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316 Chapter 9
Copyright © 2017 Pearson Education, Inc.
Solutions to Problems
1.
DEE is formed when HCl is eliminated from DDT. (See the box on page 392.)
Cl
Cl
Cl
Cl
DDE
2.
Methoxychlor has methoxy groups in place of the chlorines on the benzene rings of DDT. The oxygen of
the methoxy groups can form hydrogen bonds with water, making methoxychlor more soluble in water
and, therefore, less soluble in fatty tissues.
3.
rate
=
k
3
alkyl halide
4 3
nucleophile
4
original: rate
=
k
3
1.0
4 3
1.0
4
a.
rate
=
k
3
1.0
4 3
3.0
4
=
3.0
The rate is tripled.
b.
rate
=
k
3
0.50
4 3
1.0
4
=
0.50
The rate is cut in half.
c.
rate
=
k
3
0.5
4 3
2.0
4
=
1.0
The rate is not changed.
4.
Increasing the height of the energy barrier decreases the magnitude of the rate constant; this causes the
reaction to be slower.
5.
The closer the methyl group is to the site of nucleophilic attack, the greater the steric hindrance to
nucleophilic attack and the slower the rate of the reaction.
>
CH
3
CH
2
CH
2
CH
2
CH
2
Br
CH
3
CHCH
2
CH
2
Br
CH
3
> CH
3
CH
2
CHCH
2
Br
CH
3
CH
3
CH
2
CBr
CH
3
CH
3
>
6.
a.
Solved in the text.
b.
CH
3
O
−
(
S
)-2-methoxybutane
C
CH
3
Br
H
CH
3
CH
2
(
R
)-2-bromobutane
C
CH
3
CH
3
O
H CH
2
CH
3
c.
HO
−
(
R
)-3-hexanol
C
CH
2
CH
2
CH
3
Cl
CH
3
CH
2
(
S
)-3-chlorohexane
C
CH
2
CH
2
CH
3
HO
CH
2
CH
3
H
H
d.
HO
−
3-pentanol
CH
3
CH
2
CHCH
2
CH
3
I
3-iodopentane
OH
CH
3
CH
2
CHCH
2
CH
3
7.
Solved in the text.