NaOH + I2 Yellow ppt. (A)
–F
(i) H2O/H⊕ Product (L) (ii) SOCl2 (iii) (R)/AlCl3 (iv) H⊕, Δ
The correct statement about the product (L) is (a) Product (L) on reaction with Tollen’s reagent gives silver mirror (b) Product (L) on reaction with H2N–NH2/–OH, ∆ gives diphenyl methane (c) Product (L) on reaction with HCN gives a compound which contains a chiral centre (d) All of these
Alc . 75. Compound (T) KCN → Product is
(a)
OH – CH – CN
(b) – CH2CN
OH (c)
– C – CN
OH
(d)
– CH – C – O
Passage 8 Consider the aromatic anthracene molecule, C14H10 , shown in the figure: 8 7 6 5
14 13
9
10
11 12
1 2 3 4
Approximate calculation of the π-bond order for C–C bonds yield the following results Bond p-bond order 1–2 0.738 1–11 0.535 2–3 0.586 9–11 0.606 11–12 0.485
esr amines and phenols Also, considering the electron displacement effect in combination with bond order data, answer the following questions. 76. Which of the following carbon is most likely to be attacked by an electrophile (NO +2 in acetic anhydride at 15–20°C)? (a) C–1 (b) C–9 (c) C–2 (d) C–11 77. Which of the following C–C bond has least percentage of single bond character? (a) C1–C2 (b) C1–C11 (c) C11–C12 (d) C2–C3 78. Which of the following (C–C) bonds are shortest and longest respectively? (a) 11–12 and 1–2 (b) 1–2 and 11–12 (c) 9–11 and 1–2 (d) 2–3 and 9–11 Passage 9 Benzene gives electrophilic substitution reaction with strong electrophilic. The leaving group of this reaction is H in the form of H⊕, –COOH in the form of CO2 and –SO3H in the form of SO2. The reaction is known as aromatic electrophilic substitution (ArSE) reaction. 79. Benzene can be obtained by
(a) Conc. HNO3/Conc. H2SO4/Benzene (b) NO2BF4/Benzene (c) NO2ClO4/Benzene (d) Phenol/Zn
80. Consider the following statements
(i) Benzene reacts with electrophile to form reaction intermediate known as cyclohexadienyl cation. (ii) Formation of carbon-electrophilic bond is rate-determining step in ArSE reaction. (iii) Breaking of C – H bond is rate-determining step (iv) Sulphonation of benzene is a reversible reaction The correct statements from the above are (a) i, ii, iii and iv (b) i, ii and iv (c) i, iii and iv (d) ii, iii and iv
81. In the given reaction OH
OH COOH
Br2 H2O
Br
Br
Br The leaving group(s) in the form of electrolphile is 2H⊕ only (a) (b) One H⊕ and one CO2 (c) (d) One CO2 only 2H⊕ and one CO2
6.51
6.52
chapter six Passage 10 Based on the Lewis structure of benzene H H
C
C
C
H
H C C C H H Benzene 82. What is the bond angle for each H-C-C and each C-C-C on benzene? (a) 120º and 120º (b) 109.5º and 120º (c) 120º and 109.5º (d) 180º and 120º (e) None of these 83. What one of the following is the best description for the overall shape of benzene molecule? (a) Linear (b) Triangular (c) Tetrahedron (d) Planar (e) Goofy
Matrix Type 84. Match the columns. Column I (alkene)
Column II (o/p ratio in nitration)
CH3 (a)
(b)
(c)
(d)
CH2CH3
CHMe2
CMe3
(p) 0.22
(q) 0.92
(r) 1.57
(s) 0.48
85. Match the columns. Column I Column II (reagents used for the desired product in major amount) OH
OH
(a)
COOH
(p) CHCl3/NaOH
esr amines and phenols OH
OH
COOH
(b)
(q) CCl4/NaOH
Cl
(c)
N H
N
OH
OH
(r) NaOH followed by CO2
CHO
(d)
(s) KOH followed by CO2
86. Identify reaction correct match with its reagent Reaction Reagent O C
N
C
(a) OMe
(b)
OMe O
O
O
O
H (p) DIBAL–H/H3O+
O
(q) TSCl/LAH
O
HO
(c)
O
NO2
NO2
(r) O3/Zn
(d)
(s) Zn–Hg/HCl
CH3
C H O
87. Match the reduction in Column I with their products listed in Column II. Column I Column II NO2 (a)
NH2 (i) Sn/HCl
(p)
(ii) OHQ NO
NO2
(b)
Zn/NaOH/C2H5OH
(q)
6.53
6.54
chapter six NHOH
NO2
Zn/NH4Cl
(c)
(r) N – N – Ph
NO2
Fe/H2O
(d)
(s)
88. Match the processes in Column I with properties in Column II. Column I Column II (pair of compounds) (reagent used to distinguish pair of compounds) OH (a)
OH
and
(p) Br2/H2O test
OH (b)
and
(q) Tollen’s reagent
O (c) Me – C – H and
(r) Iodoform test
O (d) Me – CH2 – C ≡ CH and Me – C ≡ C – Me
(s) Lucas reagent (t) Ammonical cuprous chloride
89. Match the Column I with Column II. Column I Column II (a) Toluene (p) On oxidation by KMnO4 in acid medium gives benzoic acid (b) Cumene (q) Used in the manufacture of phenol (c) Benzene (r) Symmetrical trimethyl benzene (d) Mesitylene (s) On oxidation (V2O5/O2) at 250–450°C gives maleic anhydride 90. Match the columns. Column I Column II (pair of compounds) (reagents used for identification) OH (a)
NH2
and O
(p) Br2 + H2O test O
(b) Et – C – H and Me – C – Me
(q) CHCl3 + NaOH test
(r) Iodoform test
(c) Me–C≡C–H and Me–C≡C–Me and O
O (d) OH
O
(s) Tollen’s reagent
esr amines and phenols 91. Match the columns. Column I (reaction)
Column II (reagents)
O (a) R – C – NH2
RNH2
(p) KOBr
O
(b) R – C – NH – R
RNH2
(q) OH–/H2O
O
(c) R – C – OH
RNH2
(r) N3H/H⊕
O
(d) R – C – NH – NH2
RNH2
92. Match the columns. Column I (pair)
(s) HNO2/∆/H3O⊕ Column II
O CH3 – C – Cl/NaN3 (a)
(p) Lossen rearrangement
O CH3 – C – NH2/NaOBr (b)
(q) Schmidt rearrangement
(c) CH3COOH/N3H
(r) Hofmann rearrangement
O
O
(d) C6H5 – C – NH – O – C – CH3/Base (s) Curtius rearrangement
93. Match the Column I with Column II. Column I Column II (Intermediate/Product) O (a) CH3 – C – NH2 O
(b) CH3 – C – OH O
(c) CH3 – C – OH
(d) CH3 – C – Cl
O
KOH + Br2
N3H H2SO4 NH3 ∆ (i) NaN3
(ii) H3O ⊕
(p) CH3N=C=O
O (q) CH3–C–NHBr O (r) CH3–C–ONH4
(s) CH3NH2
94. Match Column I with Column II. Column I (elements/compounds)
Column II (tests)
(p) Br2/H2O
(a) Halogens O
R – C – CH3 (b)
(q) Baker-Mulliken test
6.55
6.56
chapter six OH (c)
HO
(r) Iodoform test
OH
NO2
(d)
(s) Beilstein test
95. Match Column I with Column II. Column I [name of reaction] (a) Haloform reaction (b) Aldol addition (c) Witting reaction (d) Hofmann bromamide reaction
Column II [substrate(s) of reaction] (p) α-methyl carbonyl compound (q) Acid amide (r) Aldehyde (s) Halide and carbonyl
96. Column I (reaction) (a) Wurtz reaction (b) Dehydration of alcohol with Conc. H3PO4
(c) Kolbe’s electrolysis (d) Diazotisation
Column II (intermediate) (p) Carbocation (q) Electrophile (excluding free radicals) (r) Free radical (s) Carbanion (t) N2 gas liberated in intermediate step
Integer Type 97. Identify compounds which are aromatic. ⊕
⊕
⊕ O
O
O
⊕
O
O
N
98. Identify compounds which are nonaromatic. OH
⊕
N
O O
⊕
O N
esr amines and phenols 99. Identify compounds which are antiaromatic.
⊕
N H B
O O
⊕
N
100. Identify compounds which react faster than benzene in ArSE reaction? OH
NH2
BH2
CN
NO2
COOEt
CD3
NHCOR
OCOR
NO
CHO
101. Identify compounds which react slower than benzene in ArSE reaction? OAc
NHAc
BH2
CN
NO2
COOEt
CHO
COOH
CD3
NHCOR
OCOR
NO
6.57
6.58
chapter six
Answer Keys Level 1 1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
b
b
c
c
c
b
a
a
c
b
c
c
c
c
b
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
b
a
b
c
d
d
d
d
b
d
b
c
b
cd
b
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
c
b
d
d
b
b
c
d
d
a
b
a
a
d
b
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
c
b
a
b
b
b
b
a
c
b
c
b
d
a
c
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
d
c
c
d
a
c
a
ac
c
b
a
c
d
d
a
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
a
b
b
a
b
b
b
15
b
a
c
c
d
b
b
c
91
92
93
94
95
96
97
98
b
d
a
a
c
d
ab
c
Level 2 1
2
3
4
5
6
7
8
9
10
11
12
13
14
c
a
b
b
d
a
d
a
c
a
b
b
b
b
c
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
d
a
a
c
c
c
b
b
a
b
a
a
a
d
b
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
d
abc
abc
bc
ab
bd
bc
bc
acd
acd
abcd
ab
abd
ac
abd
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
abcd
ab
abd
bd
ad
abc
bcd
abc
ac
a
b
c
c
b
b
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
a
d
a
d
b
b
d
b
d
c
c
d
c
d
d
76
77
78
79
80
81
82
83
b
b
b
d
b
c
a
d
84(a) 84(b) 84(c) 84(d) 85(a) 85(b) 85(c) r
q
s
p
s
qr
p
85(d) 86(a) 86(b) 86(c) 86(d) 87(a) 87(b) 87(c) 87(d) 88(a) 88(b) 88(c) 88(d) 89(a) 89(b) p
p
q
r
s
p
s
r
q
rs
pq
qr
qt
p
pq
89(c) 89(d) 90(a) 90(b) 90(c) 90(d) 91(a) 91(b) 91(c) 91(d) 92(a) 92(b) 92(c) 92(d) 93(a) s
r
q
rs
s
r
p
q
r
s
s
r
q
p
pqs
93(b) 93(c) 93(d) 94(a) 94(b) 94(c) 94(d) 95(a) 95(b) 95(c) 95(d) 96(a) 96(b) 96(c) 96(d) ps
r
ps
s
r
97
98
99
100
101
5
4
3
6
7
p
q
prs
pr
prs
q
rs
pq
r
pqt
esr amines and phenols
Workbook Exercises Exercise 1 Identify complete reaction sequence H3C
CH3
N
H3C SO3 / H2SO4
1.
O2N
Cl
3.
OEt Na / Liq. NH3
2. H3C H3C
NaSMe / MeSH
HNO3 / H2SO4
4.
Cl
CH3 CH3
H3C
5.
Cl
NaNH2 / NH3(l)
Br2 / NaOH
6. HO COOH
7.
Br2 / NaOH HO
8.
HO3S HO
SO3H
COOH
COOH
9.
Br2 / NaOH
Br2 / NaOH
HO
10.
H3C H3C
CH3 Br2 / Fe
COOH CH3 CH3 I2 / CuCl2
11.
NO2
12.
SO3H Cl
13.
NO2
NaSMe / MeSH
NO2
14.
O
HNO3 / H2SO4 CH3
H3C
15.
HNO3 / H2SO4
CH3
HNO3 / H2SO4
CH3 Con. H2SO4
16. OH
17.
Con. H2SO4 ∆
18.
Con. H2SO4
6.59
6.60
chapter six H3C
OH V2O5 / 500 °C
19.
CH3 Con. KMnO4
20.
O
21.
H3C
I2 / CuCl2
Cl
22.
SO3H
Cl
23. NO2
NO2 O
H3C
Cl AlCl3
24.
O
O O
Br2 / NaOH CH3
H3C
25.
Cl AlCl3
(1) OH−/∆ (2) PhN2Cl
CH3 CHCl3/NaOH
26.
CH3
OH OEt
V2O5/500°C
27.
H3C
NO2
29.
Conc. H2SO4
28.
V2O5/500 °C
CH3 Con. KMnO4
30. CH3
esr amines and phenols
Exercise 2 Identify reagent used and intermediate products in the following conversion. A. Multiple-step synthesis CH3Br AlCl3
i
A HNO3 H2SO4
ii
Br
NH2
(a)
iii
Heat (b) HO−
HN2
H2Pt/C
NH2 NH
B. Multiple-step synthesis H3C
N
CH3 CH3
NH2 CH3I K2CO3
CH3
NaNO2 HCl
v
H2O, H+ and heat
vi
NaNO2 HCl
iv
B
C CH3
D
CH3
F CH3
CH3
6.61
6.62
chapter six
Exercise 3 Identify reagent used and intermediate products in the following conversion. NO2 CH3
B
CH3
H2, Pt
ii
NaNO2 HCl
iii
H2O H+, heat
iv
A C
CH3 Na2Cr2O7 H+, heat
i
D CH3
CH3
Br
E
F F
CN CH3
CH3
CH2CH3
Exercise 4 Identify reagent used and intermediate products in the following conversion. A and F are a pair of enantiomers OH F +
OH CH3 G
A
OH H2O, H+
a CH3 Br2
H2 Pt or Pd
+ D
b B
C
Cl CH3 E
C and D are a pair of enantiomers
esr amines and phenols
Solution for Workbook Exercises Exercise 1 Identify complete reaction sequence. H3 C
N
C H3
SO3 / H2 SO4
1.
H3C N
SO 3 H
H3C
OEt
H3C
H3 C
OEt
O2 N
Cl
2.
3.
Na / liq. NH3
NaSMe / MeSH
O2 N
Cl
Cl
SMe
H3C H3C
H3C
HNO3 / H2SO4
4.
NO 2
H3C
C H3 H3 C
5.
6.
CH 3
C H3
H3C
NaNH2 / NH3(l)
Cl
H2N
Br2 / NaOH
Br
HO
Br
HO COOH
Br
Br2 / NaOH
7. HO
Br
Br
HO SO3 H
8.
Br
Br2 / NaOH
HO3 S
HO
HO
Br
COOH COOH
Br
Br
Br
Br
Br2 / NaOH
9. H O
HO COOH
Br
CH 3
6.63
6.64
chapter six H3 C
10.
C H3
H3C
H3C
Br2 / Fe
C H3
H3C
Br
CH 3 C H3
11.
CH 3
12.
I
H3 C
SO3 H NO2
SO3 H
I2 / CuCl2
HNO3 / H 2SO4
NO2
O2 N
CH3
CH3
NO2
NO2 Cl
SMe
NaSMe / MeSH
13.
NO2
NO2 NO2
14.
O
HNO3 / H2SO4
CH3
CH3 H3C
O
H3C
CH3
CH3 NO
2
HNO3 / H2SO4
15.
SO3H
Con. H2SO4
16.
Con. H2SO4
17. OH
18.
Con. H2SO4
SO3H
OH
SO 3 H
esr amines and phenols OH
O
V2O5 / 500 °C
19.
O
H3C
C H3
COOH
Con. KMnO4
20.
I
I2 / CuCl2
21. Cl
Cl SO3H
SO3H O H3 C
22.
AlCl3
NO 2
No reaction
Cl NO 2 O
Cl
23.
H3 C
Cl Cl
No reaction
AlCl3
NO 2
NO 2 Br
Br2 / NaOH
O
O
24. CH3
CH3 H3 C
H3 C
CH3
CH3 N2 Ph
O O
25.
(i) OH – / (ii) PhN2Cl
OH
CH3
CHCl3 /NaOH
26.
OHC
OH
27.
OH
V2O5 / 500 °C
O O
O
6.65
6.66
chapter six OEt
Con. H2SO4
28.
OEt
SO3H
NO 2
V2O5 / 500 °C
29.
NO2 O O O
H3C
CH3
Con. KMnO4
30.
HOOC CH3
COOH
esr amines and phenols
Exercise 2 A. Multiple-step Synthesis NH2
H2N
CH3 Br AlCl3
NH
Br2/Fe
H2 Pt/C HNO3 H2 SO4
O2 N
NH2
(a)
Br
Br NO2
O2 N
heat (b) HO–
NH NO2
B. Multiple-step Synthesis H3 C
N
CH3 CH3
CH3 I K2 CO 3
NH2
NaNO CH3 HCl 2
N2 Cl
OH CH3
H 2 O,H+ , heat
NaNO2 HCl H3 C
N
CH3 CH3
NO
H3PO2 CH3
MeMgCl
HBF4
CH3
F CH3
CH3
CH3
6.67
6.68
chapter six
Exercise 3 Identify reagent used and intermediate products in following conversion. NH2
NO 2 CH3
CH3
HNO3
CH3 NaNO 2 HCl
H 2 , Pt
N2{ Cl| CH3 H2 O H+, heat
OH CH3
H2SO4 EtCl / AlCl3 CuBr HBr
COOH
CH3 Na2 Cr2 O7 H +, heat
NaCN KCN
H3PO2 CH3
CH3
HBF4 F
CN
Br
CH3
CH3
COOH
CH2 CH3
Exercise 4 Identify reagent used and intermediate products in following conversion. A and F are a pair of enatiomers OH F OH
OH CH3
H2O, H+
G
OH
+
OH a = OSO4 CH3
Br2
Br
+
H2 Pt or Pd b = HCl/CCl4 CH3
Cl E
CH3
Br
Br C and D are a pair of enatiomers
Br
esr amines and phenols
Reaction Mechanism Chart
H3PO2
Butter yellow
Azobenzene
N Aniline/H+
N
N N
Phenol/OH−
+
N N Cl−
+
N N
OH
p-hydoxy azobenzene
N N
COOH Methyl red
NH2
p-amino azobenzene
N N
N
N N
N N
+
Methyl orange NaO3S
COOH +
O Br
Br
N N
+
N N
KI
CuBr/HBr
Benzene
N
I
Br
CuCN/HCN
HBF4
CuCl/HCl
N N
NaO3S
CN
F
Cl
(1) MeMgCl (2) H3O+ Br
Br
NH2
Br2/ Br H O 2
NH2
COOH
H3O
HNO2 CN
(1) HNO2 (2) CuCN/KCN
Br CONH2 Br Br
(1) HNO2 HNO2 (2) CuCN/HCN Conc. H2SO4
Br
(1) H3O
OH (2) NaOH (3) Electolysis
OH
Br
Br
Biphenyl
Tri bromo benzamide
Br OH
OH
H2O/Heat Br
+
N N
+
N N Cl−
CN
CHO Br (1) DIBALH
OH
(2) H3O+
N N
Br AcOAc/Py OAc
NaOH/CCl4
KH/MeI OMe
OH
CONH2
COOH
+
Conc. H2SO4
H3O
Br Tri bromo benzoic acid
+
(2) EtOH/H
Ethyl benzoate
Tri bromo benzaldehyde
COOH Br Br
COOEt
+
(1) H3O
OAc HOOC Aspirin
AcOAc / Py
+
MeOH/H
Benzamide
OH COOMe Oil of winter green
6.69
This page is intentionally left blank
CHAPTER
7
Biomolecules Question Bank
Level 1 1. Which of the following statements is correct? (a) The Ruff procedure lengthens an aldose chain and gives a single product. (b) (c) The Kiliani-Fischer procedure shortens an aldose chain and gives a single product. (d) The Kiliani-Fischer procedure lengthens an aldose chain and gives two epimers. 2. Which of the following is not a disaccharide? (a) sucrose (b) mannose (c) lactose
(d) maltose
3. Which statement about the pyranose form of mannose is not correct? (a) it exists as two anomeric stereoisomers. (b) it reacts with Tollen’s reagent to give a silver mirror (i.e., it is a reducing sugars). (c) reaction with excess CH3I and AgOH gives a non-reducing penta-O-methyl derivative. (d) it resists reduction with aqueous sodium borohydride. 4. Two aldopentoses X and Y give the same osazone derivative. X is oxidised to an optically active aldaric acid by dilute nitric acid. Ruff degradation of Y gave a tetrose which was similarly oxidised to an optically active aldaric acid. Assign the structures of X and Y from the following list.
7.2
chapter seven O H H (i) H
O
OH
HO
H
HO
OH (ii) HO
H
(iii) H
OH
OH
H
(a) X = i and Y = iii (c) X = v and Y = iv
O H
H
H
OH
OH
O
OH
OH (iv) HO
H
OH
OH
H
OH
OH
(b) X = iv and Y = ii (d) X = iii and Y = i
5. Which of the structures 1 through 4 is methyl-d-galactopyranoside? O H
OH
HO
H
HO
H
H
OH OH
D-Galactose
HO H (i) HO
OH HO O H (ii) HH H HH H H OH OH OMe H OMe HO OH
O
H (2) H H(1) H O O HO HO (iii) (iv) H OH H H H H HO OH OH H OMe HO OMe H (a) i (b) ii (c) iii (d) iv (3) (4) 6. What is invert sugar, and why is it so named? (a) the sugar mixture from hydrolysis of sucrose; fructose is isomerised to glucose. (b) the sugar mixture from hydrolysis of sucrose; the optical rotation changes from (+) to (–). (c) the sugar mixture from hydrolysis of starch; a-glycosidic bonds are changed to b-glycosidic bonds. (d) the sugar mixture from hydrolysis of starch; glucose is isomerised to fructose. 7. Which of the following compounds is a b-aldopentafuranose? HO OH
(i)
H
OH
O H
(ii)
H H
OH
OH
OH
O H
HO
H OH
H
OH
biomolecules H (iii) H
H
(a) i
OH
O
HO H
OH
HO
OH
O
(iv) OH
H
H
H
H H
(b) ii
(c) iii
OH (d) iv
8. When octa-O-methyl D-cellobiose is hydrolysed by an aqueous acid, two O-methyated glucose derivatives are formed. One is a tetramethyl derivative, and the other is a trimethyl derivative. Why is a single methyl substituent lost in this process? (a) one methoxy group is lost by b-elimination. (b) one methoxy group is an ester and the others are all ethers. (c) one methoxy group is part of an acetal, the others are all ethers. (d) one glucose is an a-methyl glycoside; the other is a b-methyl glycoside. 9. Acid-catalysed reaction of d-glucose with benzaldehyde produces the 4,6-O-benzylidene derivative. Reduction with NaBH4, followed by excess HIO4 cleavage and acid hydrolysis yields a C4H8O4 tetrose and benzaldehyde. What is the configuration of this tetrose? (a) 2S, 3S (b) 2R, 3S (c) 2R, 3R (d) 2S, 3R 10. Gentiobiose is a disaccharide incorporated into the chemical structure of crocin, the chemical compound that gives saffron its colour. Deduce the structure of gentiobiose from the following information. (i) Acid hydrolysis of gentiobiose yields only d-glucose. (ii) Gentiobiose is hydrolysed by β-glucosidase enzymes, but not by α-glucosidase enzymes. (iii) Gentiobiose is a reducing sugar and reacts with sodium borohydride. (iv) Methylation of gentiobiose followed by hydrolysis of the glycosidic bonds yields the two d-glucose derivatives shown below. CHO H Gentiobiose
CH3I NEt3
H+
OCH3
H3OC
H2O
H
H
OH
H
OH CH2OCH3
CH2OH O OH OH
CHO
OH β – glucose
OH
H +
H3OC
OCH3 H
H
OCH3
H
OH CH2OCH3
7.3
7.4
chapter seven What is the structure of gentiobiose? CH2OH O
OH
CH2OH
OH
O
OH (a)
O O
(b) OH OH
O O
OH OH
OH
OH
OH
OH
OH
OH OH CH2OH
CH2OH
O OH
O CH2OH
O
OH (c)
OH
(d)
O
OH
O
O OH
OH
OH OH
OH
OH
OH OH
OH
11. Choose the answer that has correctly selected the major species of the following two acids to be present in blood naturally buffered at pH = 7.2. CH3 ⊕ H3C N H
CH3 H3C
CH3 pKa = 9.8
+ H⊕
N CH3
Acids
Conjugate bases O
O
O
OH
pKa = 4.2 O
CH3 (a) H3C
N CH3
+
O
CH3 ⊕ (b) H3C N + CH3
O O
biomolecules O
O
CH3 ⊕ (c) H3C N H +
OH
(d)
OH
CH3 + H3C
CH3
N CH3
[Possible species in blood buffered at pH = 7.2] 12. Which one of the following is a non-reducing sugar? (a) Glucose (b) Mannose (c) Fructose
(d) Sucrose
13. Which of the following compounds will not show mutarotation? (a) Methyl-α-d-glucopyranoiside (b) α-d (+) glucospyranose (c) β-d (+) glucopyranose (d) β-d (+) galactopyranose 14. α-d-glucose and β-d-glucose are (a) anomers (b) C2-epimers
(c) C3-epimers
(d) enantiomers
15. At isoelectric point, the amino acid has (a) Least viscosity (b) Maximum surface tension (c) Minimum solubility (d) All of these 16. Which one of the following is not correct for monosaccharides? (a) They are optically active polyhydroxy carbonyl compounds (b) Fructose is ketose sugar and hence it does not give red precipitate with Fehling’s solution (c) α-d (+) glucose and β-d (+) glucose are anomers (d) Glucose and mannose are epimers 17. Which of the following is not a surfactant? CH3 (a) CH3 – (CH2)15 – N+ – CH3Br–
(b) CH3 – (CH2)14 – CH2 – NH2
CH3
(c) CH3 – (CH2)16 – CH2OSO2– Na+
(d) OHC – (CH2)14 – CH2 – COO– Na+
18. Tertiary structure of protein contains which type of forces? (a) Electrostatic forces only (b) Electrostatic as well as hydrogen bonds (c) Electrostatic, hydrogen bonds and Vander waal forces (d) Electrostatic, hydrogen bonds, Vander waal forces, dipole–dipole attractions and disulphide crosslinkage. 19. Which of the following is an addition and homopolymer? (i) Neoprene (ii) Polystyrene (iii) Nylon-6,6 (a) only i (b) i, ii and iv (c) i and ii (d) i, ii, iii and iv
(iv) Nylon-6
7.5
7.6
chapter seven 20. Identify structure of thymine O
O (a)
H3C
N NH (b)
NH
NH
O
NH NH2 (c)
HO
NH2 OH
O
(d)
N
NH
N
O
OH
21. Identify structure of adenine O
NH2 (a) N NH
N (b)
NH
NH
O
NH
NH2
O
NH2
N (c)
N
N
(d)
H3C
N
NH NH
O
22. Identify structure of cytosine NH2 N (a) NH
O
N
(b)
H3C NH
N O
N (c) NH
NH O
NH2 (d) N
NH N
NH2
NH
O
23. Identify structure of guanine O
NH2 N (a) NH
N N
(b)
N NH
NH N
NH2
biomolecules NH2 (c)
O
N
(d)
H3C
NH
O
NH
O
NH
24. Identify structure of adenine deoxyribo-nucleoside NH2
NH2
N
N
N (a) HO
N
O
(b) N HO O
N
OH
OH
NH2 N (c)
O
O (d) HO P O
N
NH
O
N
OH
NH O
N
O
OH 25. Identify structure of Riboso-5-triphosphate O
O
O
O
HO P O P O (a) OH OH
O
OH
HO P O P O (b) OH OH
O
O
HO P O P O P O (c) OH OH OH
O
O
OH
O
O
(d) HO P O P O P OH OH
OH
OH
OH OH 26. Identify structure of Guanine deoxyribo-nucleotide NH2
NH2
N
N
N (a) HO
O
OH
N
OH
OH
OH OH O
O
N
(b) N HO O
OH
O
7.7
7.8
chapter seven O N
O
NH
O
(c) H3C
N (d) HO P O O OH
NH NH
O
N
NH2
OH
27. Identify structure of Cytosine deoxyribo-nucleoside NH2
NH2 N
N (a) HO
O
N
N O (b) HO O
N
N
OH
OH O N O (c) HO P O
O
OH
N
O NH
N
N
NH
O
NH2 (d) HO P O OH
O
N
N
OH
OH 28. Identify structure of Thymine deoxyribo-nucleotide
O
O N
NH
O (a) HO P O
O
OH
N
N
NH
O
NH2 (b) HO P O
O
OH OH
NH2 N
N O
OH
N
O
OH
NH2
(c) HO
N
N O (d) HO O
OH
N N
NH2
biomolecules 29. Identify structure of Guanine ribonuleotide O N N
O
N
NH
O (a) HO P O OH
NH2
NH2 (b) HO
N
N
O
OH OH
N N
OH OH NH2
O N
NH
O (c) HO P O OH
N
O
(d) HO
N
N
O P O OH
OH OH
OH OH
30. Identify structure of poly(diethylene glycol) OH (a) CH
CH2 (c)
CH2
O
CH3 C (b) NH O n
CH
CH
CH
CH2
CH2 (d)
n
CH2
n
CH2
CH2
O
31. Identify structure of poly(methyl acrylate) CH2 (a)
O
N
O
CH2
O
CH2
CH2
CH2
O
n
O C
(b) O
O
NH
CH3
n
C H CH2 n
(c) CH2
CH
CH
CH2
n
CH CH2 (d) C H3C O O
32. Identify structure of Nylon-6 (a) CH2 (b)
CH2
CH2 CH2
O
CH2
CH2
CH2
CH
CH2
n
C
NH
n CH
CH2 CH2
O
O
Cl (c)
CH2
O
n
(d) H3C O
CH2
C O
n
n
7.9
7.10
chapter seven 33. Identify structure of neoprene Cl CH2 (a)
C
CH
CH2
n
(b)
Cl
CH2 CH2
CH (c) 2
CH2
C
n
O
C
CH
CH2
n
(c) CH2
CH2 CH3
C
O
CH2
n
n
CH2 CH
O
n
CH
(d) N
C CH3
CH
O
Cl
(b)
Cl O
CH
(d) N
34. Identify structure of poly(methylmetacrylate) CH2 (a)
CH2
O
n
35. Among the following polymer identify homopolymer (a) Nylon-6 (b) Buna-N (c) Buna-S
(d) Polyethylene
36. Among the following polymers, identify the copolymer (a) Nylon-6 (b) Starch (c) PVC
(d) Protein
37. Which of these is a hypnotic? (a) Metaldehyde (b) Acetaldehyde
(c) Paraldehyde
(d) None of these
38. An ester used as medicine is (a) ethyl acetate (b) methyl acetate
(c) methyl salicylate (d) ethyl benzoate
39. Nylon threads are made of (a) polyvinyl polymer (c) polyamide polymer
(b) polyester polymer (d) polyethylene polymer
40. Paracetamol is an (a) antibiotic (b) antipyretic
(c) antimalarial
41. Antiseptic, chlorozylenol is (a) 4-chloro-3,5-dimethyl phenol (c) 4-chloro-2,5-dimethyl phenol
(b) 3-chloro-4,5-dimethyl phenol (d) 5-chloro-3,4-dimethyl phenol
42. Phenacetin is used as on (a) antipyretic (b) antiseptic
(c) analgesic
(d) analgesic
(d) antimalarial
biomolecules 43. Which of the following colours is imparted by alizarin dye in the presence of Cr3+ ion? (a) Violet (b) Brown-red (c) Pink (d) Red 44. Which of the following polymers can be used for lubrication and as an insulator? (a) SBR (b) PVC (c) PTFE (d) PAN 45. A hybrid rocket propellant uses (a) a liquid oxidiser and a solid fuel (c) a biliquid propellant
(b) a composite solid propellant (d) a solid liquid and gas as a propellant
46. Buna-N synthetic rubber is a copolymer of Cl (a) H2C=CH– = CH2 and H2C = CH – CH = CH2 C (b) H2C = CH – CH = CH2 and H5C6 – CH = CH2 (c) H2C = CH – CN and H2C = CH – CH = CH2 Cl (d) H2C = CH – CN and H2C = CH – = CH2 C 47. Among cellulose, polyvinyl chloride, nylon and natural rubber, the polymer in which the intermolecular force of attraction is weakest is (a) nylon (b) polyvinyl chloride (c) cellulose (d) natural rubber
H N 48. The drug
CH2 CH2 NH2 is used as an
N (a) antacid
(b) analgesic
(c) antimicrobial
(d) antiseptic
49. What is the complementary RNA sequence for the DNA segment AATCAGTT? (a) AAUCAGUU (b) CCAUCGAA (c) AACUGAUU (d) UUAGUCAA 50. In DNA replication the complementary nucleotide sequence for 5’-ACGT-3’ is which of the following? (a) 3’-ACGT-5’ (b) 3’-TGCA-5’ (c) 5’-AGCT-3’ (d) 5’-TCGA-3’ 51. Which of the following is not a disaccharide? (a) sucrose (b) mannose (c) lactose
(d) maltose
52. Shown below are five representations of the molecule alanine. Which one best represents the structure of alanine in the blood stream (a buffered solution of about pH 7.4)? The pka values for alanine are 2.3 (–CO2H) and 9.7 (–NH3+). H3C H H3C H ⊕ H ⊕ H ⊕ O O H (a) N (b) N
H
H
H3C H ⊕ (c) N H
H
O
H
H
H H3C
H O
O
(d) N
H
H
O
H
H O O
7.11
7.12
chapter seven 53. Identify the final product of the reaction O HO
H
HO
H
(i) HNO3 (ii) H2O2 / Fe+3
H
OH
(iii) HNO3
H
OH OH COOH
COOH HO (a) H
H OH
(b)
HO
H
HO
H COOH
COOH
CHO
CHO HO (c) HO
H H
(d)
HO
H
HO
H CHO
COOH 54. Identify the final product of the reaction O HO
H
HO
H
H
OH
H
OH
(i) Br2, H2O (ii) H2O2 / Fe+3 (iii) Br2, H2O (iv) H2O2 / Fe+3 (v) HNO3
OH COOH
COOH HO (a) H
HO (c) HO
H
(b)
OH
HO
H
HO
H
COOH
COOH
CHO
CHO
H H COOH
(d)
HO
H
HO
H CHO
biomolecules 55. Identify the final product of the reaction CHO H
OH
H
OH
(i) Br2, H2O (ii) H2O2 / Fe+3 (iii) KCN, NH4Cl (iv) H3O+
HO COOH HO (a) H
COOH
H
(b)
OH
H2N
H
HO
H
CH2OH
COOH
CHO
CHO
HO (c) HO
H
H
(d)
H2N
H
HO
H CHO
COOH 56. Identify structure of α-d-Lyxofuranose H H (a) H H
OH OH O OH
CH2OH
H H (b) H H H
OH CH2OH
H OH OH HO H OH O O (d) HO H OH H
HOH2C H (c) H H
CH2OH
H 57. Identify structure of α-d-Ribulofuranose H H (a) H H
OH OH O OH
OH OH O OH CH2OH
HO
OH O
(b)
H
H
OH
OH OH
H
H OH OH H O HO H O (c) H (d) H HO H H OH H OH OH CH2OH
7.13
7.14
chapter seven 58. Identify structure of α-d-Xylofuranose HO O OH
(a)
HO
H
O
(b) O H OH H
H
H H
OH O H
H
H
OH OH
H HO (d) HO H
OH
OH OH O OH H
OH OH O H H CH2OH
OH OH O H OH
H H
OH
OH H O H
H H (b) HO HO H
CH2OH H H HO (c)
OH
CH2OH
59. Identify structure of α-d-Glucopyranose H H H (a) HO H
H
H
OH
HO (c)
OH
HOH2C H HO (d) H H
OH OH O H OH H
CH2OH 60. Identify structure of α-d-Arabinopyranose H
H
HO (a) H
O H OH
H
O H (b) OH H H
OH
H H
O OH H
H
HO H
H
HO (c) HO
H
H
HO
OH
HO
OH
H
HO (d) H
H
61. Identify structure of polyethene O
C (a) CH
Cl
OH CH2
n
(b)
C Cl
CH2
n
OH
O OH OH H
HO
OH
H
OH
biomolecules CH2
CH n
(c) H3C
C
(d) CH2 CH2 n
CH2 62. Identify structure of guanine O
H N
(a) HN O
O
(b)
N
NH
NH O
NH
NH2
O
(c) N NH
(d)
N
NH
NH
O
N
NH2
63. Identify structure of adenine O
NH2 N (a)
N
NH
N
(b)
NH
N
NH2 (c)
N
NH2
O
N NH
NH
(d)
O
NH NH
O
64. The pupils of eyes are dilated with a very dilute solution of an alkaloid which is (a) adrenaline (b) atropine (c) equanil (d) ephedrine 65. The pKa values of aspartic acid, a naturally occurring amino acid are shown to the right. Choose from below, the structure of the major species present at a pH of 7.2. pKa = 9.82
pKa = 3.86 ⊕ NH3 HO C CH2 CH O
C O OH pKa = 2.10
Assorbic acid pKa values
7.15
7.16
chapter seven ⊕
NH3
NH2
O C CH2 CH O C CH2 CH (b) (a) C O O C O O O
O
⊕
NH2
NH3
HO C CH2 CH HO C CH2 CH (c) (d) C O C O O O OH
OH
66. Penicillin was first discovered by (a) A. Fleming (b) L. Pasteur
(c) G. Thompson
67. The poisonous gas evolved in Bhopal tragedy was (a) COCl2 (b) CH3NCO (c) CH3CN
(d) A. Noble (d) CO
68. In making lemon pickle (a) chillies are used to kill all germs and bacteria (b) lemon oil acts as a preservative (c) salt plays the same role as sugar in jam (d) citric acid acts as a preservative 69. Identify the sugar present in vitamin B12 O
H2N
H2N
O
O
NH2
H2N
N N
O N
Co+ N
N
O NH2
NH O
O P H
HO
N O
O–
O
O
HO N H
H O
H Vitamin B12
NH2
biomolecules
(a) Triose (c) Hexose
(b) Pentose (d) Tetrose
NH2 N
70.
HO
N
O
O
HIO4
Product is
OH OH NH2
NH2
N
N (a) HO
O O
O
O
O O
O
(c)
O
O
N O (b) O O
N
O
(d) O
O
O
71. Identify structure of cellulosetriacetate is OAc (a)
OAc O
H H
H
O OAc
OAc
H
H
H
AcO H
O
n
O
n
OAc H
OAc
OAc (b)
O
H H
OAc
H
O
OAc
O H
H
AcO H
H
O
OAc
H
7.17
7.18
chapter seven OAc
OAc
O H OH
(c) HO
O
H
H
HO
H
H
HO
H
H
OH (d)
O OH
H
O
n
O
n
H
OH O OH
O
H
H
O H OH
HO
H
H
H
H
72. Identify the structure which gives Biurate test O
C
OH
(a) CH CH2 O (b)
n
O N H
N H Cl CH2
(c) CH2
CH
(d) CH2
CH2
O n
CH2
CH2
CH2
C
NH
O
n
73. Identify the correct statement about the following disaccharide OH
HO H
H H
H
O
OH
HO
OH O
H H
H
H
OH
HO
(a) Both rings are pyranose (c) Non-reducing sugar
O OH H
(b) Reducing sugar (d) (a) and (b) both are correct
74. Identify the structure of cellulose OH (a)
OH
H H
H HO
O
OH H
O
H H
H HO
O
OH
O H
n
biomolecules OH (b)
OH O
H H
HO
O OH
H
H
H (d) CH2
O
n
OH
O H OH
HO
O OH H
H
H
OH (c)
H
HO
H
CH2
O
O H OH
HO
H
H
CH2
CH2
H CH2
O
n
H C
NH n
O 75. Identify the structure of Vitamin C HO O
O
HO (a) HO
OH
O (b)
NH2
N NH2 N
N (c)
N H
N H3C
CH3
CH3
CH3
(d)
OH CH3
76. Identify the structure of Vitamin A HO O O HO (b) (a) HO
OH
N
O NH2
7.19
7.20
chapter seven NH2 N (c) N
H3C N
CH3
CH3
CH3
OH
(d)
N H
CH3
77. Identify the structure of neoprene O (a) CH2
CH2
C O
n
O
(b) N H
N H
Cl CH2 (c) CH2
CH
(d) CH2 C CH CH2
O n
n
Cl
78. Synthetic polymer which resembles natural rubber is (a) chloroprene (b) glyptal (c) nylon
(d) neoprene
79. d-(+)-Glucose shows mutarotation because (a) it undergoes interconversion with d-(–)-fructose (b) it undergoes interconversion between its pyranose structure and furanose structure (c) it undergoes interconversion between its α-d-(+)-glucopyranose and β-d-(+)- glucopyranose structures via the open-chain structure (d) it is dextrorotatory 80. Which of the following is not a biopolymer? (a) Nucleic acid (b) Rubber (c) Protein 81. Lysergic acid diethylamide (LSD) is (a) antibiotic (c) psychedelic drug
(d) Starch
(b) synthetic fibre (d) sweetening agent
82. PVC polymer can be prepared by which of the monomers? (a) H2C = CHCl (b) C6H5CH = CH2 (c) CH3CH = CH2 (d) H2C = CH2 83. Diabetes is detected by testing the urine of a patient usually with (a) Benedict’s reagent (b) Nessler’s reagent (c) Fenton’s reagent (d) Tollen’s reagent 84. Which of the following sets contains only addition polymers? (a) Bakelite, PVC, polyethylene (b) Polyethylene, PVC, acrilon (c) Buna-S, nylon, polybutadine (d) Polyethylene, polypropylene, terylene 85. Which of the following is an example of azo dye? (a) Malachite green (b) Congo red (c) Martius yellow (d) Indigo
biomolecules 86. Which of the following is not an example of natural polymer? (a) Leather (b) Silk (c) Wool
(d) Nylon
87. Heroin is a derivative of (a) nicotine (b) morphine
(d) caffeine
(c) cocaine
88. Which of the following fibres is not made up of polyamides? (a) Natural silk (b) Artificial silk (c) Wool
(d) Nylon
89. An aldose is converted into its next higher homologue by (a) Amadori rearrangement (b) Wohl’s method (c) Killiani’s reaction (d) Mutarotation 90. Nylon is (a) polyethylene methyl acrylate fibre (c) polythene derivative
(b) polyamide fibre (d) polyester fibre
91. Polythene is a resin obtained by polymerisation of (a) butadiene (b) ethylene (c) styrene
(d) isoprene
92. Which of the following is used as an antipyretic? (a) Chloroquine (b) Paracetamol (c) Chloramphenicol (d) LSD 93. Point out the wrong statement (a) Phenacetin is a very important antibiotic (b) Penicillin was discovered by A. Flemming (c) Chloroquine is an antimalarial drug (d) Ether is an anaesthetic 94. The aqueous solution of carbohydrate gave a dark blue colour with iodine solution. The carbohydrate is (a) glucose (b) sucrose (c) fructose (d) starch 95. Aspirin is a/an (a) anaesthetic
(b) antipyretic
(c) tranquillizer
96. Which one of the following is a protein fibre? (a) Rayon (b) Cotton (c) Silk
(d) narcotic (d) Polyester
97. The monomers used in the manufacture of nylon-6, 6 are (a) adipic acid and butadiene (b) sebacic acid and hexamethylene diamine (c) sebacic and butadiene (d) adipic acid and hexamethylene diamine 98. The antibiotic used for the treatment of typhoid is (a) penicillin (b) terramycin (c) chloramphenicol (d) sulphadiazine 99. A polyamide synthetic polymer prepared by prolonged heating of caprolactum is (a) glyptal (b) nylon-6 (c) nylon-6, 10 (d) nylon-6, 6 100. Reserine is (a) harmone
(b) antibiotic
(c) vitamin
(d) tranquilizer
7.21
7.22
chapter seven 101. Which one of the following is a chromophore group? (a) –SO3H (b) –OH (c) –N = N–
(d) –NH2
102. The specific rotation of a freshly prepared solution of α-d-glucose changes from a value of x° to a constant value of y°. The value of x and y are respectively (a) 112° and 52.5° (b) 19° and 52.5° (c) 52.5° and 19° (d) 52.5° and 112° 103. The basic dye among the following is (a) congo red (b) antiline yellow
(c) alizarin
(d) indigo
104. Which of the following is an chain growth polymer? (a) Glyptal (b) Pholypropylene (c) Nylon-6
(d) Nylon-6, 6
105. Starch is a polymer of (a) ribose (b) glucose
(d) fructose
(c) lactose
106. The presence of carbohydrate in a sample can be detected by (a) Benedict’s test (b) Tollen’s test (c) Biuret test
(d) Molish test
107. Which of the following is an example of condenasation polymer? (a) Nylon-6, 6 (b) Bakelite (c) Buna-S rubber (d) All of these 108. Molisch test is used for the detection of (a) alkaloid (b) carbohydrates
(c) alkyl halide
(d) fats
109. In making lemon pickle (a) citric acid acts as a preservative (b) lemon oil acts as a preservative (c) salt plays the same role as sugar in jam (d) chillies are used to kill all germs and bacteria 110. Neoprene is a polymer of (a) butadiene (b) isoprene
(c) styrene
(d) chloroprene
111. Which of the following is an antibiotic? (a) Paracetamol (b) Aspirin
(c) Terramycin
(d) Chloroquine
112. Hydrazine as a drug is used in the treatment of (a) typhoid (b) malaria (c) cholera
(d) tuberculosis
113. Arsenic drugs are mainly used in the treatement of (a) jaundice (b) syphilis (c) typhoid
(d) cholera
114. Sorbitol can be obtained by the reduction of (a) fructose (b) glucose (c) sarbose
(d) all of these
115. Bakelite is obtained from phenol by reacting with (a) chlorobenzene (b) acetaldehyde (c) formaldehyde (d) acetal 116. Which of the following is an alkaloid? (a) Cocaine (b) Atropine
(c) Nicotine
(d) All of these
biomolecules 117. A raw material used in making nylon is (a) isoprene (b) butadiene
(c) adipic acid
118. Polypropylene is not used in (a) clothes (c) ropes
(b) parachute ropes (d) heat-resistant plastics
119. The drug which is effective in curing malaria is (a) analgin (b) aspirin (c) salol
(d) ethylene
(d) quinine
120. A substance which can act both as an antiseptic and disinfectant is (a) phenol (b) aspirin (c) analgin (d) sodium pentothal 121. Dacron is an example of (a) polypropylene (c) polyurethane
(b) polyamide (d) polyester
122. Which of the following is used as an anaesthetic? (a) CO2 (b) N2O (c) CH4 123. Dettol consists of (a) cresol + ethanol (c) xylenol + terpeneol
(d) N2
(b) chloroxylenol + terpeneol (d) none of the above
124. The pupils of eyes are dilated with a very dilute solution of an alkaloid which is (a) atropine (b) adrenaline (c) equanil (d) ephedrine 125. Orlon is a unit of (a) vinylcyanide (b) acrolein
(c) glycol
(d) isoprene
126. Penicillin was first discovered by (a) A. Noble (b) L. Pasteur
(c) G. Thompson
(d) A. Fleming
127. The substances which relieve anxiety, reduce mental tension and induce sleep are called (a) tranquillizers (b) antipyretics (c) analgesics (d) anaesthetics 128. To which class of dyes does phenolphthalein belong? (a) Phthalein dyes (b) Nitro dyes (c) Triphenylmethane dyes (d) Azo dyes 129. The poisonous gas evolved in Bhopal tragedy was (a) CH3CN (b) CH3NCO (c) COCl2
(d) CO
130. (+)-Sucrose is made up of (a) l-fructose and l-glucose (b) d-glucose and l-fructose (c) d-fructose and l-glucose (d) d-glucose and l-fructose 131. Which of the following sugars is obtained from nature, usually in a levorotaory form? (a) Maltose (b) Fructose (c) Sucrose (d) Glucose 132. An example of natural biopolymer is (a) rubber (b) nylon
(c) teflon
(d) DNA
7.23
7.24
chapter seven 133. In the ring structure of fructose, the anomeric carbon is (a) C-6 (b) C-5 (c) C-2
(d) C-1
134. Monosaccharides are assigned d- or l-configuration depending upon whether its s tandard Fischer projection formula has a right or left orientation respectively of the hydroxy group at the (a) anomeric carbon (b) bottom most asymmetric carbon (c) carbon number 2 (d) topmost asymmetric carbon 135. Teflon is a polymer of the monomer (a) CHCl = CHCl (b) CHF = CHCl
(c) CHF = CH2
(d) F2C = CF2
136. Cane sugar and invert sugar are (a) levorotatory and dextrorotatory respectively (b) dextrorotatory and levorotatory respectively (c) both levorotatory (d) both dextrorotatory 137. The major compound of sugar present in honey is (a) lactose (b) glucose (c) invert sugar
(d) sucrose
138. Which one of the following statements is wrong? (a) PVC stands for polyvinyl chloride (b) Buna-S stands for natural rubber (c) PTFE stands for teflon (d) PMMA stands for polymethyl methyl acrylate 139. Cellulose is a linear polymer of (a) α-d-fructose (b) β-d-glucose (c) α-d-glucose (d) β-d-fructose 140. Aldoses can be differentiated from ketoses by (a) periodic acid (b) Tollen’s reagents (c) bromine water
(d) both (a) and (c)
141. Which of the following sugars exhibits mutarotation? (a) Fructose (b) Glucose (c) Lactose
(d) All of these
142. Heating of rubber with sulphur is known as (a) vulcanisation (b) bessemerisation (c) galvanisation
(d) sulphonation
143. Which of the following is the C-2 epimer of d-glucose? (a) d-Fructose (b) l-Glucose (c) d-Galactose (d) d-Mannose 144. Glucose reacts with an excess of phenylhydrazine to form (a) glucosone (b) glucose phenylhydrazone (c) glucosazone (d) fructose phenlhydrazone 145. Which of the following is a natural polymer? (a) Bakelite (b) Polythene (c) Buna-S
(d) Protein
146. Which of the following pairs of sugars form identical osazone derivative? (a) d-(+)-Glucose and d-(–)-arabinose (b) d-(+)-Glucose and d-(–)-fructose (c) d-(+)-Glucose and (+)-maltose (d) d-(+)-Glucose and (+)-lactose
biomolecules 147. Which of the following sugars forms an osazone derivative which is identical with that of d-glucose? (a) d-Mannose (b) d-Galactose (c) d-Fructose (d) Both (a) and (c) 148. Upon hydrolysis lactose breaks down into (a) glucose and arabinose (b) glucose and fructose (c) glucose and galactose (d) glucose and mannose 149. Cellulose is a linear polymer of (a) β-glucose (b) α-fructose (c) α-glucose
(d) amylose
150. On hydrolysis of starch, we finally get (a) sucrose (b) glucose
(d) both (b) and (c)
(c) fructose
151. d-glucose and d-fructose all form the same osazone derivative because all of them have (a) the same configuration at C-5 (b) the same constitution at C-1 and C-2 (c) the same constitution (d) the same constitution and configuration at C-3, C-4, C-5 and C-6 but different constitution and configuration at C-1 and C-2 which becomes identical by osazone formation 152. The fibre obtained by the condensation of hexamethylene diamine and adipic acid is (a) nylon-6, 6 (b) dacron (c) rayon (d) teflon 153. In the formation of osazone derivatives of aldohexoses and ketohexoses, the carbon atom(s) that participate(s) in the reactions is (a) C-1 and C-2 (b) C-2 and C-3 (c) C-1 (d) C-2 154. In an aqueous solution of d-glucose the percentages of α- and β-anomer at the equilibrium condition are respectively (a) 20% and 80% (b) 80% and 20% (c) 36% and 64% (d) 64% and 36% 155. Which of the following is a polysaccharide? (a) Cellobiose (b) Polyethene (c) Cellulose
(d) Nylon
156. Which one of the following is a thermosetting polymer? (a) SBR (b) Nylon-6, 6 (c) Bakelite
(d) Nylon-6
157. Glucose gives postive silver mirror test with ammoniacal silver nitrate because it contains (a) aldehyde group (b) hydroxy group (c) ketone group (d) vicinal diol group 158. Which functional groups of glucose interact to from cyclic heiacetal leading to pyranose structure? (a) Ketone group at C-2 and hydroxy group at C-5 (b) Aldehyde group and hydroxy group at C-5 (c) Aldehyde group and hydroxy group at C-4 (d) Aldehyde group and hydroxy group at C-6 159. Which of the following reagents may be used to identify glucose? (b) Ammoniacal AgNO3 solution (a) NaHSO3 (c) CHCl3 and alcoholic KOH (d) Neutral FeCl3 solution
7.25
7.26
chapter seven 160. Fructose reduces Fehling’s solution due to the presence of (a) hydroxy group (b) ketone group (c) aldehde group (d) α-hydroxyketone group 161. Natural rubber is a polymer of (a) butadiene (b) isoprene
(c) chloroprene
(d) neoprene
162. The formation of furanose structure of fructose involves the interaction of functional groups present at (a) C-1 and C-4 (b) C-1 and C-5 (c) C-2 and C-5 (d) C-2 and C-6 163. The widely used plastic PVC is a polymerisation product of (a) CHCl = CHCl (b) H2C = CCl2 (c) H2C = CH2 (d) H2C = CHCl 164. d-Glucose reacts with anhydrous methyl alcohol in the presence of dry HCl gas to form (a) β-methyl d-glucopyranside (b) α-methyl d-glucopyranoside (c) 2, 3, 4, 5, 6-penta-O-methyl d-glucose (d) both (a) and (b) 165. Consider the following sequence of reactions +
/AcOH 2 3O Glucose PhNHNH → A H → B Zn →C heat ( excess )
The product (C) is expected to be (a) mannose (b) fructose
(c) sorbitol
166. Which of the following fibres is made of polyamides? (a) Raon (b) Orlon (c) Nylon
(d) arabinose (d) Dacron
167. In the multi-step conversion of an aldose into next higher aldose by Kiliani-Fischer synthesis, the reagent emplyed in the first step is (a) HCN (b) NH2OH (c) Br2/H2O (d) C6H5NHNH2 168. Salol can be used as (a) antiseptic (b) antipyretic
(c) both (a) and (b) (d) none of these
169. When methyl d-glucopyranoside is oxidised with periodic acid, how many moles of the oxidising agent are consumed per mole of the sugar? (a) 2 (b) 3 (c) 4 (d) 5 170. The urine of a diabetic patient contains (a) glucose (b) fructose
(c) sucrose
(d) galactose
171. d-Glucose and d-mannose are (a) epimers (b) anomers
(c) diastereomers
(d) both (a) and (c)
172. In which of the following sets do the carbohydrates contain disaccharides only? (a) Maltose, lactose, starch (b) Sucrose, lactose, cellulose (c) Maltose, sucrose, lactose (d) Maltose, lactose, mannose
biomolecules 173. When glucose is treated with an excess of HIO4, the products formed are (a) one mole of oxalic acid (COOHCOOH), three moles of HCOOH and one mole of HCHO (b) five moles of HCOOH and one mole of HCHO (c) one mole of glyoxal (CHOCHO), one mole of HCHO and three moles of HCOOH (d) six moles of HCOOH 174. Malisch test is performed for the detection of (a) carbohydrates (b) fats (c) alkaloids
(d) alkyl halides
175. Methyl d-glucoside on reaction with HIO4 consumes two moles of the reagent and produces the dialdehyde (A) and one mole of HCOOH. HOH2C
CH
O
CHO
CH
OCH3
CHO (A)
The result of this reaction proves that glucose has (a) a four-membered ring structure (b) a furanose structure (c) an open-chain structure (d) a pyranose structure
176. Plants store their reserve carbohydrates in the form of (a) starch (b) cellulose (c) glycogen 177. Which one is an example of vat dye? (a) Indigo (b) Alizarin
(d) cellobiose
(c) Malachite green (d) Congo red
178. Starch consists of two polymeric units, namely (a) glycogen and collagen (b) cellulose and cellobiose (c) amylose and amylopectin (d) inulin and pectin 179. Ampicillin is (a) an antibiotic
(b) an analgesic
180. Charring of sugar is due to (a) reduction and hydration (c) dehydration
(c) an antimalarial (d) an antipyretic (b) reduction (d) oxidation
181. Isoprene substances are used for making (a) natural rubber (b) propane (c) petrol
(d) liquid fuel
182. Glucose gives silver mirror with ammoniacal silver nitrate because it has (a) ketone (b) aldehyde (c) ester (d) alcoholic AgNO3 183. Lactose on hydrolysis gives (a) glucose + galactose (c) fructose + glucose
(b) fructose (d) glucose
184. Chloroquine is (a) an antipyretic (b) an antibiotic
(c) an antimalarial (d) an analgesic
7.27
7.28
chapter seven 185. Terylene is a condensation polymer of ethylene glycol and (a) salicylic acid (b) terephthalic acid (c) benzoic acid (d) phthalic acid 186. Which of the following groups would you introduce into a dye to make it water soluble? (a) –NO2 (b) –SO3H (c) –Cl (d) –OH 187. Polymer obtained by condensation polymerisation is (a) PVC (b) teflon (c) polythene (d) phenol–formaldehyde resin 188. A dye absorbs the wavelength corresponding to blue colour of light. The observed colour will be (a) blue (b) orange (c) green (d) red 189. The product of addition polymerisation reaction is (a) polythene (b) glyptal (c) nylon
(d) terylene
190. With which of the following cations, alizarin will impart a violet colour on the fabrics? (a) Cr3+ (b) Fe3+ (c) Ba2+ (d) Al3+ 191. Glucose cannot be classified as (a) a hexose (c) an aldose
(b) a carbohydrate (d) an oligosaccharide
192. In the molecule of d-fructofuranose, the anomeric carbon is (a) C-5 (b) C-2 (c) C-1
(d) C-6
193. Glucose is treated with excess of HIO4. How many moles of HIO4 will be consumed per mole of the sugar? (a) 5 (b) 4 (c) 3 (d) 2
biomolecules
Level 2 Single and Multiple-choice Type O 1. Which of the following represents (tyrosine) HO and pH = 12? O
CH2–CH
CH2–CH
C–O
HO (b)
+
NH3
CH2–CH
O CH2–CH
C–O NH2
at a pH = 2
C–OH +
NH3 O
–
(c) HO
NH2 O
–
(a) HO
C–OH
–
–
(d) O
CH2–CH
C–O NH2
2. Which of the following is/are co-polymer (s)? (a) Nylon-66 (b) Bakelite (c) Teflon
(d) Polystyrene
3. Which of the following do not undergo hydrolysis? (a) Glucose (b) Fructose (c) Cane sugar
(d) Maltose
4. Among the following polymers, peptide linkage is present in (a) Nylon-66 (b) Protein (c) Nylon-6
(d) Tafflon
5. Identify the compound that gives same Osazone O
O H H (a) H H
OH
HO
OH
H
OH
H
OH
HO (c) H
H
OH
H
OH
(b)
OH
O
O
H
H
OH
HO
H
HO (d) HO
H
OH OH
H
H
H OH
OH
OH
O
OH
O
HO
H
O
HO
H
HO
H
HO (c) OH HO OH H
H
HO (d) HO
H
OH
OH
OH
OH
6. Identify the compound that gives same Osazone O H HO (a) HO H
OH H H OH OH
(b)
H H
H OH
H
H OH OH
7.29
7.30
chapter seven 7. Identify the compounds which are inter-convertible in basic medium O
OH
H
O OH
H
H (c) H OH
H
OH
O H H (a) H H
HO
OH OH OH
(b)
OH
H
OH
H
OH
OH
O HO
H
HO (d) OH HO OH H
H
OH
OH
8. Among the following polymers, identify the co-polymer (a) Nylon-6 (b) Buna-N (c) Buna-S
(d) Protein
9. Among the following polymers, identify the co-polymer (a) Terylene (b) Glyptal (c) PVC
(d) Protein
H OH
10. Among the following polymers, identify the homopolymer (a) Bakelite (b) Dacron (c) Natural rubber (d) Orlon
Comprehension Type Passage 1 Amino acids contain both a basic group (–NH2) and an acidic group (–CO2H). In the dry solid state, amino acids exist as dipolar ions, a form in which the carboxylic group is present as a carboxylate ion, –CO2– and the amino group is present as on amonium ion, –NH3⊕. In aqueous solution, an equilibrium exists between the dipolar ion (zwitter ions) and the anionic and cationic forms of an amino acid. –H3O⊕ ⊕ ⊕ H3N–CH–COOH H2N–CH–COO H3N–CH–COO ⊕ +H3O R R R Cationic form (Ka1) Dipolar ion (Ka2) Anionic form (Zwitter ion) In strongly acidic solutions (pH ≈ 0) all amino acids are present primarily as cations, in strongly basic solution they are present as anions. At some intermediate pH, called the isoelectric point (pI), the concentration of the anions and cations is equal. Each amino acid has particular i soelectric point. 11. For the phenyl alanine, the first and second dissociation constants are given as pK a1 = 1.8 and pK a2 = 9.1. What will be the pH at isoelectric point?
(a) 4.5
(b) 5.45
(c) 7
(d) 4.2
12. The formula of lysine is H2N(CH2)3 ⋅ CH2–CH–COOH for lysine the value of pK a1 , pK a2 and pK a3
NH2 are 2.2, 9.0 and 10.5 respectively. The pH at isoelectric point of lysine is
(a) 5.6
(b) 7
(c) 6.35
(d) 9.75
biomolecules 13. The dicationic form of the lysine is shown as ⊕
H3N–CH2(CH2)2CH2CH–COOH (c) (a) ⊕ NH3 (b)
Arrange the shown hydrogen in the order of their acidic strength (a) a > b > c (b) c > b > a (c) a > b = c (d) b = c > a
Passage 2 Classification of Polymers (A) Condensation polymers and condensation polymerisation: (i) Condensation polymerisation is also known as step polymerisation. (ii) For condensation polymerisation, monomers should have at least two functional groups. Both functional groups may be same or different. (iii) Monomers having only two functional groups always give a linear polymer. For example O O Condenation H– NH–R–NH–C–R′–C– OH + (n – 1)H2O nNH2–R–NH2 + nHOOC–R′–COOH reaction Polyamide n
O
O
nHO–R–OH + nHO–C–R′–C–OH
Condensation
O
O OH + (n–1)HOH
H– O–R–O–C–R′–C– n
Polyester O nNH2–R–COOH⎯→ H– NH–R–C–
OH n
Polyamide (iv) Condensation polymers do not contain all the atoms initially present in the monomers. Some atoms are lost in the small molecule that is eliminated. (v) Monomer having three functional groups always gives cross-linked polymer. Examples are: urea formaldelyde resin, phenol–formaldehyde resin, alkyde resin.
(B) Addition polymer: (i) Polymers which are formed by addition reaction are known as addition polymers. (ii) If monomer is ethylene or its derivative then addition polymer is either linear polymer or branch-chain polymer. Examples are: Polyethylene, polyvinylchloride, polystyrene polytetrafluoroethylene, polyvinyl cyanide, etc. (iii) If monomer is 1,3-butadiene or 2-substituted-1,3 butadiene CH2=C–CH=CH2 then G polymer is always branch chain polymer which is always an elastomer. E xample are: Monomer Polymer G G nCH2=C–CH=CH2
–CH2–C=CH–CH2–
n
(i) G = H, 1,3-butadiene (i) Polybutadiene (ii) G = CH3, 2-methyl-1,3-butadiene (ii) Polyisoprene (iii) G = Cl, 2-chloro-1, 3-butadiene or chloroprene (iii) Polychloroisoprene (Neoprene) (iv) Addition polymers retain all the atoms of the monomer units in the polymer. (v) Addition polymerisation takes place in three steps: Initiation, chain propagation and chain termination. (vi) Addition polymers are also known as chain growth polymers.
7.31
7.32
chapter seven 14. Which one of the following is a monomer of condensation polymer? (a) CH3(CH2)5–COOH (b) HO–CH2–CH2–OH (c) CH3–CH=CH–NH2 (d) CH3–CH=CH–CH2–CONH2 15. Natural rubber is which type of polymer? (a) Condensation (b) Addition (c) Coordinate
(d) None of these
16. Among the following, identify the condensation polymer (a) Nylon-6 (b) Buna-N (c) Polystyrene
(d) Nylon-6-6
Passage 3 The carbohydrates in which the following properties are found are called reducing sugars. The reduction of Tollen’s reagent, Fehling’s solution, Benedict’s solution. All monosaccharides are reducing sugars. Contrary to this the carbohydrates in which the above properties are not found are called non-reducing sugars. For example, sucrose, starch, cellulose, etc. The disaccharides, in which carbonyl group of any one monosaccharide from both the monosaccharides, is present as hemiacetal or ketal and does not involve in glycosidic linkage formation, are reducing. For example, maltose and lactose. Two diastereomeric monosaccharides are called epimers when their configuration differs only at stereogenic centre. Monosaccharides form glycoside with alcohol in the presence of an acid. All monosaccharides show mutarotation. 17. Which of the following is a non-reducing sugar? 6
6
CH2OH CH2OH O O H 5 H H 5 H H H (a) 4 (b) 1 1 4 OH HO OH H 2 2 HO 3 HO 3 OH OH H H H OH 6
1
HOH2C (c)
5
H
CH2OH
O H 4
OH
OH 3
H
2
OCH3
6
CH2OH O HO 5 H (d) 4
H
OH 3
H
H
6
1
2
O
CH2OH O H 5 OH H 4
H
OH
OH 3
H
H
1
2
H
OH
18. Which one of the following is C-2 epimers? (a) Glucose and galactose (b) Glucose and mannose (c) Glucose and fructose (d) Galactose and fructose 19. Which of the following statements about lactose is not correct? (a) It does not reduces Tollen’s reagent (b) It is a disaccharide. On hydrolysis, it produces two monosaccharides (c) It possess glycosidic linkage (d) All of them Passage 4 Monosaccharides have —CHO (or C=O) and —OH groups, so they undergo usual oxidation and reduction. Further, monosaccharides form osazone when treated with excess of phenylhydrazine (3 equivalents). In osazone formation only the first two carbon atoms are involved. Thus
biomolecules monosaccharides having identical configuration on rest of C atoms except first two will form same osazone. The same is the case with glucose and fructose. A, B and C are three hexoses and form same osazone D. Compounds A to D behave as shown below: Zn (i) D HCl → CH → d-Fructose COOH
3
− Hg (ii) A → → Na →B+ C H O+ Ni , H2
HNO 3
3
3 (iii) B HNO → Optically active glyceric acid
3 → Optically active glyceric acid (iv) C
HNO
20. Compound D is a osazone which can be obtained from (a) Only one compound (b) Two compounds (c) Three compounds (d) Four compounds 21. Compound A should be (a) d-glucose (b) d-fructose (c) l-glucose (d) l-fructose 22. Compound B and C, respectively, are (a) d-glucose and d-mannose (b) d-mannose and d-glucose (c) d-glucose and l-glucose (d) d-glucose and l-mannose
Integer Type CH2OH H 23.
O
H OH
H
Br2 H2O
H OH
HO H
Compound (A) ; Number of chiral centre in c ompound A is
OH
24. Identify the total number of carbohydrates which have d-configuration O H HO
O
OH
HO
H
HO
H
HO
H
H HO
OH
OH
O
O
OH
OH
O
O
H OH H
HO H HO
OH
H HO
HO
H
H
H
HO
H
OH H OH
O
OH
H
O
OH
HO
H
HO
H
HO
H
H
OH
H
OH
HO
H
HO
H
H
OH
H
OH
H
OH
OH
OH OH
H
OH OH
7.33
7.34
chapter seven 25. Identify the total number of carbohydrates which give mutarotation OMe H OAc O O O H H H H H H HO HO HO H H H O O O HO H HO H HO H O O O H H HH H H OH OH OH H H H OMe H OH H H H H H H OHH OHOH OHH HO HO HO H
OH
H
H OH H OH OMe O O HO HO O O HO HO HH HH H H H O H O HO H HO H H OHO H H OHO H OH O H H OHO H H O O H H H H O O H H H H H H H H OMe OAc H H H H OMe OH OHH OHH HO HO OH OH H H HO OMe H
OH
H
26. Identify the total number of carbohydrates which give mutarotation OH OH H H HO HO H H
OH OH OH OH H H OH O OH O OH O H H H O H H H OMe H OH HO H H OH OMe H OH OH H OH OH HO OH OH H OH OH O OH OH O H OH H OH H OH OH H
HOH2C HOH2H C H H H
OH OMe OH OMeO OH O OH H H
H H H H
OH O OH H OHO H HO OMe OH H OMe OH
HOH2C HOHHO 2C H HO H H H H
H OH H OH O OH O H OH
H H
O H OHO H HO
H H
OH OH H OH OHOH H OH H OMe H OMe O OH O H OH H OH H H H OH H OH CH2OH
CH2OH HOH2C OMe H HOHHO OMeO 2C H OH O HO H H OH H CH2OH CH2OH
biomolecules 27. Identify total number of carbohydrates which give ⊕ ve tollen test. MeO
H
H
HO
H
HO
H
OH
H
O
O
H CH2OH
H
OMe
H
H
OH
H
OH O
H
OH O
H
H
H
OH
H
H
OH
H
OH
O
OAc
CH2OH
H
O OH
H
H
OH
H
H
OH
H
OH
O
CH2OH
OH
HO
H
HO
OH
HO
H
H
OH
H
OH
HO
H
H
OH
H
O
O
O
CH2OH
OH
H
H
OH
H
H
OH
H
OH
H
O
CH2OH
O OH
H
H
OH
H
H
OH
H
OH
H CH2OH
H
OH
H
OH
O
CH2OH
H
H
OH
CH2OH
H
O
H H
H
H CH2OH
O
O
H O OAc H CH2OH
HO H
OH H OH
H CH2OH
CH2OH
O
7.35
7.36
chapter seven
Answer Keys Level 1 1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
d
b
d
c
a
b
d
c
c
d
b
d
a
a
c 30
16
17
18
19
20
21
22
23
24
25
26
27
28
29
ab
b
d
c
a
c
d
b
a
c
d
a
b
a
d
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
d
b
a
c
ad
d
c
c
c
ab
a
a
a
c
a
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
c
d
a
d
b
b
c
a
b
a
d
c
a
c
a
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
d
d
a
b
a
a
b
c
b
a
b
b, d
d
b
a
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
d
d
d
c
b
c
a
a
b
b
d
b
c
c
b
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
b
b
a
d
b
c
d
c
b
d
c
a
b
b
b
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
d
ab
b
c
d
cd
d
b
b
c
d
c
b
d
a
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
d
b
b
a
a
d
a
a
b
bd
c
d
c
b
d
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
b
d
b
b
d
d
a
d
c
d
b
d
c
a
b
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
d
a
a
c
c
c
a
b
b
d
b
c
d
d
b
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
c
a
a
a
a
a
c
b
a
d
a
a
c
a
c
181
182
183
184
185
186
187
188
189
190
191
192
193
a
b
a
c
b
abd
d
b
a
a
d
b
a
11
12
13
14
15
a
b
b
Level 2 1
2
3
4
5
6
7
8
9
10
bd
ab
ab
abc
ab
acd
abc
bcd
abd
cd
b
d
16
17
18
19
20
21
22
23
24
25
26
27
ad
c
b
a
d
b
a
4
4
3
4
3
CHAPTER
8
Organic Reaction Mechanisms and Reagents Question Bank Level 1
1. When the compound shown below is heated it undergoes a rearrangement to form an isomer. Identify the product. O heat
C8H12O
C8H12O O (a)
O
OH (b)
isomer
OH (c)
(d)
2. Organometallic reactions can be classified into fundamental reaction types. Classify the following reaction.
(C6H5)3P – Pd – P(C6H5)3 +
Br
(C6H5)3P
Pd Br
(a) Ligand insertion
(b) Ligand dissociation
(c) Reductive elimination
(d) Oxidative addition
P(C6H5)3
8.2
chapter eight 3. What is the electron count for the following transition metal complex? H (C6H5)3P
P(C6H5)3
Rh C O
(a) 14
(b) 15
(c) 16
(d) 17
4. Predict the product of the following reaction sequence. O
O
Br NaOEt
Br NaOEt Cl2 [(C6H5)3 P]2 Ru
H C6H5
O
O
(a)
O
O
(b)
(c) O
O
(d) O
O
5. Consider the relative basicity of these three amines. Which statement is true? NH2
NH2
NH2
NO2
(a) Cyclohexylamine is the strongest base and aniline is the weakest base (b) Cyclohexylamine is the strongest base and 4-nitroaniline is the weakest base (c) Aniline is the strongest base and cyclohexylamine is the weakest base (d) Nitroaniline is the strongest base and cyclohexylamine is the weakest base
6. Which of the following syntheses of benzylamine is the least likely to work? O (a)
(c)
NH2 (i) LiAlH4
(b)
(ii) H2O NH2 O
Br NaOH
(d)
Br
NaCN
(ii) H2O NH3 (large excess)
Br
7. Predict the product of the following reaction sequence. CH3 Cl2 AlCl3
HNO3 H2SO4
H2 Ni
(i) LiAlH4
(i) NaNO2, H3O⊕
(ii) BF4
heat
organic reaction mechanisms and reagents CH3
CH3
CH3
CH3 NO2
F
F (a)
(b)
(c)
NO2 (d)
Cl
F Cl
F
Cl
8. Predict the product of following reaction sequence. O
Br
O
LDA
(i) Hydrolysis (ii) CH3Br (ii) SOCl2
OEt
OEt
(i) NaN3 (ii) Heat
(i) LDA
(iii) H2O
H N
(a)
NH2
(b)
O (c)
NH2 (d)
NH2
9. Choose the major product of the following reaction. CH3 HNO3 H2SO4
Major product?
OH CH3
CH3
CH3
NH2
OH
NO2 (a)
(b)
CH3
(c)
(d) NO2
OH
OH
OH
OH
10. Choose the answer that has the following compounds arranged correctly with respect to increasing reactivity with Br2/FeBr3.
O
O O
O
CH3
(a)
O
OCH3
OCH3
(b)
Increasing reactivity
Increasing reactivity
O
CH3
8.3
8.4
chapter eight
O
O O
OCH3
CH3
O
OCH3
O
(c)
CH3
O
(d)
Increasing reactivity
Increasing reactivity
11. Choose the reaction sequence that could be used to perform the following transformation. NO2
Br HNO (a) 3 H2SO4
HNO3 NBS (b) H2SO4
Br2 FeBr3
NaNO2 (c) HCl
HNO3 Br2 (d) FeBr3 H2SO4
Br2 FeBr3
12. Predict the major product of the following reaction NO2 Br2
(i) H2/Ni
FeBr3
(ii) NaNO2 / H+ H2N
H2N (a)
CuCN 90° – 100°
(i) LiAlH4 (ii) H2O HO
HO
(b)
(c)
O
(d)
Br Br 13. Which of the following compounds is the most acidic? (lowest pKa)
Br
Br
H O (a)
O
H O
O (b)
H O
O
(c)
CH3
H O
(d)
NO2
NH2
14. What could be reagents A and B for the following reactions? Reagent A
Reagent B
O
CO2H
organic reaction mechanisms and reagents
(a) (b) (c) (d)
Reagent A: CH3CH2Cl / AlCl3; reagent B: Na2Cr2O7, heat Reagent A: CH3COCl / AlCl3; reagent B: Na2Cr2O7, heat Reagent A: HNO3, H2SO4; reagent B: RCO3H, heat Reagent A: CH3COCl / AlCl3; reagent B: H2, Ni, heat
15. What could be the major product from the following reactions? –H2O, H3PO4
OH
RCO3H
?
∆ OH
O (b)
(a)
(c)
OH
(d)
OH
OH
O
16. What could be the major product from the following reactions? –H2O, H3PO4
OH
OsO4
?
∆
OH (a)
O (c)
(b)
OH OH
OH
(d) O
17. What could be the reagent to complete the following reaction? O OH
H
Reagent
(a) K2Cr2O7 (c) H2CrO4
(b) PCC in dried CH2Cl2 (d) OsO4
18. What could be the major product for the following reaction? SN2 + NH3 (2 equivalents) Product + NH4Cl Cl (a)
(b)
(c) NH2
(d)
NH2
19. Choose order that has the following compounds correctly arranged with respect to increasing rate of reaction with LiAlH4 (most reactive compound on the right). (a)
O
< O
(b)
O
H
< O
H2O
(b) MeOH > Me2CHOH > Me3COH > H2O > CH3C ≡ CH
(c) Me3COH > Me2CHOH > MeOH > H2O > CH3C ≡ CH
(d) MeOH > H2O > Me2CHOH > Me3COH > CH3C ≡ CH
68. Arrange the following in the decreasing order of acidic strength
(i) Phenol
(ii) p-nitrophenol (iii) m-cresol
(iv) p-cresol
(a) ii > iii > iv > i
(b) ii > i > iii > iv
(c) ii > i > iv > iii
(d) iii > iv > ii > i
69. Which of the following will be most acidic
(a) o-Aminophenol
(b) p-Aminophenol
(c) m-Aminophenol
(d) None of these
70. Arrange the following in increasing acidic character (i) Phenol (ii) m-nitrophenol (iii) m-chlorophenol (iv) m-cresol (a) iv < i < iii < ii (b) iv < i < ii < iii (c) i < iv < iii < ii (d) iii < ii < iv < i 71. Which of the following compounds can react with hydroxylamine? OH (a)
(b) OH
OH
OH
OH OH (c) OH
HO
OH
(d) OH
OH
72. Which of the following statement is true regarding amount of AlCl3 required during Friedel-Craft acetylation using acetyl chloride or acetic anhydride? (a) Both require same amount (b) Acetylation with acetyl chloride requires more amount (c) Acetylation with acetic anhydride requires more amount (d) Nothing is definite 73. Which of the following gives effervescenes of CO2 with NaHCO3 solution? (a) HCOOH (b) 2,4,6-trinitrophenol (c) Both (a) and (b) (d) None of these 74. 2,4,6-Trinitrophenol can be prepared in good yield (a) by the nitration of 2,4-dinitrochlorobenzene (b) by the nitration of 2,4-dinitrophenol (c) by both (a) and (b) (d) neither by (a) nor by (b)
organic reaction mechanisms and reagents 75. The correct stability order of the following three quinones is O
O O (iii) (i) (ii) O
O
O
(a) i > iii > ii
(b) i = iii > ii
(c) i = ii > iii
(d) iii > i > ii
76. Which of the following is most stable, and which one is least stable?
(i) HCHO
(ii) CH3CHO
(a) (iii) is most stable and (i) is least (c) (iii) is most stable and (iv) is least
(iii) CH3COCH3
(iv) Cl3CCHO
(b) (iv) is most stable and (i) is least (d) All the four are equally stable
77. Which of the following has highest and lowest hydration equilibrium constant? HCHO, CH3CHO, CH3COCH3 (a) HCHO-Highest, CH3CHO-Lowest (b) CH3CHO-Highest, HCHO-Lowest (c) HCHO-Highest, CH3COCH3-Lowest (d) CH3COCH3-Highest, HCHO-Lowest −
, Cl 2 78. CH3COCH2Cl OH → Product P is
(a) ClCH2COCH2Cl (c) Both (a) and (b)
(b) CH3COCHCl2 (d) ClCH2COOH + CH3Cl
79. Which of the following is an example of nucleophilic addition? O NNH2 (a) | | || NH2NH2, H+ C6H5CCH3 C6H5CCH3 O (b) | | C6H5CCH3
LiAlH4
OH | C6H5CHCH3
(c) Both (a) and (b) (d) None of the two
80. Propanal and propanone, both have same molecular formula (C3H6O), what do you expect about their boiling points? (a) Both have same boiling point. (b) Boiling point of propanal is higher than the boiling point of propanone. (c) Boiling point of propanal is lower than the boiling point of propanone. (d) Nothing can be predicted. 81. Which of the following statement is false about 1,3-dithane, S (a) 1,3-Dithane can react with RLi (b) It can be alkylated by CH3CH2CH2Br
S
?
8.15
8.16
chapter eight
(c) It can be alkylated by Me2CHX (d) 1,3-Dithane can be used for preparing aldehydes and ketones
82. In dilute aqueous solution, formaldehyde exists as
(a) Formaldehyde (b) Paraldehyde
(c) Trioxymethylene (d) Methyleneglycol
83. The major driving force for the hydration of chloral is (a) less steric hinderance in the product (b) less force of repulsion in the product (c) hydrogen bonding in the product (d) electronegativity of the three chlorine atoms 84. The products A and B in the following reactions are 1 Eq. H2/catalyst (a)
,
O
[A]
O3
[B]
, (b) O
(c) Both (a) and (b)
(d)
,
O
O || 4 OH 85. CH3CC2H5 + NaCN + NH4Cl NH → Z; Z is CN CH3 OH NH2 CH3 CH3 CH3 OH (a) C (b) (c) (d) C C C C2H5 C2H5 COOH COOH C2H5 CN C2H5 CN O O || || 86. The compound having the formula, CH3 − C − CH2 − C − OC2H5
(a) forms dioxime (c) both (a) and (b)
(b) undergoes iodoform test (d) neither of the two
87. Fehling’s solution can be used for distinguishing between (a) CH3CHO and C6H5CHO (b) CH3CHO and CH3COCH2OH
(c) Both (a) and (b)
(d) None of these
88. Which of the following is least reactive with a nucleophile?
(a) Methanal
(b) Propanone
(c) 3-Pentanone
89. Aldehydic group can be protected (a) by acetal formation against alkaline oxidizing agents. (b) by mercaptal formation against acidic oxidizing agents. (c) both (a) and (b) (d) none of the above CHO 90. 2 | COOH
OH
COO− COO− | | CH2OH+ COO−
(d) 2-Pentanone
organic reaction mechanisms and reagents The above reaction can said to be an example of
(a) Intramolecular Cannizzaro reaction
(b) Intermolecular Cannizzaro reaction
(c) Crossed Cannizzaro reaction
(d) Tischenko reaction
91. Ninhydrin has three keto groups, which of the keto group is expected to be hydrated most easily? O
3
2
O
1
O
(a) 2
(b) 3
(c) 1
(d) All are equally hydrated
O || 92. C2H5O − C − OC2H5 + 2CH3MgBr ⎯→ A ; A is OH | OH (a) | (b) C2H5C−CH3 | (CH3)2C−C2H5 C2H5 93.
(i) O3 / H2O (ii) Heat
(c) CH3COOH
(d) CH3COCH3
(c) HCOOH
(d) HCHO
A; A is
(a) CH2(COOH)2 (b) CH3COOH
94. Which is least reactive towards addition of HCl? (a) CH3CH2CH=CH2 (b) CH2=CH–CH=CH2 (c) CH3CH2C≡CCH3 (d) CH3CH=CHCHO 95. Which of the following is true regarding preparation of aldehydes and ketones? (i) Both can be prepared by the oxidation of the concerned alcohol with copper at about 250ºC. (ii) Both can be prepared by the oxidation of the concerned alcohol by Oppenauer oxidation. (iii) Both can be prepared by the oxidation of respective alcohol with acidic dichromate.
(a) i
(b) ii and iii
(c) i and iii
(d) All the three
96. Observe the following structures and pick up the correct statement. (i) C = O
+
(ii) C = OH
(a) Carbonyl carbon of (i) is more electrophilic than that of (ii). (b) Carbonyl carbon of (i) is less electrophilic than that of (ii). (c) Carbonyl carbon of both structures has equal electrophilic character. (d) It depends upon the complete structure of the compound
8.17
8.18
chapter eight 97. Acetal formation is a reversible reaction R H
H+
C = O + R'OH
R H
C
OH
R'OH,H+
R H
OR'
OR'
C
+ H2O
OR'
Under what conditions, the reaction can be forced to proceed only in right (forward) direction? (a) Using excess of alcohol (b) Using high temperature (c) Using dilute acid and excess of alcohol (d) Using dry acid and excess of alcohol
98. Which of the following does not react with sodium bisulphite?
(i) HCHO
O (ii) CH3COC2H5 (iii)
(a) iii and iv
(b) ii and iv
COCH3 (iv)
(c) i
(d) All reacts
99. Which of the following reagent can be used for carrying out the reaction outlined below? O H
Reagent
OH O OC2H5
(a) BrMgCH2COOC2H5 (b)
BrZnCH2COOC2H5
(c) LiCH2COOC2H5
(d) Any of the three
100. Which of the following statement is false?
(a) Cannizzaro reaction is given by aldehydes in presence of alkali
(b) Aldol condensation is given by aldehydes in presence of alkali
(c) Aldol condensation is given by aldehydes and ketones in presence of acids
(d) None of these
101. Carbonyl compounds, sensitive to both acids as well as bases, can be reduced to hydrocarbons by
(a) Clemmensen reduction
(b) Wolf-Kishner reduction
(c) Thioacetal reduction
(d) All of the three
102. What should be the product when ethylmethyl ketone is treated with peracetic acid
(a) Ethyl acetate
(b) Methyl propanoate
(c) Both (a) and (b)
(d) Only acetic acid
103. Which of the following complex hydride is a stronger reducing agent?
(a) Li+[AlH4]–
(b) Li+[Al(OCMe3)3H]–
(c) Al(CH2CHMe2)2H
(d) All are strong reducing agents
organic reaction mechanisms and reagents 104. O2N
COCl + R
O2N
The reagent R may be (i) CH3CH2MgBr (iii) (CH3CH2)2Cd (a) i or ii (b) i or ii or iii
COCH2CH3
(ii) CH3CH2Li (iv) (CH3CH2)2CuLi (c) iii or iv
(d) Any of the four
105. Which one does not belong to the same compound? (a) Paraformaldehyde (b) Paraldehyde (c) Trioxane (d) Formalin 106. Which of the following is not a good reagent in Wittig reaction? + −
(a) Ph3P = CH2
(b) Ph 3 P C HCH 2 CH 3
(c) (CH3)3CCH=PPH3
(d) C6H5COCH=PPh3
107. Which of the following is not formed in iodoform reaction?
(a) CH3COCH2I (b) ICH2COCH2I
(c) CH3COCHI2
(d) CH3COCI3
CH=CHNO2 Zn/Hg → Product. Here, the product is HCl
108. COCH3
CH=CHNH2
CH=CHNO2 (a)
(b)
CH2CH3
(c)
(d) CH2CH3
CH2CH3
CH2CH2NO2
CH2CH2NH2
CH2CH3
O 6 H 5 COOOH C → Product. Here, the product is
109.
O
O
(a) O (b) O
COOH COOH (c) O (d) COOH
110. Acetyl chloride does not react with (a) Water (c) 2-methylpropene
(b) Sodium acetate (d) It reacts with all the three
111. Which of the following statement is true? (a) At room temperature, formyl chloride is present in the form of CO and HCl. (b) Acetamide behaves as a weak base as well as a weak acid. (c) CH3CONH2 LiAlH 4 → CH3CH2NH2. (d) All of the above.
8.19
8.20
chapter eight 112. Which of the following reaction is possible? (i) CH3COCl + H2O ⎯→ CH3COOH + HCl (ii) CH3COOCH3 + HBr ⎯→ CH3COBr + CH3OH (iii) CH3CONH2 + HBr ⎯→ CH3COBr + NH3 (iv) CH3COOCOCH3 + H2O ⎯→ 2CH3COOH
(a) i and iv
(b) i, iii and iv
(c) i, ii and iv
(d) All the four
113. Which of the following is not possible? (a) ICH2COOH + NaCl Acetone → ClCH2COOH + NaI (b) ClCH2COOH + NaI Acetone → ICH2COOH + NaCl (c) Both (a) and (b) (d) None of these 114. Acid amide do not undergo the usual properties of carbonyl, C=O group because (a) it is a weak base (b) it is a weak acid (c) it is amphoteric (d) its carbonyl carbon is not electron deficient 115. Which of the following statement is true regarding aspirin, a commonly used antipyretic and analgesic? Given pKa for aspirin = 3.5; pH in stomach and small intestine is 2.5 and 8, respectively. (a) It is completely ionized in the stomach and almost un-ionized in the small intestine. (b) It is ionized in the small intestine and almost un-ionized in the stomach. (c) It is ionized in the stomach and almost un-ionized in the small intestine. (d) It is neither ionized in stomach nor in intestine. 116. Which of the following will undergo alkaline hydrolysis most rapidly? COOCH3 (a)
(b)
COOCH3
COOCH3
COOCH3
(c)
CH3
(d)
Cl
NO2
117. HVZ reaction involves the use of P and Cl2 , Cl 2 CH3CH2COOH P → CH3CHClCOOH
The function of phosphorus is (a) as a catalyst (b) in the formation of PCl3 which carries out halogenation at the α-carbon atom (c) in the formation of PCl3 which converts –COOH into –COCl (d) none of the these
118. Hydrolysis of esters in presence of an acid is a reversible reaction. What is true about ester hydrolysis in presence of a base? (a) It is irreversible because salts of carboxylic acids are insoluble. (b) It is irreversible because salts of carboxylic acids have high melting points. (c) It is irreversible because carboxylate ion is resonance stabilized. (d) It is a reversible reaction.
organic reaction mechanisms and reagents CH3 119. Compound A is formed by the interaction of
O
O
CH3
[A]
(a) CH3COOH and HO
(b) CH3CHO and HO
(c) CH3COCH2COOH and HO
(d) CH3CHO and
CHO OH
COOH CHO OH
OH COOH
HO
COOH is heated? COOH
120. What is the main product when HOOC (a) COOH COOH
CH2COOH
(b) O O C O O (d) C
(c) HOOC
O 121. The yield of ester in esterification can be increased by CH3CH2OH + CH3COOH CH3COOCH2CH3 + H2O
(a) removing water (c) taking acetic acid in excess
(b) taking ethanol in excess (d) all the above factors
O 122. CH3CH2CH2COOH +
HCl → Product is NCl
O Cl | (a) CH3CH2CHCOOH
(b) ClCH2CH2CH2COOH
Cl | (c) CH3CHCH2COOH
(d) All the three
123. The correct order of decarboxylation of the three acids is OH
(i) O
(a) iii > ii > i
OH
(ii)
(iii)
O (b) iii = ii > i
(c) iii > ii = i
O
O OH
(d) iii = ii = i
8.21
8.22
chapter eight 124. Which statement is true regarding oxidation of the following two compounds? (i)
(ii)
(a) Both are oxidizable to benzoic acid under similar conditions (b) It is very difficult to oxidize either of the two (c) Compound (i) is oxidizable to benzoic acid easily while compound (ii) is oxidizable only under vigorous conditions to benzoic acid (d) Compound (i) is oxidizable to benzoic acid, while (ii) is oxidizable only under vigorous conditions to 2,2-dimethylpropanoic acid
125. Predict the nature of end product in the following reaction O O ( i ) NaBH 4 → Product ( ii ) H3 O + OH (a) O (b) O
OH O (c) OH
O
(d) O
126. The correct order for the acidic character of the following carboxylic acids is COOH COOH COOH OH (iii) (i) (ii) COOH HO (iv) OCH3 (v)
OH
COOH OH
(a) iv > i > ii > iii > v (c) v > ii > iv > iii > i
(b) v > ii > iii > i > iv (d) v > ii > iv > i > iii
127. Salicylic acid is treated with bromine under two different conditions. OH COOH Br2in Br2 [X] [Y] water CH3COOH Predict the nature of [X] and [Y] in the following reactions Br
OH
OH COOH
(a)
;
[X] OH (c) Br [X]
OH COOH (b)
OH ;
;
Br
Br [Y] OH
OH
COOH
Br
Br [Y]
OH Br
Br [X]
Br [Y]
COOH
COOH
Br
COOH
Br
;
(d) Br [X]
Br [Y]
organic reaction mechanisms and reagents 128. Which of the following statements is true? (a) Hydrogen bonding always increases the acidic character of a species. (b) Hydrogen bonding always decreases the acidic character of a species. (c) Hydrogen bonding may increase or decrease the acidic character of a species. (d) Hydrogen bonding play no role in determining the acidity of a species. 129. Choose the correct statement regarding acidic character of acetic acid, CH3COOH and peroxyacetic acid, CH3COOOH. (a) Peroxyacetic acid is stronger acid than acetic acid since the former has one extra oxygen, an electronegative element. (b) Peroxyacetic acid is stronger than acetic acid because its conjugate base is a weaker base than acetate. (c) Peroxyacetic acid is weaker than acetic acid because its conjugate base is less stable than that of acetate ion. (d) Both are equally strong. 130. A carboxylic acid can best be converted into acid chloride by using (a) PCl5 (b) SOCl2 (c) HCl (d) ClCOCOCl 131. The yield of acid amide in the reaction, RCOCl + NH3 ⎯→ RCONH2, is maximum when (a) acid chloride and ammonia are treated in equimolar ratio (b) acid chloride and ammonia are treated in 1:2 molar ratio (c) acid chloride and ammonia are treated in 2:1 molar ratio (d) All the three give nearly similar result 132. Which of the following statement is not upto the mark? O O || || − (a) R − C − OR′ OH → R − C − O− + R’OH (a base-catalyzed reaction) −
(b) CH3COOC2H5 OH → CH3COOH + C2H5OH (reaction involves acyl-oxygen fission)
+
(c) C6H5COOH + CH3OH H→ C6H5COOCH3 + H2O (reaction involves acyl-oxygen fission) OH − – (d) CH3COOCH(CH3)C2H5 → CH3COO + HOCH(CH3)C2H5 (configuration of the reactant is retained)
133. The products in the following reaction are 2 − Pd/ C C6H5COOCH2C6H5 H →
(a) C6H5CH2OH + C6H5CH2OH (c) C6H5CH2OH + C6H5CH3
(b) C6H5CH3 + C6H5CH3 (d) C6H5COOH + C6H5CH3
CH3 | 134. Pyrolysis of CH3COOCHCH2CH3 gives
(a) 1-butene and 2-butene in equimolar ratio (b) 1-butene and 2-butene in 1:2 molar ratio (c) 1-butene and 2-butene in 3:2 molar ratio (d) 1-butene and 2-butene in 2:3 molar ratio
8.23
8.24
chapter eight 135. The relative stability of the four acid derivatives towards nucleophiles is (a) Amide > Ester > Acid anhydride > Acid chloride (b) Amide > Acid anhydride > Ester > Acid chloride (c) Acid chloride > Acid anhydride > Ester > Amide (d) Acid chloride > Ester > Acid anhydride > Amide 136. Which of the following statement is true about the hydrolysis of acetic anhydride? (i) It is more easily hydrolyzed in acidic medium than in neutral. (ii) It is more easily hydrolyzed in alkaline medium than in neutral. (iii) It is equally hydrolyzed in all the three media. (iv) It is more easily hydrolyzed in neutral than in acidic media. (v) It is more easily hydrolyzed in neutral than in alkaline medium. (a) i and ii (b) iii (c) iv and v (d) i and v 137. Which of the following compounds can undergo nucleophilic substitution easily? (i)
(iii)
O
(ii)
C O C–CCl3
(iv)
(a) Only ii (c) ii, iii and v
O
O
C–O–C O C
F
O F
(v)
C
(b) i, ii, iii and iv (d) ii, iii and iv
138. Which statement is true regarding the following structure? N CH3 C3H7 C2H5
(a) It is a chiral molecule (c) Both (a) and (b)
(b) It exists in two resolvable optically active forms (d) Neither (a) nor (b)
139. Introduction of a methyl group in ammonia markedly increases the basic strength of ammonia in aq. solution, but introduction of the second methyl group increases only marginally the basic strength of methyl amine in water. This is due to (a) different type of hybridization in the two amines. (b) protonated dimethyl amines are more solvated than methyl amine. (c) protonated dimethyl amine is more solvated than the protonated methyl amine. (d) protonated dimethyl amine is less stable than the protonated methyl amine. 140. The basic character of ethyl amine, diethyl amine and triethyl amine in chlorobenzene is (a) C2H5NH2 < (C2H5)2NH < (C2H5)3N (b) C2H5NH2 < (C2H5)3N < (C2H5)2NH (c) (C2H5)3N < (C2H5)2NH < C2H5NH2 (d) (C2H5)3N < C2H5NH2 < (C2H5)2NH 141. The correct order of decreasing basic character of the three aliphatic primary amines is (i)
(a) i > ii > iii
NH2 (ii) (b) iii > ii > i
NH2 (iii) (c) i > ii ≈ iii
NH2
(d) i = ii ≡ iii
organic reaction mechanisms and reagents 142. Which of the statement is true regarding the basicity of the following two primary amines? (i)
CH2NH2
CH2NH2 (ii)
(a) Both are equally basic because both are 1º amines. (b) i > ii because it is an aromatic amine. (c) ii > i because it is an aliphatic amine (d) i < ii because of difference in the nature of β-carbon.
143. The correct order of decreasing basic character is (i) C6H5NH2 (ii) C6H5CH2NH2 (iii) (C6H5)2NH (a) ii > i > iii > iv (b) iv > ii > i > iii (c) iv > iii > ii > i (d) iv > ii > iii > i
(iv) C6H11NH2
144. The correct order of increasing basicity is
NH O (iii) | | (i) CH3CH2NH2 (ii) | | CH3CNH2 CH3CNH2
(a) ii < iii < i
(b) i ≈ iii < ii
(c) i < ii < iii
(d) iii < i < ii
145. The relative order of basic character of the following compound is (i) (ii) (iii) N N N H COCH3 S
O
(iv) (v) N N H H
(a) ii > i > iii > iv > v (c) ii > v > iv > i > iii
(b) ii > iii > iv > v > i (d) ii > iv > v > iii > i
146. The basic character of the following alcohols is CH2OH CH2OH CH2OH CH2OH (i) (ii) (iii) (iv) Cl
(a) iv > i > ii > iii (c) iv > ii > iii > i
NO2
OCH3
(b) ii > iii > iv > i (d) i > ii > iii > iv
147. When aniline is treated with acetyl chloride in presence of anhydrous aluminium chloride, the main product is (a) o-aminoacetophenone (b) p-aminoacetophenone (c) Both (a) and (b) (d) m-aminoacetophenone
8.25
8.26
chapter eight NaNO , HCl
2 → P. P is 148. CH3CH2CH2NH2 0° C
(a) CH3CH2CH2OH (c) Both (a) and (b)
(b) (CH3)2CHCl (d) Reaction not possible
149. Benzenediazonium chloride when treated with phenols gives an azo dye, to get best result the pH of the medium should be
(a) around 4
(b) around 8
(c) around 10
(d) 12
150. In the following reaction, the reagent X should be . H 2 SO4 RCOOH + [X] Conc → RNH2
(a) NH3
(b) HN3 (c) Either of the two
(d) None of the two
151. Which of the following can undergo electrophilic substitution when treated with nitrous acid at 0ºC?
(a) C6H5NH2
(b) C6H5NHCH3
(c) C6H5N(CH3)2
(d) None of these
152. Which of the two reactions proceed faster? (i) Conc. HNO3, NH2 Conc. H2SO4 (i) + HOH (ii) Sn/HCl D D (ii) D
D
(i) Conc. HNO3, D Conc. H2SO4
D
(ii) Sn/HCl
D
D NH2
D
+ HOD
D D
(a) i
(b) ii
(c) i = ii
(d) Not definite
153. Which of the following does not reduce C6H5NO2 to aniline?
(a) Sn/HCl
(b) SnCl2/HCl
(c) Zn/HCl
(d) LiAlH4
154. Which of the following amines can be resolved into two enantiomers? N CH2CH3 N CH3 (i) (ii) CH3 CH3 H H NH2
H3C (iii) N
(iv) C CH2CH3 CH3
(a) i, iv
H (b) i, ii
CH3
(c) i, iii, iv
(d) iii, iv
155. Which of the following statement is false? (a) Dimethyl amine as well as trimethyl amine are soluble in water. (b) Trimethyl amine forms hydrogen bond neither with itself nor with water. (c) Trimethyl amine can act as hydrogen bond acceptor only, while dimethyl amine can serve as both a hydrogen bond donor and acceptor. (d) All the three statements are false.
organic reaction mechanisms and reagents 156. Ephedrine is a secondary amine. It is widely used in cold and allergy conditions in the form of its hydrochloride but not as such because (a) the amine itself has an unpleasant smell, while its salt is odourless. (b) the amine is insoluble in water, while the salt is soluble in water. (c) the amine is unstable and easily oxidized by air, while the salt is resistant to atmospheric oxidation. (d) of all the above facts 157. Benzamide and benzyl amine can be distinguished by (a) cold. dil. NaOH (b) cold dil. HCl (c) both (a) and (b) (d) NaNO2, HCl, 0ºC, then β-naphthol 158. The correct order for the basic character of the compounds i to iv should be (i) (ii) (iii) N N N H H
(a) iv < iii < i < ii (c) iv < ii < iii < i
(iv) CH3CN
(b) iv < i < iii < ii (d) iv < iii < ii < i
159. Which of the following is true regarding basic character of pyridine and pyrrole? (a) Pyrrole is more basic because its non-bonding electrons occupy sp3 orbital.
(b) Pyridine is more basic because its non-bonding electrons are not part of aromatic sextet. (c) Both are equally basic. (d) Pyridine is less basic because it is a tertiary amine.
160. Pyrrole and pyridine both are basic and form salts with acids. H+ N H (i)
+
N N H2 (iii) (ii)
H+
+
N H (iv)
Which of the following statement is true regarding the aromatic character of the four species? (a) All the four are aromatic (b) i, iii and iv are aromatic (c) i, ii and iii are aromatic (d) i and iii are aromatic
161. Ethylene can be prepared in good yield by (a) CH3CH2N+(CH3)3I– Heat → CH2 = CH2 + (CH3)3N + HI
(b) CH3CH2N+(CH3)3OH– Heat → CH2 = CH2 + (CH3)3N + H2O (c) Both (a) and (b) (d) CH3CH2NH2 Heat → CH2 = CH2 + NH3
162. Which one of the following is not an oxidation product of a primary amine? (a) A hydroxylamine (b) A nitroso compound (c) A nitro compound (d) None of these
8.27
8.28
chapter eight 163. Which of the following method is used for eliminating nitrogen of an amine present outside the ring? (a) Hofmann elimination (b) Cope elimination (c) Both (a) and (b) (d) Emde degradation 164. Which of the following does not react with nitrous acid?
(a) C6H5NH2
(b) C6H5NHCH3
(c) C6H5N(CH3)2
(d) None of these
165. Which of the following leads to carbon–carbon double bond? (a) 1º amine + RCHO ⎯→ (b) 2º Amine + R2CO ⎯→ (c) 2º amine + RCHO ⎯→ (d) Both (b) and (c) 166. Electrophilic aromatic substitution of pyridine resembles with
(a) benzene
(b) aniline
(c) nitrobenzene
(d) none of these
167. Arrange the following compounds in decreasing order of reactivity towards electrophilic substitution. (i) (ii) (iii) N N H
(a) i > ii > iii
(b) i > ii = iii
(c) iii > ii > i
(d) iii > i > ii
168. Which reaction seems to be incorrect?
3 (a) Me3CCl NH → Me3CNH2
(c)
Cl
NH3
3 (b) Me3CCl NH → Me2C = CH2
(d) CH2Cl
NH3
169. Which of the statement regarding following structure is true? H HO (i) H H
CHO CHO CHO OH H OH HO H H HO H HO H (ii) (iii) OH HO H H OH OH H OH H OH CH2OH CH2OH CH2OH
(a) (i) and (ii) are epimers (c) Both (a) and (b) are true
(b) (i) and (iii) are epimers (d) All the three are epimers
170. Which of the following pair represents an example of diastereoisomers (i) (+)-Tartaric acid and meso-tartaric acid (ii) Maleic acid and fumaric acid (iii) d(+)-Galactose and d(+)-mannose (iv) (+)-Lactic acid and (–)-Lactic acid
(a) i and iii
(b) i, iii and iv
(c) i, ii and iii
(d) iv
CH2NH2
organic reaction mechanisms and reagents
Level 2 Single and Multiple-choice Type 1. What could be the reagent for the following reaction? O CH3
(a) CH3COCH3
Reagent cat. acid Removal of H2O
(b) CH3OH
H3CH2CO
OCH2CH3 CH3
(c) CH3CH2OH
(d) HOCH2CH2OH
2. What could be the product for the following reaction? CH3
(i) Mg, Et2O (ii) CD2O
Br
(iii) H2O
D
CH3
CH2OD (a)
Product?
(b)
CH3
(c)
CH3
OH
D (d)
CH3
D
H
3. What could be the major product for the following reaction? O (i) EtMgBr (1 equivalent)
OH
(ii) HCl, H2O HO
HO
(a)
Product?
O
(b)
(c)
O OH
(d)
4. What could be the product for the following reaction? O
(i) NaBH4 H
(a)
OH
(ii) H+, H2O
OH
O
(b)
(c) OH
5. What could be the product for the following reaction? O
Product?
(i) CH3MgBr (ii) H+, H2O
H H
Product?
OH (d)
8.29
8.30
chapter eight OH
OH
O (a)
(b)
H H
OH
(c)
OH (d)
6. What is not the name for the following compound? CH3 C H3C
(a) 2-Acetaldehyde
(b) propanone
O (c) acetone
(d) dimethyl ketone
7. What could be the reagent for the following reaction? O
NCH2CH3
Reagent
(a) H2N–Ph, removal of water (b) H2NCH2CH3, CH3CO2H, removal of water (c) H2NCH3, H2O, removal of water (d) H2NCH2CH2CH3, CH3CO2H, removal of water
8. What could be the reagent for the following reaction? O
O
O
Reagent cat. acid Removal of H2O
(a) CH3COCH3
(b) HOCH2CH2OH (c) CH3CH2OH
(d) CH3OH
OH OH
9. O
Dil. H2SO4
Major product is?
OH OH
OH (a)
OH
O
(b) O
Conc. H2SO4 OH OH
OH
(c) OH H
10.
OH
OH
(d) O
Major product is?
OH
O
OH
organic reaction mechanisms and reagents
(a)
(b)
O
OH
(c)
O
(d) OH O
OH 11.
Conc. H2SO4 ∆
Major product is? OH
(a)
O
(b) HO
(c)
(d)
OH Conc. H2SO4 ∆
12.
(a)
Major product is?
(b)
O (c)
Dil. H2SO4
13. HO
(d)
Major product is?
OH OH
HO
(a) HO
OH
(b) HO
OH
8.31
8.32
chapter eight
(c)
O
(d) H
H
O
O
O
O 14.
Conc. H2SO4 ∆
Major prodcut is? OH
O (a)
(b)
(c)
(d)
OH
15.
1 equivalent mCPBA OH
O (a)
OH
(c)
Major product is? OH
O
(b)
OH (d)
O
O
O (i) O3
16.
(ii) PPh3
Major product is?
OEt O
O
H
H (a) O
O
H H
O
H
(b) O
O
OEt O Et O (c)
OEt O
H
H H
O H O
O
O
OH
(d) None of these
H O O
H
organic reaction mechanisms and reagents O
Me 17.
(i) BH3 - THF
O
(ii) H2O2 Me
O
Me
Major product is? O
Me
O
Me OH OH
O (a)
(b) O
H
OH
(c) O H
H 18.
H
OH
(i) mCPBA (ii) DIBAL-H (iii) H3O+
(d) O OH
OH
Major product is?
Me H
H (a) Me HO
(b) H Me Me OH
H Me H
(c) Me
H (d)
OH
Me
Me
OH Me
O Cl
19. HO
(i) Excess of Me MgCl (ii) H2O / H+
Major product
OH
OH (a)
(b) HO
HO
(c) HO
OH
(d) OH
8.33
8.34
chapter eight (i) O3 / H2O2 (ii) Excess of MeOH /H+
20.
(iii) NaOMe / MeOH
Major product is?
O
O
(a)
(b)
O
O
O OMe
O
O
(c)
OMe
O
(d)
OMe
MeO
(i) MeOH / H+ (ii) NaOMe / MeOH
O 21. OH
(iii) Aqueous NaOH (iv) H+ /∆
Major product of reaction is?
O (a)
O OMe
(b)
(c)
O
O (d)
O
22.
(i) SH SH / H+ (ii) 2 eq. RLi/Cl
O H
C
H
Major product is?
(iii) H3O+
O (a)
(b)
O
O (c)
(i) SOCl2 (ii) NaN3 (iii) Ag2O /∆
O 23.
Cl
OH
(iv) H2O (v) (vi) LAH
O (d)
Major product is?
O OH N
organic reaction mechanisms and reagents H (a)
(b)
O
(d)
N
N H N
(c)
24.
Ph
(i) NaCN (ii) NH3 /∆ / H+ (iii) HCN
O
(iv) H3O+ HOOC (a)
COOH Ph COOH
(c) Ph
NH2
MeO
HOOC (b) Ph
COOH NH2
COOH (d) Ph
OEt
H
H
Major product is?
(i) PBr3 (2 eq.) (ii) O O
CH2OH
25.
NH2
(iii) Aq. NaOH (iv) H+ /∆
OMe
NaOEt Major product is?
CH2OH O MeO (b)
MeO (a)
MeO
MeO
O
O MeO (d)
MeO (c) MeO O 26.
O
MeO
(i) HCN (ii) LiAlH4 (iii) NaNO2 + HCl
Major product is?
8.35
8.36
chapter eight OH (a)
O
(b) O
NH2 (c)
(d)
Me (i) 1% HgSO4 / dil H2SO4
27.
Major product is?
(ii) OH /∆
O
(a)
(b)
O
(c)
O
(d)
O
O O 28.
(i) KOH
NH
Major product is?
(iii) KCN, NH4Cl (iv) H3O+ /∆
O
COOH
H2N (a)
Br
(ii) O3 / Me2S
COOH (b) NH2
NH2
COOH COOH (d)
(c) H2N
NH2 S
29.
S
(i) BuLi (ii) 5 equivalent Br (iii) Dil. H2SO4 (iv) OH /∆ O
O (a)
Br
(b)
Major product is?
O
O Me
Et
(c)
(d)
organic reaction mechanisms and reagents
H⊕ OH OH (ii) BuLi (excess)
O
O 30.
(i)
OH
(iii) Dil. H2SO4 (iv) OH /∆
(a)
O
Major product is?
(b) O
O (c)
(d) O
CNa⊕ (ii) HgSO4, dil H2SO4 (i) CH
31.
O
(iii) Ph–CHO / OH
Major product is? O
O (a)
Ph (b)
Ph
(c)
O (d) OH
NH2 32.
(i) AC2O (ii) HNO3, H2SO4 (iii) H3O+ (iv) Br2 + NaHCO3
NH2
NO2
NO2 (b) Br
COOH
(c) Br
Ph
Major product of reaction?
(v) NaNO2 + HCl (vi) H3PO2 (vii) Fe + HCl (viii) OH / H2O
(a)
Ph
Br
(d) Br
Br
Br
Br
8.37
8.38
chapter eight (i) 2 equivalent NaOEt O
O
33. EtO
(ii) Br OEt
(a)
Br
(iii) H3O+/∆
COOH O
Major product is?
O
(c) HO
O
(b)
C
OEt
COOH OH (d)
CH3 (i) Br2 / Fe (ii) K2Cr2O7 / H+ / ∆
34.
(iii) Li / Et2O (iv) CO2 / H+ O
CH3
(a)
HO CH3 35.
Identify product?
OH
(b)
O
(c)
HO
(i) HNO3 / H2SO4 /∆ (ii) LAH (iii) NaNO2 + HCl / 0–5°C
(a)
CN
COOH
(b)
CN
(d)
Br
O
(iv) CuCN CH3
OH
O
Identify product?
NO2
(c)
CN
Cl
36.
(i) HNO3 / H2SO4 /∆ (ii) CH3Cl / AlCl3 (iii) Sn /HCl (iv) NaOH /H2O
Identify product?
(d)
organic reaction mechanisms and reagents Cl
Cl
Cl
Cl COOH
CH3 (a)
(b)
NH2 Cl
(c)
NO2
NH2
NH2 (i) Li / Et2O (ii) HCHO Then H+ (iii) HCl
37.
(d)
Identify product?
(iv) Li / Et2O (v) CO2, Then H+
COOH
Cl
COOH
COOH (a)
HO
(b)
(c)
O
(d)
Cl
COOH
CONH2 NaOH / Br2
38.
Identify product?
MeO OMe NH2
COOH
(a)
(b)
(c)
MeO
MeO
NH2
(d) MeO
OMe
OMe
OMe
39. In the presence of a base, the compound below cyclizes to give a compound Y. O H3C
CH3 Na2CO3 H2O O
Identify the structure of compound Y.
OMe
8.39
8.40
chapter eight
(a)
CH3 O (b) HO OH
40.
HO
OH
(i) CH3COCl / AlCl3 (ii) Zn–Hg /HCl
CH3
CH3 O (d)
CH3 O (c)
Identify product?
(iii) Br2 / hν Br
Br
Br (b)
(a)
(c)
H3C
O
H3C
O
OH
O
HO
H3C
41.
(d)
H3C
Br
O O
CH3
Identify product?
N OH
O
O
O O (a)
O
O
HO (b)
OH
O HO (c)
(d) O CH3 O
O 42. OH
+
N O
Br
Product. Identify product?
O
organic reaction mechanisms and reagents O O
O
O
(a)
(b) Br O
O O
(c)
O
43. H3C
BF3 / MeCN
H
H
(d)
O
O
Identify product?
CONH2 N
H3C
N
CH3
(a)
(b)
O
H2NOC
O
H2NOC CH3
O
H3C (c) H3C
H3C
N
SPh (d) H3C
O
O
COOH (i) NaOH, H2O
44. O
(ii) H3O+
O OH
HOOC
Identify product? HOOC
(a)
OH
(b) CH3
COOH
COOH COOH
OH
OHC (c)
(d) COOH CHO OH
O
H3C H3C
CH3
H2NOC
HOOC
45.
CH3
O
O
PhSNa, H2O
Identify product?
8.41
8.42
chapter eight CH3
O
H3C (a) H3C
O
OH
O
H C SPh (b) 3 H3C
SPh O
OH
CH3 CH3
O
H3C (c) H3C
H C SPh (d) 3 H3C
O
SPh
O
OH
O
Excess of NaOH, H2O
46. O
CH3
O
Excess of HCHO
O
Identify product?
CH3
H3C
OH H3C (a)
CH3 O
H3C
HO
CH3
OH
O
OH
OH
(d) OH O O
O CH3
H3C
(i) NaOH, H2O
O
47.
O OH
OH
O
OH
(b)
O
H3C
(c) O
OH
OH
(ii) H3O+
CH3
CH3
Identify product?
CH3
(a) HOOC
H3C
CH3
H3C (b) COOH O
CH3
COOH H3C O (c)
CH3
COOH C H 3 COOH (d) CH3 O COOH
organic reaction mechanisms and reagents O N
48.
OTs +
2eq. BuLi
Identify product?
O O O (a)
(b)
N O
N H
O
O O (c)
(d) N H
Br
O N H
O
Br BuLi
49.
Identify product?
O (a)
Br
(b)
(c)
Br 2 eq. of NaI Acetone /∆
50.
Br (a)
C
Identify product?
Br (b)
(d)
8.43
8.44
chapter eight
(c)
(d)
H2N
NaNO2, then HCl 0 °C then, ∆
51.
Identify product?
NH (a)
(c)
(b)
(d) N H
N
COOH NH2
H2N
H3O+ ∆
52.
Identify product?
NH2 NH2
H2N (a)
NH2
HO (b)
NH2
NH2 OH
HO (c)
(d) OH
O 53. 2EtO
O
O
CHO OEt
+
(i) 2eq. NaOMe / ∆ (ii) NaOH / ∆
Identify product?
CHO COOH O (b)
O (a) O
COOH
O
HOOC COOH
organic reaction mechanisms and reagents COOH
COOH
O (c)
O (d) O
HOOC
O
HOOC
H3C
O CHO
54.
(i) NaOMe / ∆
H2C
+
H3C O
O
O (a)
Identify product?
CH3
(b)
(c) H3C
CH3
(d)
CH3
Cl HC 55.
O NaOD / D2O Dioxane
S
Identify product?
CH2 O
CH2 O (a)
D (b)
S
(c)
(d)
CH2 O
D
CH3 CH2
56.
CH2
H3C HO
KH 18- Crown- 6 / THF Identify product?
8.45
8.46
chapter eight CH3
(a)
CH3 (b)
H3C
H3C
O
O OH
HO (c)
(d) OH OH
57.
Conc. H2SO4
Identify product?
OH CH3 (a)
(b) O
O CH3 (c) H3C
(d) O
O
CH3 58. H C 3
Conc. H2SO4
Identify product?
O CH3
(a) O
CH3
CH3 (b)
CH3 H3C (c) O
CH3
O CH3
H3C (d) O CH3
CH3
organic reaction mechanisms and reagents O
H3C
Conc. H2SO4
59.
Identify product?
CH3 H3C
CH3
(a) H3C
CH3
CH3 CH3
H3C (b)
CH3
H3C
CH3
CH3
CH3
CH3
(c)
(d)
H3C
CH3 CH3 Ph
CH3
H2C
60.
P
Ph Ph
RLi / ∆
Identify product?
O
O
CH3
CH3
CH3 (a) O
(b) O
CH3
O
CH2
CH3
CH3 CH3
(c)
(d)
H2C
H2C (i) CH2N2 (ii) NaH
61.
(iii) MeI O
Identify product?
CH3
8.47
8.48
chapter eight
(a)
(b)
MeO
OMe
OMe H3C
(c)
H3C
(d)
MeO
OMe
O (i) MeMgCl (ii) HClO4 (aq.)
62.
(iii) NaOH (aq.) H3C
Identify product?
CH3
O OH
OH
(a)
OH
OH
HO (c)
(d) H3C
OH AcO
O
O
Aq. NaOH /∆
O
63. H3C
CH3
Identify product?
CH3 CH3 O
O
(b)
(a) CH3
H3C
(c)
CH3
HC (b) 3
O
H3C
(d)
organic reaction mechanisms and reagents O Ac2O
64. H3C
Identify product?
CH3
(a)
OH
CH3
(b) CH3
CH3
CH3
OAc
OAc
(c)
(d) CH3 CH3
CH3
O OH 65.
NaOH
H3C
Identify product?
O2N COOH
O O
(b)
(a) H3C
H3C O2N
NO2
COOH
(c)
COOH
(d) COOH
NO2
NO2
8.49
8.50
chapter eight COOH NaBH4
'A' product
66. O2N
C
LiAlH4
H
'B' product
O Identity true statement for A and B products.
OH
CH2OH
(a) ‘A’ is
H2N
(b) ‘B’ is H2N
CH2OH
OH OH COOH
(c) ‘A’ is
OH
O2N O
67. O
O2N OH
(i) HO H
(d) ‘B’ is
OH
(ii) NH2NH2 / OH– /∆ (iii) H3O+ (iv) LiAlH4 (v) SOCl2
(A)
(i) PPh3 (ii) BuLi
(B)
MeO (iii)
OMe H
O (iv) H3O+ Identify correct statement for (A) and (B) products.
Cl
(a) Structure of ‘A’ is
O
(b) Structure of ‘B’ is
O H
(c) Structure of ‘A’ is
Cl
(d) Structure of ‘B’ is
organic reaction mechanisms and reagents O
(i) HO
OH CH2
(ii) PPh3 68.
Major product is?
O+
(iii) H3 O O
CH2
(a)
(b)
(d) O
O
O
(i) mCPBA (ii) LAH O (iii)
69.
O
(c)
CH2
O
PPH3
OEt / H+ O
Major product is?
(iv) LAH (v) H3O+ O (a)
O
(b)
OH
O OEt (c)
(d) OH
70. Identify correct reaction sequence NO2
NH2 LiAlH4
(a)
C H O
O
O
(c)
O
NaBH4
O
O C OEt
(b)
C H O
OH
OH LiAlH4
C H O
OH
NO2 O
(d)
NH2 Sn + HCl
OH
71. Identify correct reaction sequence O (a)
O (c)
O Pd / C H2 OH LiAlH4
O (b)
Ni H2
O (i) HS (d) (ii) Ni / H2
SH/H+
8.51
8.52
chapter eight 72. Identify correct reaction sequence NO2
NH2 Zn–Hg HCl
(a)
NO2
NO2 NH2 –NH2 OH– /∆
(b) C Me O
C Me O NO2
NO2 NaBH4
(c)
O
NH2
NO2 LiAlH4
(d)
HO
O
HO
73. Identify correct reaction sequence Cl
(a) O
Cl
(b) O
Cl
(c)
Pd / BaSO4 H2
C O
Pd / BaSO4 H2
C
Ni / H2 OH
Cl
LiAlH4 OH
O CHO 74.
H
OH
H
OH
H
O
O (d)
Cl
(i) MeOH / H+ (ii) HIO4 (iii) NaBH4
Major product is?
CH3OH O
O (a)
(b) OMe
MeO MeO
O
OMe
(c) HO
OMe
HO O
OMe
(d) OH
HO
OH
organic reaction mechanisms and reagents COOH
(i) Br2, NaOH (ii) MeOH / H+
75.
(iii) NaOMe
Major product is?
O
O
COOH (a)
(b)
C
OMe
O
O
COOMe (c)
(d) COOMe
COOMe O
(i) 2 eq. NaOEt (ii) Me–I
O
76.
OEt
Cat. NaOEt /∆
(iii)
Major product is?
O O
(a)
(b) O
O
O
O O (c)
(d) O
O
(i) MeOH (ii) Red P + Br2 Major product is? (iii) NH3 (excess) (iv) H3O+
77. O
O
O
COOH
(a) NH2
COOH (c) NH2
NH2
NH2 (b) HOOC
COOH HOOC (d) NH2 (i) 2 eq. LDA
O 78.
(ii) 2 eq. OEt
COOH
(iii) O3 / Zn (iv) OH– /∆
Br
Major product is?
8.53
8.54
chapter eight O
O (a)
(b)
(c)
(d)
COOEt
79. Me
(i) 2eq. CN (ii) H3O+ (iii) MeOH / H+
NH2
(iv) NaOMe / MeOH (v) H3O+ /∆
COOEt
O
Major product is?
O
O (a)
O
O
O
O
(b)
(c)
(d)
N
N
N
N
Me
Me
Me
Me OMe
(i) NaOMe O
COOMe
80. Active 'H'
H
(a) N
(b)
Major product is?
(ii) Aq. NaOH (iii) H+ /∆(CO2↑)
N
O (c)
N
(d)
N
O
O
O
O H
81.
Me +
O
OH
ΟΗ– ∆ [Intramolecular aldol]
Major product is?
O (a)
(b)
O
O O
O (c)
O
(d) O
organic reaction mechanisms and reagents O 82.
LAH
O
Major product is?
O t-Bu HO
O (a) t-Bu
H (c)
(b) HO
O
O C
O (d)
(i) LDA (ii) 1-Bromopentane
83.
(iii) BH3– THF (iv) MeCOOD H
Major product is?
D
D
(a)
(b)
D
H
(c)
(d) H
84.
H
OH
D (i) H3PO4 /∆ (ii) BH3 – THF (iii) H2O2 / OH (iv) SOCl2
Major product is?
N
(v) NaSMe (a)
OH (b)
Br Br
(d)
(c) SMe
85.
(i) 2 eq. NaNH2 (ii) Pd / BaSO4 / H2 (iii) OsO4, then NaHSO3 (iv) HIO4 (v) H2CrO4
Me
Me
Me
SMe
Major product is?
SMe
8.55
8.56
chapter eight Br
O
Br (b) OH
(a)
O (c)
O
COOH
(d)
COOH
O (i) BuLi (ii) 86.
OH
I
(iii) NaNH2 (iv) CH3–I (v) Br2 / CCl4
Major product is?
Br (a)
(b)
O
Br
O Br
O
(c)
O (d) O
O
(i)
H2SO4
(ii) NaNH2 (iii)
87. HO
I
Major product is? (iv) H3O+ (v) H2 / Lindlar’s catalyst (vi) m·CPBA O
(a)
(b)
O OH
O O (c) HO
O (d) HO
OH
Br
organic reaction mechanisms and reagents (i) Conc. nH2SO4 / ∆ 88.
(ii) BuLi
OH
O H
C
H
Major product is?
(iii) Pd / BaSO4 / H2 (iv) Zn–Cu / CH2 I2 ether OH (a)
O O O (c)
(b)
OH
(d)
89. Which of the following structures is the product from the self-condensation of two molecules of pentan-3-one? O
O (a)
(b)
O
O
(c)
H
O 90.
(i) HO–(CH2)2–OH, H+
OMe
O
(ii) Excess MeMgBr, then H3O+
O (a)
91.
(a)
(c)
(b) MeO
C
(d)
C
CH3
H
Br
C
C
H
H
H
H
C
C
Br
H
O
OH
OH
Major product is?
O
(c)
(d) H
Me
(i) Na, NH3 (ii) HBr
Major product is? Br
CH3 (b)
Br CH3 (d)
OH
O
8.57
8.58
chapter eight O
(i) Mg, Ether (ii) EtOH
Br
92. O
(iii) Catalytic H+, H2O H
Major product is?
OH OEt
(a) O
(b) O
OEt
H
O
OH (d) O
O (c)
93. Select all of the following statements about the cross Aldol experiment that are true: (a) The ketone was added to a solution containing the aldehyde and base. (b) The reaction can be catalyzed by an acid. (c) The electrophile is the enolate ion. (d) The aldehyde is used in excess. 94. CH3CO2H
(i) SOCl2 (ii) 3-Methylaniline (iii) LiAlH4, then H3O+
Major product is?
NH2
H3C (a)
NH2
H3C
CH3 (b)
OH
O (c) H3C
N H
(i) O3, then Zn in H2O
CH3
NH H3C (d)
CH3
CH3 HO
95. (ii) NaBH4 (iii) Excess PBr3 (iv) Excess KCN (v) H+, H2O, Heat
OH O
O
Identify reactant? CH3 (a)
CH3 (b)
CH3
CH2
(c) (d)
organic reaction mechanisms and reagents H3C
OH
+ 96. (i) HO–CH2CH2–OH, Catalytic H (ii) Mg, THF then H2O=O, then H3O+ (iii) H3O+, heat
O
Identify reactant? O (a)
Br CH3
(b)
H O
Br H (c)
Br (d)
O
O
Br
97.
(i) Ph3P, then n-BuLi (ii) Cyclohexanone (iii) CH2I2, Zn–Cu
Identify reactant? OH (a)
Br
O (b)
NH2
(c) (d)
OH 98. BrMg–(CH2)4–MgBr then, H3O+
OH
Identify reactant? O
O (a)
(b) O
O
(c) OEt
CH2CH3 Br2 99.
H H
CH2CH3
Br Br
+
Br
H
Br
H
CH3 (50:50 of these enantiomers) Identify reactant?
CH3
O
O (d) O
O
8.59
8.60
chapter eight
(a)
(b)
(c)
(i) LDA (ii) CH3I
100. O
Major product is?
(iii) NaBH4/MeOH
OH
O
OH3C (a)
(d)
(b)
OH
(c)
(d)
(i) HBr (dark, N2) 101.
(ii) PH3P, then nBuLi O (iii)
(a)
(b)
Major product is?
(c)
(d) OH
(i) (CH3CO)2O/AlCl3
102.
(ii) Zn/Hg HCl (iii) CH3Cl/ AlCl3
Major product is? O
(a)
(b)
(c)
(d)
O 103. H
CO2CH2CH3
O
(a) HO OH (c)
(i) HOCH2CH2OH/H+/heat (ii) LiAlH4, then H3O+ (iii) H3O+ / heat
Major product is?
OH OH (b) H
O
OH
(d) OH3C
OH
organic reaction mechanisms and reagents
Comprehension Type Passage 1 When the following three different types of esters are hydrolyzed in a basic medium, O O || || Ar − S − O − R R − O − P − OH R–C | || OR OH O Carboxylate Sulphonate Phosphate O
the hydroxide anion attacks the acyl carbon in carboxylates while it attacks the alkyl carbon in sulphonates leading to a difference in the site of cleavage. More interestingly, phosphate esters lie somewhat in between carboxylates and sulphonates in that cleavage can occur in either direction. In an acidic solution, all the three types of phosphates (monoalkyl, dialkyl and trialkyl) are hydrolyzed to phosphoric acid, while in a basic solution only trialkyl phosphates undergo hydrolysis and only one alkoxy group is removed. 104. Which of the following factor explains the difference in attack of the nucleophile, OH– on carboxylates and sulphonates? (a) Sulphonate anions are weakly basic and hence good leaving groups. (b) Carboxylate anions are strongly basic and hence poor leaving groups. (c) Both (a) and (b) (d) None of the these 105. Competition between phosphorus and alkyl carbon to nucleophilic attack is due to the fact that (a) Phosphorus can accept an additional pair of electrons. (b) Phosphoric acid lies between carboxylic acid and sulphonic acid. (c) Both (a) and (b) (d) None of the these 106. The rate of hydrolysis of monoalkyl phosphates tends to ................. with increase in pH. (a) Decrease (b) Increase (c) Remains unaffected (d) None of these 107. In an aqueous solution, a monoalkylphosphate ester can exist as (a) A neutral ester (b) A monoanion and dianion (c) A monoanion, dianion and protonated ester (d) A monoanion, dianion, protonated ester and neutral ester
8.61
8.62
chapter eight Passage 2 Grignard reagents (RMgX) are prepared by the reaction of an organic halide and magnesium metal is in ether solvent. −O −R R–X + Mg R → R–MgX
The solvent (usually diethyl ether or tetrahydrofuran) plays a crucial role in the formation of a Grignard reagent. Alkyl halides are more reactive than aryl and vinyl halides. Indeed, aryl and vinyl chlorides do not form Grignard reagent in diethyl ether. However, an alkyl halide containing an alcoholic –OH group can be converted to Grignard reagent by first protecting the –OH group to tert–butyldimethylsilyl ether which is inert to Grignard reagent. The protecting group is finally liberated by treatment with fluoride ion. CH3 | R – O – H + Cl Si − C(CH3)3 | CH3
CH3 | R − O − Si − C(CH3)3 | CH3
tert–butylchlorodimethylsilane N+F–
(C4H9)4 THF
CH3 | R − O − H + F − Si − C(CH3)3 | CH3
108. Grignard reactions generally occur in dry ether because (a) The stronger acid diethyl ether will displace the weaker RH acid from its salt. (b) The stronger acid H2O will displace the weaker acid RH from its salt. (c) Water slows down the reaction. (d) Water mixes with ether preventing ether to perform its function. 109. Grignard reagent cannot be prepared from Cl (a) HO
Br (b)
Cl (c) (d) Cl Cl
110. H2N(CH2)3Br cannot be converted into corresponding Grignard reagent because of (a) Reaction between –NH2 and –Br groups present in the same molecule (b) Strong nucleophilic character of the Grignard reagent (c) Strong basic nature of the Grignard reagent (d) All the three factors 111. The function of tetrahydrofuran in the preparation of Grignard reagent is that it (a) Acts as a solvent (b) Helps in maintaning the reactivity of magnesium (c) Both (a) and (b) (d) None of the these
organic reaction mechanisms and reagents Passage 3 Grignard reagents are powerful nucleophiles and strong bases. They act as nucleophiles by attacking a variety of compounds including saturated and unsaturated carbon atoms. Examples of reaction on saturated carbon include oxiranes (epoxides) which form alcohols as the final product. δ− δ+
R MgX + H2C—CH2 O
(i) Ether (ii) H3O+
R – CH2 – CH2OH C = O, –C ≡ N,
Examples of reaction on unsaturated carbon are attack on R R′
H3O+
C = O + R′′MgX
R R′
C = S, etc.
R′′ C – OH
When R and R’ = H, product is 1º alcohol. When R and R’ = Alkyl group, product is 3º alcohol. When one R or R’ is alkyl, product is 2º alcohol. 1 2 3 112. C6H5MgBr + H2C–CHCH3 O
(i) Et2O (ii) H3O+
Product.
Here, the nucleophile C6H5– attacks
(a) C1
(b) C2
(c) C3
(d) Any of the three
113. Epoxides react with Grignard reagent to form (a) Primary alcohols (b) Secondary alcohols (c) Tertiary alcohols (d) Any of the three 114. On the basis of the above two passages, predict which of the reaction is feasible. OH (i) N H
Br (i) Mg, ether (ii) C6H5CHO (iii) H3O+ MgBr
(ii)
HO
OH CH2CH3
(i) CH3CH2MgBr
(iii) OH (a) Only ii
N H
CH3CHO, H3O+
O
CHC6H5
(ii) H3O+ (b) i and ii
OH (c) All the three
(d) None of three
8.63
8.64
chapter eight 115. On the basis of the above two passages, steps involved in the following conversion are OH Br HOH2C
HOH2C H2C–CHCH3 O
(a) Protection of the –OH group, followed by reaction with
(b) Protection of the –OH group, followed by reaction with CH3CH2CHO (c) Protection of the –OH group, followed by reaction with (CH3)2CHCHO (d) Reaction is not feasible to give quantitative yield
Passage 4 Alkyl halides and alcohols easily undergo nucleophilic substitution either through SN1 or SN2 mechanism. The relative case of these two processes depends upon the nature of the substrate (alkyl group as well as leaving group), nature of nucleophile and also upon the nature of solvent. SN1 mechanism involves the formation of carbocation as intermediate while SN2 mechanism involves the formation of a transition pentavalent state. SN1 is the main mechanism in 3º alkyl halides and alcohols, while SN2 mechanism is the path adopted by most of the 1º alkyl halides and 2º alkyl halides may follow SN1 as well as SN2. 116. Which of the following solvent will give maximum yield for an alkyl halide undergoing SN1 mechanism?
(a) Water
(b) Ethanol
(c) Diethyl ether
(d) n-hexane
117. Rearrangement of alkyl groups occur when hydrogen halides react with alcohols except with most primary alcohols. The best explanation is that (a) The 1º carbocations are unstable and hence are not formed. (b) The 1º carbocations are unable to undergo rearrangement. (c) Both (a) and (b) are true (d) Both (a) and (b) are false 118. Neopentyl alcohol, Me3CCH2OH, reacts with HX according to (a) SN1 mechanism (b) SN2 mechanism (c) Both (a) and (b) (d) None Passage 5 119. A chemist treated a compound X with NaOH in presence of acetone as solvent. H owever, he recovered the starting material as such, and instead isolated a small amount of the product A. The product A was shown to have C, H and O and it had a molecular weight of 116g/mol. It gave a positive iodoform test and was found to be identical with a compound obtained by the aldol self-condensation of acetone. Although the product A did not discharge colour of bromine in CCl4, its dehydration product B with hot sulphuric acid discharged bromine dissolved in CCl4.
organic reaction mechanisms and reagents 120. What is the molecular weight of a compound that undergoes an aldol self-condensation reaction and whose dehydrated product has a molecular weight of 70?
(a) 35
(b) 44
(c) 49
(d) 58
121. The aldol self-condensation of acetone is in equilibrium that favours acetone over its corresponding product. Which of the following conditions is most likely to shift the position of equilibrium toward product A? (a) By using a catalytic amount of NaOH. (b) By using only a catalytic amount of acetone. (c) By removing product A as soon as it is formed. (d) By increasing reaction temperature. 122. Which of the following compounds will give a positive iodoform test? (a) Only compound A (b) Only compound B (c) Both (a) and (b) (d) None of these 123. The compound X can be O || (a) CH3CH
O || (b) CH3 − C − CH3
(d) n–CH3CH2CH2CH3
(c) HCHO
Passage 6 Amides undergo hydrolysis to yield carboxylic acid plus amine on heating in either aqueous acid or aqueous base. The conditions required for amide hydrolysis are more severe than those required for the hydrolysis of esters, anhydrides or acid chlorides, but the mechanism is similar (nucleophilic acyl substitution). Nucleophilic acyl substitutions involve a tetrahedral intermediate, hence these are quite different from alkyl substitution (RCH2Br NaCN → RCH2CN) which involves a pentavalent intermediate or transition state. One of the important reactions of esters is their reaction with two equivalent of a Grignard reagent to give tertiary alcohols. 124. The mechanism involved during the hydrolysis of acid derivatives is (a) elimination-addition (b) addition-elimination (c) nucleophilic addition-elimination (d) electrophilic addition-elimination 125. Which of the following constitutes the best substrate during the acidic hydrolysis of amides? O OH+ O OH+ || + || || || + R − C − NH2 (b) R − C − NH3 (c) (a) R − C − NH2 (d) R − C − NH3 126. For which functional derivative of carboxylic acids, acidic hydrolysis is avoided? (a) Acid chlorides (b) Acid amides (c) Acid anhydrides (d) Esters
8.65
8.66
chapter eight 127. When
O
O is treated with two equivalent of methyl magnesium iodide, the product
that acidified the final product will be (a) OH
OH
HO (c)
(b)
OH OH
(d) OH
OH
OH
128. Which of the following methods is more general for preparing nitriles? (a) RCH2Br + NaCN ⎯→ RCH2CN + NaBr 4 O10 (b) RCH2CH2CONH2 P → RCH2CH2CN (c) Both (a) and (b) (d) None of these Passage 7 Methanoic acid, the first member of carboxylic acid series, when warmed with concentrated sulphuric acid decompose in the following way and evolve carbon monoxide O || H − C − OH
H+
O || + H − C − OH2
−H2O
O H
C
−H+
⊕
C ≡ O + H+
The driving force for this reaction lies in the fact that the HC ≡ O+ ion is very unstable acid and thus easily loses H+. 129. Formic acid on heating with conc. H2SO4 gives
(a) CO2 + H2
(b) CO + H2O
(c) CO
(d) H2O
130. What happens when acetic acid is treated with conc. H2SO4?
(a) CO + H2O
(b) CH4 + CO2
(c) CO + CH4
(d) No reaction
131. If acetic acid is replaced by triphenylacetic acid, the product formed will be (a) (C6H5)3CH + CO (b) (C6H5)3CH + CO2 (c) (C6H5)3COH + CO (d) No reaction 132. If formic acid is replaced by benzoylformic acid, C6H5COCOOH, the product formed will be (a) C6H5COOH + CO + CO2 (b) C6H5COOH + CO2 (c) C6H5COOH + CO (d) C6H5CHO + CO2
organic reaction mechanisms and reagents
Answer Keys Level 1 1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
d
a
c
d
b
b
a
d
d
d
d
a
c
a
a
a
b
b
d
a
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
c
b
d
b
a
d
c
b
d
b
b
b
b
c
d
c
a
d
b
c
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
c
c
d
d
b
b
c
c
c
d
c
c
d
d
c
c
c
c
b
b
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
c
a
a
c
b
c
d
b
c
a
c
c
c
b
d
c
c
b
c
c
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
c
d
b
d
c
b
a
c
c
b
a
d
b
d
a
b
d
b
b
d
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
c
a
a
c
b
d
b
b
a
d
d
a
a
d
b
d
c
c
d
c
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
d
a
b
d
b
d
b
c
c
d
b
d
d
c
a
a
c
a
d
a
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
a
d
b
d
c
a
d
c
b
b
c
c
d
d
b
d
b
a
b
b
161
162
163
164
165
166
167
168
169
170
b
d
b
d
d
c
d
a
c
c
Level 2 1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
c
d
c
c
c
a
b
b
b
a
d
b
c
b
a
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
a
c
d
c
b
c
d
b
b
c
b
d
a
b
a
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
d
c
a
b
a
b
b
c
c
c
a
b
a
b
b
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
d
b
b
c
d
c
a
a
c
d
b
a
a
b
b
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
b
d
a
c
b
bc
ad
b
c
bcd
ad
abcd
bcd
d
b
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
c
d
b
a
b
a
b
a
cd
d
b
c
a
b
c
91
92
93
94
95
96
97
98
99
100
1 01
1 02
1 03
1 04
105
c
d
abd
d
b
a
c
d
d
d
a
c
a
c
a
106
1 07
108
1 09
110
111
112
113
114
115
116
117
118
119
120
a
d
b
a
c
c
a
d
d
d
a
d
a
b
c
121
1 22
123
124
125
126
127
128
129
130
131
132
c
d
c
c
c
b
b
b
b
c
c
c
8.67
8.68
chapter eight
Workbook Exercises Exercise 1 Matrix Type Identify reagents (1 to 9) used in the following conversion from reagent present in the second Column II (A to L). Column I (Conversion) Column II (Reagent)
Br
(A) Br2 (B) NaBr / acetone (C) Br2 / UV light
Br
(D) Br2 / FeBr3 ii
i
(E) HBr / dark
iii
(F) HBr / light (G) EtBr
v
iv
Br vi
vii
viii
ix Br Br
(H) EtBr / AlCl3 (I) KOH / EtOH / ∆ (J) CH2CHCHCH2 / ∆ (K) H2SO4 (L) H2 /Pd
organic reaction mechanisms and reagents
Exercise 2 Identify reagents (1 to 10) used in the following conversion from reagent present in the second Column II (A to P). Column I (Conversion) Column II (Reagent) O OH
O
i
OEt
O
ii
O
O
O
iii
OEt
OEt Br iv
O
O – PPh3Br +
vi
O
O
viii
Br
Br
vii O
O
v
O
O
ix O
O
O
PPh3
O
x O O Brevicomin
O
HO OH
(A) CH3CH2CH2CH2Li / THF (B) CH3CH=CH2 (C) CH3CO2H (D) CH3CO3H (E) (CH3)2C=O/H+ (F) CH3CH2CHO (G) PBr3 / Et3N (H) PPh3 (I) CH3CH2CH2MgBr / THF, then H3O+ (J) H3O+ / Δ (K) Conc. H2SO4 / Δ (L) NaOEt, then Br(CH2)3Br (M) NaOEt / EtOH (N) LiAlH4, then H3O+ (O) HOCH2CH2OH/H+ (P) EtOH /H+ / heat
8.69
8.70
chapter eight
Exercise 3
Identify reagents (1 to 9) used in the following conversion from reagent present in the second Column II (A to S). Column I (Conversion) Column II (Reagent)
i
ii
iii
CO2Et + iv
CO2Et
vi
CO2H
v
CO2Et vii viii
ix
OH O
(A) KOH / H2O / H3O+ / Δ (B) NaOEt / EtOH (C) CH3ONa / CH3OH (D) CH3CH2OH / H+ Cl (E) CH3OH / H+ (F) Excess CH3I (G) Conc. H2SO4 (H) BH3, then aq. NaOH / H2O2 CO2Et (I) CH Cl / AlCl 3 3 (J) CH COCl / AlCl 3 3 CO2Et (K) Excess CH3MgI, then H3O+ (L) Conc. HCl (M) NCS or Cl2 (N) LiAlH4, then H3O+ (O) NaBH4 (P) Ph3P=CH2 (Q) tBuOH / H+ (R) tBuCl / KOH (S) H2O / HgSO4 / H2SO4
organic reaction mechanisms and reagents
Exercise 4 Identify products in the following matrix. Reagents
Compounds HO OH OH OH OH
OH HO
OH
OH
OH
OH
OH HO
OH OH
OH OH
OH
HO
OH OH
PCC
K2Cr2O7
NaH/Mel
MnO2
Conc. KMnO4
8.71
8.72
chapter eight
Solution for Workbook Exercises Exercise 1 Column I (Conversion) Column II (Reagent)
Br (A) Br2
Br
(B) NaBr / acetone
1=A
(C) Br2 / uv light
3=H
2=J
(D) Br2 / FeBr3
4= L
(E) HBr / dark
5= D Br
6=I 7=F
8= E
Br
9= C Br
(F).HBr / light (G) EtBr (H) EtBr / AlCl3 (I) KOH / EtOH/ (J) CH2CHCHCH2 / (K) H2SO4 (L) H2 /Pd
organic reaction mechanisms and reagents
Exercise 2 Column I (Conversion) Column II (Reagent) O
1= P OH
O
2= M OEt
O
O
O OEt
O
3=L
OEt
Br 4=J O
O 7=A
O
O
6= H + O PPh3Br 8= F O PPh3
O 5=O
O
Br
Br 9=D
O
O
O 10 = J
O O BREVICOMIN
O
O
HO OH
(A) CH3CH2CH2CH2Li / THF (B) CH3CH=CH2 (C) CH3CO2H (D) CH3CO3H (E) (CH3)2C=O/H+ (F) CH3CH2CHO (G) PBr3 / Et3N (H) PPh3 (I) CH3CH2CH2MgBr / THF then H3O+ (J) H3O+ / D (K) Conc. H2SO4 /D (L) NaOEt then Br(CH2)3Br (M) NaOEt / EtOH (N) LiAlH4 then H3O+ (O) HOCH2CH2OH/H+ (P) EtOH /H+ / heat
8.73
8.74
chapter eight
Exercise 3 Column I (Conversion) Column II (Reagent) 1= Q
2=I
3= M
CO2Et
6= D
CO2H
4=B
CO2Et +
5= A
CO2 Et
7=K 8= G
9= J
OH O
(A) KOH / H2O / (B) NaOEt / EtOH Cl (C) CH3ONa / CH3OH (D) CH3CH2OH / H+ (E) CH3OH / H+ (F) Excess CH3I (G) conc. H2SO4 CO2 Et (H). BH3 then aq. NaOH / H2O2 CO2 Et (I) CH3Cl / AlCl3 (J) CH3COCl / AlCl3 (K) excess CH3MgI then H3O+ (L) conc. HCl (M) NCS or Cl2 (N) LiAlH4 then H3O+ (O) NaBH4 (P) Ph3P=CH2 (Q) tBuOH / H+ (R) tBuCl / KOH (S) H2O / HgSO4 / H2SO4
organic reaction mechanisms and reagents
Exercise 4 Reagents Compounds
PCC
HO
NaH/MeI
K2 Cr 2 O 7
O
O
OH
OMe
O
O
Conc.KMnO 4
MnO 2 HO
O
OMe
O
OH
OH
OH OH
OH
OH
O
O
OMe
OH
O
O
OH O
OMe
OH
OH O
OH OH
OH O + CO2
O OH HO
OH
O HO
HO O
OMe
HO
O
OH
OH
OH
O OMe MeO
OMe
O HO
O
HO OH
HO
COOH
OH OH
O
OH HO
HO
O
OH
O OH
COOH
OMe
O C H
HO
OMe OMe
OH OH
O
O
O
OH
OH
O
HO
O
OMe
HO
O
MeO
O
OH OMe
HO
O
OH
O OH
HO
O
OH
OH OH
O
O HOOC HOOC
OH
O
OH
O
OH
OMe
HO
O
O
O
O
OMe
OH
O
OMe
OH
HOOC HOOC
O O
COOH
COOH
COOH
COOH
O
OMe
HO
O
O O C OH
HO
O
MeO
O
OH
O
OH
OH
HOOC HOOC
O
O
O
OMe
OH
OH
OMe
OH
HOOC HOOC
O OH
8.75
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Practical Organic Chemistry
CHAPTER
9
Question Bank
Level 1 1. Sodium nitroprusside Na2[Fe(CN)5NO] is used as reagent for detection of _____ and the compound formed is ____. (a) Sulphur, Na4[Fe(CN)5NOS] (b) Nitrogen, Na4[Fe(CN)6]
(c) Sulphur, Na2[Fe(CN)4NOS]
(d) Sulphur, Na2[Fe(CN)5NOS]
2. The prussian blue colouration obtained in the test for nitrogen in the organic compound is (a) K4[Fe(CN)]6 (b) Fe4[Fe(CN)6]3 (c) Fe[Fe(CN)6] (d) Fe3[Fe(CN)6]2 3. If N and S both are present in an organic compound during Lassaigne’s test, both will change into (a) Na2S and NaCN (b) NaSCN (c) Na2SO3 and NaCN (d) Na2S and NaCNO 4. Which of the following will not give test for ‘N’ in sodium extract?
(a) C6H5NHNH2 (b) NH2CONH2
NH2
(c) NH2–NH2 (d) SO3H
5. Which of the following will be blood red colour with FeCl3 in sodium extract (Lassaigne extract)? (a) NH2CONH2 (b) NH2CSNH2 (c) C6H5NHNH2 (d) CH3C≡N
9.2
chapter nine 6. A mixture of acetone and CCl4 can be separated by (a) Azeotropic distillation (b) Fractional distillation (c) Steam distillation (d) vacuum distillation 7. Phenol and benzoic acid can be separated by (a) NaHCO3 (b) NaOH solution (c) FeCl3 solution (d) All of these 8. Anthracene can be purified by (a) Distillation (c) Filtration
(b) Sublimation (d) Fractional distillation
9. KOH can be used as a drying agent for (a) amines (b) phenols
(c) acids
(d) esters
10. Silver salt method is used to determine molecular weight of (a) organic acids (b) organic bases (c) both acids and bases (d) none of these 11. Which of the following observations is correct and is used in the identification of c arboxylic acids? (a) Carboxylic acids liberate CO2 gas from NaHCO3 solution. (b) They produce fruity smell of esters when heated with alcohol in presence of Conc. H2SO4. (c) Both (a) and (b) (d) Iodoform test 12. An organic compound is heated with HNO2 at 0ºC and then the resulting solution is added to a solution of β-naphthol whereby a brilliant red dye is produced. The observations indicate that the compound possesses (a) –NO2 group (b) –CONH2 group (c) aromatic NH2 group (d) aliphatic NH2 group 13. An organic compound contains C, H, N, S and Cl. For the detection of chlorine, the sodium extarct of the compound is first heated with a few drops of concentrated HNO3 and then AgNO3 is added to get a white ppt. of AgCl. The digestion with HNO3 before the addition of AgNO3 is (a) to prevent the formation of NO2 (b) to create a common ion effect (c) to convert CN– and S2– to volatile HCN and H2S, or else they will interfere with the test forming AgCN or Ag2S (d) to prevent the hydrolysis of NaCN and Na2S 14. Rectified spirit contains (a) 95.6 per cent ethanol and 4.4 per cent methanol (b) 100 per cent ethanol (c) 95.6 per cent ethanol and 4.4 per cent water (d) 95.6 per cent ethanol and 4.4 per cent benzene 15. Aniline can be separated from phenol using (a) NaHCO3 (b) NaNO2 + HCl at 0ºC (c) NaCl (d) Acidified KMnO4
practical organic chemistry 16. Identify correct statement for A, B and C in the following sequence.
Ether layer
20%NaOH Diethyl Ether H 2O
N
O where
NH
C ppt.
OH
and
Isoquinoline
A B Solution
Aqueous 10%HCl layer H2O pH = 2
O
Evaporation
Benzoic acid
(a) A = benzoic acid, B = sodium chloride and C = isoquinoline (b) A = isoquinoline, B = benzoic acid and C = sodium chloride (c) A = isoquinoline, B = sodium chloride and C = benzoic acid (d) A = sodium chloride, B = isoquinoline and C = benzoic acid
17.
Dil. H2SO4
O
P1 + P2
P1 and P2 products are identify by (a) Tollen’s reagent (c) Br2 + H2O test
(b) Iodoform test (d) 1 per cent alkaline KMnO4
18. In the following extraction procedure, choose the number where nicotine would be found.
Naphthalene +
N Nicotine
Diethyl 10% HCl H2O Ether
Aqueous Make basic with layer 20% NaOH H2O
Aqueous Evaporate (iii) layer Ether Evaporate (ii) layer
Ether Evaporate (i) layer
N H
(a) i = Nicotine
(b) i + iii = Nicotine (c) ii = Nicotine
(d) ii + iii = Nicotine
19. Choose the answer that has the following compounds located correctly in the s eparation scheme. Dilute Dilute HCl Precipitate (i) NaOH dilute NO2 4-nitrotoluene H3C Ether NaOH Dilute Evaporate HCl Precipitate (ii) Ether OH p-cresol H3C p-toluidine H3C
NH2
dissolved in ether
Dilute HCl
Dilute NaOH
Precipitate (iii)
9.3
9.4
chapter nine
(a) i = 4-nitrotoluene, ii = p-cresol, iii = p-toluidine (b) i = 4-nitrotoluene, ii = p-toluidine, iii = p-cresol (c) i = p-toluidine, ii = 4-nitrotoluene, iii = p-cresol (d) i = p-cresol, ii = 4-nitrotoluene, iii = p-toluidine
20. Choose the answer that has the following compounds located correctly in the separation scheme. Aqueous CO2H
+
Ether (X) Aqueous HCl
(i) NaHCO3 (ii) Ether
+
pKa = 4.3
Aqueous HCl
OH
pKa = 10
Aqueous Ether (Y)
Ether NaOH Ether (Z)
(a) toluene is in (Y); phenylacetic acid is in (Y); phenol is in (Z) (b) toluene is in (Y); phenylacetic acid is in (X); phenol is in (Z) (c) toluene is in (Z); phenylacetic acid is in (Y); phenol is in (X) (d) toluene is in (Z); phenylacetic acid is in (X); phenol is in (Y)
21. Among the following which compound gives precipitate with AgNO3 solution? Br Br H2C (a) (b) (c) (d) None of these Br 22. Disodium pentacyanonitrosyl ferrate reagent gives purple colour when which of the following element is present? (a) N (b) Cl (c) F (d) S 23. Which of the following compound can liberate CO2 when treated with NaHCO3? OH O2N (a)
NO2 NO2
(c) HCO2H
(b) CH3CO2H OH (d)
. H2 SO 4 24. Phenol + Phthalic anhydride Conc → B. B gives which of the following colour in alkafusion line medium? (a) Yellow (b) Colourless (c) Pink (d) Violet
25. Among the following, which will respond to iodoform test? O O H3C (a) (b) OH H3C CH3
practical organic chemistry OH (c) H3C
O CH3
(d) H3C
O OCH2H5
26. Among the following, which statement is not correct? O (a) H3C C OH will not respond to haloform test (b) Schiff ‘s regent and Schiff ‘s base are different compounds (c) Fehling’s solution is a good reagent to detect aromatic aldehydes (d) Both aldehyde and ketone can react with 2, 4-dinitrophenylhydrazise reagent 27. To separate a mixture of amines from each other, one should follow (a) Beckmann’s method (b) Hinsberg’s method (c) Zeisel’s method (d) Victor Meyer’s Method 28. Phenol can be distiguished from ethanol by (a) Tollen’s reagent (b) Benedict’s reagent (c) FeCl3 (d) Schiff ‘s base 29. p-Cl — C6H4NH2 and PhNH3 +Cl– can be distinguished by (a) NaOH (b) AgNO2 (c) LiAlH4
(d) Zn
9.5
9.6
chapter nine
Level 2 Single and Multiple-choice Type 1. In Lassaigne’s test, the organic compound is first fused with sodium metal. The sodium metal is used because (a) The melting point of sodium metal is low. (b) Sodium metal reacts with elements present in organic compounds to form inorganic compounds. (c) All sodium salts are soluble in water. (d) All sodium salts are not soluble in water. 2. Molecular weight of acids can be detemined by (a) Silver salt method (b) Volumetric method (c) Plants chloride method (d) Victor Meyer’s method 3. Ethanol and ethanal are distinguished by (a) Fehling’s solution test (b) Tollen’s reagent test (c) Iodoform test (d) Cerric ammonium nitrate 4. Which of the following statements are correct? (a) An organic compound is pure if mixed melting point is same. (b) Ethanol and water can be separated by azeotropic distillation because it forms azeotrope. (c) Impure aniline is purified by steam distillation as it is steam volatile. (d) Glycerol is purified by vaccuum distillation because it decomposes at its normal boiling point. 5. Which of the following will respond to iodoform test? O || (a) CH3 – C – COOH
OH | (b) CH3 – CH – COOH
OH | CH3 – CH – CH3 (c)
(d) CH3CH2OH
6. Which of the following will not show iodoform test? O O O || || || (a) CH3 – C – NH2 (d) CH3–COOH CH3 – C – CH3 (b) CH3 – C – Cl (c) 7. HCOOH and CH3COOH can be distinguished by (a) Tollen’s reagent (b) Fehling’s solution (c) KMnO4 (d) NaHCO3 8. The desiccants used for absorbing water during Liebig’s method for estimation of carbon and hydrogen are (a) anhydrous CaCl2 (b) anhydrous Na2SO4 (c) Mg(ClO4)2 (d) MgSO4 ⋅ 7H2O
practical organic chemistry CHO 9. An organic compound has the structure
. It will give OH CH2 – COOH
(a) cerric ammonium nitrate test (b) brick effervescence with sodium bicarbonate (c) a characteristic colouration with neutral ferric chloride after decarboxylation and reduction by Clemenson’s method (d) Fehling’s test
10. Which of the following organic compounds will give white precipitate with AgNO3? (b) NaCl (a) C6H5NH3+Cl– (c) 2,4,6-trinitro chlorobenzene (d) Benzyl chloride 11. Which of the following reactions occur during the detection of nitrogen in organic substances by Lassaigne’s test? (a) Na + C + N ⎯→ NaCN (b) FeSO4 + 6NaCN ⎯→ Na4[Fe(CN)6] + Na2SO4 (c) 3Na4[Fe(CN)6] + 2Fe2(SO4)3 ⎯→ Fe4[Fe(CN)6]3 + 6Na2SO4 (d) None of these 12. Compound A reacts with CHCl3 and KOH and gives an offensive smelling compound. A can be (a) Primary aliphatic amine (b) Primary aromatic amine (c) Secondary amine (d) Tertiary amine 13. HCOOH and HCHO may be distinguished by (a) Tollen’s test (b) Sodium bicarbonate test (c) 2,4-DNP test (d) Benedict’s test CHO 14.
and CH3CHO can be distinguished by
(a) Tollen’s test
(b) Benedict’s test
(c) Iodoform test
(d) 2,4-DNP test
15. Acetic acid and CH3COCl can be distinguished by (a) NaHCO3 test (b) Na metal test (c) Ester formation test (d) Br2(aq.) test
Comprehension Type Passage 1 Steam distillation is used to purify a compound which is steam volatile and insoluble in water. The impurities should not be steam volatile. It is based on the principle that liquid will boil when partial vapour pressure of liquid and partial vapour pressure of steam both become equal to atmospheric pressure, P = p1 + p2. It reduces the boiling point of a liquid. Weight of water distilled M. Wt. of water × VP of steam = Wt. of substance distilled M. Wt. of substance × VP of aniline
9.7
9.8
chapter nine 16. Isolation of essential oils from flowers, etc. is done by (a) Steam disitllation (b) Distillation (c) Fractional distillation (d) Distillation under reduced pressure 17. Which of the following is steam volatile? (a) o-nitrophenol (b) p-nitrophenol (c) p-hydroxy benzaldehyde (d) Ethanol 18. Calculate weight of aniline distilled if weight of water distilled is 100 g when Porganic compound = 100 mm and PH2 O = 200 mm. (a) 250 g (b) 258 g (c) 100 g (d) 25.8 g 19. Steam distillation is based on (a) Dalton’s law of partial pressures (b) Graham’s law of diffusion (c) Raoult’s law of non-volatile solute (d) None of these 20. Which of the following cannot be separated by steam distillation? (a) Nitrobenzene (b) Essential oil (c) Aniline (d) Glycerol Passage 2 Test (Q). A compound X was fused with Na metal and the extract gave a white precipitate with AgNO3. The Lassaigne’s extract gave a red colouration with neutral FeCl3. Test (R). While compound Y when fused with Na metal and subsequent analysis on its L assaigne’s extract did not give any characteristic test. Test (S). While compound Y on fusion with fusion mixture (sodium carbonate + potassium nitrate) or Na2O2, followed by extraction, followed by addition of Conc. HNO3 and ammonium molybdate gave a yellow precipitate. 21. Compound X contains (a) N (b) S
(c) N + S
22. Compound X (a) will contain halogens (c) may contain only sulphur
(b) may contain halogens (d) will contain only nitrogen
23. Compound Y contain (a) N (b) S
(c) X
(d) P
(d) P
24. The chemical reaction taking place in Y, when it is fused with fusion mixture is (a) 3Na + P + 4O ⎯→ Na3PO4 (b) 3Na2CO3 + 2P + [O] ⎯→ 2Na3PO4 + 3CO2 (c) 3KNO3 + P + 3O ⎯→ K3PO4 + 3NO2 + O2 (d) None of these 25. The formula of yellow precipitate is (a) (NH4)3PO4 (c) (NH4)3PO4 ⋅ 12Mo3O3
(b) Mo(PO4) (d) Mo(PO4)2
practical organic chemistry Passage 3 The 0.2 g of anhydrous organic acid gave on combustion 0.04 g of water and 0.195 g of CO2. The acid is a dibasic acid and 0.5 g of its silver salt leaves on ignition 0.355 g of silver. 26. The percentage of carbon in the compound is (a) 50 (b) 52 (c) 26.6
(d) 90
27. The percentage of hydrogen in the compound is (a) 5.6 (b) 2.22 (c) 4.44
(d) 10
28. The empirical weight of the compound is (a) 90 (b) 100 (c) 10
(d) 45
29. The molecular weight of the compound is (a) 90 (b) 100 (c) 10
(d) 45
30. The molecular formula of the compound is (a) CHO (b) CHO2 (c) C2H2O4
(d) C3H6O2
Passage 4 A student in a lab had a mixture of three compounds, 4-methylbenzoic acid, 4-methylcyclohexylamine and 1,4-dimethylbenzene. In order to separate the three compounds the following extraction (separation) scheme was followed. At the end of the procedure the student had six separate flasks containing either an aqueous or an ether solution. Locate each compound by designating the flask expected to contain each compound. Some relevant pKa data is given. CO2H
CH3 pKa = 4.4
CO2H
NH2
CH3
CH3
CH3
CH3
⊕ NH3
CH3
(i) Ether (ii) HCl (aqueous)
xi
Ether
Aqueous
NaOH
Aqueous
Ether iii
HCl
Aqueous i
NaOH
Ether ii
Ether iv
Aqueous HCl
Ether v
Aqueous vi
9.9
9.10
chapter nine 31. Which flask contains the 4-methylcyclohexylamine? (a) 1 (b) 2 (c) 3
(d) 4
32. Which flask contains the 4-methylbenzoic acid? (a) 1 (b) 2 (c) 3
(d) 4
33. Which flask contains the 1,4-dimethylbenzene? (a) 1 (b) 2 (c) 3
(d) 4
Matrix Type Match the columns: 34. Column I (pair of compounds) OH OH and (a)
(p) Libermann nitroso test ⊕ N2Cl
NH2
OH (b)
Column II (test to distinguish)
(q) (Dye test)
and
NH2 Me and (c) Me
NH
(r) Iodoform
CH2OH O H H (d) H and OH H OH HO OH H
O
(t) NaHSO3
35. Column I (pair of compounds) (a)
and
OH (b)
and
(s) Lucas
Column II (identification test)
(p) Tollen’s reagent test
OH
(q) Br2 + H2O test
O O (c) H – C – OH and CH3 – C – OH
(r) Lucas test
(d)
(s) Iodoform test
and
(t) Ammonical Cu2Cl2 test
practical organic chemistry 36. Column I (reagents) (a) Product of reaction of propyne with 1 per cent HgSO4 and Dil. H2SO4 (b) Br2 water test given by
Column II (p) Me–CH=CH–Me
(c) Addition of HBr can be with
(r)
(d) Tollen’s reagent give white ppt. with
(s) Me–CH=CH2 O
(t) Me – C – Me
37. Column I (compound)
Column II (tests)
(a)
–C
O H
O (b) CH3 – C –
(q) Me–C≡C–H C ≡ C – CH3
(p) 2,4-DNP test
(q) Yellow ppt. with NaOH + I2
O (c) CH3 – C – H O
(d) H3C
(r) Red ppt. with Fehling’s solution
CH3
(s) Silver mirror with Tollen’s reagent
38. Column I (reagents) (a) Tollen’s reagent give white ppt. with (b) Br2 + H2O test given by
Column II (p) Me–CH=CH–Me (q) Me–C≡C–H
(c) Product of reaction of acetylene with 1 per cent HgSO4 and Dil. H2SO4
(r) CI NH 3 − NH 2
(s) Me – C – H
(d) Pd/H2 reacts with
⊕
O O
Me – C – Me (t)
39. Column I (pair of compounds)
Column II (test of identification) O
O
Ph – C – H and Me – C – H (a) O
O
(b) Me – C – Me and Me – C – H OH (c)
(p) Tollen’s reagent (q) Fehling’s reagent
OH and
(d) Me – C ≡ C – H and Me – C ≡ C – Me
(r) Iodoform test (s) Victor Meyer’s test (t) Lucas test
9.11
9.12
chapter nine
Answer Keys Level 1 1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
a
b
b
c
b
b
a
b
a
a
c
c
c
c
b
16
17
18
19
20
21
22
23
24
25
26
27
28
29
b
ab
c
d
d
b
d
abc
c
abcd
c
b
c
b
Level 2 1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
abc
ab
abd
abcd
abcd
bcd
abc
ac
abc
abcd
abc
ab
bc
bc
ab
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
a
a
b
a
d
c
b
d
bc
c
c
b
d
a
c
31
32
33
d
b
c
34(a) 34(b) 34(c) 34(d) 35(a) 35(b) 35(c) 35(d) 36(a) 36(b) 36(c) 36(d) rs
pq
p
rt
q
rs
p
pt
t
37(a) 37(b) 37(c) 37(d) 38(a) 38(b) 38(c) 38(d) 39(a) 39(b) 39(c) 39(d) ps
pq
pqrs
pq
qr
pq
s
pqst
qr
pq
rst
p
pqrs
pqrs
q
CHAPTER
10
Nomenclature Question Bank
Single and Multiple-choice Type 1. The IUPAC name of the compound shown here is OH O O
(a) 5-Ethyl-1-hydroxyoctan-1,4-dioic acid (b) 2-Carboxyethyl-3-hexyl ketone (c) 3-(3-Hexylcarbonyl) propanoic acid (d) 5-Ethyl-4-ketooctanoic acid
2. Which of the following compounds are not correctly matched? Compound IUPAC name OH (a) HO
OH Cyclohexane-1,2,4-triol
H3C (b)
OH 4-Methylcyclohexanol
10.2
chapter ten CH3 (c)
OH
2-Ethyl-6-methylcyclohexanol
C2H5 Cl 3-Bromo-1-chlorocyclohexane
(d) Br
3. The no. of secondary C-atoms present in the following compounds respectively is
OH ,
(a) 7, 9, 4
(b) 5, 12, 8
, N (c) 6, 9, 8
N
(d) 5, 9, 4
4. The organic compound (Cyclohex-3-enyl) 2-ethyl cyclobutanecarboxylate does not contains (a) two 3°-carbon atoms (b) two 1°-carbon atoms (c) 9 secondary C-atoms (d) one 1°-carbon atoms 5. The IUPAC name of the compound given below is O OH
OH
(a) 2-Hydroxy-3-(4’-hydroxyphenyl) cyloprop-2-en-1-one (b) 2-Hydroxy-3-(4’-hydroxyphenylmethyl) cyloprop-2-en-1-one (c) 4-(2’-Hydroxy-3’-oxocycloprop-1’-enylmethyl) phenol (d) 4-(1’-Hydroxy-3’-oxocycloprop-1’-enylmethyl) phenol
6. The correct IUPAC name of the compound is HO H
OCOCHCH3
(a) 2-Bromopropyl-3-hydroxy-1-methylcyclopentane carboxylate (b) 3’-Hydroxy-1’-methylcyclopentyl-2-bromopropanoate (c) 1’-Hydroxy-3’-methylcyclopentyl-2-brompropanoate (d) None of these
7. The IUPAC name of
Me Br
O C – NH – C6H5 is
(a) N-Cyclohexylbenzamide (b) N-Phenyl-N-cyclohexylmethanamide (c) N-phenylcyclohexane carboxamide (d) N-Cyclohexyl-N-phenylmethyl amide
nomenclature 8. The IUPAC name of the given compound is CHO CH3–CH–CH
CONH2 CH–CH–COOH
COCl Br (a) 2-Bromo-4-carbamoyl-5-chloroformyl-3-formylhexanoic acid (b) 5-Bromo-3-carbamoyl-3-chloroformyl-4-formylhexanoic acid (c) 4-Formyl-2-chloroformyl-3-carbamoyl-5-bromohexanoic acid (d) 2-Chloroformyl-3-carbamoyl-4-formyl-5-bromohexanoic acid
9. The correct IUPAC name of the compound given below is CHCHCH2OH
(CH2)3CHOOC
Br
(a) 3-(3’-isopropoxycarbonyl cyclopentylidene) propan-1-ol (b) 3-(2’-Bromo-3’-hydroxypropylidene) cyclopentanecarboxylate (c) Isopropyl-3-(2’-bromo-3’-hydroxypropylidenyl) cyclopentanecarboxylate (d) Isopropyl-3-(2’-bromo-3’-hydroxypropylidene) cyclopentanecarboxylate
10. IUPAC name of isopentyl alcohol is (a) 1-Hydroxy-2-methyl pentane (c) 2-Methyl propanol
(b) 3-Methyl butan-1-ol (d) 2-Methyl-2-butanol
11. Which of the following structure represent Dimethyl butanedioate? (a) CH2 – CO – CH3
(b) CH3 – COOCH2
CH2 – CO – CH3
CH3 – COOCH2
(c) CH3 – OOC – CH2
(d) COOCO
CH3 – OOC – CH2
CH3 CH 2 – CH3
12. IUPAC name of the following compound is COOH COOH
COOH
(a) 2-(1-carboxyethyl)-4-methyl pentanoic acid (b) 3,5-Dicarboxy-2-methyl hexanoic acid (c) 2,4,5-Hexane tricarboxylic acid (d) 2,3,5-Hexane tricarboxylic acid
13. Which of the following compound has incorrect IUPAC nomenclature? (a) CH3CH2–CH2–COOC2H5 : Ethyl butanoate (b) CH3 – CH – CH – CH3 : 2-Methyl butan-3-ol OH CH3 (c) CH3 – CH – C – CH2 – CH3 : 2-Methyl pentan-3-one CH3 O CH3 – CH – CH2 – CHO : 3-Methyl butanal (d) CH3
10.3
10.4
chapter ten 14. Select the structure with correct numbering for the IUPAC name of the given compound. SH 5
SH
SH
4
3
(a)
OH
2
6
5
(b)
6
2
4
1
OH
1
6
2
(c)
5
OH
3
3
2
1
6
(d)
3
OH
5 4
4
OH
OH
SH
1
OH
OH
15. In which of the following H-bonding is responsible for low volatility? OH
OH
(a)
(b)
F
NO2 OH
(c)
(d) None of these
COOH 16. Which of the following is not correctly matched? H3C O CH3 – C – C – O – C2H5 (a)
Ethyl-2-methyl-2-phenyl propanoate
(b) –CH – CCl3
1,1,1-Trichloro-2,2-diphenyl ethane
(c)
6-Ethyl-3,3-dimethyl cyclohex-1-ene
H2N – CH – CH – CHO (d)
2-Formyl-3-amino-1,4-butane dinitrile
CN
CN
17. IUPAC name of the following compound is O –C–N
(a) N,N-Dimethyl cyclopropanamide (b) N-Methyl cyclopropanamide (c) N,N-Dimethyl cyclopropane carboxamide (d) N,N-Dimethyl cyclopropolonamide
CH3 CH3
nomenclature 18. Correct IUPAC name of the given compound HO
NH2 CHO
(a) 5-amino-3-hydroxy benzene carbaldehyde (b) 3-amino-5-formyl benzenol (c) 3-amino-5-hydroxy benzaldehyde (d) 3-formyl-5-hydroxy aniline
19. The IUPAC name of the given structure
Br
(a) 5-Bromo-6-chloro cyclohex-1-en-3-yne (b) 6-Bromo-5-chloro cyclohex-1-ene-3-yne (c) 6-Bromo-5-chloro cyclohex-3-ene-1-yne (d) 4-Bromo-3-chloro cyclohex-1-ene-5-yne
20. The IUPAC name of
is
Cl
OH CH3
is
(a) 3-Methyl cyclobut-1-ene-2-ol (b) 2-Methyl cyclobut-3-ene-1-ol (c) 4-Methyl cyclobut-1-ene-3-ol (d) 4-Methyl cyclobut-2-en-1-ol
21. Correct name for (C2H5)2C = C(CH3)CH2CO2H (a) 4, 4-Diethyl-3-methyl-3-butenoic acid (b) 4-Ethyl-3-methyl-3-hexenoic acid (c) 3-Ethyl-4-methyl-3-hexenoic acid (d) 3-Ethyl-4-methyl-3-hexen-6-oic acid 22. Which statement is incorrect in the following? (a) Methyl acetate is the first higher homologue of methyl formate. (b) Propanoic acid and propionic acid are identical. (c) Vinyl alcohol is the lower homologue of propionaldehyde. (d) CH3–NH–CH2–CH3 is the lower homologue of CH3 – CH – NH – CH3. CH3 23. Match the following CH3 – CH – CH2 (i) Isobutyl (a) CH3 CH3 (b) – CH2 – CH CH3
(ii) Tert-pentyl
10.5
10.6
chapter ten CH3 (c) –C – CH3
(iii) Isopentyl
CH2CH3 – H2C – CH2 (d) CH3– CH – CH3
(iv) Sec. butyl
(b) a - iv; b - i; c - iii; d - ii (d) a - iv; b - ii; c - i; d - iii
(a) a - ii; b - iv; c - ii; d - iii (c) a - iv; b - i; c - ii; d - iii
24. Number of C-atoms in first higher homologue of first member of ester family is (a) 5 (b) 4 (c) 3 (d) 2 25. In a given compound if number of σ- and π-bonds are X and Y, respectively then (X + Y) will be OOCH
(a) 28
(b) 26
(c) 27
(d) 24
26. Which statement is correct in the following? (a) Alicyclic compounds are acyclic compounds. (b) In secondary amine, nitrogen is attached to 2° carbon atom. (c) 1°, 2°, 3° amines are homologues of each other. (d) HCOOCH3 and CH3COOH are not homologues of each other. 27. The correct systematic IUPAC name of the given compound is OH CH2 – C – CH2 – C – NH2 CONH2
H2NCO
(a) 3-Carbamoyl-3-hydroxybutanediamide (b) 2-Hydroxypropane-1,2,3-tricarbamoyl (c) 2-Hydroxypropane-1,2,3-tricarboxamide (d) 2-Bis(carbamoyl)-2-hydroxyethanamide H C
28. The correct name for
O
is
COOC2H5
(a) 2-Oxocyclopentanecarboxylate (b) 2-Formylcyclopentanecarboxylate (c) Ethyl-2-formylcyclopentanecarboxylate (d) Ethyl-2-oxocyclopentanecarboxylate CH3
29. The IUPAC name of
CH3 CH2CH3
is
O
nomenclature
(a) 2, 3-Methyl-1-ethylcyclohex-4-ene (b) 5-Ethyl-3, 4-dimethylcyclohex-1-ene (c) 4-Ethyl-5, 6-dimethylcyclohex-1-ene (d) 1-Ethyl-2, 3-dimethylcyclohex-4-ene
30. Which of the following names is correct? (a) 4, 4-Dimethyl-3-ethylpentane (b) 3-Methyl-4-oxobutanoic acid (c) 1-Ethyl-2-methylpent-4-ene (d) Bicyclo[1.2.3]heptane CH2 – CHO 31. IUPAC name of the compound OHC – CH2 – CH2 – CH – CH2 – CHO is (a) 4, 4-Di (formylmethyl) butanal (b) 2-(formylmethyl) butane-1, 4-dicarbaldehyde (c) Hexane-3-acetal-1, 6-dial (d) 3-(formylmethyl) hexanedial 32. The correct IUPAC name of the following compound is C2H5 CH3 – CH – C – CH2 – CH – CH3 CH3
(a) 3-Ethyl-3,5,-dimethylhexane (c) 2,4-Dimehtyl-4-ethylhexane
CH3 (b) 4-Ethyl-2,4,-dimethylhexane (d) 4-Ethyl-2,4,-dimethylhexene
33. The number of functional groups present in the following compounds is H2N
O
H O
NH O
O O
(a) 5
O OH
(b) 7
O
(c) 6
34. Write the IUPAC name of the following compound C C–C C–C–C–C=C–C C–C–C C
(a) 3-(1,1-dimethylethenyl)-3-ethyl-2-methyl-1,4 hexadiene (b) 3-ethyl-2-methyl-3-(1,1-dimethylethenyl)-1,4 hexadiene (c) 3-ethyl-2-2-dimethyl-3-(1-methylethenyl)-1,4 hexadiene (d) 3-ethyl-3-(1-methylethenyl)-2-2-dimethyl-1,4 hexadiene
35. Hybridization of which atom changes in the following reaction? O PCl5 C6H5 – NH – C – CH3 C6H5 – C – CH3 N – OH
(d) 8
10.7
10.8
chapter ten
(a) C and O (c) N and O
36.
⊕ C a
C b
(b) C and N (d) No change in the hybridization of any atom – C d
C c
; carbon atoms a, b, c and d are in
(a) sp2, sp3, sp2 and sp3 hybrid states respectively (b) sp, sp2, sp and sp3 hybrid states respectively (c) sp2, sp, sp2 and sp3 hybrid states respectively (d) sp2, sp2, sp2 and sp3 hybrid states respectively
37. Ratio of π- and σ-bonds in Ph–COOH will be (a) 5 : 3 (b) 3 : 5 (c) 3 : 16
(d) 4 : 15
38. Which of the following compound has incorrect IUPAC nomenclature?
(a) CH3CH2–CH2–COOC2H5 : Ethyl butanoate
CH3 – CH – CH – CH3 : 2-Methyl butan-3-ol (b) OH
CH3
CH3 – CH – C – CH2 – CH3 : 2-Methyl pentan-3-one (c) CH3 O (d) CH3 – CH – CH2 – CHO : 3-Methyl butanal CH3 39. Identify incorrect matching in the following (a) Allyl alcohol-Prop-2-en-1-ol (b) Vinyl alcohol-Ethenol (c) Propargyl alcohol-But-3-yn-1-ol (d) Acrylaldehyde-2-Propenal O O – C – CH3 CO2H 40. IUPAC name of the following compound
(a) Aspirin (c) Acetyl salicylic acid
(b) 2-Acetyl benzoic acid (d) 2-Acetoxy benzoic acid
41. How many functional groups are present in the given molecule?
HO
O
O
OMe
O
Me
O H2N
H2N O
(a) 4
(b) 5
(c) 6
(d) 7
nomenclature 42. What is the ratio of number of σ- and π-bonds in the molecule HC – CH2CH2 – COOH?
(a) 5
(b) 6
O (d) none of these
(c) 4
43. Which is not a first member of given homologous series? (a) Alkadiene CH2=C=CH2 (b) Alkenyne HC≡C–CH=CH2 O O
(c) Ethyl ester CH3CH2 – O – C – CH3 (d) Ketone CH3 – C – CH3
44. Consider the given statements (i) Acetone and acetaldehyde are homologues. (ii) N is secondary amine while H (iii) HO
is a secondary alcohol while O
(iv)
is a tertiary amine.
N
OH
is a tertiary alcohol.
O and
both have different functional groups
Cl Cl Which is not incorrect? (a) i, ii, iii (b) ii, iii, iv
(c) i, ii, iv
(d) i, iii, iv
45. Number of functional groups present in the given compound is O
O
O
OMe
O
N O
(a) 5
HO
(b) 6
O NH2
O (c) 7
(d) 8
46. Which of the following compounds has isopropyl group?
(a) 2,2,3,3-Tetramethyl pentane (c) 2,2,3-Trimethyl pentane
(b) 2,2-Dimethyl pentane (d) 2-Methyl pentane
47. What is the order of solubility in water of the following compounds? OH (i)
NH2 (ii)
Cl (iii)
(iv) OH HO
(a) i > ii > iii > iv (c) iv > i > iii > ii
(b) iii > iv > i > ii (d) iv > i > ii > iii
10.9
10.10
chapter ten 48. The correct IUPAC name of the given compound is NH2 CH2
C
CH2
O C
OH
COOH COOH
(a) 3-Carboxy-3-hydroxy butane dioic acid (b) 2-Amino propane-1,2,3-tricarboxylic acid (c) 3-Amino butanedioic acid (d) 2-Bis(carboxymethyl)-2-hydroxy ethanoic acid
49. Total number of isomers of group C5H11 is (a) 5 (b) 3 (c) 8
(d) 9
50. Write the correct name from the incorrect name 2,3-, dichloro-2,4-dibromohept-4-ene (a) 2, 4-dibromo-2,3-dichloro hept-4-ene (b) 4, 6-dibromo-5,6-dichloro hept-3-ene (c) 4, 6-dibromo-5,6-dichloro hept-4-ene (d) 5, 6-dichloro-4,6-dibromo hept-3-ene 51. In IUPAC nomenclature of compounds O O O – C – Cl – C – OH (iii) – C – NH2 (ii) (i) O –C≡N – C – H (v) (iv)
The priority order of group is/are (a) ii > i > iii > iv > v (c) ii > iii > v > i > iv
(b) ii > iii > i > v > iv (d) ii > iii > i > iv > v
52. The correct systematic IUPAC name of the given compound is OH CH2 H2NCO
CH2
CONH2
(a) 3-Carbamoyl-3-hydroxybutanediamide (b) 2-Hydroxypropane-1,2,3-tricarbamoyl (c) 2-Hydroxypropane-1,2,3-tricarboxamide (d) 2-Bis(carbamoyl)-2-hydroxyethanamide Br
53.
C
Br
(a) trans-1,1-dibromocyclohexene (b) 1,1-dibromocyclohex-3-ene (c) 3,3-dibromocyclohexene (d) 4,4-dibromocyclohexene
C O
NH2
nomenclature
54.
(a) 1-Ethyl-3,3-dimethylcyclohexane (c) 3-Ethyl-1,1-dimethylcyclohexane
(b) 3,3-Dimethyl-1-ethylcyclohexane (d) 1,1-Dimethyl-3-ethylcyclohexane
O C
55.
O
Et
(a) ethyl 2-ethyl-3-methyl-2-butenoate (b) O,2-diethyl-3-methyl-2-butenaote (c) 1-ethoxy-2-ethyl-3-methyl-2-butenal (d) 2-methyl-2-pentenyl propanaote
56.
(a) 4-Isobutyl-3-pentyloctane (b) 5-Ethyl-4-methyl-6-(2-methylpropyl)decane (c) 6-Ethyl-7-methyl-5-(methylpropyl)decane (d) 4-Butyl-5-ethyl-2,6-dimethylnonane
57. (2E, 5R)-5-methylhept-2-en-4-one O
O (a)
(c)
(b)
O
O (d)
58. 2-Ethylphenol OH (a)
(b)
OH (c)
OH
(d)
10.11
10.12
chapter ten 59. (S)-(N,4)-dimethyl-3-aminopentan-2-one O O (b) NH
(a) NH O (c)
O
(d)
NH
NH2
60. Methyl (2Z,4Z,6Z)-3,6,9-trimethyl-2,4,6,8-decatetraenoate CO2CH3 (b)
(a)
CO2CH3 CO2CH3
(c)
(d) CO2CH3
OH 61.
(a) (E)-5-methyl-3-heptanal (c) (E)-5-methyl-4-hepten-3-ol
(b) (Z)-3-methyl-3-hepten-5-al (d) (Z)-5-methyl-4-hepten-3-ol
O 62.
(a) 5,5-Dimethylcyclohexanol (c) 1,1-Dimethylcyclohexanone
63.
(b) 3,3-Dimethylcyclohexanone (d) 3,3-Dimethylcyclohexanal
O
(a) Dibenzyl ether (c) Benzyl phenyl ester
(b) Benzyl phenyl ether (d) 3,3-Dibromocyclohexene
64. Which name is correct for the following compound? CH3 – CH – C ≡ N CH3
nomenclature
(a) 2-Methyl propanenitrile (c) Isobutyronitrile
(b) Isobutyl cyanide (d) Isopropyl cyanide
65. IUPAC name of which of the following compounds is correct? Compound IUPAC name (a) – COOH :
Cyclohexanoic acid
COOH HOOC – (b)
– COOH :
(c) H3C – Br – (d)
1,2,4-Benzene tricarboxylic acid
– COOH :
4-Methyl cyclohexane carboxylic acid
– COOH :
66. Name(s) of CH3
4-Bromobenzoic acid
CH CN is/are CH3
(a) Isopropyl cyanide (c) Isobutyro nitrile
(b) Sec-propyl cyanide (d) 2-methyl propane nitrile
67. In Lassaigne’s test, the organic compound is at first fused with sodium metal. The sodium metal is used because (a) The melting point of sodium is low; so, it is easily fused with organic substances. (b) Sodium is very much effective to bring about destructive reductions of organic compounds forming ionic inorganic salts such as NaCN, Na2S and NaX. (c) All sodium salts are soluble in water. (d) None of these. 68. Chromatographic technique can be used for separation of (a) Volatile solids (b) Amino acids (c) Plant pigments (d) Sugars
Comprehension Type Passage 1 The IUPAC has set guidelines for logical and methodical naming of organic compounds. The complex substituents are written in brackets and their numbering is done separately. The bivalent radicals are named by adding ‘idene’ to the name of alkyl group. In polyfunctional compounds, all lower priority groups are written as a prefix. Now, name the following compounds.
69. (CH3)2CHOOC
CHCHCH2OH Br
is
(a) 3-(3’-isopropoxycarbonyl cyclopentylidene) propane-1-ol (b) 3-(2’-bromo-3’-hydroxypropylidene) cyclopentane carboxylate (c) Iso-propyl-3-(2’-bromo-3’-hydroxypropylidenyl) cyclopentane carboxylate (d) Iso-propyl-3-(2’-bromo-3’-hydroxypropylidene) cyclopentane carboxylate
10.13
10.14
chapter ten C2H5 70. CH3CH2O
(a) 2-(3’-Ethylcyclohexyl)-1-(4’-ethoxycyclohexyl) ethane (b) 1-Ethyl-3-(2’-(4”-ethoxycyclohexyl) ethyl) benzene (c) 1-(3’-Ethylcyclohexyl)-2-(4’-ethoxycyclohexyl) ethane (d) None of these Cl
71.
is
– CH2CH2 –
N OH
O
is
O (a) 3-Chlorocarbonyl-6-(N,N-diethylamino) hex-4-ene-1-oic acid (b) 4-Chlorocarbonyl-3-(N,N-diethylamino) butanoic acid (c) 3-Chlorocarbonyl-3-(3-N,N-diethylamino prop-1’-enyl) butane-1-oic acid (d) 3-Chlorocarbonyl methyl-6-(N,N-diethylamino) hex-4-en-1-oic acid
Passage 2 Rules for IUPAC nomenclature of compounds containing one functional group, multiple bonds and substituents are given hereunder. (a) Select the longest possible chain of carbon atoms containing the functional group and the maximum number of multiple bonds as the parent chain without caring whether it also denotes the longest possible carbon chain or not. (b) After selecting the parent chain, the numbering should be done in such a way that it gives lower possible number the functional group. (c) When a chain containing functional groups such as –CHO, –COOH, COOR, –COCl, etc. is present, it is always given number 1 and number 1 is usually omitted from the final name of the compound. (d) If the organic compound contains a functional group, multiple bond, side chain or substituent, the following order of preference should be followed. Functional group > Double bond > Triple bond > Substituent
(e) If a compound contains two or more like groups, the numerical prefixes di, tri, tetra, etc. are used and terminal ‘e’ from the primary suffix is retained. On the basis of the above rules, give answers for the following questions:
72. Consider the given statements (i) Acetone and acetaldehyde are homologues. (ii) N is a secondary amine while H (iii) HO
N
is a secondary alcohol while O
(iv)
OH
is a tertiary alcohol.
O and
Cl
is a tertiary amine.
Cl
both have different functional groups.
nomenclature Which is not incorrect? (a) i, ii, iii (c) i, ii, iv
(b) ii, iii, iv (d) i, iii, iv
73. Correct IUPAC name from the incorrect name 4-amino-3-hydroxy-2-butene is (a) 1-Amino-2-hydroxy-2-butene (b) 4-Amino-2-buten-3-ol (c) 1-Amino-2-buten-2-ol (d) 1-Amino-2-butenol 74. Which of the following has incorrect IUPAC name?
(a) Cl
5-Bromo-6-chloro cyclohex-1-en-3-yne
Br OH (b)
2-Methyl cyclopent-4-en-1-ol Me Et
(c)
5-Ethyl-1-methyl cyclohexene
Me (d) Me Et
2,4-Dimethyl hexane
Passage 3 Rules for IUPAC nomenclature of compounds containing one functional group, multiple bonds and substituents are given hereunder. (a) Select the longest possible chain of carbon atoms containing the functional group and the maximum number of multiple bonds as the parent chain without caring whether it also denotes the longest possible carbon chain or not. (b) After selecting the parent chain, the numbering should be done in such a way that it gives lower possible number for the functional group. (c) When a chain containing functional groups such as –CHO, –COOH, COOR, –COCl, etc. is present, it is always given number 1 and number 1 is usually omitted from the final name of the compound. (d) If the organic compound contains a functional group, multiple bond, side chain or substituent, the following order of preference should be followed.
Functional group > Multiple bond > Substituent (e) If a compound contains two or more like groups, the numerical prefixes di, tri, tetra, etc. are used and terminal ‘e’ from the primary suffix is retained. On the basis of the above rules, give answers for the following questions:
75. Which of the following is not correctly matched? H3C O CH3 – C – C – O – C2H5 (a)
Ethyl-2-methyl-2-phenyl propanoate
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(b)
1,1,1-Trichloro-2,2-diphenyl ethane
CH – CCl3
(c)
6-Ethyl-3,3-dimethyl cyclohex-1-ene
H2N – CH – CH – CHO (d)
2-Formyl-3-amino-1,4-butane dinitrile
CN CN 76. IUPAC name of the following compound is O C
CH3
N
CH3
(a) N,N-Dimethyl cyclopropanamide (b) N-Methyl cyclopropanamide (c) N,N-Dimethyl cyclopropane carboxamide (d) N,N-Dimethyl cyclopropolonamide
77. IUPAC name of the following compound is COOH COOH
COOH
(a) 2-(1-carboxyethyl)-4-methyl pentanoic acid (b) 3,5-Dicarboxy-2-methyl hexanoic acid (c) 2,4,5-Hexane tricarboxylic acid (d) 2,3,5-Hexane tricarboxylic acid
Passage 4 IUPAC system is the most rational and widely used system of nomenclature in organic chemistry. Any given molecule has only one IUPAC name and any given IUPAC name denotes only one molecular structure. Numbering the principal chain order is principal functional group > multiple bond > substituents. 78. IUPAC name of CH3 – CH – CH2 – CH – CH3 CH3
(a) 2-Cyano-4-methylpentane (c) 2,4-Dimethyl pentane nitrile
CN (b) 2-Methyl-4-cyanopentane (d) 2-Dimethyl-4-cyanopentane
nomenclature 79. The IUPAC name of the following compound is O C – OH
HO
C≡N
(a) 4-Hydroxy-3-cyano cyclohex-5-ene carboxylic acid (b) 3-Hydroxy-5-cyano cyclohex-5-enoic acid (c) 5-Cyano-3-hydroxy cyclohex-2-ene carboxylic acid (d) 3-Carboxy-5-hydroxycyclohex-5-ene carbonitrile
80. The correct IUPAC name of the following compound is
(a) 5-(1’,1’ 2’-trimethyl propyl)-2-2-dimethyl nonane (b) 4-Butyl-2,3,3,7,7-pentamethylnonane (c) 2,3,3,7, 7-Pentamethyl-4-butyloctane (d) 2,2-Dimethyl-5-(1’, 1’, 2’ trimethylpropyl)nonane
Matrix Type 81. Column I
Column II OH C OH and
(a)
(p) Functional groups are same pair of compound
CH2 O O
C
CH3
O (b)
and
(q) DBE is same
O OH (c)
OH
(r) Functional groups are different in pair of compound
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chapter ten O H2C (d)
O CH3
C
(s) Even number of 2° carbon ‘C’ atom present in both compounds
and
(t) Odd number of 2° ‘C’ atom present in pair of compound in both compounds
82. Column I
Column II OH
(a)
(b)
(p) Odd number of 3° ‘C’
(q) Odd DBE (double bond equivalents)
(r) Even DBE (double bond equivalents)
(c) N N
(d) O
(s) Heterocyclic ring is present (t) Even number of 2° ‘C’ atom
83. Column I
Column II O O
O O (a)
N
O
O NH2
HO
O
(p) DU/DBE is odd
nomenclature O
OH
O O
HO O
(b)
(q) DBE/DU is even
NH2
H2N O OH
OH O
O
(c) HO O
N
(r) Functional groups are odd
N Me
OH O O
O O
(d) HO
(s) Functional groups are even
O NH
(t) Number of 2° ‘C’ even (u) Loctore is present as functioanl group
84. Column I Column II
(a) Cyclohexa-1, 3-diene
(p) DU is odd
(b) 4, 5, 6-Triethenlnona-1, 8-diene
(q) DU is even
(c) Cyclo octa-1, 3, 5-triene
(r) Compound has 1 : 1 : 1 ratio for 1°, 2° and 3° ‘C’ atoms
(d) 1, 3, 5-trimethyl benzene
(s) Unsaturated compound
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Answer Keys 1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
d
d
d
b
b
b
c
b
d
b
c
d
b
b
c
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
d
c
c
a
d
b
c
c
c
c
d
c
c
b
b
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
d
b
c
d
d
c
d
b
c
d
c
b
c
b
c
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
d
d
b
c
b
b
c
d
c
a
b
b
d
a
c
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
abcd
abc
b
d
d
d
b
c
b
d
c
b
b
acd
bcd
76
77
78
79
80
c
d
c
b
a
81(a) 81(b) 81(c) 81(d) 82(a) 82(b) 82(c) 82(d) 83(a) 83(b) r
83(c) 83(d) 84(a) 84(b) 84(c) 85(d) qst
qstu
ps
ps
qs
qrs
qrt
pqs
pq
pr
q
qst
qst
pstu
qrt