Chapter 22 Review Questions PDF

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CHAPTER 22—REACTIONS OF BENZENE AND ITS DERIVATIVES MULTIPLE CHOICE 1. What is the major organic product obtained from the following reaction?

a. 1 c. 3 d. 4 ANS: B 2. What is the major organic product obtained from the following reaction?

a. 1 c. 3 d. 4 ANS: B 3. What is the major organic product obtained from the following reaction?

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a. 1 b. 2 c. 3 ANS: D 4. What is the major organic product obtained from the following reaction?

a. 1 c. 3 d. 4 ANS: B 5. What is the major organic product obtained from the following reaction?

a. 1 c. 3 d. 4 ANS: B

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6. What is the electrophile in the reaction of benzene with a mixture of nitric acid and sulfuric acid? a. HONO c. NO2+ d. benzene ANS: B 7. What is the electrophile in the reaction of benzene with acetyl chloride, CH3COCl, and AlCl3? b. CH3 + c. CH3CO2 d. benzene ANS: A 8. What is the electrophile in the reaction of benzene with tert-butyl chloride and AlCl3? a. CH3 + b. Cl+ d. benzene ANS: C 9. What is the role of AlCl3 in Friedel Crafts acylations using acid chlorides? b. electrophile c. base d. nucleophile ANS: A 10. What is the role of FeBr3 in electrophilic aromatic bromination of benzene using Br2? a. nucleophile b. electrophile d. base ANS: C 11. Which of the following undergoes the most rapid nitration upon treatment with HNO3/H2SO4? b. benzene c. bromobenzene d. nitrobenzene ANS: A 12. Which of the following undergoes the most rapid bromination upon treatment with Br 2/FeBr3? a. benzene b. nitrobenzene c. bromobenzene ANS: D

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13. Which of the following undergoes the most rapid sulfonation upon treatment with fuming sulfuric acid? b. benzoic acid c. benzonitrile d. nitrobenzene ANS: A 14. Which of the following undergoes the most rapid acylation upon treatment with acetyl chloride and AlCl3? a. benzene c. chlorobenzene d. 1,4-dichlorobenzene ANS: B 15. Which of the following sets of substituents are all ortho/para directing in electrophilic aromatic substitution reactions? a. Cl, CH3, CN b. Br, OH, COCH3 d. CN, NO2, COCH3 ANS: C 16. Which of the following sets of substituents are all ortho/para directing in electrophilic aromatic substitution reactions? a. Br, CH3, NO2 c. Cl, OCH3, COCH3 d. NO2, COCH3, COOH ANS: B 17. Which of the following sets of substituents are all meta directing in electrophilic aromatic substitution reactions? b. CH3, OCH3, COCH3 c. Cl, NH2, CH3 d. CH3, NH3, OCH3 ANS: A 18. Which of the following sets of substituents are all meta directing in electrophilic aromatic substitution reactions? a. CH3, OH, Br b. Cl, NH2, CN d. NH2, COCH3, OH ANS: C

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19. Which of the following sets of substituents are all activating groups in electrophilic aromatic substitution reactions? a. CH3, OCH3, COCH3 b. Cl, CN, NO2 c. Cl, NH2, CH3 ANS: D 20. Which of the following sets of substituents are all activating groups in electrophilic aromatic substitution reactions? a. Br, NH2, CH3 c. OH, COCH3, CH3, d. Br, CN, NO2 ANS: B 21. Which of the following sets of substituents are all deactivating groups in electrophilic aromatic substitution reactions? b. Cl, NH2, CH3 c. CH3, OCH3, COCH3 d. CH3, NH2, OCH3 ANS: A 22. Which of the following sets of substituents are all deactivating groups in electrophilic aromatic substitution reactions? a. Cl, OH, CH2CH3 b. CH3, Br, COCH3 c. CH3, NH2, OH ANS: D 23. Which of the following substituents is ortho/para directing and deactivating in electrophilic aromatic substitution reactions? a. OH c. CH3 d. NO2 ANS: B 24. Which of the following substituents is ortho/para directing and deactivating in electrophilic aromatic substitution reactions? a. COCH3 b. NH3 d. CH2CH3 ANS: C

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25. Which of the following reactions or reaction sequences will not give isopropylbenzene as the major product? a. treatment of benzene with isopropyl alcohol and HF b. treatment of benzene with 1-chloropropane and AlCl3 d. treatment of benzene with 1-propene and HF ANS: C 26. Which of the following reactions or sequences will provide 1-propylbenzene as the major product? a. treatment of benzene with isopropyl alcohol and HF

c. treatment of benzene with 1-chloropropane and AlCl3 d. treatment of benzene with 1-propene and HF ANS: B 27. Which of the following are valid resonance structures of the electophile involved in Friedel-Crafts acylation of benzene upon treatment with CH3COCl and AlCl3?

b. 2 c. 3 d. 4 ANS: A 28. Which of the following is the structure of the complex of Br2 with FeBr3 involved in the electrophilic bromination of benzene?

a. 1 b. 2 c. 3 ANS: D

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29. Which of the following sets of reagents does not result in alkylation of benzene? a. tert-butyl chloride + AlCl3 b. tert-butyl alcohol + H3PO4 c. methylpropene + HF ANS: D 30. Why does nitrobenzene fail to undergo Fieldel-Crafts alkylation with tert-butyl chloride and AlCl3? a. nitrobenzene reacts with AlCl3 c. the nitro group is a strong electron donating group d. the tert-butyl cation is a poor electrophile ANS: B 31. Why does anisole undergo bromination with Br2 in the absence of FeBr3 whereas bromination of benzene requires the presence of FeBr3? b. the methoxy group of anisole is an inductive electron withdrawing substituent c. Br2 is a good nucleophile d. the reaction is accelerated by light ANS: A 32. What is the major organic product obtained from the following reaction?

a. 1 c. 3 d. 4 ANS: B

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33. What is the major organic product obtained from the following reaction?

a. 1 b. 2 d. 4 ANS: C 34. What is the major organic product obtained from the following reaction?

b. 2 c. 3 d. 4 ANS: A 35. What is the major organic product obtained from the following reaction?

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a. 1 c. 3 d. 4 ANS: B 36. What is the major organic product obtained from the following reaction?

a. 1 c. 3 d. 4 ANS: B 37. What is the major organic product obtained from the following reaction?

a. 1 b. 2 c. 3 ANS: D

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38. What is the major organic product obtained from the following reaction?

a. 1 b. 2 c. 3 ANS: D 39. What is the major organic product obtained from the following reaction?

a. 1 b. 2 c. 3 ANS: D

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40. What is the major organic product obtained from the following reaction?

a. 1 c. 3 d. 4 ANS: B 41. What is the major organic product obtained from the following reaction?

a. 1 b. 2 c. 3 ANS: D

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42. What is the major organic product obtained from the following sequence of reactions?

b. 2 c. 3 d. 4 ANS: A 43. What is the major organic product obtained from the following sequence of reactions?

a. 1 b. 2 d. 4 ANS: C

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44. What is the major organic product obtained from the following sequence of reactions?

b. 2 c. 3 d. 4 ANS: A 45. What is the major organic product obtained from the following sequence of reactions?

a. 1 b. 2 d. 4 ANS: C

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46. What is the major organic product obtained from the following sequence of reactions?

a. 1 b. 2 c. 3 ANS: D 47. What is the major organic product obtained from the following sequence of reactions?

b. 2 c. 3 d. 4 ANS: A

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48. Which of the following cannot be prepared from benzene in two synthetic steps?

a. 1 b. 2 c. 3 ANS: D 49. Which of the following cannot be prepared from benzene in two synthetic steps?

b. 2 c. 3 d. 4 ANS: A

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50. Which of the following is the reactive intermediate in the nucleophilic substitution of 4-bromo-1nitrobenzene with sodium hydroxide?

b. 2 c. 3 d. 4 ANS: A 51. Which of the following is the reactive intermediate in the nucleophilic substitution of 4-bromo-1toluene with sodium amide?

a. 1 b. 2 c. 3 ANS: D

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52. Which of the following is the reactive intermediate formed in the electrophilic bromination of toluene with Br2, FeBr3?

a. 1 b. 2 d. 4 ANS: C 53. Which of the following is the reactive intermediate formed in the electrophilic nitration of nitrobenzene with HNO3 and H2SO4?

a. 1 c. 3 d. 4 ANS: B

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54. Which of the following is the reactive intermediate formed in the electrophilic Friedel-Crafts acylation of toluene with CH3COCl and AlCl3?

a. 1 b. 2 c. 3 ANS: D 55. Which of the following compounds undergoes the most rapid nucleophilic substitution with hydroxide ion?

a. 1 b. 2 c. 3 ANS: D

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56. Which of the following compounds undergoes the most rapid nucleophilic substitution with hydroxide ion?

a. 1 b. 2 d. 4 ANS: C 57. Which of the following chlorobenzenes produces a single isomer upon treatment with NaNH2?

a. 1 b. 2 c. 3 ANS: D 58. Which of the following chlorobenzenes does not undergo nucleophilic aromatic substitution upon treatment with NaNH2?

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b. 2 c. 3 d. 4 ANS: A 59. Which mechanism accounts for the reaction of 4-bromo-1-nitrobenzene with sodium hydroxide to form 4-nitrophenol? a. Bimolecular nucleophilic substitution (SN2) b. Nucleophilic aromatic substitution by elimination-addition d. Electrophilic aromatic substitution ANS: C 60. Which mechanism accounts for the reaction of chlorobenzene with acetyl chloride and AlCl3 to form 4-chloroacetophenone? a. Bimolecular nucleophilic substitution (SN2) b. Nucleophilic aromatic substitution by elimination-addition c. Nucleophilic aromatic substitution by addition-elimination ANS: D 61. Which mechanism accounts for the reaction of benzyl chloride with sodium cyanide to form cyanomethylbenzene (phenylacetonitrile, PhCH2CN)? b. Nucleophilic aromatic substitution by elimination-addition c. Nucleophilic aromatic substitution by addition-elimination d. Electrophilic aromatic substitution ANS: A 62. Which mechanism accounts for the reaction of 4-bromotoluene with sodium amide to form a mixture of 3- and 4-aminotoluene? a. Bimolecular nucleophilic substitution (SN2) c. Nucleophilic aromatic substitution by addition-elimination d. Electrophilic aromatic substitution ANS: B 63. What type of intermediate is formed in the reaction between chlorobenzene and tert-butyl chloride and AlCl3 to give 4-chloro-1-tert-butylbenzene? a. Meisenheimer complex b. benzyne d. benzyl radical ANS: C

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64. What type of intermediate is formed in the reaction between bromobenzene and sodium amide to give aniline? a. Meisenheimer complex c. cyclohexadienyl cation d. benzyl radical ANS: B 65. What type of intermediate is formed in upon irradiation of a mixture of toluene and chlorine to give benzyl chloride? a. Meisenheimer complex b. benzyne c. cyclohexadienyl cation ANS: D 68. Which of the following is not true about benzynes? a. They are planar b. They are formed upon dehydrohalogenation of aryl halides c. They are aromatic

ANS: D

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69. Predict the product of the following reaction: E

E

B)

E

C) E

D) E

E)

none of these ANS: A

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70 What major product would you expect from the following reaction? OH HNO3 ? H2SO 4

OH

NO2

B) OH

O2N

C) OH NO2

D) OH

NO2

E) OH

NO2 A

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71. Predict the major organic product of the following reaction.

O NO2

Br2 / FeBr3 ?

CH3O NO2

O NO2

Br CH3O NO2 B)

Br

O NO2

CH3O NO2 C)

O

Br NO2

CH3O NO2 D)

Br

OH NO2

CH3O NO2

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E)

O NO2 Br

CH3O NO2

PROBLEM 1. What is the major organic product obtained from the following reaction?

ANS:

2. What is the major organic product obtained from the following reaction?

ANS:

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3. What is the major organic product obtained from the following reaction?

ANS:

4. What is the major organic product obtained from the following reaction?

ANS:

5. What is the major organic product obtained from the following reaction?

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ANS:

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6. What is the major organic product obtained from the following reaction?

ANS:

7. What is the major organic product obtained from the following sequence of reactions (if a reaction is likely to give you a mixture of ortho and para disubstituted compounds you should assume that they can be separated; continue the synthesis with either one)?

ANS:

8. What is the major organic product obtained from the following reaction (if a reaction is likely to give you a mixture of ortho and para disubstituted compounds you should assume that they can be separated; continue the synthesis with either one)?

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ANS:

9. What is the major organic product obtained from the following sequence of reactions (if a reaction is likely to give you a mixture of ortho and para disubstituted compounds you should assume that they can be separated; continue the synthesis with either one)?

ANS:

10. What is the major organic product obtained from the following reaction (assume that mixtures of ortho and para disubstituted compounds can be separated; continue the synthesis with either one)?

ANS:

or ortho isomer

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11. What is the major organic product obtained from the following reaction (assume that mixtures of ortho and para disubstituted compounds can be separated; continue the synthesis with either one)?

ANS:

12. Provide the structure (a single resonance contributor) of the key intermediate in the electrophilic aromatic nitration of chlorobenzene.

ANS:

13. Provide the structure (a single resonance contributor) of the key intermediate in the electrophilic aromatic chlorinatio of nitroobenzene.

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ANS:

14. Provide the structure (a single resonance contributor) of the key intermediate in the following reaction.

ANS:

15. Provide the structure (a single resonance contributor) of the key intermediate in the following reaction .

ANS:

16) Provide a series of synthetic steps by which 2-bromo-4-nitrobenzoic acid can be prepared from toluene.

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Answer:

Diff: 3

17) Provide a series of synthetic steps by which 3-bromoethylbenzene can be prepared from benzene. Answer:

Diff: 3

18) Provide a series of synthetic steps by which 4-t-butylbenzoic acid can be prepared from toluene. Answer:

Diff: 3

19) Provide a series of synthetic steps by which p-nitrobutylbenzene can be prepared from benzene. Answer:

Diff: 3

20) Provide a series of synthetic steps by which 4-phenylheptan-4-ol can be prepared from benzene. Answer:

Diff: 3

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