Organic Chemistry. Carey/Giuliano 9th edition. Chapter 7

Transcription

1 Organic Chemistry Carey/Giuliano 9th edition Chapter 7 Copyright 2014 The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

2 Question 1 Which of the following compounds is chiral? A) 2-methyl-2-pentanol B) 2-bromobutane C) methylcyclohexane D) 2-propanol

3 Question 2 Which of the molecules below is optically active? A) 1 only B) 1 and 3 C) 1 and 2 D) 1, 2 and 3

4 Question 3 How many chirality centers are in the molecule shown at the right? A) 1 B) 2 C) 3 D) 4

5 Question 4 How many chirality centers are in the molecule shown at the right? A) 1 B) 2 C) 3 D) 4

6 Question 5 Determine the absolute configuration of the molecule shown. A) (S) B) (R) C) not optically active

7 Question 6 What is the absolute configuration of the molecule shown? A) (R) B) (S) C) not optically active

8 Question 7 What is the relationship between the Fischer projections shown? A) identical B) enantiomers C) diastereomers D) different compounds

9 Question 8 Determine the relationship between the compounds shown below. A) identical B) enantiomers C) diastereomers D) meso

10 Question 9 Which conformation shown is (S)- bromochlorofluoromethane? A) B) C) D)

11 Question 10 What product(s) will be isolated from the reaction shown? A) cis-1,3-cyclohexanediol B) trans-1,3-cyclohexanediol C) mixture of cis- and trans-1,3-cyclohexanediol D) cyclohexanol only

12 Question 11 Which one of the following groups has the highest ranking when precedence is assigned according to the Cahn-Ingold- Prelog rules? A) -CH=CH 2 B) -CH=O C) -CH 2 CH 2 Br D) -CH 2 F

13 Question 12 Which one of the following compounds is chiral? A) 1-methylcyclohexanol B) cis-2-methylcyclohexanol C) trans-4-methylcyclohexanol D) cyclohexanol

14 Question 13 Which one of the following is achiral? A) 2-chloropentane B) 3-chloropentane C) 1,2-dichloropentane D) 1,3-dichloropentane

15 Question 14 Which one of the following has the most stereoisomeric forms? A) 2-chloro-1-butene B) 2-chloro-2-butene C) 5-chloro-2-pentene D) 4-chloro-2-pentene

16 Question 15 Which one of the following is a diastereomer of meso-3,4-dibromohexane? A) threo-2,4-dibromohexane B) (2R, 5R)-2,5-dibromohexane C) (3R, 4R)-3,4-dibromohexane D) (3R, 4S)-3,4-dibromohexane

17 Question 16 Which one of the following statements is false? A) A racemic mixture is achiral. B) A compound can contain more than one stereogenic center and be achiral. C) A compound can contain more than one stereogenic center and be chiral. D) Any compound that contains a plane of symmetry is achiral.

18 Question 17 A certain substance (+)-X, when optically pure, has a specific rotation [α] of +40. A mixture of (+)-X and its enantiomer (-)-X has a specific rotation of -8. What percent of the mixture is (+)-X? A) 30% B) 35% C) 40% D) 45%

19 Question 18 (+)-Glucose has the Fischer projection shown. How many compounds are diastereomers of (+)-glucose? A) 8 B) 14 C) 15 D) 16

20 Question 19 Which compound gives only a single stereoisomer of 1,3-dimethylcyclopentane on catalytic hydrogenation? A) B) C) D) both A and B

21 Question 20 Which one of the following is (R)-2- bromobutane? A) B) C) D)

22 Answer Key Chapter 7 1. B 2. A 3. B 4. A 5. A 6. B 7. B 8. C 9. B 10. C 11. D 12. B 13. B 14. D 15. C 16. A 17. C 18. B 19. C 20. B

23 Organic Chemistry Carey/Giuliano 9th edition Chapter 8 Copyright 2014 The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

24 Question 1 Which alkyl chloride will react faster with NaI in acetone? A) B) C) D)

25 Question 2 Which alkyl halide will react faster with CH 3 OH under S N 1 conditions? A) B) C) D)

26 Question 3 Select the major organic product when (S)-2- propanol is reacted with SOCl 2 in pyridine followed by the addition of NaSH in ethanol. A) B) C) D)

27 Question 4 Which of the following is not a good nucleophile for an S N 1 reaction? A) NaOCH 3 B) CH 3 OH C) CH 3 CH 2 OH D) H 2 O

28 Question 5 Select the most reactive alkyl halide for the general reaction depicted below: R-X + H 2 O R-OH + HX A) methyl halide B) primary C) secondary D) tertiary

29 Question 6 The reaction of butyl iodide with NaSCH 3 will proceed at a faster rate in which solvent? A) acetone B) acetic acid C) propanol D) water

30 Question 7 Which chloride will react faster with NaI in acetone? A) B) C) D)

31 Question 8 What is the major product of the reaction of the dihalide at the right with 1 equivalent of NaSH in dimethyl sulfoxide? A) B) C) D)

32 Question 9 Methyl bromide reacts with sodium ethoxide in ethanol by this mechanism: A) S N 1 B) S N 2 C) E1 D) E2

33 Question 10 3-bromo-3-methylpentane reacts with sodium ethoxide in ethanol by this mechanism: A) S N 1 B) S N 2 C) E1 D) E2

34 Question 11 Reactions proceeding through this mechanism give a racemic mixture: A) S N 1 B) S N 2 C) E1 D) E2

35 Question 12 Which one of the following statements is true? A) CH 3 CH 2 -S - is both a stronger base and more nucleophilic than CH3CH 2- O - B) CH 3 CH 2 -S - is a stronger base but less nucleophilic than CH 3 CH 2- O - C) CH 3 CH 2- S - is a weaker base but is more nucleophilic than CH 3 CH 2- O - D) CH 3 CH 2- S - is both a weaker base and less nucleophilic than CH 3 CH 2- O -

36 Question 13 Which one of the following statements is true concerning substitution and elimination in tert-butyl bromide? A) the mechanism generally believed to be available to (CH 3 ) 3 CBr are S N 1 and E1 B) the mechanism generally believed to be available to (CH 3 ) 3 CBr are S N 1, S N 2 and E1 C) the mechanism generally believed to be available to (CH 3 ) 3 CBr are S N 1, S N 2 and E2 D) the mechanism generally believed to be available to (CH 3 ) 3 CBr are S N 1, E1 and E2

37 Question 14 Which one of the solvents below is the most polar protic solvent? Dielectric constants (e) are given in parenthesis. A) acetic acid (e = 6) B) water (e = 78) C) methanol (e = 33) D) formic acid (e = 58)

38 Question 15 The best combination of reactants for preparing (CH 3 ) 3 CSCH 3 is: A) (CH 3 ) 3 CCl + CH 3 SK B) (CH 3 ) 3 CBr + CH 3 SNa C) (CH 3 ) 3 CSK + CH 3 OH D) (CH 3 ) 3 CSNa + CH 3 Br

39 Question 16 What combination is the best choice in order to prepare 3-chloro-1-iodobutane? A) 1-iodobutane + Cl 2 (400 C) B) 1,3-dichlorobutane + NaI (1 equiv) in acetone C) 1,3-iodobutane + NaCl (1 equiv) in acetone D) 3-bromo-1-iodobutane + NaCl (1 equiv) in acetone

40 Question 17 Which one of the following compounds gives the highest subtitution-to-elimination ratio (most substitution least elimination) on reaction with 2-bromobutane? A) NaOCH 3 B) NaNH 2 C) NaC N D) NaC CH

41 Question 18 Which one of the following alkyl halides would be expected to give the highest ratio of substitution to elimination on treatment with sodium ethoxide in ethanol (50 C)? A) 1-bromopentane B) 2-bromopentane C) 3-bromopentane D) 2-bromo-3-methylbutane

42 Question 19 Which combination of reactants will give 1- iodobutane as the major product? A) CH 3 CH 2 CH 2 CH 3 + HI B) CH 3 CH 2 CH 2 CH 2 OH + KI C) CH 3 CH 2 CH 2 CH 2 Br + NaI in acetone D) CH 3 CH 2 CH=CH 2 + I 2 in water

43 Question 20 Which one of the following statements does not correctly describe unimolecular nucleophilic substitution (S N 1) reactions of alkyl halides? (">" means "reacts faster than") A) Carbocations are intermediates in unimolecular nucleophilic substitutions. B) The order of decreasing reactivity as a function of leaving group is RI > RBr > RCl. C) The order of alkyl bromide reactivity is R 3 CBr > R 2 CHBr > RCH 2 Br > CH 3 Br. D) The rate of an S N 1 reaction depends on the concentration of the nucleophile.

44 Answer Key Chapter 8 1. B 2. D 3. B 4. A 5. D 6. A 7. B 8. B 9. B 10. D 11. A 12. C 13. D 14. B 15. D 16. B 17. C 18. A 19. C 20. D

45 Organic Chemistry Carey/Giuliano 9th edition Chapter 9 Copyright 2014 The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

46 Question 1 Which of the following bases is strong enough to completely deprotonate propyne? A) NH 3 B) CH 3 OH C) NaNH 2 D) NaOH

47 Question 2 Which alkyl halide will react faster with the acetylide ion (HC CNa) in an S N 2 reaction? A) bromopropane B) 2-bromopropane C) tert-butyl iodide D) 1-bromo-2-methylbutane

48 Question 3 How many equivalents of sodium amide (NaNH 2 ) are needed to carry the double dehydrohalogenation of 1,2-dibromopentane? A) one B) two C) three D) Sodium amide is not strong enough to carry out the reaction.

49 Question 4 In addition to NaNH 2, what other base can be used to convert 1,1-dichlorobutane into 1-butyne? A) NaOCH 3 B) NaOH C) NaOCH 2 CH 3 D) KOC(CH 3 ) 3

50 Question 5 Select the most effective way to synthesize cis- 2-pentene from 1-propyne. A) 1) NaNH 2 2) CH 3 CH 2 Br 3) H 2, Pd B) 1) NaNH 2 2) CH 3 Br 3) H 2, Lindlar Pd C) 1) NaNH 2 2) CH 3 CH 2 I 3) H 2, Lindlar Pd D) 1) NaNH 2 2) CH 3 CH 2 Br 3) Na,NH 3

51 Question 6 What is the structure of Compound Y in the following synthetic sequence? A) pentane B) cis-2-pentene C) trans-2-pentene D) 2-pentyne

52 Question 7 Which reagent would accomplish the transformation of 3-hexyne into trans-3- hexene? A) H 2 /Ni B) H 2, Lindlar Pd C) Na, NH 3 D) NaNH 2, NH 3

53 Question 8 What product is formed when 2-butyne is subjected to ozonolysis? A) B) C) D)

54 Question 9 Arrange ethane, ethene, and ethyne in order of increasing C-C bond length. A) ethane < ethene < ethyne B) ethene < ethane < ethyne C) ethyne < ethene < ethane D) ethane < ethyne < ethene

55 Question 10 How would you accomplish the following conversion? A) NaNH 2 B) H 2, Lindlar Pd C) Na, NH 3 D) either B or C

56 Question 11 What is the product of the acid catalyzed hydration of 1-hexyne? A) B) C) D)

57 Question 12 What product will be isolated when an excess of HCl is added to 1-butyne? A) 2,2-dichlorobutane B) 1,1-dichlorobutane C) 1,2-dichlorobutane D) 1,2-dichloro-1-butene

58 Question 13 Which one of the following is the strongest acid? A) water B) ammonia C) 1-butene D) 1-butyne

59 Question 14 Which would be the best sequence of reactions to use in order to prepare cis-3-nonene from 1-butyne? A) 1. NaNH 2 in NH 3 ; 2. 1-bromopentane; 3. H 2, Lindlar Pd B) 1. NaNH 2 in NH 3 ; 2. 1-bromopentane; 3. Na, NH 3 C) 1. H 2, Lindlar Pd; 2. NaNH 2 in NH 3 ; bromopentane D) 1. Na, NH 3 ; 2. NaNH 2 in NH 3 ; bromopentane

60 Question 15 Which of the following compounds yield 1- heptyne on being treated with three moles of sodium amide (in liquid ammonia as the solvent) followed by adding water to the reaction mixture? A) 1,1,2,2-tetrachloroheptane B) 1-bromo-2-chloroheptane C) 1,1,2-trichloropentane D) all of the above

61 Question 16 Which one of the following statements best explains the greater acidity of terminal alkynes (RC CH) compared with monosubstituted alkenes (RCH=CH 2 )? A) The sp-hybridized carbons of the alkyne are less electronegative than the sp 2 carbons of the alkene. B) The two p bonds of the alkyne are better able to stabilize the negative charge of the anion by resonance. C) The sp-hybridized carbons of the alkyne are more electronegative than the sp 2 carbons of the alkene. D) The question is incorrect - alkenes are more acidic than alkynes.

62 Question 17 Consider the reaction of each of the following with cyclohexyl bromide. For which one is the ratio of substitution to elimination highest? A) NaOCH 2 CH 3, ethanol, 60 C B) NaSCH 2 CH 3, ethanol-water, 25 C C) NaNH 2, NH 3, -33 C D) NaC CH, NH 3, -33 C

63 Question 18 Which one of the following reactions proceeds via a carbocation intermediate? A) Hydrolysis of 1-bromo-1- methylcyclopentane in aqueous formic acid. B) Reaction of 1-bromobutane with sodium cyanide in dimethyl sulfoxide. C) Reaction of 1-butyne with sodium amide in liquid ammonia. D) Reaction of cyclohexyl chloride with sodium iodide in acetone.

64 Answer Key Chapter 9 1. C 2. A 3. C 4. D 5. C 6. B 7. C 8. B 9. C 10. D 11. B 12. A 13. A 14. A 15. B 16. C 17. B 18. A

65 Organic Chemistry Carey/Giuliano 9th edition Chapter 10 Copyright 2014 The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

66 Question 1 What is the product of the Diels-Alder reaction that occurs between the reactants shown here? A) B) C) D)

67 Question 2 Rank the compounds below in order of increasing rate of the Diels-Alder reaction. A) 1 < 2 < 3 B) 3 < 1 < 2 C) 3 < 2 < 1 D) 2 < 3 < 1

68 Question 3 Select the correct starting materials to make the compound at the right through the Diels-Alder reaction. A) B) C) D)

69 Question 4 How many different products will be isolated from the reaction of 1,3-cyclohexadiene with HCl? A) one B) two C) three D) four

70 Question 5 Arrange the dienes below in order of increasing heat of hydrogenation. A) 3 < 2 < 1 B) 1 < 2 < 3 C) 3 < 1 < 2 D) 1 < 3 < 2

71 Question 6 Choose the compound that yields the same carbocation as 3-chloro-1-methylcyclohexene. A) B) C) D)

72 Question 7 What is the other product formed in the reaction shown here? A) B) C) D)

73 Question 8 How many allylic and vinylic hydrogens respectively are in cyclohexene? A) 2 and 4 B) 4 and 2 C) 2 and 2 D) 6 and 2

74 Question 9 What kind of mechanism is involved in the reaction of 2-methylpropene with N- bromosuccinimide in CCl 4 (light and heat)? A) Electrophilic addition B) Free-radical addition C) Free-radical substitution D) Nucleophilic substitution

75 Question 10 Which of the following compounds will yield the same carbocation on ionization? A) 1 and 3 B) 1 and 4 C) 3 and 4 D) 2 and 4

76 Question 11 2,3-Pentadiene, CH3CH=C=CHCH 3 is A) a planar substance. B) an allene. C) a conjugated diene. D) a substance capable of cis-trans isomerism.

77 Question 12 Hydrogenation of cyclohexene releases 120 kj/mol (28.6 kcal/mol) of heat. Which of the following most likely represent the observed heat of hydrogenation of 1,3-cyclohexadiene? A) 232 kj/mol (55.4 kcal/mol) B) 240 kj/mol (57.2 kcal/mol) C) 247 kj/mol (59.0 kcal/mol) D) 120 kj/mol (28.6 kcal/mol)

78 Question 13 Rank the following carbocations in order of increasing stability (least most) A) 1 < 2 < 3 B) 2 < 3 < 1 C) 3 < 1 < 2 D) 2 < 1 < 3

79 Question 14 Which of the following C-H bonds would have the smallest bond dissociation energy? A) B) C) D)

80 Question 15 Which compound undergoes hydrolysis (S N 1) to give a mixture of two alcohols that are constitutional isomers? A) B) C) D)

81 Question 16 Which compound undergoes 1,4-addition with Br 2? A) B) C) D)

82 Question 17 Which diene is shown in its s-cis conformation? A) B) C) D)

83 Question 18 Which one undergoes solvolysis in acetic acid at the fastest rate? A) B) C) D)

84 Question 19 Which of the structures is an allylic alcohol? A) B) C) D)

85 Question 20 Which is the product when the reaction shown is carried out under thermodynamic control? A) B) C) D)

86 Answer Key Chapter C 2. D 3. D 4. A 5. C 6. A 7. B 8. B 9. C 10. B 11. B 12. A 13. C 14. D 15. A 16. B 17. A 18. C 19. B 20. D

87 Organic Chemistry Carey/Giuliano 9th edition Chapter 11 Copyright 2014 The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

88 Question 1 What is the correct IUPAC name of the compound shown to the right? A) 4-chlorobenzoic acid B) p-4-chlorobenzoic acid C) 4-chlorobenzene carboxylic acid D) 4-carboxyl-1-chlorobenzene

89 Question 2 Which one of the following is the correct IUPAC name for the aromatic compound shown? A) 3,6-dichlorotoluene B) 1,4-dichloro-2-methylbenzene C) 2,5-dichloro-1-methylbenzene D) 2,5-dichlorotoluene

90 Question 3 How many p electrons does the compound shown have? A) 5 B) 8 C) 10 D) 12

91 Question 4 What is the hybridization of the nitrogen in N- methylpyrrole? A) sp B) sp 2 C) sp 3 D) s

92 Question 5 What is the value of N of Huckel's rule for the cyclopentadienyl cation (shown)? A) N=1/2 B) N=1/4 C) N=1 D) N=2

93 Question 6 Which compound would undergo solvolysis at a faster rate? A) B) C) D)

94 Question 7 The compound shown is classified as A) non-aromatic B) aromatic C) anti-aromatic D) none of the above

95 Question 8 The compound shown is classified as A) non-aromatic. B) aromatic. C) anti-aromatic. D) none of the above

96 Question 9 Select the best reagent(s) to accomplish the transformation shown. A) PCC, CH 2 Cl 2 B) K 2 Cr 2 O 7, H 2 SO 4, heat C) LiAlH 4 then H 2 O D) NBS then CH 3 ONa

97 Question 10 Which reagent would you use for the reaction below? A) Br 2, CCl 4 B) Br 2, FeCl 3 C) HBr, peroxides D) NBS, peroxides, heat

98 Question 11 Which of the following compounds is best classified as an aromatic heterocycle? A) B) C) D)

99 Question 12 Which compound has the lowest pk a? A) B) C) D)

100 Question 13 Which product will be siolated when 4- chlorobenzyl chloride is treated with K 2 CO 3 in H 2 O? A) B) C) D)

101 Question 14 What is the C-C bond distance in benzene? A) 134 pm B) 140 pm C) 146 pm D) 150 pm

102 Question 15 How many possible isomers of dibromophenol exist? A) 3 B) 4 C) 6 D) 8

103 Question 16 Rank the following compounds in order of increasing rate of solvolysis (S N 1) in aqueous acetone (slowest fastest). A) 1 < 2 < 3 B) 2 < 1 < 3 C) 3 < 2 < 1 D) 1 < 3 < 2

104 Question 17 Which of the following statements is correct concerning the class of reactions to be expected for benzene and cyclooctatetraene? A) Both substances undergo addition reactions. B) Both substances undergo substitution reactions. C) Benzene undergoes addition; cyclooctatetraene undergoes substitution. D) Benzene undergoes substitution; cyclooctatetraene undergoes addition.

105 Question 18 Which product(s) will be isolated from the reaction shown here? A) B) C) Equal amounts of A and B. D) Neither A nor B.

106 Question 19 Which of the following has the smallest heat of combustion? A) B) C) D)

107 Question 20 Which of the following compounds has a double bond that is conjugated with the p system of the benzene ring? A) p-benzyltoluene B) 2-Phenyl-1-decene C) 3-Phenylcyclohexene D) 3-Phenyl-1,4-pentadiene

108 Answer Key Chapter A 2. D 3. C 4. B 5. A 6. C 7. C 8. B 9. B 10. D 11. D 12. C 13. C 14. B 15. C 16. C 17. D 18. A 19. C 20. B

109 Organic Chemistry Carey/Giuliano 9th edition Chapter 12 Copyright 2014 The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

110 Question 1 Arrange the compounds below in order of decreasing rate of chlorination. A) 1 > 2 > 3 B) 2 > 3 > 1 C) 3 > 2 > 1 D) 1 > 3 > 2

111 Question 2 Which compound will react faster with Br 2 in acetic acid? A) B) C) D)

112 Question 3 Which compound will add a nitro group to the meta position? A) B) C) D)

113 Question 4 Which positions are activated for chlorination on the compound shown below? A) 2 and 3 B) 1 and 3 C) 2 and 4 D) 1 and 4

114 Question 5 Which combination of reactants will yield n- propylbenzene as the major product when reacted with benzene? A) CH 3 CH 2 C(=O)H, AlCl 3 B) CH 3 CH 2 CH 2 Cl, AlCl 3 C) CH 3 CH 2 C(=O)Cl, AlCl3 followed by Zn(Hg), HCl D) CH 3 CH 2 CH 3, AlCl 3

115 Question 6 A Friedel-Craft acylation cannot be performed on which compound? A) 3 only B) 4 only C) 1 and 2 D) 3 and 4

116 Question 7 The carbocation formed in the first step of the electrophilic aromatic substitution mechanism is known as: A) arenium ion B) s-complex C) cyclohexadienyl cation D) all of the above

117 Question 8 Which compound undergoes electrophilic aromatic substitution with (CH 3 ) 3 CCl and AlCl 3 at the slowest rate (or not at all)? A) B) C) D)

118 Question 9 Which of the following statements concerning nucleophilic aromatic substitution in 1,2,3,4,5,6-hexafluorobenzene is true? A) 1,2,3,4,5,6-hexafluorobenzene is less reactive than fluorobenzene. B) 1,2,3,4,5,6-hexafluorobenzene is more reactive than 1,2,3,4,5,6-hexachlorobenzene. C) The reaction takes place in a single elementary step. D) The carbon-fluorine bond breaks in the ratedetermining step.

119 Question 10 Which substituent is classified as deactivating and ortho-para directing in electrophilic aromatic substitution? A) -Cl B) -CH=O C) -NH 2 D) -SCH 3

120 Question 11 Which reactants combine to give the species shown at the right as a reactive intermediate? A) Benzene, isopropyl bromide, and HBr B) Bromobenzene, isopropyl chloride, and AlCl 3 C) Isopropylbenzene, Br 2, FeBr 3 D) Isopropylbenzene, light, and heat

121 Question 12 Which of the following is the most reasonable way to begin an effective synthesis of the compound shown? A) Treat benzene with isopropyl chloride and AlCl 3. B) Treat chlorobenzene with propene and AlCl 3. C) Treat benzene with 2-chloropropene and AlCl 3. D) Treat benzene with 3-chloropropene and AlCl 3.

122 Question 13 Which phenol is most acidic? A) phenol B) 2-methyl-6-nitrophenol C) 3-methyl-5-nitrophenol D) 2,6-dimethyl-3-nitrophenol

123 Question 14 Which of the following is the most activating substituent in electrophilic aromatic substitution? A) -C N B) -CO 2 CH 3 C) -NHC(=O)CH 3 D) -SO 3 H Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

124 Question 15 Which compound will react faster with NaOCH 3 in methanol (50 o C)? A) B) C) D)

125 Question 16 Which organic product would you expect to isolate from the reaction of p-fluoronitrobenzene with potassium methoxide? A) B) C) D)

126 Question 17 Which of the structures below is the most stable resonance structure for the reaction of p- fluoronitrobenzene with sodium methoxide? A) 1 only B) 2 only C) 3 only D) 1 and 2

127 Question 18 What is the product of the reaction of 2- chloropyridine with KOCH 3 (shown below)? A) B) C) D)

128 Question 19 Which is the product of the reaction of p- chloronitrobenzene with NH 3? A) B) C) D)

129 Question 20 What is the product of the synthetic sequence shown at the right? A) B) C) D)

130 Question 21 What product will be isolated when o- bromotoluene is treated with NaNH 2 in NH 3? A) B) C) D) Both A and B

131 Question 22 What combination of reactants will give the species shown as a reactive intermediate? A) 1-bromo-4-nitrobenzene and NaOH B) bromobenzene and HONO 2 C) 4-nitrophenol with HBr D) 4-nitrophenol, Br 2 and FeBr 3

132 Question 23 The reaction shown below most likely involves which of the following aromatic substitution mechanisms? A) addition-elimination B) electrophilic substitution C) elimination-addition D) both A and C

133 Question 24 Which of the following compounds give a single benzyne intermediate on reaction with sodium amide? A) 1 only B) 1 and 3 C) 3 only D) 1 and 2

134 Question 25 Which of the following compounds is the least reactive toward nucleophilic aromatic substitution? A) 1-chloro-4-nitrobenzene B) 1-iodo-2-nitrobenzene C) 1-fluoro-4-nitrobenzene D) 1-bromo-3-nitrobenzene

135 Question 26 Identify the rate law for the addition-elimination mechanism of nucleophilic aromatic substitution. A) Rate = [aryl halide] B) Rate = [aryl halide][nucleophile] C) Rate = [aryl halide][nucleophile] 2 D) Rate = [nucleophile]

136 Question 27 Which of the following statements is true regarding nucleophilic aromatic substitution reactions (S N Ar)? A) A nitro (NO 2 ) group strongly activates the ring toward S N Ar. B) The S N Ar reaction is facilitated when electrons flow from the attacking species to the aromatic ring. C) The S N Ar follows second-order kinetics. D) All of the statements above are true.

137 Question 28 How many different methylaniline isomers will be formed in the reaction of p-chlorotoluene with KNH 2 in NH 3? A) 1 B) 2 C) 3 D) 4

138 Question 29 How many different methylaniline isomers will be formed in the reaction of m-chlorotoluene with KNH 2 in NH 3? A) 1 B) 2 C) 3 D) 4

139 Question 30 Arrange the aryl halides in order decreasing reactivity with magnesium. A) ArF > ArCl > ArBr > ArI B) ArF > ArCl > ArI > ArBr C) ArI > ArBr > ArCl > ArF D) ArF > ArBr > ArCl > ArI

140 Question 31 Which one of the following compounds has the greatest dipole moment (m)? A) Chlorohexane B) Chlorobenzene C) Benzene D) 1,3-Pentadiene

141 Question 32 How many signals would be observed in the 1 H-NMR of the product isolated from the reaction of p-fluoronitrobenzene with potassium methoxide in methanol? A) 2 B) 3 C) 4 D) 5

142 Question 33 Which of the following aromatic compounds will not react with KNH 2 via the elimination-addition mechanism? A) Chlorobenzene B) 1-ethyl-4-iodobenzene C) 2-Bromotoluene D) Benzylbromide

143 Question 34 What type of nucleophilic aromatic substitution is the reaction of m-dinitrophenol with NaOH (shown)? A) S N 2 B) elimination-addition C) addition-elimination D) The reaction is an electrophilic aromatic substitution.

144 Answer Key Chapter A 2. A 3. D 4. C 5. C 6. A 7. D 8. B 9. B 10. A 11. C 12. A 13. B 14. C 15. D 16. C 17. C 18. B 19. B 20. C 21. D 22. A 23. C 24. B 25. D 26. B 27. D 28. B 29. C 30. C 31. A 32. B 33. D 34. C