Chapter 26 Answers
Practice Examples
C
C C C C C C
CH3CH2CH2CH2CH2CH3
C
C
C C C C C
(CH3)2CHCH2CH2CH3
C
C
C
C
C C C C C
CH3CH2CH(CH3)CH2CH3
C
C
C
C
C
C
C
(CH3)3CCH2CH3
(CH3)2CHCH(CH3)2
1a.
C
C
C
C C
C
C C
CH3CH2CH2CH2CH2CH2CH3
C
C C
C
C
C C
(CH3)2CHCH2CH2CH2CH3
C
C C
C
C C
CH3CH2CH(CH3)CH2CH2CH3
C
C
C
C
C C
C
C
C
(CH3)2CHCH2CHC(CH3)2
C
C C
C C
C
C
(CH3)2CHCH(CH3)CH2CH3
C
C
C
C C
C C
C
C
C
(CH3)3CCH2CH2CH3
C C
C
C
CH3CH2C(CH3) 2CH2CH3
C
C C
C
C
(CH3)3CCH(CH3)2
C
C
C
C
C C
C
CH(CH2CH3)3
1b.
2a. 3,6,6-trimethyloctane
2b. 3,6-dimethyloctane
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3a.
CH3
H3C
CH
CH3
CH
H3C
3b.
CH2
CH
CH3
4a.
conformations have the same energy.
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4b.
5a.
5b.
6a. (a) Achiral; (b) Chiral; (c) Chiral.
6b. (a) Achiral; (b) Chiral; (c) Chiral.
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7a.
7b.
8a. (a) R configuration; (b) R configuration; (c) R configuration.
8b. (a) Enantiomers; (b) Enantiomers.
9a. (a) (E) stereoisomer; (b) (Z) stereoisomer; (c) (Z) stereoisomer.
H3CH2C
C
9b.
H
C
H3CH2C
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H3C
H
Cl
CH2CH3
H3CH2C
C
H
C
H
C
, (E) stereoisomer H3CH2C
CH3
C
CH3
C
H
C
H
C
(b) (Z) stereoisomer H3CH2C
(c) (Z) stereoisomer
, (E) stereoisomer
CH2CH3
Cl
H
C
C
H
(a) (Z) stereoisomer
H3CH2C
CH3
, (E) stereoisomer
H3C
C
CH3
4
10a.
10b.
Integrative Example
A. CH3-CH2-CH2-OH (Compound A), CH3-CH2-CH2-COOH (Compound B), CH3-CH2-CH2COO-CH3-CH2 (Compound C).
B. Compounds (a) and (b) are both ethers. Ethers are relatively unreactive and the ether linkage
is stable in the presence of most oxidizing and reducing agents, as well as dilute acids and
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alkalis. Compound (c) is unsaturated secondary alcohol. It will decolorize a Br2/CCl4 solution.
Compound (d), on the other hand is an aldehyde. On treatment with chromic acid it will be
oxidized to carboxylic acid.
Exercises
Br Br
C
1a.
C
C
C
C
C
C
C
C
C
C
1b.
C
C
C
C
C
C
C
C
C
C
C
C
C
C
1c.
CH3
3a. H3C
CH3
NO2
OH
3b.
Cl
COOH
Cl
3c.
NH2
H Cl H
H C C C H
5a.
H H H
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H H
H O C
C O H
H H
5b.
H
C O
H C
H H
5c.
7a. Each carbon atom is sp 3 hybridized. All of the C – H bonds in the structure are sigma
bonds, between the 1s orbital of H and the sp 3 orbital of C. The C–C bond is between sp 3
orbitals on each C atom.
H
H
H H
H
C
C
C H
C
H H H H
7b. Both carbon atoms are sp 2 hybridized. All of the C – H bonds in the structure are sigma
bonds between the 1s orbital of H and the sp 2 orbital of C. The C–Cl bond is between the sp 2
orbital on C and the 3p orbital on Cl. The C = C double bond is composed of a sigma bond
between the sp 2 orbitals on each C atom and a pi bond between the 2 pz orbitals on the two C
atoms.
H
C
C
Cl
H H
7c. The left-most C atom is sp 3 hybridized, and the C–H bonds to that C atom are between the
sp 3 orbitals on C and the 1s orbital on H. The other two C atoms are sp hybridized. The righthand C – H bond is between the sp orbital on C and the 1s orbital on H. The C ≡ C triple bond
is composed of one sigma bond formed by overlap of sp orbitals, one from each C atom, and two
pi bonds, each formed by the overlap of two 2p orbitals, one from each C atom (that is a
2 p y  2 p y overlap and a 2 pz  2 pz overlap).
H
H
C
C
C H
H
9a. Identical
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9b. Constitutional isomers
9c. No relationship
9d. Constitutional isomers
9e. Stereoisomers
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
11.
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
13a. Carbon 2 is chiral.
13b. There are no chiral carbon atoms.
13c. Carbon 2 is chiral.
15a. Carbon 2 is chiral.
15b. Carbon 2 is chiral.
15c. There are no chiral carbon atoms.
17a. Alkyl halide
17b. Aldehyde
17c. Ketone
17d. Phenol, hydroxyl group, and phenyl group.
19a. The hydroxyl group.
19b. An aldehyde has a carbonyl group with a hydrogen and a carbon group attached. In a
ketone, the carbonyl group is attached to two carbons.
19c. The essential difference is the presence of the — OH group in acetic acid.
21a. Carboxylic acid, hydroxyl group and disubstituted aromatic ring.
21b. Ester group
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21c. Ketone and carboxylic acid group.
21d. Aldehyde, hydroxyl group, and disubstituted aromatic ring.
23.
O
O
H
O
O
25.
O
O
O
O
H
OH
O
OH
H
H
O
H
O
O
O
O
OH
OH
O
O
O
OH
H
H
O
O
O
O
O
O
HO
O
O
O
HO
O
O H
O
O
O
O H
O
H
O
O
27.
H
OH
OH
O
OH
O
29.
OH
31a. 3,5-dimethyloctane
31b. 2,2-dimethylpropane
31c. 3,3-dichloro-5-ethylheptane
33a. 2,2-dimethylbutane
33b. 2-methylpropene
33c. 1,2-dimethylcyclopropane
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33d. 4-methyl-2-pentyne
33e. 3,4-dimethylhexane
33f. 3,4-dimethyl-2-propyl-1-pentene
35a. Insufficient
35b. Sufficient
35c. Insufficient
35d. Insufficient
35e. Sufficient
35f. Insufficient
NO2
O2N
CH3
NO2
37a.
O
COCH3
OH
37b.
37c. HOOCCH 2 C ( OH )( COOH ) CH 2 COOH
39a. N,N-diethylamine
39b. p-nitroaniline
39c. N-cyclopentyl-N-ethylamine
39d. N,N-diethyl-N-methylamine
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41a.
41b.
43. The Anti conformation is lowest in energy.
45.
47a.
47b.
49. In the case of ethene there are only two carbon atoms between which there can be a double
bond. In the case of propene, there can be a double bond only between the central carbon atom
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and a terminal carbon atom. The case of butene is different since 1-butene is distinct from 2butene.
51a. (E) configuration
51b. (Z) configuration
51c. (E) configuration
53a.
53b.
C
CH
55a.
Cl
55b.
Cl
55c. 1,3,5-trihydroxybenzene
57.
59a. Identical
59b. Identical
59c. Isomers
59d. Enantiomers
59e. Identical
61a. (S)-3-bromo-2-methylpentane
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61b. (S)-1,2-dibromopentane
61c. (R)-3-(bromomethyl)-1-chloropentan-3-ol
61d. (S)-1-bromopropan-2-ol
63a. (Z)-pent-2-ene
63b. (E)-1-chloro-2-methylbut-1-ene
63c. (E)-4-(chloromethyl)-3,7-dimethyloct-3-ene
63d. (Z)-5-bromo-3-(bromomethyl)-2-methylpent-2-enal
65a.
65b.
65c.
65d.
65e.
Integrative and Advanced Exercises
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79a. C6 H 5 NO 2 + 7 H + + 2 Fe 
→ C6 H 5 NH 3+ + 2 H 2 O + 2 Fe3+
79b. 3 C6 H 5CH 2 OH + 2 Cr2 O7 2− + 16 H + 
→ 3 C6 H 5COOH + 4 Cr 3+ + 11 H 2 O
79c. 3 CH 3CH= =
CH 2 + 2 MnO 4 − + 4 H 2 O 
→ 3CH 3CHOHCH 2 OH + 2 MnO 2 + 2 OH −
81. C4H8N2O2
84. The unknown must be 1-butanol or butyraldehyde. The identity of the unknown can be
established by treatment with a carboxylic acid.
89a. Ester, amine(tertiary), arene.
89b. C1= sp2, C2 = sp3, C3 = sp3, C4 = sp3, N = sp3.
89c. Carbons 2 and 4 are chiral.
Self-Assessment Exercises
101. The correct answer is (c).
102. The correct answer is (b).
103. The correct answer is (e).
108. The correct answer is (c).
109. C4H8
110a. C6H12
110b. C3H7OH
110c. C6H5COOH
111a.
111b.
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111c.
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