Quiz 11 Flashcards

1
Q
  1. Which of the following reactions corresponds to a substitution?
    A. propene ® 1,2-dibromopropane
    B. 1-iodopropane ® propene
    C. propene ® propane
    D. 1-iodopropane ® 1-bromopropane
A

D. 1-iodopropane ® 1-bromopropane

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2
Q
  1. Which of the following reactions corresponds to a substitution?
    A. tert-butanol ® tert-butyl chloride
    B. tert-butanol ® 2-methylpropene
    C. 3,3-dimethyl-2-butanol ® 2,3-dimethyl-2-butene
    D. cyclohexene ® 1,2-dichlorocyclohexane
A

A. tert-butanol ® tert-butyl chloride

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3
Q
  1. Which of the following statements related to SN1 reactions is not true?
    A. The heterolysis of a bond between atoms which do not bear formal charges always produces a cation and an anion
    B. The charged carbon atom of a carbocation has a complete octet of valence shell electrons
    C. Carbocations are Lewis acids
    D. Nucleophiles seek centers of low electron density
A

B. The charged carbon atom of a carbocation has a complete octet of valence shell electrons

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4
Q
  1. Which of the following statements related to SN1 reactions is not true?
    A. The SN1 reaction can be described as a heterolytic bond cleavage followed by nucleophilic attack
    B. Carbocations are electrophilic
    C. The charged carbon atom of a carbocation has an unfilled valence shell
    D. Nucleophiles are Lewis acids
A

D. Nucleophiles are Lewis acids

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5
Q
  1. What is the equation for the rate of formation of tert-butyl alcohol from the reaction of tert-butyl bromide (t-BuBr) with water by an SN1 mechanism?
    A. Rate = k [t-BuBr]
    B. Rate = k [t-BuBr][H2O]
    C. Rate = k [H2O]
    D. Rate = k [t-BuBr]2
A

A. Rate = k [t-BuBr]

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6
Q
  1. What is the equation for the rate of formation of 1-iodobutane from the reaction of 1-chlorobutane (BuCl) with NaI by an SN2 mechanism?
    A. Rate = k [BuCl]
    B. Rate = k [BuCl][NaI]
    C. Rate = k [NaI]
    D. Rate = k [BuCl]2
A

B. Rate = k [BuCl][NaI]

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7
Q
  1. The reaction of methyl iodide with sodium azide, NaN3, proceeds by an SN2 mechanism. What is the effect of doubling the concentration of NaN3 on the rate of the reaction?
    A. the rate remains the same
    B. the rate decreases by a factor of 2
    C. the rate increases by a factor of 2
    D. the rate increases by a factor of 4
A

C. the rate increases by a factor of 2

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8
Q
  1. The reaction of 1-bromopropane with sodium iodide gives 1-iodopropane. What is the effect of doubling the concentration of NaI on the rate of the reaction?
    A. the rate remains the same
    B. the rate decreases by a factor of 2
    C. the rate increases by a factor of 2
    D. the rate increases by a factor of 4
A

C. the rate increases by a factor of 2

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9
Q
  1. The reaction of tert-butyl bromide, (CH3)3CBr, with methanol in an inert solvent proceeds by an SN1 mechanism to give tert-butyl methyl ether, (CH3)3COCH3. What is the effect of doubling the concentration of methanol on the rate of the reaction?
    A. the rate remains the same
    B. the rate decreases by a factor of 2
    C. the rate increases by a factor of 2
    D. the rate increases by a factor of 4
A

A. the rate remains the same

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10
Q
  1. The reaction of tert-butyl chloride, (CH3)3CCl, with water in an inert solvent gives tert-butyl alcohol, (CH3)3COH. What is the effect of doubling the concentration of water on the rate of the reaction?
    A. the rate remains the same
    B. the rate decreases by a factor of 2
    C. the rate increases by a factor of 2
    D. the rate increases by a factor of 4
A

A. the rate remains the same

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11
Q
  1. Which of the following alkyl halides undergoes the fastest SN2 reaction with sodium azide, NaN3?
    A. 1-fluorohexane
    B. 1-chlorohexane
    C. 1-bromohexane
    D. 1-iodohexane
A

D. 1-iodohexane

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12
Q
  1. Which of the following alkyl halides undergoes the fastest SN2 reaction with sodium cyanide, NaCN?
    A. methyl iodide
    B. ethyl iodide
    C. 2-iodopropane
    D. tert-butyl iodide
A

A. methyl iodide

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13
Q
  1. Which of the following alkyl halides undergoes the fastest SN2 reaction with sodium methylthiolate, NaSMe?
    A. methyl iodide
    B. ethyl iodide
    C. 2-bromopropane
    D. tert-butyl chloride
A

A. methyl iodide

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14
Q
  1. Which of the following alkyl halides undergoes the fastest solvolysis reaction with formic acid, HCOOH?
    A. tert-butyl fluoride
    B. tert-butyl chloride
    C. tert-butyl bromide
    D. tert-butyl iodide
A

D. tert-butyl iodide

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15
Q
  1. Which of the following alkyl halides undergoes the fastest solvolysis reaction with methanol, CH3OH?
    A. methyl chloride
    B. ethyl chloride
    C. 2-chloropropane
    D. tert-butyl chloride
A

D. tert-butyl chloride

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16
Q
  1. What is the major product formed upon treatment of (R) 1-bromo-4-methylhexane with sodium cyanide?
    A. (R) 1-cyano-4-methylhexane
    B. (S) 1-cyano-4-methylhexane
    C. (R) 4-methyl-1-hexene
    D. (S) 4-methyl-1-hexene
A

A. (R) 1-cyano-4-methylhexane

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17
Q
  1. What is the major product formed upon treatment of (R) 2-bromohexane with sodium cyanide?
    A. (R) 2-cyanohexane
    B. (S) 2-cyanohexane
    C. 1-hexene
    D. 2-hexene
A

A. (R) 2-cyanohexane

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18
Q
  1. What is(are) the major organic product(s) obtained from the following substitution reaction?
A

D. 1, 2 and 3

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19
Q
  1. What is(are) the major organic product(s) obtained from the following substitution reaction?
A

D. 1, 2 and 3

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20
Q
  1. In which of the following solvents would the reaction of 1-bromobutane with sodium azide, NaN3, proceed the fastest?
    A. acetic acid
    B. ethanol
    C. water
    D. acetonitrile
A

D. acetonitrile

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21
Q
  1. Which of the following anions is the most nucleophilic in polar protic solvents?
    A. F-
    B. Cl-
    C. Br-
    D. I-
A

D. I-

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22
Q
  1. Which of the following anions is the most nucleophilic in polar aprotic solvents?
    A. F-
    B. Cl-
    C. Br-
    D. I-
A

A. F-

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23
Q
  1. Which of the following compounds is the most nucleophilic in polar protic solvents?
    A. H2O
    B. NH3
    C. H2S
    D. PH3
A

D. PH3

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24
Q
  1. Which of the following is the most nucleophilic?
    A. sodium ethoxide
    B. acetic acid
    C. methanol
    D. water
A

A. sodium ethoxide

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25
Q
  1. Which of the following anions is the best leaving group in an SN1 reaction?
    A. F-
    B. HO-
    C. NH2-
    D. Cl-
A

D. Cl-

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26
Q
  1. Which of the following is the best leaving group in an SN2 reaction?
    A. F-
    B. H3C-
    C. CH3O2SO-
    D. HO-
A

C. CH3O2SO-

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27
Q
  1. Which of the following statements is not true regarding the SN2 reaction of (R)-2-bromobutane with sodium cyanide?
    A. the reaction proceeds with inversion of configuration
    B. the rate is proportional to the concentration of sodium cyanide
    C. the rate is proportional to the concentration of (R)-2-bromobutane
    D. the rate of the reaction is independent of the identity of the solvent
A

D. the rate of the reaction is independent of the identity of the solvent

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28
Q
  1. Which of the following statements is true regarding the reaction of tert-butyl bromide with water?
    A. the rate is proportional to the concentration of tert-butyl bromide
    B. the rate is proportional to the concentration of water
    C. the rate is independent of the identity of the solvent
    D. the rate of the reaction is independent of the temperature
A

A. the rate is proportional to the concentration of tert-butyl bromide

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29
Q
  1. Which of the following is not a characteristic of SN2 reactions?
    A. the electrophilic carbon undergoes inversion of stereochemistry
    B. the rate is proportional to the concentration of substrate
    C. the rate is proportional to the concentration of nucleophile
    D. the rate is independent of the solvent
A

D. the rate is independent of the solvent

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30
Q
  1. Which of the following is not a characteristic of SN1 reactions?
    A. the electrophilic carbon undergoes inversion of stereochemistry
    B. the rate is proportional to the concentration of substrate
    C. the reaction proceeds faster in a more polar solvent
    D. the rate is independent of the concentration of nucleophile
A

A. the electrophilic carbon undergoes inversion of stereochemistry

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31
Q
  1. Which of the following statements is not true regarding SN2 reactions?
    A. A carbocation intermediate is formed.
    B. The mechanism has only one step.
    C. Aprotic solvents are good choices for SN1 reactions.
    D. The stereochemical outcome is inversion at the carbon bearing the leaving group.
A

A. A carbocation intermediate is formed.

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32
Q
  1. Which of the following statements is not true regarding SN1 reactions?
    A. A carbocation intermediate is formed.
    B. The mechanism has only one step.
    C. Polar, protic solvents are good choices for SN1 reactions.
    D. The stereochemical outcome is racemization at the carbon bearing the leaving group.
A

B. The mechanism has only one step.

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33
Q
  1. Which of the following energy diagrams represents the course of an exothermic SN1 reaction?
A

A. 1

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34
Q
  1. Which of the following energy diagrams represents the course of an exothermic SN2 reaction?
A

C. 3

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35
Q

1) What is the nucleophile in the reaction shown below?

A

B) II

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36
Q

2) Which of the following is not a nucleophile?

A

C) +CH3

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37
Q

3) Which of the following best describes the carbon-chlorine bond of an alkyl chloride?

A) nonpolar; no dipole

B) polar; δ+ at carbon and δ- at chlorine

C) polar; δ- at carbon and δ+ at chlorine

D) ionic

E) none of the above

A

B) polar; δ+ at carbon and δ- at chlorine

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38
Q

4) Which of the following is not normally considered to be a nucleophile?

A

D) CH3CH2+

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39
Q

7) Identify the alkyl halide that reacts the fastest in a SN2 reaction.

A) 2-chloro-2-methylpropane

B) 2-chlorobutane

C) 1-chlorobutane

D) chloromethane

A

D) chloromethane

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40
Q

8) Identify the alkyl halide that reacts the fastest in an SN2 reaction.

A) 1-chloropropane

B) 1-bromopropane

C) 1-fluoropropane

D) 1-iodopropane

A

D) 1-iodopropane

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41
Q

9) Identify the strongest nucleophile in an SN2 reaction.

A) isopropoxide ion

B) tert-butoxide ion

C) ethoxide ion

D) tert-pentoxide ion

A

C) ethoxide ion

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42
Q

10) Which of the following are the substitution products of the reaction shown below?

CH3CH2Br + -OH → ?

A) CH3CH2BrH+ + O-

B) HOCH2CH2Br

C) CH3CH2OH + Br-

D) CH2CH2 + Br- + H2O

E) CH2CHBr + H2O

A

C) CH3CH2OH + Br-

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43
Q

11) Which of the following alkyl halides gives the slowest SN2 reaction?

A
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44
Q

12) Assuming no other changes, what is the effect of doubling only the concentration of the alkyl halide in the above SN2 reaction?

A

B) doubles the rate

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45
Q

13) Assuming no other changes, what is the effect of doubling both the alkyl halide and the nucleophile concentrations in the above reaction?

A) no change

B) doubles the rate

C) triples the rate

D) quadruples the rate

E) rate is halved

A

D) quadruples the rate

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46
Q

14) Which of the following SN2 reactions is the fastest?

A

B) CH3CH2CH2I + HO- → CH3CH2CH2OH + I-

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47
Q

15) Which of the following SN2 reactions is the slowest?

A
48
Q

16) Which of the following compounds will undergo an SN2 reaction most readily?

A) (CH3)3CCH2I

B) (CH3)3CCl

C) (CH3)2CHI

D) (CH3)2CHCH2CH2CH2Cl

E) (CH3)2CHCH2CH2CH2I

A

E) (CH3)2CHCH2CH2CH2I

49
Q

17) Which of the following is a secondary alkyl halide?

A) CH3Br

B) (CH3)3CBr

C) (CH3)2CHBr

D) (CH3)2CHCH2Br

A

C) (CH3)2CHBr

50
Q

18) Which of the following SN2 reactions is the fastest?

A) CH3CH2CH2CH2Br + OH- → CH3CH2CH2CH2OH + Br-

B) CH3CH2CH2CH2Br + H2O → CH3CH2CH2CH2OH + HBr

C) CH3CH2CHBrCH3 + OH- → CH3CH2CHOHCH3 + Br-

D) CH3CH2CHBrCH3 + H2O → CH3CH2CHOHCH3 + HBr

A

A) CH3CH2CH2CH2Br + OH- → CH3CH2CH2CH2OH + Br-

51
Q

19) Which of the following SN2 reactions is the slowest?

A) CH3CH2CHBrCH3 + OH- → CH3CH2CHOHCH3 + Br-

B) CH3CH2CHBrCH3 + H2O → CH3CH2CHOHCH3 + HBr

C) CH3CH2CH2CH2Br + OH- → CH3CH2CH2CH2OH + Br-

D) CH3CH2CH2CH2Br + H2O → CH3CH2CH2CH2OH + HBr

A

B) CH3CH2CHBrCH3 + H2O → CH3CH2CHOHCH3 + HBr

52
Q

20) Which of the following does not provide evidence that there are two different mechanisms for nucleophilic substitution?

A) reaction products when CH3I is used as the substrate

B) reaction products when (CH3)3CCH2I is used as substrate

C) the stereochemistry of nucleophilic substitutions

D) the effect of nucleophile concentration on rate

A

A) reaction products when CH3I is used as the substrate

53
Q

21) What product results from the SN2 reaction between (R)-2-chloropentane and hydroxide?

A) (R)-2-pentanol

B) (S)-2-pentanol

C) racemic pentanol

D) 1-pentanol

E) 3-pentanol

A

B) (S)-2-pentanol

54
Q

35) Which of the following is the strongest nucleophile in an aqueous solution?

A) HO-

B) F-

C) Cl-

D) Br-

E) I-

A

E) I-

55
Q

36) Which of the following is the best leaving group?

A) HO-

B) F-

C) Cl-

D) Br-

E) I-

A

E) I-

56
Q

37) Which of the following species is most reactive in an SN2 reaction?

A) CH3CH2—Cl

B) CH3CH2—Br

C) CH3CH2—I

D) CH3CH2—F

E) CH3CH2—OH

A

C) CH3CH2—I

57
Q

38) Which of the following species is the least nucleophilic?

A) (CH3)3CO-

B) H2O

C) (CH3)3N

D) BF3

E) CN-

A

D) BF3

58
Q

39) Which of the following is the best nucleophile in water?

A) I-

B) CH3SCH3

C) CH3OCH3

D) Cl-

A

A) I-

59
Q

40) Which of the following statements concerning SN2 reactions of alkyl halides is not correct?

A) The rate of reaction depends on the concentration of the nucleophile.

B) The rate of reaction depends on the concentration of the alkyl halide.

C) The rate of reaction of a particular alkyl bromide depends on the steric accessibility of the carbon of the C-Br bond.

D) All alkyl iodides react more rapidly than all alkyl chlorides.

E) The rate of reaction depends on the relative nucleophilicity of the nucleophile.

A

D) All alkyl iodides react more rapidly than all alkyl chlorides.

60
Q

41) Which of the following correctly describes the relative nucleophilicities of methoxide and tert-butoxide?

A) These alkoxides have essentially the same nucleophilicities since the negative charge in both is localized on an oxygen atom.

B) Methoxide is more nucleophilic because the nucleophilicity of tert-butoxide is diminished by steric effects.

C) tert-Butoxide is more nucleophilic because it contains three methyl groups which increase the charge on its oxygen by donating electron density.

D) tert-Butoxide is more nucleophilic because it is more basic.

E) none of the above

A

B) Methoxide is more nucleophilic because the nucleophilicity of tert-butoxide is diminished by steric effects.

61
Q

42) Which of the following bromides reacts readily via an SN2 reaction with NaN3?

A) C6H5Br

B) CH3CH2CH=CHBr

C) (C6H5)3CBr

D) (CH3)3CCH2CH2CH2Br

E) 1-bromo-1-methylcyclohexane

A

D) (CH3)3CCH2CH2CH2Br

62
Q

43) Which halide reacts most rapidly via an SN2 mechanism?

A) (CH3)CCH2CH2F

B) (CH3)CCH2CH2Cl

C) (CH3)CCH2CH2Br

D) (CH3)CCH2CH2I

E) All primary halides react at the same rate in SN2.

A

D) (CH3)CCH2CH2I

63
Q

44) Which halide reacts most rapidly via an SN2 mechanism?

A

E

64
Q

45) Which halide reacts most rapidly via an SN2 mechanism?

A

Answer: E

65
Q

49) Which of the following iodides undergoes SN2 reaction with cyanide (CN-) the fastest?

A) 1-iodo-3-methylpentane

B) 2-iodopentane

C) 2-iodo-2-methylpentane

D) 3-iodopentane

E) 1-iodo-2,2-dimethylpentane

A

A) 1-iodo-3-methylpentane

66
Q

59) Assuming no other changes, what is the effect of doubling only the concentration of the nucleophile in the above reaction?

A) no change

B) doubles the rate

C) triples the rate

D) quadruples the rate

E) rate is halve

A

A) no change

67
Q

60) Assuming no other changes, what is the effect of doubling both the concentration of the alkyl halide and the nucleophile in the above reaction?

A) no change

B) doubles the rate

C) triples the rate

D) quadruples the rate

E) rate is halved

A

B) doubles the rate

68
Q

64) Which of the following carbocations is the most stable?

A

C

69
Q

66) Which of the following carbocations is the least stable?

A

A) I

70
Q

67) Which of the compounds below undergoes solvolysis in aqueous ethanol most rapidly?

A) cyclohexyl bromide

B) methyl iodide

C) isopropyl chloride

D) 3-chloropentane

E) 3-iodo-3-methylpentane

A

E) 3-iodo-3-methylpentane

71
Q

78) When (S)-2-bromobutane undergoes an SN2 reaction with CH3O-, the product is the compound shown below. What is/are the configuration(s) of the product(s) obtained from this reaction?

A

B) R only

72
Q

85) Identify the halide(s) that react in a SN2 reaction.

A) benzyl bromide

B) bromobenzene

C) 1-bromo-1-butene

D) 1-bromo-2-butene

E) 2-bromo-2-phenylpropane

A

A and D

73
Q

87) Which of the following can’t undergo nucleophilic substitution reactions?

A

B) II

74
Q

88) Which of the following is classified as a vinyl halide?

A) CH3CHCHOH

B) CH3CHCHCl

C) CH3CHCHCH2Cl

D) CH3CH2CH2CH2Br

E) BrCH2CHCH2

A

B) CH3CHCHCl

75
Q
  1. What is the equation for the rate of formation of 2-methoxypropane, (CH3CH(OCH3)CH3, from the reaction of 2-bromopropane (i-PrBr) with sodium methoxide (NaOCH3)?
    A. Rate = k [i-PrBr]
    B. Rate = k [i-PrBr]2
    C. Rate = k [NaOCH3]
    D. Rate = k [i-PrBr][NaOCH3]
A

D. Rate = k [i-PrBr][NaOCH3]

76
Q
  1. What is the equation for the rate of formation of 2-methoxypropane, CH3CH(OCH3)CH3, from the reaction of 2-bromopropane (i-PrBr) with methanol?
    A. Rate = k [i-PrBr]
    B. Rate = k [i-PrBr]2
    C. Rate = k [CH3OH]
    D. Rate = k [i-PrBr][CH3OH]
A

A. Rate = k [i-PrBr]

77
Q
  1. Which of the following alkyl halides undergoes the fastest solvolysis reaction with ethanol, CH3CH2OH?
    A. methyl fluoride
    B. ethyl bromide
    C. 2-chloropropane
    D. tert-butyl bromide
A

D. tert-butyl bromide

78
Q
  1. Which of the following is best set of conditions for the preparation of tert-butanol?
    A. tert-butyl fluoride in water
    B. tert-butyl bromide in water
    C. tert-butyl fluoride and NaOH in DMSO
    D. tert-butyl bromide and NaOH in DMSO
A

B. tert-butyl bromide in water

79
Q
  1. Which of the following is the best set of conditions for the preparation of tert-butyl methyl ether?
    A. tert-butyl fluoride and NaOCH3 in CH3OH
    B. methanol and sodium tert-butoxide in tert-butanol
    C. fluoromethane and sodium tert-butoxide in tert-butanol
    D. tert-butyl bromide and CH3OH
A

D. tert-butyl bromide and CH3OH

80
Q
  1. Which of the following solvents is the best choice for the reaction of 1-chlorohexane with sodium bromide?
    A. dimethylsulfoxide
    B. water
    C. hexane
    D. toluene, PhCH3
A

A. dimethylsulfoxide

81
Q
  1. Which of the following solvents is the best choice for the reaction of 1-chlorohexane with sodium bromide?
    A. water
    B. N,N-dimethylformamide
    C. hexane
    D. toluene, PhCH3
A

B. N,N-dimethylformamide

82
Q
  1. Which of the following alkyl bromides reacts the slowest with NaSCH3 in DMF?
A

A. 1

83
Q
  1. Which of the following represents the transition state of the rate-determining step in the SN1 reaction between tert-butyl chloride and water?
A

B. 2

84
Q
  1. Which of the following represents the transition state of the rate-determining step in the reaction between tert-butyl bromide and methanol?
A

A. 1

85
Q
  1. Which of the following represents the transition state of the reaction between methyl iodide and ammonia?
A

C. 3

86
Q
  1. Which of the following represents the transition state of the reaction between methyl bromide and sodium methylthiolate, NaSCH3
A

D. 4

87
Q
  1. Which of the following sets consists of only polar aprotic solvents?
    A. water, hexane, methanol
    B. acetic acid, DMF, toluene
    C. DMSO, ethanol, acetonitrile
    D. DMF, acetonitrile, DMSO
A

D. DMF, acetonitrile, DMSO

88
Q
  1. Which of the following sets consists of only polar protic solvents?
    A. water, DMF, DMSO
    B. acetic acid, methanol, water
    C. DMSO, ethanol, acetonitrile
    D. DMF, acetonitrile, DMSO
A

B. acetic acid, methanol, water

89
Q

56) Identify the alkyl halide that reacts the fastest in an SN1 reaction.

A) 2-chloro-2-methylpropane

B) 2-chlorobutane

C) 1-chlorobutane

D) chloromethane

A

A) 2-chloro-2-methylpropane

90
Q

57) Identify the alkyl halide that reacts the fastest in an SN1 reaction.

A) 2-chloropropane

B) 2-bromopropane

C) 2-fluoropropane

D) 2-iodopropane

A

D) 2-iodopropane

91
Q

58) Assuming no other changes, what is the effect of doubling only the concentration of the alkyl halide in the above SN1 reaction?

A) no change

B) doubles the rate

C) triples the rate

D) quadruples the rate

E) rate is halved

A

B) doubles the rate

92
Q

61) Which of the following alkyl halides gives the fastest SN1 reaction?

A

C

93
Q

62) Which of the following alkyl halides gives the fastest SN1 reaction?

A

C

94
Q

63) Which of the following factors has no effect on the rate of SN1 reactions?

A) the nature of the alkyl halide

B) the nature of the leaving group

C) the concentration of the alkyl halide

D) the concentration of the nucleophile

E) the value of the rate constant

A

D) the concentration of the nucleophile

95
Q

65) Which of the following is the rate law for SN1 mechanisms?

A) Rate = k[Alkyl Halide] [Nucleophile]

B) Rate = k[Nucleophile]

C) Rate = k[Alkyl Halide]

D) Rate = k[Alkyl Halide] [Nucleophile] + k2[Alkyl Halide]

E) Rate = k1[Alkyl Halide] + k2[Nucleophile]

A

C) Rate = k[Alkyl Halide]

96
Q

68) In the SN1 hydrolysis mechanism of (CH3)3CBr, there are ________ elementary steps, ________ distinct transition states, and ________ distinct intermediates.

A) 2, 2, 2

B) 2, 2, 3

C) 2, 3, 2

D) 3, 2, 3

E) 3, 3, 2

A

E) 3, 3, 2

97
Q

74) Which of the following iodides undergoes SN1 solvolysis in water the fastest?

A) 1-iodo-3-methylpentane

B) 2-iodopentane

C) 2-iodo-2-methylpentane

D) 3-iodopentane

E) 1-iodo-2,2-dimethylpentane

A

C) 2-iodo-2-methylpentane

98
Q

80) SN1 reactions usually proceed with ________.

A) equal amounts of inversion and retention at the center undergoing substitution

B) slightly more inversion than retention at the center undergoing substitution

C) slightly more retention than inversion at the center undergoing substitution

D) complete inversion at the center undergoing substitution

E) complete retention at the center undergoing substitution

A

B) slightly more inversion than retention at the center undergoing substitution

99
Q

82) When (S)-1-bromo-1 phenylethane undergoes an SN1 reaction with methanethiol (CH3SH), the product is the compound shown. What is/are the configuration(s) of the product obtained from this reaction?

A

D) a mixture of the enantiomers, with slightly more R than S

100
Q

86) Idenitfy the halide(s) that react in a SN1 reaction.

A) benzyl bromide

B) bromobenzene

C) 1-bromo-1-butene

D) 1-bromo-2-butene

E) 2-bromo-2-phenylpropane

A

A,D

101
Q

93) Which of the following solvents is aprotic?

A

C) CH3CH2OCH2CH3

102
Q

94) Which of the following solvents is protic?

A

D) CH3CH2OH

103
Q

95) Protic and aprotic solvents are very similar as solvents except for their ________.

A) polarity

B) dielectric constant

C) ability to stabilize anions by hydrogen bonding

D) ability to stabilize cations by hydrogen bonding

E) ability to stabilize cations with unshared pairs of electrons

A

C) ability to stabilize anions by hydrogen bonding

104
Q

96) Which of the following best explains why SN1 reactions involving a neutral reactant are faster in polar solvents?

A) The substrate is more soluble in polar solvents.

B) The substrate is less soluble in polar solvents.

C) The nucleophile is solvated by polar solvents.

D) Solvation by polar solvents stabilizes the carbocation.

E) Solvation by polar solvents stabilizes the transition state.

A

E) Solvation by polar solvents stabilizes the transition state.

105
Q

97) Which of the following statements is generally true for SN1 reactions?

A) Complete inversion of configuration occurs.

B) These reactions are favored by nonpolar solvents.

C) These reactions are favored by polar solvents.

D) Reaction rates depend only on the concentration of the nucleophile.

E) The mechanism is a one-step back attack.

A

C) These reactions are favored by polar solvents

106
Q

98) The hydrolysis of tert-butyl chloride proceeds more rapidly in a solvent mixture which is 70% water/30% acetone than in one which is 30% water/70% acetone. Why?

A) The transition state in the carbocation formation step is better stabilized in the more polar solvent mixture.

B) The reaction proceeds by an SN2 mechanism wherein the rate is increased by increasing the concentration of the nucleophile water.

C) The reaction proceeds by an SN1 mechanism wherein the rate is increased by increasing the concentration of the nucleophile water.

D) The solvent which contains a greater percentage of water is less polar, and this destabilizes the tert-butyl chloride.

E) none of the above

A

A) The transition state in the carbocation formation step is better stabilized in the more polar solvent mixture.

107
Q

105) What is the leaving group in the reaction shown below?

A

A

108
Q

106) Give the product(s) for the reaction of (R)-2-bromopentane with methanol.

A) (S)-2-methoxypentane

B) (R)-2-methoxypentane

C) (S)-2-ethoxypentane

D) (R)-2-ethoxypentane

E) (R)-2-pentanol

F) (S)-2-pentanol

A

A,B

109
Q

107) Give the SN2product(s) for the reaction of (R)-2-bromopentane with an excess of sodium methoxide.

A) (S)-2-methoxypentane

B) (R)-2-methoxypentane

C) (S)-2-ethoxypentane

D) (R)-2-ethoxypentane

E) (R)-2-pentanol

F) (S)-2-pentanol

A

A) (S)-2-methoxypentane

110
Q

108) Give the name(s) of the product(s) of the SN2 reaction of 3-bromo-2,2-dimethylbutane with hydroxide.

A) 2,2-dimethyl-1-butanol

B) 3,3-dimethyl-2-butanol

C) 3,3-dimethyl-1-butanol

D) 2,3-dimethyl-2-butanol

E) 2,3-dimethyl-1-butanol

A

B) 3,3-dimethyl-2-butanol

111
Q

109) Give the name(s) of the product(s) of the SN1 reaction of 3-bromo-2,2-dimethylbutane with water.

A) 2,2-dimethyl-1-butanol

B) 3,3-dimethyl-2-butanol

C) 3,3-dimethyl-1-butanol

D) 2,3-dimethyl-2-butanol

E) 2,3-dimethyl-1-butanol

A

D) 2,3-dimethyl-2-butanol

112
Q

110) Give the name(s) of the product(s) for the following SN2 reaction.

A

C) (S)-3-hexanol

113
Q

111) Give the name(s) of the product(s) for the following SN1 reactions.

A

C,D

114
Q

113) Which of the following alkyl bromides undergoes solvolysis in methanol without rearrangement?

A) (R)-2-bromo-3-ethylpentane

B) (S)-2-bromo-3-ethylpentane

C) (R)-3-bromo-2-methylpentane

D) (S)-3-bromo-2-methylpentane

E) 3-bromo-3-ethylpentane

A

E) 3-bromo-3-ethylpentane

115
Q

114) Which of the following alkyl bromides is likely to undergo rearrangement by a 1, 2-methyl shift?

A) benzyl bromide

B) 2-bromo-3-ethylpentane

C) 3-bromo-3-methylpentane

D) 2-bromo-3, 3-dimethylpentane

E) 3-bromo-2, 3-dimethylpentane

A

D) 2-bromo-3, 3-dimethylpentane

116
Q

115) A 1,2-methyl shift occurs when which of the following iodides is heated in ethanol?

A) C6H5CHICH(CH3)2

B) (CH3)2CHCHICH3

C) (CH3)3CCH2CH2I

D) (CH3)2C=CHI

E) (CH3)3CCHICH2CH3

A

E) (CH3)3CCHICH2CH3