1
Q
A
C. only 1 and 2
2
Q
- 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
3
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-
4
Q
- 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
5
Q
- What is the correct assignment of the names of the following heterocycles?
A. 1 = pyrrole; 2 = thiophene; 3 = pyridine
B. 1 = thiophene; 2 = furan; 3 = pyrrole
C. 1 = furan; 2 = pyrrole; 3 = thiophene
D. 1 = furan; 2 = thiophene; 3 = pyrrole
A
C. 1 = furan; 2 = pyrrole; 3 = thiophene
6
Q
- What is the index of hydrogen deficiency of a compound with a molecular formula of C6H8?
A. 0
B. 1
C. 2
D. 3
A
D. 3
7
Q
A
A. 3,4-dimethyl-1-hexen-5-yne
8
Q
A
C. 3
9
Q
11) Due to electron delocalization, one would predict that the carbon-oxygen bond in acetamide, CH3CONH2, ________.
A) is nonpolar
B) has more double bond character than the carbon-oxygen bond of acetone, (CH3)2CO
C) is longer than the carbon-oxygen bond of dimethyl ether, (CH3)2O
D) is longer than the carbon-oxygen bond of acetone, (CH3)2CO
E) is formed by overlapping sp3 orbitals
A
D) is longer than the carbon-oxygen bond of acetone, (CH3)2CO
10
Q
- 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
11
Q
A
C. ethynylcyclohexane
12
Q
A
C. 3
13
Q
- 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
14
Q
A
B. (S)-4-methyl-2-hexyne
15
Q
A
B. 2
16
Q
A
D. only 1 and 4
17
Q
A
A. (R)-3-methyl-1-penten-4-yne
18
Q
A
B. 2
19
Q
- 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
20
Q
A
B. only 1 and 2
21
Q
A
C. 3
22
Q
- 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
23
Q
Which of the following is the strongest acid?
A. propane
B. cyclopropane
C. propene
D. propyne
A
D. propyne
24
Q
A
C. 3
25
15. 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. methyl iodide
26
15. Which of the following has the lowest pKa?
A. butane
B. 1-butene
C. 1-butyne
D. 2-butyne
C. 1-butyne
27
C. only 2 and 4
28
15. Which of the following molecular formulae corresponds to a compound with a hydrogen deficiency of 2?
A. C5H8O2
B. C5H10O
C. C6H15N
D. C5H10Br2
A. C5H8O2
29
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
E) (CH3)2CHCH2CH2CH2I
30
B. 1 = acid; 2 = base; 3 = conjugate base; 4 = conjugate acid
31
B. 2
32
16. 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
D. tert-butyl iodide
33
16. Which of the following molecular formulae corresponds to a compound with a hydrogen deficiency of 1?
A. C5H8N2
B. C5H11N
C. C6H11N
D. C5H13NO2
B. C5H11N
34
17) Which of the following is a secondary alkyl halide?
A) CH3Br
B) (CH3)3CBr
C) (CH3)2CHBr
D) (CH3)2CHCH2Br
C) (CH3)2CHBr
35
B. 2
36
17. 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
D. tert-butyl chloride
37
D. only 1,3 and 4
38
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) CH3CH2CH2CH2Br + OH- → CH3CH2CH2CH2OH + Br-
39
B. 2
40
18. 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
D. tert-butyl bromide
41
D. 4
42
D. i = p;; ii = sp2
43
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
B) CH3CH2CHBrCH3 + H2O → CH3CH2CHOHCH3 + HBr
44
B. only 2
45
C. 3
46
19. Which of the following does not correspond to a molecular formula of a neutral compound?
A. C5H5Br
B. C5H7Cl2
C. C5H5Br3
D. C5H8Cl4
B. C5H7Cl2
47
19. 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
B. tert-butyl bromide in water
48
2. What is the approximate value of the H-C-H bonds angle in ethene?
A. 90
B. 109
C. 120
D. 180
C. 120
49
B. only 2
50
2. 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. tert-butanol ® tert-butyl chloride
51
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) reaction products when CH3I is used as the substrate
52
B. only 3
53
B. 2
54
20. Which of the following does not correspond to a molecular formula of a neutral compound?
A. C6H9NO2
B. C5H7N2O2
C. C8H12O3
D. C7H7N
B. C5H7N2O2
55
20. 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
D. tert-butyl bromide and CH3OH
56
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
B) (S)-2-pentanol
57
C. only 3
58
B. 2-methyl-3-heptyne
59
B. 2
60
21. 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. (R) 1-cyano-4-methylhexane
61
21. Which of the following does not correspond to a molecular formula of a neutral compound?
A. C4H8BrNO
B. C5H9ClN2O
C. C7H14BrO3
D. C8H14ClN
C. C7H14BrO3
62
C. 3
63
D. 3-methyl-4-nonyne
64
C. 3
65
22. 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
B. (S) 2-cyanohexane
66
B. 2
67
22. Which of the following reaction coordinate diagrams explains the formation of different thermodynamic (T) and kinetic products from the same reactants (R)?
C. 3
68
C. (E) 2,3-dibromobutene
69
B. 2
70
A. (E) 3,4-dibromohexene
71
C. 3
72
B. 2
73
24. Which of the following substituents has the highest priority according to the Cahn-Ingold-Prelog system used in assigning E and Z configurations of carbon-carbon double bonds?
A. -CH(CH3)2
B. -CH2OCH3
C. -CH2CH3
D. -CH2Br
D. -CH2Br
74
B. 2,2,3,3-tetrabromobutane
75
D. 4
76
25. Which of the following substituents has the highest priority according to the Cahn-Ingold-Prelog system used in assigning E and Z configurations of carbon-carbon double bonds?
A. -COOH
B. -Cl
C. -CH2OH
D. -CH3
B. -Cl
77
D. 3,3,4,4-tetrabromohexane
78
A. 1 \> 2 \> 3
79
C. only 3
80
D. 2,2-dibromobutane
81
A. 1 \> 2 \> 3
82
B. 3,5-dimethyl-1,4-hexadiene
83
D. only 1 and 2
84
B. 3,3-dibromohexane
85
A. 1 \> 2 \> 3
86
A. butanal
87
B. 2
88
B. 2 \> 3 \> 1
89
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
B) polar; δ+ at carbon and δ- at chlorine
90
How many alkynes are there with the molecular formula C6H10?
A. 4
B. 5
C. 6
D. 7
D. 7
91
C. 3,4-dimethyl-1,3-pentadiene
92
C. 3,4-dimethyl-1,3-pentadiene
93
C. 3,4-dimethyl-1,3-pentadiene
94
3. 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
B. The charged carbon atom of a carbocation has a complete octet of valence shell electrons
95
D. 1,6-dimethylcyclohexene
96
B. hexanal
97
A. 1
98
D. 2 \> 1 \> 3
99
A. 1
100
A. butanal
101
D. 4
102
D. only 1 and 2
103
D. cis-4-methyl-1-vinylcyclohexane
104
B. hexanal
105
33) Identify the most stable structure(s).
Answer: A
106
B. allylcyclohexane
107
C. only 3
108
A. 1
109
34. 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
D. acetonitrile
110
A. only 1
111
D. 4
112
35) Which of the following is the strongest nucleophile in an aqueous solution?
A) HO-
B) F-
C) Cl-
D) Br-
E) I-
E) I-
113
D. OsO4; followed by NaHSO3
114
D. 4
115
35. 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. dimethylsulfoxide
116
36) Which of the following is the best leaving group?
A) HO-
B) F-
C) Cl-
D) Br-
E) I-
E) I-
117
36) Which of the following statements concerning resonance contributors and resonance hybrids is not correct?
A) The fewer nearly equivalent resonance contributors are in the structure, the greater the resonance energy.
B) A resonance hybrid is more stable than the predicted stability of any of its resonance contributors.
C) The greater the number of relatively stable resonance contributors, the greater the resonance energy.
D) The greater the predicted stability of a resonance contributor, the more it contributes to the resonance hybrid.
E) none of the above
A) The fewer nearly equivalent resonance contributors are in the structure, the greater the resonance energy.
118
C. Br2, H2O
119
D. 4
120
36. 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
B. N,N-dimethylformamide
121
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
C) CH3CH2—I
122
C. B2H6; followed by H2O2, NaOH
123
B. 2
124
37. Which of the following anions is the most nucleophilic in polar protic solvents?
A. F-
B. Cl-
C. Br-
D. I-
D. I-
125
38) Aromatic molecules contain ________ π electrons.
A) no
B) 4n + 2 (with n an integer)
C) 4n + 2 (where n = 0.5)
D) 4n (with n an integer)
E) unpaired
B) 4n + 2 (with n an integer)
126
38) Which of the following species is the least nucleophilic?
A) (CH3)3CO-
B) H2O
C) (CH3)3N
D) BF3
E) CN-
D) BF3
127
A. O3; followed by (CH3)2S
128
38. Which of the following anions is the most nucleophilic in polar aprotic solvents?
A. F-
B. Cl-
C. Br-
D. I-
A. F-
129
39) Which of the following is the best nucleophile in water?
A) I-
B) CH3SCH3
C) CH3OCH3
D) Cl-
A) I-
130
39. How many alkenes have the formula C5H10?
A. 4
B. 5
C. 6
D. 7
C. 6
131
B. Hg(OAc)2 and H2O; followed by NaBH4
132
C. 3
133
39. Which of the following compounds is the most nucleophilic in polar protic solvents?
A. H2O
B. NH3
C. H2S
D. PH3
D. PH3
134
How many terminal alkynes are there with the molecular formula C7H12?
A. 5
B. 7
C. 8
D. 9
C. 8
135
C. 3-methyl-1,4-pentadiene
136
4. What type of orbitals overlap to provide stability to the tert-butyl carbocation by hyperconjugation?
A. 3 C 2p atomic orbital + 3 C sp2 atomic orbital
B. 3 C 2p atomic orbital + methyl C-H s molecular orbital
C. 3 C sp2 atomic orbital + methyl C-H s molecular orbital
D. 3 C 2p atomic orbital + methyl C 2s atomic orbital
B. 3 C 2p atomic orbital + methyl C-H s molecular orbital
137
4. 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
D. Nucleophiles are Lewis acids
138
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.
D) All alkyl iodides react more rapidly than all alkyl chlorides.
139
40. How many constitutional isomeric alkenes are there with the formula C6H12?
A. 9
B. 11
C. 12
D. 13
C. 12
140
D. 4
141
40. Which of the following is the most nucleophilic?
A. sodium ethoxide
B. acetic acid
C. methanol
D. water
A. sodium ethoxide
142
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
B) Methoxide is more nucleophilic because the nucleophilicity of tert-butoxide is diminished by steric effects.
143
41. How many isomers of 1,6-heptadiene exist?
A. 1
B. 2
C. 3
D. 4
A. 1
144
D. trans-2-butene
145
41. Which of the following anions is the best leaving group in an SN1 reaction?
A. F-
B. HO-
C. NH2-
D. Cl-
D. Cl-
146
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
D) (CH3)3CCH2CH2CH2Br
147
42. How many isomers of 1,3-heptadiene exist?
A. 1
B. 2
C. 3
D. 4
B. 2
148
B. 2
149
42. Which of the following is the best leaving group in an SN2 reaction?
A. F-
B. H3C-
C. CH3O2SO-
D. HO-
C. CH3O2SO-
150
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.
D) (CH3)CCH2CH2I
151
43) Which of the following is an aromatic hydrocarbon?
C) III
152
43. How many isomers of 2,4-heptadiene exist?
A. 1
B. 2
C. 3
D. 4
D. 4
153
C. cis-2-butene
154
44) Which of the following is aromatic?
C) III
155
44. How many isomers of 1,3,5-heptatriene exist?
A. 1
B. 2
C. 4
D. 8
C. 4
156
A. 1
157
45) Which of the structures below would be aromatic?
C) III and IV
158
C. cis-2-butene
159
D. 4
160
46) Which of the following is aromatic?
B) II
161
A. 1
162
C. 3
163
47) Which of the following is aromatic?
A) cyclopentadienyl cation
B) 1,3-cyclohexadiene
C) cyclobutenyl anion
D) 1,3,5-hexatriene
E) cycloheptatrienyl cation
E) cycloheptatrienyl cation
164
D. 2 moles of HBr
165
A. 1 \> 2 \> 3
166
C. only 3
167
A. 1 mole of Br2
168
49) Which of the following compounds is aromatic?
D) IV
169
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) 1-iodo-3-methylpentane
170
D. only 1 and 2
171
B. 1. 3 moles of NaNH2; 2. H3O+
172
49. Which of the following is not true regarding alkenes?
A. alkenes are non polar
B. alkenes burn in air to give H2O and CO2
C. alkenes are highly miscible with water
D. the strongest intermolecular force between alkene molecules is the van der Waals interaction
C. alkenes are highly miscible with water
173
49. 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
D. the rate of the reaction is independent of the identity of the solvent
174
5. 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. Rate = k [t-BuBr]
175
A. (3S,4E)-3-ethyl-3,4-dimethyl-1,4-hexadiene
176
A. (3S,4E)-3-ethyl-3,4-dimethyl-1,4-hexadiene
177
5. Which of the following concepts explains Markovnikov's rule as applied to the addition of HBr to propene?
A. the relative stability of carbocations
B. the nucleophilicity of bromide anion
C. the acidity of HBr
D. the Aufbau principle
A. the relative stability of carbocations
178
50) Which of the following is aromatic?
A) I
179
C. Na/NH3
180
50. Which of the following compounds is most reactive (least stable)?
A. (Z)-cycloheptene
B. (E)-cycloheptene
C. (Z)-cyclooctene
D. (E)-cyclooctene
B. (E)-cycloheptene
181
50. 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. the rate is proportional to the concentration of tert-butyl bromide
182
B. H2/Lindlar catalyst
183
51. 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
D. the rate is independent of the solvent
184
C. (sia)2BH; followed by H2O2, NaOH
185
52. 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. the electrophilic carbon undergoes inversion of stereochemistry
186
D. BH3; followed by H2O2, NaOH
187
A. 1
188
54. 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 carbocation intermediate is formed.
189
55) Which of the following is antiaromatic?
D) IV
190
D. butanone, CH3COCH2CH3
191
55. 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.
B. The mechanism has only one step.
192
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) 2-chloro-2-methylpropane
193
C. (Z)-6-phenyl-2-hexene
194
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
D) 2-iodopropane
195
D. heptane
196
B. (E)-2-heptene
197
D. only 1 and 2
198
6) Which of the following pairs are resonance structures?
C) III
199
6) Which of the following pairs are resonance structures?
C) III
200
6) Which of the following pairs are resonance structures?
C) III
201
6. 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
B. Rate = k [BuCl][NaI]
202
C. 3
203
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
D) the concentration of the nucleophile
204
64) Which of the following statements about the π molecular orbital description of cyclobutadiene is not correct?
A) Cyclobutadiene has two degenerate nonbonding π molecular orbitals.
B) Cyclobutadiene has a single bonding π molecular orbital.
C) Cyclobutadiene has two electrons in nonbonding π molecular orbitals.
D) Cyclobutadiene has one electron in an antibonding π molecular orbital which makes it antiaromatic.
E) none of the above
D) Cyclobutadiene has one electron in an antibonding π molecular orbital which makes it antiaromatic.
205
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]
C) Rate = k[Alkyl Halide]
206
66) Which of the following is an allylic cation?
B) II
207
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
E) 3-iodo-3-methylpentane
208
67) Which of the following is a benzylic cation?
D) IV
209
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
E) 3, 3, 2
210
68) Which of the following is the most stable cation?
C) III
211
68. 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
D. DMF, acetonitrile, DMSO
212
69) How many allylic hydrogen atoms are present in the following molecule?
E) zero
213
69. 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
B. acetic acid, methanol, water
214
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
D) chloromethane
215
7) Which of the following pairs are resonance structures?
C) III
216
B. 3 \> 1 \> 2
217
7. 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]
D. Rate = k [i-PrBr][NaOCH3]
218
70) How many benzylic hydrogens are present in the following molecule?
E) zero
219
71) Which of the following is the most stable diene?
C) III
220
74) What descriptive term is applied to the type of diene represented by 2,4-hexadiene?
A) conjugated diene
B) cumulated diene
C) isolated diene
D) alkynyl diene
E) none of the above
A) conjugated diene
221
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
C) 2-iodo-2-methylpentane
222
75) What descriptive term is applied to the type of diene represented by 1, 5-octadiene?
A) conjugated diene
B) cumulated diene
C) isolated diene
D) alkynyl diene
E) none of the above
C) isolated diene
223
76) Which of the following is a cumulated diene?
C) III
224
77) Which of the following is a conjugated diene?
A) I
225
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
D) 1-iodopropane
226
8) Which of the following is not a resonance structure of the species shown?
D) IV
227
8) Which of the following is not a resonance structure of the species shown?
D) IV
228
D. i = sp2; ii = sp2; iii = sp3
229
8. 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. Rate = k [i-PrBr]
230
B. 2
231
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
B) slightly more inversion than retention at the center undergoing substitution
232
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 and D
233
86) Identify the most stable carbocation.
234
87) Identify the most stable carbocation.
235
88) Which of the following is classified as a vinyl halide?
A) CH3CHCHOH
B) CH3CHCHCl
C) CH3CHCHCH2Cl
D) CH3CH2CH2CH2Br
E) BrCH2CHCH2
B) CH3CHCHCl
236
9) Identify the strongest nucleophile in an SN2 reaction.
A) isopropoxide ion
B) tert-butoxide ion
C) ethoxide ion
D) tert-pentoxide ion
C) ethoxide ion
237
9) In which of the following does resonance delocalization of electron density not play a role?
A) allyl cation
B) benzyl anion
C) CO32-
D) O3
E) cyclohexyl radical
E) cyclohexyl radical
238
9. 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
C. the rate increases by a factor of 2
239
C. 1 = pyridine; 2 = thiophene; 3 = furan
240
9. What is the index of hydrogen deficiency of a compound with a molecular formula of C5H10?
A. 0
B. 1
C. 2
D. 3
B. 1
241
B. 2
242
96) Which of the following is/are the major product(s) of the following reaction?
A) I
243
97) Which of the following is the strongest acid?
244
98) Which of the following is the strongest acid?
D) IV
245
Aromatic, not aromatic, or antiaromatic?
not aromatic
246
Aromatic, not aromatic, or antiaromatic?
Not aromatic
247
Aromatic, not aromatic, or antiaromatic?
Aromatic
248
Aromatic, not aromatic, or antiaromatic?
not aromatic
249
Aromatic, not aromatic, or antiaromatic?
antiaromatic
250
C. only 1 and 2
251
8. Which of the following is not one of Hückel's criteria for aromaticity?
A. The compound must be cyclic
B. The compound must have one p-orbital on each atom of a ring
C. The compound must be planar or nearly planar so that there is a continuous overlap of p orbitals
D. The compound must have a closed loop of six pi electrons
D. The compound must have a closed loop of six pi electrons
252
1. What is the approximate value of the C-C-C bond angle in propene?
A. 90
B. 109
C. 120
D. 180
C. 120
253
3. Which of the following concepts explains why tertiary carbocations are more stable than primary and secondary carbocations?
A. electronegativity
B. resonance
C. hyperconjugation
D. the octet rule
C. hyperconjugation
254
What is the approximate C-C-C bond angle in propyne?
A. 90
B. 109
C. 120
D. 180
D. 180
255
Heterocyclic compound
Has a ring of atoms other than carbon
256
If the conjugated diene is not symmetrical, what do you do?
Protonate to form the more stable carbocation
257
monocyclic hydrocarbons with alternating single and double bonds
annulenes
258
most of the time, the 1,2 addition product is the ...
kinetic product
259
most of the time, the 1,4-addition product is the
thermodynamic product
260
The kinetic product predominates when the reaction is....
irreversible
1,2-addition
261
The thermodynamic product predominates when the reaction is...
reversible
262
What is the hybridization of the nitrogen atom of pyridine?
A. s
B. sp
C. sp2
D. sp3
C. sp2
263
What is the hybridization of the oxygen atom of furan?
A. s
B. sp
C. sp2
D. sp3
C. sp2
264
What is the IUPAC name of the following compound?
(CH3)2CHCH2-CºC-CH(CH3)2
A. 2,6-dimethyl-3-heptyne
B. 2,6-dimethyl-4-heptyne
C. 1,1,5,5-tetramethyl-2-pentyne
D. 4-nonyne
A. 2,6-dimethyl-3-heptyne
265
What is the IUPAC name of the following compound?
CH3CH2CH2-CºC-CH(CH3)2
A. 1-isopropyl-1-pentyne
B. 2-methyl-3-heptyne
C. 6-methyl-4-heptyne
D. isopropyl propyl ethyne
B. 2-methyl-3-heptyne
266
What is the kinetic product obtained from the addition of 1 mole of bromine to 1,3-butadiene?
A. 3,4-dibromo-1-butene
B. (E)-1,4-dibromo-2-butene
C. (Z)-1,4-dibromo-2-butene
D. (Z)-2,3-dibromo-2-butene
A. 3,4-dibromo-1-butene
267
What is the reactive intermediate in the reaction of 1,3-butadiene with HBr resulting in 1,2-addition?
A. cyclic bromonium cation
B. allylic cation
C. allylic radical
D. dienophile
B. allylic cation
268
What is the relative stability of carbocations?
benzyl cation ~ allyl cation ~ tertiary carbocation \> secondary carbocation \> primary carbocation \> methyl cation \> vinyl cation
269
What is the smallest cycloalkyne that is stable at room temperature?
A. cyclohexyne
B. cyclononyne
C. cyclododecyne
D. cycloeicosyne
B. cyclononyne
270
What is the thermodynamic product obtained from the addition of 1 mole of bromine to 1,3-butadiene?
A. 3,4-dibromo-1-butene
B. (E)-1,4-dibromo-2-butene
C. (Z)-1,4-dibromo-2-butene
D. (Z)-2,3-dibromo-2-butene
B. (E)-1,4-dibromo-2-butene
271
What is this?
Tertiary benzylic cation
272
purine
273
pyrimidine
274
What is this?
secondary allylic cation
275
What is this?
Secondary benzylic cation
276
What is this?
Benzyl cation
277
What is this?
Tertiary allylic cation
278
What is this?
vinyl cation
279
pyrrole
280
Furan
281
What is this?
secondary alkyl carbocation
282
What is this?
Allyl cation
283
thiophene
284
quinoline
285
indole
286
pyridine
287
imidazole
288
What type of intermediate s formed in the Hg2- catalyzed hydration of an alkyne??
A. an alcohol
B. an enol
C. a 1,2-diene
D. an epoxide
B. an enol
289
What type of reaction mechanism accounts for the reaction of an alkene with aqueous acid to give an alcohol?
A. nucleophilic addition
B. electrophilic addition
C. radical addition
D. elimination
B. electrophilic addition
290
What type of reaction mechanism accounts for the reaction of an alkene with HBr to give an alkyl bromide?
A. nucleophilic addition
B. electrophilic addition
C. radical addition
D. elimination
B. electrophilic addition
291
What type of reactive intermediate is formed in the reaction of an alkene with HBr to give a bromoalkane?
A. carbocation
B. carbanion
C. radical
D. cyclic bromonium ion
A. carbocation
292
What type of reactive intermediate is formed in the reaction of an alkene with Br2 and water to give a bromohydrin?
A. carbocation
B. carbanion
C. radical
D. cyclic bromonium ion
D. cyclic bromonium ion
293
What type of reactive intermediate is formed in the reaction of an alkene with aqueous acid to give an alcohol?
A. carbocation
B. carbanion
C. radical
D. carbene
A. carbocation
294
Which atomic orbitals overlap to form the carbon-carbon single bond of 1-propyne?
A. 2s + sp
B. sp + sp2
C. sp + sp3
D. sp2 + sp3
C. sp + sp3
295
Which atomic orbitals overlap to form the carbon-carbon triple bond of an alkyne?
A. 2s + 2s; sp + sp; 2p + 2p
B. sp + sp; sp + sp; 2p + 2p
C. sp + sp; 2p + 2p; 2p + 2p
D. sp2 + sp2; sp + sp; 2p + 2p
C. sp + sp; 2p + 2p; 2p + 2p
296
Which of the following compounds is antiaromatic?
A. ethane
B. cyclobutadiene
C. benzene
D. cyclooctatetraene
B. cyclobutadiene
297
Which of the following compounds is aromatic?
A. ethane
B. cyclobutadiene
C. benzene
D. cyclooctatetraene
C. benzene
298
Which of the following is not a major organic product obtained from the addition of 1 mole of bromine to (E)-1,3-pentadiene?
A. (E)-4,5-dibromo-2-pentene
B. 3,4-dibromo-1-pentene
C. (E)-1,4-dibromo-2-pentene
D. (E)-1,2-dibromo-2-pentene
D. (E)-1,2-dibromo-2-pentene
299
Which of the following is not true about cyclooctatetraene?
A. The planar conformation is antiaromatic
B. In the planar conformation there are two electrons in degenerate nonbonding pi orbitals.
C. In the tub conformation the pi system is not conjugated
D. The tub conformation is aromatic
D. The tub conformation is aromatic
300
Which of the following reactions of alkenes is not stereospecific?
A. bromination (treatment with Br2 in CHCl3)
B. hydrogenation (treatment with H2/Pt)
C. acid-catalyzed hydration (treatment with aqueous H2SO4)
D. bromohydrin formation (treatment with Br2/H2O)
C. acid-catalyzed hydration (treatment with aqueous H2SO4)
301
Which of the following reactions of alkenes is stereospecific?
A. addition of HCl (treatment with HCl)
B. hydrogenation (treatment with H2/Pt)
C. addition of HBr (treatment with HBr)
D. acid-catalyzed hydration (treatment with aqueous H2SO4)
B. hydrogenation (treatment with H2/Pt)
302
Which of the following reactions of alkenes takes place with anti stereospecificity?
A. bishydroxylation (treatment with OsO4 followed by NaHSO3)
B. hydrogenation (treatment with H2/Pt)
C. addition of HBr (treatment with HBr)
D. bromohydrin formation (treatment with Br2, H2O)
D. bromohydrin formation (treatment with Br2, H2O)
303
Which of the following reactions of alkenes takes place with syn stereospecificity?
A. addition of bromine (treatment with Br2)
B. hydrogenation (treatment with H2/Pt)
C. addition of HBr (treatment with HBr)
D. acid-catalyzed hydration (treatment with aqueous H2SO4)
B. hydrogenation (treatment with H2/Pt)
304
Which of the following statements is not true about the structure of benzene?
A. six atomic 2p-orbitals overlap to form six p-molecular orbitals
B. there are three bonding p-molecular orbitals and three p-antibonding molecular orbitals
C. the ground state electronic configuration of benzene has six electrons in three p-bonding molecular orbitals
D. the bonds alternate in length around the ring
D. the bonds alternate in length around the ring
305
Which of the following statements is not true about the structure of benzene?
A. the carbon-carbon bonds are all the same length
B. the structure rapidly transforms between two resonance contributors
C. the structure is an average of two resonance contributors
D. the ring of six carbon atoms is planar
B. the structure rapidly transforms between two resonance contributors
306
Which of the following terms describes the mechanism for the addition of Br2 to butadiene?
A. electrophilic addition
B. nucleophilic addition
C. pericyclic addition
D. conjugate addition
A. electrophilic addition
307
Which orbital contains the lone pair on the nitrogen atom of pyrrole?
A. s
B. p
C. sp
D. sp2
B. p
308
Which orbital contains the lone pair on the nitrogen atom of pyridine?
A. s
B. p
C. sp
D. sp2
D. sp2
309
Which sequence of reactions can be used to convert (Z) 2-pentene to 2-pentyne
A. Treatment with Br2; followed by treatment with NaNH2
B. Treatment with Br2, H2O; followed by treatment with NaOH
C. Treatment with Br2; followed by treatment with H2SO4
D. Treatment with HBr; followed by treatment with NaOH
A. Treatment with Br2; followed by treatment with NaNH2
310
Which sequence of reactions can be used to convert 1-pentene to 1-pentyne
A. Treatment with HBr; followed by treatment with NaOH
B. Treatment with Br2; followed by treatment with NaNH2
C. Treatment with Br2; followed by treatment with H2SO4
D. Treatment with Br2, H2O; followed by treatment with NaOH
B. Treatment with Br2; followed by treatment with NaNH2
311
Which of the following reagents react with 2-butyne to form butane
A. H2/Lindlar catalyst
B. H2/Pd
C. (sia)2BH followed by CH3COOH
D. Na/NH3
B. H2/Pd
312
32. What is(are) the major organic product(s) obtained from the following substitution reaction?
D. 1, 2 and 3
313
33. What is(are) the major organic product(s) obtained from the following substitution reaction?
D. 1, 2 and 3
314
56. Which of the following energy diagrams represents the course of an exothermic SN1 reaction?
A. 1
315
57. Which of the following energy diagrams represents the course of an exothermic SN2 reaction?
C. 3
316
1) What is the nucleophile in the reaction shown below?
B) II
317
2) Which of the following is not a nucleophile?
C) +CH3
318
4) Which of the following is not normally considered to be a nucleophile?
D) CH3CH2+
319
11) Which of the following alkyl halides gives the slowest SN2 reaction?
320
12) Assuming no other changes, what is the effect of doubling only the concentration of the alkyl halide in the above SN2 reaction?
B) doubles the rate
321
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
D) quadruples the rate
322
14) Which of the following SN2 reactions is the fastest?
B) CH3CH2CH2I + HO- → CH3CH2CH2OH + I-
323
15) Which of the following SN2 reactions is the slowest?
324
44) Which halide reacts most rapidly via an SN2 mechanism?
E
325
45) Which halide reacts most rapidly via an SN2 mechanism?
Answer: E
326
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) no change
327
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
B) doubles the rate
328
64) Which of the following carbocations is the most stable?
C
329
66) Which of the following carbocations is the least stable?
A) I
330
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?
B) R only
331
87) Which of the following can't undergo nucleophilic substitution reactions?
B) II
332
46. Which of the following alkyl bromides reacts the slowest with NaSCH3 in DMF?
A. 1
333
60. Which of the following represents the transition state of the rate-determining step in the SN1 reaction between tert-butyl chloride and water?
B. 2
334
61. Which of the following represents the transition state of the rate-determining step in the reaction between tert-butyl bromide and methanol?
A. 1
335
62. Which of the following represents the transition state of the reaction between methyl iodide and ammonia?
C. 3
336
63. Which of the following represents the transition state of the reaction between methyl bromide and sodium methylthiolate, NaSCH3
D. 4
337
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
B) doubles the rate
338
61) Which of the following alkyl halides gives the fastest SN1 reaction?
C
339
62) Which of the following alkyl halides gives the fastest SN1 reaction?
C
340
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?
D) a mixture of the enantiomers, with slightly more R than S
341
93) Which of the following solvents is aprotic?
C) CH3CH2OCH2CH3
342
94) Which of the following solvents is protic?
D) CH3CH2OH
343
105) What is the leaving group in the reaction shown below?
A
344
110) Give the name(s) of the product(s) for the following SN2 reaction.
C) (S)-3-hexanol
345
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
C) ability to stabilize anions by hydrogen bonding
346
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.
E) Solvation by polar solvents stabilizes the transition state.
347
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.
C) These reactions are favored by polar solvents
348
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) The transition state in the carbocation formation step is better stabilized in the more polar solvent mixture.
349
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) (S)-2-methoxypentane
350
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
B) 3,3-dimethyl-2-butanol
351
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
D) 2,3-dimethyl-2-butanol
352
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
E) 3-bromo-3-ethylpentane
353
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
D) 2-bromo-3, 3-dimethylpentane
354
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
E) (CH3)3CCHICH2CH3
355
106) What compound results from the 1, 4-addition of one equivalent of HBr to 1, 3-butadiene?
A) 1-bromo-1-butene
B) 2-bromo-2-butene
C) 4-bromo-1-butene
D) 3-bromo-1-butene
E) 1-bromo-2-butene
E) 1-bromo-2-butene
356
103) Which of the following is/are the main product(s) of the following reaction?
E) A and C
357
104) What is/are the product(s) from the following reaction?
D) I is major, II is minor
358
105) What is/are the product(s) of the following reaction?
E) I and III
359
107) Which of the following is/are the major product(s) of the following reaction?
C) II
360
108) What is/are the product(s) from the following reaction?
A) I and II
361
119) Which of the following is a correct statement considering thermodynamic versus kinetic control of organic reactions?
A) When a reaction is under thermodynamic control, the relative amounts of products depend on the activation energies of the steps leading to their formation.
B) The kinetic product always predominates when the reaction is reversible.
C) Higher temperatures and longer reaction times typically favor the kinetic product over the thermodynamic product.
D) When the products are in equilibrium under the reaction conditions, the relative amounts of products depend on their stabilities and the reaction is under thermodynamic control.
E) none of the above
D) When the products are in equilibrium under the reaction conditions, the relative amounts of products depend on their stabilities and the reaction is under thermodynamic control.
362
133) Which of the following terms best describes a Diels-Alder reaction?
A) a [4+2] cycloaddition
B) a [2+2] cycloaddition
C) a sigmatropic rearrangement
D) a 1, 3-dipolar cycloaddition
E) a substitution reaction
A) a [4+2] cycloaddition
363
134) When 1, 3-butadiene reacts with CH2CHCN, which of the terms below best describes the product mixture?
A) a mixture of two diastereomers
B) a single compound
C) a racemic mixture
D) optically active
E) a mixture of bicyclic compounds
C) a racemic mixture
364
135) The Diels-Alder reaction is a concerted reaction; this means that \_\_\_\_\_\_\_\_.
A) a mixture of endo and exo products is formed
B) all bond making and bond breaking occurs simultaneously
C) the products contain rings
D) the reaction follows Markovnikov's rule
E) the reaction is highly endothermic
B) all bond making and bond breaking occurs simultaneously
365
136) Which of the following statements is (are) true of the Diels-Alder reaction?
A) When the diene is electron-rich, the reaction works best when the dienophile contains one or more electron-withdrawing groups conjugated to its CC.
B) Substituents which are cis in the dienophile remain cis in the product.
C) Dienes which cannot achieve an s-cis conformation do not react in Diels-Alder reactions.
D) Secondary orbital interactions typically cause the endo product to be favored kinetically over the exo.
E) all of the above
E) all of the above
366
137) When 1, 3-cyclopentadiene reacts with the cis-isomer of NCCH=CHCN, the major product is \_\_\_\_\_\_\_\_.
A) optically active
B) a meso compound
C) a racemic mixture
D) a spirocyclic compound
E) a fused bicyclic compound
D) a spirocyclic compound
367
111) Give the major organic product for the reaction.
368
112) Give the major organic product for the reaction.
369
113) Give the major organic product(s) for the reaction.
Answer: A, B
370
115) Give the major organic product(s) for the reaction.
Answer: D, E
371
117) What is the thermodynamic product for the following reaction?
D) IV
372
118) What is the kinetic product for the following reaction?
E) V
373
120) What is/are the product(s) from the following reaction?
B) II Major, III Minor
374
121) What is/are the product(s) from the following reaction?
C) III only
375
128) What is the product of the following reaction?
E) V
376
129) What is the product from the following reaction?
B) II
377
130) Which of the following conjugated dienes would not react with a dieneophile in a Diels-Alder reaction?
E) I and III
378
131) Which of the following dienes is the most reactive in a Diels-Alder reaction?
C) III
379
132) What diene and what dieneophile would be used to synthesize the following compound?
B) II
380
158) Give the major organic product for the reaction.
381
159) Give the major organic product for the reaction.
382
160) Give the major organic product for the reaction.
E) No reaction
383
164) Which of the following is an isolated diene?
D) IV
384
166) Give the major organic product for the reaction.
385
20. Which of the following is trigonal planar?
A. boron trifluoride, BF3
B. methyl anion, CH3-
C. methane, CH4
D. ammonia, NH3
A. boron trifluoride, BF3
386
21. Which of the following molecules is not linear?
A. H2O
B. CO2
C. HCºCH
D. Cl2
A. H2O
387
22. What is the approximate value of the H-C-H bond angles in methane, CH4?
A. 90
B. 109
C. 120
D. 180
B. 109
388
23. What is the approximate C-C-C bond angle in propene, CH3CH=CH2?
A. 90
B. 109
C. 120
D. 180
C. 120
389
24. What is the approximate C-C-C bond angle in propyne, HCºCCH3?
A. 90
B. 109
C. 120
D. 180
D. 180
390
25. What is the approximate H-C-O bond angle in formaldehyde, H2C=O?
A. 90
B. 109
C. 120
D. 180
C. 120
391
26. Which of the following elements has the highest electronegativity?
A. N
B. C
C. O
D. S
C. O
392
27. Which of the following elements has the highest electronegativity?
A. C
B. P
C. Si
D. Cl
D. Cl
393
28. Which of the following bonds is the most polar?
A. F-F
B. H-F
C. C-H
D. C-Si
B. H-F
394
29. Which of the following bonds is the most polar?
A. O-H
B. C-H
C. C-C
D. H-H
A. O-H
395
30. Which of the following is a polar covalent bond?
A. Na-F
B. C-H
C. C-O
D. Cl-Cl
C. C-O
396
31. Which of the following is a polar covalent bond?
A. Na-Cl
B. C-Cl
C. C-H
D. Cl-Cl
B. C-Cl
397
32. Which of the following is an ionic bond?
A. Br-Br
B. C-Cl
C. C-S
D. Na-O
D. Na-O
398
33. Which of the following is an ionic bond?
A. F-F
B. C-H
C. Li-O
D. C-N
C. Li-O
399
40. Which of the following best represents the shape of the 2s atomic orbital of carbon?
A. 1
400
41. Which of the following best represents the shape of a 2p atomic orbital of carbon?
B. 2
401
42. Which of the following best represents an sp2 hybridized atomic orbital of carbon which overlaps with the 1s atomic orbital of hydrogen to form a C-H s bonding molecular orbital in ethene, H2C=CH2
C. 3
402
43. Which of the following best represents an sp3 hybridized atomic orbital containing the lone pair of electrons of ammonia, NH3?
C. 3
407
44. Which atomic orbitals overlap to form the C=O bond of acetone, (CH3)2C=O?
A. C 2sp3 + O 2sp2
B. C 2sp2 + O 2p
C. C 2sp2 + O 2sp2
D. C 2sp3 + O 2sp
C. C 2sp2 + O 2sp2
408
45. Which atomic orbitals overlap to form the C-O bond of dimethyl ether, (CH3)2O?
A. C 2sp3 + O 2sp2
B. C 2sp2 + O 2p
C. C 2sp2 + O 2sp2
D. C 2sp3 + O 2sp3
D. C 2sp3 + O 2sp3
409
48. Which of the following statements is not true regarding resonance structures?
A. All resonance structures must have the same number of electrons
B. Each atom in all of the resonance structures must have a complete shell of valence electrons
C. All resonance structures must have the same arrangement of atoms
D. All resonance structures must be valid Lewis structures
B. Each atom in all of the resonance structures must have a complete shell of valence electrons
410
49. Which of the following statements is not true regarding resonance structures?
A. Each resonance structure is in rapid equilibrium with all of the other structures
B. The resonance structures may have different energies
C. All resonance structures must have the same arrangement of atoms
D. All resonance structures must have the same number of electrons
A. Each resonance structure is in rapid equilibrium with all of the other structures
411
50. Which of the following statements is not true about the carbonate anion, CO32-?
A. All of the oxygen atoms bear the same amount of charge
B. All of the carbon-oxygen bonds are the same length
C. The carbon atom bears the negative charge
D. It is basic
C. The carbon atom bears the negative charge
412
51. Which of the following statements is not true about the acetate anion, CH3CO2-?
A. The oxygen atoms bear the same amount of charge
B. The two carbon-oxygen bonds are the same length
C. The carbon atom bears the negative charge
D. It is basic
C. The carbon atom bears the negative charge
413
54. How many electrons are there in the valence shell of the carbon atom of a methyl cation, CH3+?
A. 4
B. 5
C. 6
D. 7
C. 6
414
55. How many electrons are there in the valence shell of the carbon atom of the methyl anion, CH3-?
A. 2
B. 4
C. 6
D. 8
D. 8
415
56. How many electrons are there in the valence shell of the oxygen atom of water?
A. 2
B. 4
C. 6
D. 8
D. 8
416
57. How many electrons are there in the valence shell of the nitrogen atom of ammonia?
A. 4
B. 5
C. 6
D. 8
D. 8
417
58. What is the approximate value of the H-C-H bond angles in a methyl cation, CH3+?
A. 90
B. 109
C. 120
D. 180
C. 120
418
59. What is the approximate value of the H-C-H bond angles in a methyl anion, CH3-?
A. 90
B. 109
C. 120
D. 180
B. 109
419
60. Which atomic orbitals overlap to form the carbon-hydrogen s bonding molecular orbitals of ethane, CH3CH3?
A. C2p + H1s
B. C2sp + H1s
C. C2sp2 + H1s
D. C2sp3 + H1s
D. C2sp3 + H1s
420
73. Which of the following shows curved arrows that correctly accounts for the differences between the two structures?
C. 3
421
61. Which atomic orbitals overlap to form the carbon-hydrogen s bonding molecular orbitals of ethene, H2C=CH2?
A. C2p + H1s
B. C2sp + H1s
C. C2sp2 + H1s
D. C2sp3 + H1s
C. C2sp2 + H1s
422
75. Which of the following is/are tetrahedral?
B. only 1 and 3
423
62. Which atomic orbitals overlap to form the carbon-carbon s and p bonding molecular orbitals of ethene, H2C=CH2?
A. C2sp3 + C2sp3, and C2p + C2p
B. C2sp2 + C2sp2, and C2sp2 + C2sp2
C. C2sp2 + C2sp2, and C2p + C2p
D. C2sp3 + C2sp3, and C2sp2 + C2sp2
C. C2sp2 + C2sp2, and C2p + C2p
424
63. Which atomic orbitals overlap to form the carbon-hydrogen s bonding molecular orbitals of ethyne, HCºCH?
A. C2p + H1s
B. C2sp + H1s
C. C2sp2 + H1s
D. C2sp3 + H1s
B. C2sp + H1s
425
64. Which atomic orbitals overlap to form the carbon-carbon s molecular bonding orbital of ethyne, HCºCH?
A. C2p + C2p
B. C2sp + C2sp
C. C2sp2 + C2sp2
D. C2sp3 + C2sp3
B. C2sp + C2sp
427
74. Which of the following statements is not true?
A. The sp3C-H bond of an alkane is weaker than the spC-H bond of an alkyne.
B. The carbon-carbon triple bond of an alkyne is shorter than the carbon-carbon bond of alkenes.
C. The carbon-carbon triple bond of an alkene is exactly three times as strong as a carbon-carbon single bond of an alkane.
D. The sp3C-H bond of an alkane is longer than the spC-H bond of an alkyne.
C. The carbon-carbon triple bond of an alkene is exactly three times as strong as a carbon-carbon single bond of an alkane.
429
7. Which of the following structures is different from the other three?
D. 4
430
8. Which of the following structures is different from the other three?
C. 3
431
9. Which of the following compounds is/are chiral?
A. only 1
432
1. Which of the following is the definition of a pair of enantiomers?
A. A pair of structures that are superposable mirror images of one another
B. A pair of stereoisomers that are non-superposable mirror images of one another
C. A pair of stereoisomers that are not mirror images of one another
D. A pair of stereoisomers that have equal specific rotations
B. A pair of stereoisomers that are non-superposable mirror images of one another
433
2. Which of the following is the definition of a pair of diastereomers?
A. A pair of structures that are superposable mirror images of one another
B. A pair of stereoisomers that are non-superposable mirror images of one another
C. A pair of stereoisomers that are not mirror images of one another
D. A pair of stereoisomers that have equal specific rotations
C. A pair of stereoisomers that are not mirror images of one another
434
3. Which of the following is the definition of chirality?
A. The non-superposability of an object on its mirror image
B. The superposability of an object on its mirror image
C. A molecule that has a carbon atom with four different substituents
D. A molecule with a mirror image
A. The non-superposability of an object on its mirror image
435
4. Which of the following is the definition of a meso compound?
A. A molecule with stereocenter centers which is chiral
B. A molecule with stereocenter centers which is not chiral
C. A diastereomer with no stereocenter centers
D. A chiral compound with more than one stereocenter center
B. A molecule with stereocenter centers which is not chiral
436
5. Which of the following statements is not true regarding pairs of enantiomers?
A. They have identical melting points
B. They have identical boiling points.
C. They rotate plane polarized light in opposite directions
D. They react at identical rates with chiral reagents
D. They react at identical rates with chiral reagents
437
6. Which of the following statements is true?
A. All mirror images are enantiomers
B. All molecules that have stereocenter centers are chiral
C. Isomers that are not superposable on their mirror images are enantiomers
D. Superposable structural isomers are enantiomers
C. Isomers that are not superposable on their mirror images are enantiomers
441
10. Which of the following compounds is/are chiral?
A. only 1
442
11. Which of the following have the S configuration?
C. only 1 and 2
443
12. Which of the following have the R configuration?
D. 1, 2 and 3
444
13. What is the configuration of the two chiral centers in the following molecule?
B. 3R,5S
445
14. What is the configuration of the two chiral centers in the following molecule?
C. 3S,5R
446
15. Which of the following Newman projections represents (2R,3R)-dibromobutane?
A. 1
447
16. Which of the following Newman projections represents meso-2,3-dibromobutane?
C. 3
448
17. Which of the following structures represent the same stereoisomer?
C. only 2 and 3
449
18. Which of the following structures represent the same stereoisomer?
C. only 2 and 3
450
19. Which of the following structures represent the same stereoisomer?
A. only 1 and 2
451
20. Which of the following compounds is a meso compound?
A. (2R,3R)-dibromobutane
B. (2R,3S)-dibromobutane
C. (2R,3S)-3-bromo-2-butanol
D. (2R,3R)-3-bromo-2-butanol
B. (2R,3S)-dibromobutane
452
21. How many stereoisomers of 2,3-dimethylbutane, (CH3)2CHCH(CH3)2, exist?
A. 1
B. 2
C. 3
D. 4
A. 1
453
22. How many stereoisomers of 3-chloro-2-methylbutane, (CH3)2CHCHClCH3, exist?
A. 1
B. 2
C. 3
D. 4
B. 2
454
23. How many stereoisomers of 3-bromo-2-butanol, CH3CH(OH)CHBrCH3, exist?
A. 1
B. 2
C. 3
D. 4
D. 4
455
24. How many stereoisomers of 2,3-butanediol, CH3CH(OH)CH(OH)CH3, exist?
A. 1
B. 2
C. 3
D. 4
C. 3
456
25. How many stereoisomers of 2,4-dimethylpentane, (CH3)2CHCH2CH(CH3)2, exist?
A. 1
B. 2
C. 3
D. 4
A. 1
457
26. How many stereoisomers of 4-chloro-2-methylpentane (CH3)2CHCH2CHClCH3, exist?
A. 1
B. 2
C. 3
D. 4
B. 2
458
27. How many stereoisomers of 4-bromo-2-pentanol, CH3CH(OH)CH2CHBrCH3, exist?
A. 1
B. 2
C. 3
D. 4
D. 4
459
28. How many stereoisomers of 2,4-pentanediol, CH3CH(OH)CH2CH(OH)CH3, exist?
A. 1
B. 2
C. 3
D. 4
C. 3
460
29. How many isomers (constitutional and stereoisomers) exist for dimethylcyclobutane?
A. 3
B. 4
C. 5
D. 6
D. 6
461
30. How many isomers (constitutional and stereoisomers) exist for dimethylcyclohexane?
A. 3
B. 5
C. 6
D. 9
D. 9
462
31. How many isomers (constitutional and stereoisomers) exist for dimethylcyclopentane?
A. 3
B. 5
C. 7
D. 9
C. 7
463
32. How many isomers (constitutional and stereoisomers) exist for dimethylpentane?
A. 2
B. 3
C. 4
D. 5
C. 4
464
33. Which of the following statements regarding optical rotation is not true?
A. All (+) enantiomers are dextrorotatory.
B. All R enantiomers are dextrorotatory.
C. All (-) enantiomers rotate plane-polarized light in a counterclockwise direction.
D. All (+) and (-) enantiomers rotate plane-polarized light in opposite directions.
B. All R enantiomers are dextrorotatory.
465
42. Which of the following structures has a center of symmetry?
C. 3
466
43. Which of the following structures has a center of symmetry (i.e., center of inversion)?
C. 3
467
44. Which of the following structures have a plane of symmetry?
C. only 3 and 4
468
45. Which of the following structures does not have a plane of symmetry?
A. only 2
469
46. How many stereogenic centers are there in the following molecule (the naturally occurring stereoisomer is the male hormone testosterone)?
C. Six
470
47. How many stereogenic centers are there in the following molecule (the naturally occurring stereoisomer is camphor, a pungent moth repellent)?
A. Two
471
49. Which of the following structures is chiral?
C. 3
472
50. Which of the following substituents has the highest priority according to the Cahn-Ingold-Prelog system used in assigning R and S configurations?
A. -COOH
B. -CHO
C. -CH2OH
D. -CH3
A. -COOH
473
51. Which of the following substituents has the highest priority according to the Cahn-Ingold-Prelog system used in assigning R and S configurations?
A. -NH2
B. -NHCH3
C. -CH2NH2
D. -CH2NHCH3
B. -NHCH3
474
52. What is the correct order of the Cahn-Ingold-Prelog ranking of the following substituents as used in assigning R and S configurations of chiral centers? (higher ranking \> lower ranking)
A. 3 \> 4 \> 2 \> 1
C. 3 \> 4 \> 2 \> 1
475
53. What is the correct order of the Cahn-Ingold-Prelog ranking of the following substituents as used in assigning R and S configurations of chiral centers? (higher ranking \> lower ranking)
D. 4 \> 3 \> 2 \> 1
476
54. What is the relationship between the following pair of structures?
D. They are identical
477
55. What is the relationship between the following pair of structures?
B. They are diastereomers
478
56. What is the relationship between the following pair of structures?
A. They are enantiomers
479
51. How many p orbital electrons are present in furan?
A. 4
B. 6
C. 7
D. 8
B. 6
480
52. How many p orbital electrons are present in cyclopentadienyl anion?
A. 4
B. 6
C. 7
D. 8
B. 6
481
1) Which of the following statements is incorrect about benzene?
A) All of the carbon atoms are sp hybridized.
B) It has delocalized electrons.
C) The carbon-carbon bond lengths are all the same.
D) The carbon-hydrogen bond lengths are all the same.
E) All twelve atoms lie in the same plane.
A) All of the carbon atoms are sp hybridized.
482
2) Which of the following statements about benzene is correct?
A) All of the carbon atoms are sp3 hybridized.
B) It has no delocalized electrons.
C) The carbon-carbon bond length is longer than that of ethane.
D) It is a planar molecule.
E) The carbon-hydrogen bonds are not the same length.
D) It is a planar molecule.
483
3) The delocalized π system in benzene is formed by a cyclic overlap of 6 ________ orbitals.
A) s
B) p
C) sp
D) sp2
E) sp3
B) p
484
5) Identify the resonance hybrid.
D
485
7) Which of the following pairs are resonance structures?
C) III
486
8) Which of the following is not a resonance structure of the species shown?
D) IV
487
9) In which of the following does resonance delocalization of electron density not play a role?
A) allyl cation
B) benzyl anion
C) CO32-
D) O3
E) cyclohexyl radical
E) cyclohexyl radical
488
7. How many constitutional isomers are there with the molecular formula C4H10?
A. 2
B. 3
C. 4
D. 5
A. 2
489
8. How many constitutional isomers are there with the molecular formula C5H12?
A. 2
B. 3
C. 4
D. 5
B. 3
490
9. How many constitutional isomers are there with the molecular formula C6H14?
A. 3
B. 4
C. 5
D. 8
C. 5
491
2. What is the approximate C-C-C bond angle in propane?
A. 90
B. 109
C. 120
D. 180
B. 109
492
12. What is the IUPAC name of the following compound?
B. 4-ethyl-2,2-dimethyl-heptane
493
13. What is the IUPAC name of the following compound?
D. 3-ethyl-5,5-dimethyl-heptane
494
15. What is the IUPAC name of the following compound?
C. 3-isopropyl-2,4-dimethylpentane
495
16. Which of the following compounds has 1, 2, 3 and 4 carbon atoms?
A. hexane
B. 2-methylhexane
C. 2,2-dimethylhexane
D. 2,2,3-trimethylhexane
D. 2,2,3-trimethylhexane
496
17. Which of the following compounds has only 1 and 3 carbon atoms?
A. hexane
B. 2-methylpentane
C. 3-methylpentane
D. 2,3-dimethylbutane
D. 2,3-dimethylbutane
497
25. Which of the following Newman projections does not represent 2-methylhexane?
C. 3
498
26. Which of the following Newman projections represents 2,4-dimethylpentane?
A. 1
499
27. Which of the following Newman projections represents the most stable conformation of 2,3-dimethylbutane?
C. 3
500
28. Which of the following Newman projections represents the most stable conformation of 2-methylbutane?
A. 1
501
29. Which of the following cycloalkanes has the most ring strain?
A. cyclopropane
B. cyclobutane
C. cyclopentane
D. cyclohexane
A. cyclopropane
502
30. Which of the following cycloalkanes has the least ring strain?
A. cyclopropane
B. cyclopentane
C. cyclohexane
D. cycloheptane
C. cyclohexane
503
31. Which of the following structures represents trans-1,3-dimethylcyclohexane?
B. 2
504
32. Which of the following structures represents trans-1,2-dimethylcyclohexane?
B. 2
505
33. Which of the following is the most stable conformation of cis-1-isopropyl-3-methylcyclohexane?
C. 3
506
34. Which of the following is the most stable conformation of trans-1-ethyl-3-methylcyclohexane?
D. 4
507
37. What is the IUPAC name of the following compound?
B. cis-1-isopropyl-4-methylcyclohexane
508
38. What is the IUPAC name of the following compound?
C. trans-1-tert-butyl-2-methylcyclopentane
509
39. Which one of the following structures represents a different compound from the other three?
D. 4
510
40. Which one of the following structures represents a different compound from the other three?
C. 3
511
41. In which of the following compounds are all of the carbon atoms in the same plane?
A. cyclopropane
B. cyclobutane
C. cyclopentane
D. cyclohexane
A. cyclopropane
512
42. Which of the following compounds can adopt a chair conformation in which there are no axial methyl groups?
A. 1,1-dimethylcyclohexane
B. cis-1,2-dimethylcyclohexane
C. trans-1,2-dimethylcyclohexane
D. cis-1,3-dimethylcyclohexane
C. trans-1,2-dimethylcyclohexane
513
43. Which of the following compounds can adopt a chair conformation in which there are no axial methyl groups?
A. cis-1,2-dimethylcyclohexane
B. cis-1,3-dimethylcyclohexane
C. trans-1,3-dimethylcyclohexane
D. cis-1,4-dimethylcyclohexane
B. cis-1,3-dimethylcyclohexane
514
44. Which of the following statements is not true regarding the conformation of substituted cyclohexanes?
A. ring inversion of cyclohexane between two chair conformations takes place via a boat conformation
B. substituted cyclohexanes are destabilized by 1,3-diaxial interactions
C. the boat conformation of cyclohexane is usually more stable than the chair conformation
D. the relative amount of two conformations of substituted cyclohexanes can be determined from the difference in strain energy
C. the boat conformation of cyclohexane is usually more stable than the chair conformation
515
45. What is the approximate dihedral angle between the two chlorine atoms in cis-1,2-dichlorocyclohexane?
A. 0
B. 60
C. 120
D. 180
B. 60
516
46. What is the approximate dihedral angle between the two chlorine atoms in the diequatorial conformation of trans-1,2-dichlorocyclohexane?
A. 0
B. 60
C. 120
D. 180
B. 60
517
47. What is the approximate dihedral angle between the two chlorine atoms in the diaxial conformation of trans-1,2-dichlorocyclohexane?
A. 0
B. 60
C. 120
D. 180
D. 180
518
48. Which of the following is not true regarding the properties of alkanes?
A. alkanes are nonpolar
B. alkanes burn in air to give H2O and CO2
C. alkanes are highly miscible with water
D. the strongest intermolecular force between alkane molecules is the van der Waals inte
C. alkanes are highly miscible with water
519
3. Which of the following is the correct order of decreasing basicity (stronger base \> weaker base)?
A. NH3 \> MeNH2 \> H2O \> HF
B. MeNH2 \> NH3 \> MeOH \> CH4
C. NH3 \> Me3N \> H2O \> MeOH
D. CH3COONa \> NaOH \> NaOMe \> NaNMe2
B. MeNH2 \> NH3 \> MeOH \> CH4
520
4. Which of the following is the strongest acid?
A. CH3CH3
B. CH3NH2
C. CH3OH
D. CH3F
C. CH3OH
521
5. Which of the following is the strongest acid?
A. HCl
B. HI
C. HF
D. HBr
B. HI
522
6. Which of the following is easiest to deprotonate?
A. CH4
B. CH3CH3
C. CH2=CH2
D. HCºCH
D. HCºCH
523
7. Which of the following is the strongest acid?
A. CH3OH
B. CH3CHO
C. CH3COCH3
D. CH3COOH
D. CH3COOH
524
8. Which of the following is the strongest acid?
A. CH3NH2
B. CH3PH2
C. CH3OH
D. CH3SH
D. CH3SH
525
9. Which of the following compounds is the strongest acid?
A. HF
B. H2O
C. NH3
D. CH4
A. HF
526
10. Which of the following compounds is the strongest acid?
A. CH3OCH3
B. CH3CH2OH
C. CH3CHO
D. CH3CO2H
D. CH3CO2H
527
11. Which of the following compounds is the strongest acid?
A. CH3COOH
B. ClCH2COOH
C. CH3CH2OH
D. ClCH2CH2OH
B. ClCH2COOH
528
12. Which of the following compounds is the strongest acid?
A. CH3COOH
B. FCH2COOH
C. ClCH2COOH
D. BrCH2COOH
B. FCH2COOH
529
13. Which of the following compounds is the strongest acid?
A. CH4
B. CH3CH3
C. H2C=CH2
D. HCºCH
D. HCºCH
530
14. Which of the following compounds is the strongest acid?
A. CF3OH
B. CF3CH2 CH2OH
C. CF3CH2 CH2 CH2OH
D. CF3CH2 CH2 CH2CH2OH
A. CF3OH
531
15. Which of the following compounds is the strongest acid?
A. CH3CH2CH2COOH
B. CH3CH2CHClCOOH
C. CH3CHClCH2COOH
D. ClCH2CH2CH2COOH
B. CH3CH2CHClCOOH
532
16. Which of the following is the strongest base?
A. NaOH
B. NaCO3
C. H2O
D. CH3OH
A. NaOH
533
17. Which of the following is the strongest base?
A. iodide anion, I-
B. fluoride anion, F-
C. bromide anion, Br-
D. chloride anion, Cl-
B. fluoride anion, F-
534
18. Which of the following anions is the strongest base?
A. CH3COO-
B. HO-
C. NH2-
D. Cl-
C. NH2-
535
19. Which of the following anions is the strongest base?
A. NH2-
B. NH3
C. CH3CH=N-
D. CH3CºN
A. NH2-
536
20. Which of the following compounds has the highest pKa?
A. SiH4
B. H2S
C. PH3
D. HCl
A. SiH4
537
21. Which of the following compounds has the highest pKa?
A. NH3
B. H2O
C. HCl
D. CH4
D. CH4
538
22. Which of the following compounds has the lowest pKa?
A. H2O
B. HBr
C. NH3
D. CH4
B. HBr
539
23. Which of the following compounds has the lowest pKa?
A. H2O
B. H2S
C. H2Se
D. H2Te
D. H2Te
540
24. Which of the following is present in the highest concentration upon dissolution of H2SO4 in water?
A. H2SO4
B. H+
C. H3O+
D. HO-
C. H3O+
541
25. Which of the following is present in the highest concentration upon dissolution of acetic acid in water?
A. OH-
B. H3O+
C. CH3COOH
D. CH3COOH+
C. CH3COOH
542
26. Which of the following terms describes the reactivity of boron tribromide, BBr3?
A. Brønsted-Lowry acid and Lewis acid
B. Brønsted-Lowry base and Lewis base
C. Lewis acid and not a Brønsted-Lowry acid
D. Lewis base and not a Brønsted-Lowry base
C. Lewis acid and not a Brønsted-Lowry acid
543
27. Which of the following terms describes the reactivity of trimethylamine, (CH3)3N?
A. Brønsted-Lowry acid and Lewis acid
B. Brønsted-Lowry base and Lewis base
C. Lewis acid and not a Brønsted-Lowry acid
D. Lewis base and not a Brønsted-Lowry base
B. Brønsted-Lowry base and Lewis base
544
28. Which set of curved arrows accounts for the deprotonation of an acid (A-H) by a base (:B)?
B. 2
545
29. Which sets of curved arrows accounts for the protonation of propene with HI?
D. 4
546
30. Which of the following terms describes the role of ethene in the acid-base reaction shown?
B. Brønsted-Lowry base
547
31. Which of the following terms describes the role of ethanol in the acid-base reaction shown?
B. Brønsted-Lowry base
548
32. Which of the following terms describes the role of ethanol in the acid-base reaction shown?
A. Brønsted-Lowry acid
549
33. Which of the following terms describes the role of ethyne in the acid-base reaction shown?
A. Brønsted-Lowry acid
550
34. Which species is the conjugate acid in the following acid-base reaction?
D. 4
551
38. Which of the following is a Lewis acid but not a Brønsted-Lowry acid?
A. CH3COOH
B. AlCl3
C. H2O
D. CH3OH
B. AlCl3
552
39. Which of the following is a feature of a Lewis acid?
A. proton donor
B. proton acceptor
C. electron pair donor
D. electron pair acceptor
D. electron pair acceptor
553
40. Which of the following is a feature of a Lewis base?
A. proton donor
B. proton acceptor
C. electron pair donor
D. electron pair acceptor
C. electron pair donor
554
41. Which of the following is a feature of a Brønsted-Lowry acid?
A. proton donor
B. proton acceptor
C. electron pair donor
D. electron pair acceptor
A. proton donor
555
42. Which of the following is a feature of a Brønsted-Lowry base?
A. proton donor
B. proton acceptor
C. electron pair donor
D. electron pair acceptor
B. proton acceptor
556
43. Which of the following has the highest bond dissociation energy?
A. HF
B. HCl
C. HBr
D. HI
A. HF
557
44. Which of the following concepts can be used to rationalize the observation that acetic acid is a stronger acid than methanol?
A. electronegativity
B. resonance
C. valence shell electron pair repulsion theory
D. Pauli exclusion principle
B. resonance
558
45. Which atom in the following structure is preferentially protonated by a strong acid?
A. i
559
46. What is the approximate pKa value of HCl?
A. -7
B. 5
C. 16
D. 51
A. -7
560
47. What is the approximate pKa value of acetic acid?
A. -7
B. 5
C. 16
D. 51
B. 5
561
48. Which of the following has a pKa value of approximately 16?
A. HBr
B. CH3COOH
C. CH3CH2OH
D. HCºCH
C. CH3CH2OH
562
49. Which of the following has a pKa value of approximately 25?
A. CH3CH3
B. CH2=CH2
C. HCºCH
D. CH3CH2OH
C. HCºCH
563
50. Which of the following statements is not true?
A. The position of the equilibrium for an exergonic reaction favors products
B. The products of an exergonic reaction have a higher Gibbs free energy than the reactants.
C. The equilibrium constant of a reaction for which DG = 0 is 1.
D. DG = DH - TDS
B. The products of an exergonic reaction have a higher Gibbs free energy than the reactants.
564
52. Which of the following energy diagrams represents the fastest reaction?
B. 2
565
53. Which of the following energy diagrams represents the slowest reaction?
D. 4
566
54. Which of the following is a definition of the rate-determining step of a reaction mechanism?
A. the first step
B. the last step
C. the step that crosses the highest energy barrier
D. the most exothermic step
C. the step that crosses the highest energy barrier
567
55. Which of the following is a definition of the activation energy of a reaction?
A. the difference in Gibbs free energy between the reactants and the transition state
B. the difference in Gibbs free energy between the reactants and the intermediate
C. the difference in Gibbs free energy between the reactants and the product
D. the difference in Gibbs free energy between the transition state and the product
A. the difference in Gibbs free energy between the reactants and the transition state
568
57. Which of the following energy diagrams best represents the changes in energy during addition of HBr to an alkene?
A. 1
569
24. What is the major organic product obtained from the following reaction?
A. 1
570
26. What is the major organic product obtained from the following reaction?
B. 2
571
28. What is the major organic product(s) obtained from the following reaction?
B. 2-hexyne
572
29. What is the major organic product(s) obtained from the following reaction?
C. 1-propene + propyne
573
30. What is(are) the major organic product(s) obtained from the following substitution reaction?
A. only 1
574
31. What is(are) the major organic product(s) obtained from the following substitution reaction?
D. a mixture of 1 and 2
575
43. Which of the following statements is true regarding the reactivity of 1 and 2 with potassium tert-butoxide?
A. 1 reacts faster than 2
576
44. What is the major elimination product obtained from the following reaction?
B. 2
577
45. What is the major organic product obtained from the following reaction?
A. 1
578
47. Which of the following is most likely to undergo rearrangement during reaction with methanol?
B. 2
579
48. Which of the following compounds undergoes the most rapid hydrolysis reaction?
B. 2
580
58. Which of the following energy diagrams represents the course of an exothermic E2 reaction?
C. 3
581
59. Which of the following energy diagrams represents the course of an exothermic E1 reaction?
A. 1
582
64. Which of the following represents the transition state of the rate-determining step in the reaction between 2-bromopropane and sodium methoxide leading to elimination?
A. 1
583
65. Which of the following represents the transition state of the rate-determining step in the reaction between 2-chloropropane and sodium amide leading to elimination?
C. 3
584
66. Which of the following represents the transition state of the rate-determining step in the reaction between tert-butyl bromide and methanol leading to elimination?
B. 2
585
67. Which of the following represents the transition state of the rate-determining step in the reaction between tert-butyl iodide and water leading to elimination?
A. 1
586
70. Which of the following most favors elimination rather substitution in a reaction with 2-bromopropane?
A. sodium methoxide
B. sodium ethoxide
C. sodium isoproxide
D. sodium tert-butoxide
D. sodium tert-butoxide
587
71. Which of the following most favors elimination rather substitution in a reaction with sodium methoxide?
A. bromomethane
B. bromoethane
C. 1-bromopropane
D. 2-bromopropane
D. 2-bromopropane
588
72. What is the best choice of reagent to perform the following transformation?
D. KOtBu
589
73. What is the best choice of reagent to perform the following transformation?
A. H2SO4
590
1. What is the IUPAC name of the following compound?
C. (R)-3-chloro-1-methylcyclohexene
591
2. What is the IUPAC name of the following compound?
D. (R)-3-bromo-3-methyl-1-hexene
592
3. What is the IUPAC name of the following compound?
D. (Z)-2-chloro-3,4-dimethyl-2-pentene
593
9. What is the major organic product obtained from the following reaction?
A. 1
594
10. What is the major organic product obtained from the following reaction?
D. 4
595
24. Which of the following compounds is the most reactive dienophile?
C. 3
596
25. Which of the following is the least reactive dienophile?
B. 2
597
26. Which of the following is the least reactive diene in Diels Alder reactions?
A. 1
598
27. Which of the following is the least reactive diene in Diels Alder reactions?
B. 2
599
28. What is the major organic product obtained from the following reaction?
B. 2
600
29. What is the major organic product obtained from the following reaction?
B. 2
601
30. What is the major organic product obtained from the following reaction?
C. 3
602
31. What is the major organic product obtained from the following reaction?
A. 1
603
32. What is the major organic product obtained from the following reaction?
C. 3
604
33. What is the major organic product obtained from the following reaction?
A. 1
605
34. What is the major organic product obtained from the following reaction?
B. 2
606
7. What is the hybridization of carbon atoms labeled i - iii in the following structure?
C. i = sp2; ii = sp; iii = sp2
607
29. What is the IUPAC name of the following compound?
B. (E)-3-ethyl-5-methyl-1,4-heptadiene
608
37. Which is the correct assignment of the names of the following groups?
D. 1 = vinyl; 2 = allyl; 3 = phenyl
609
38. Which is the correct assignment of the names of the following groups?
C. 1 = methylene; 2 = phenyl; 3 = vinyl
610
45. What is the smallest trans cycloalkene that is stable at room temperature?
A. (E) cyclohexene
B. (E) cycloheptene
C. (E) cyclooctene
D. (E) cyclodecene
C. (E) cyclooctene
CHM 331
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