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Chapter 9 317
Copyright © 2017 Pearson Education, Inc.
8.
a.
CH
2
CH
3
CH
3
O
CH
2
CH
3
I
CH
3
O
−
b.
CH
3
Cl
CH
3
CH
3
CH
2
O
CH
3
CH
2
O
−
9.
a.
Br
The primary alkyl halide is less sterically hindered than the secondary alkyl halide
(the
CH
3
group is farther away from the back side of the carbon attached to the Br).
b.
Br
Br is a weaker base; therefore, it is a better leaving group.
c.
Br
With one methyl and one ethyl group, this alkyl halide is less sterically hindered
than the other alkyl halide that has two ethyl groups.
d.
Br
The primary alkyl halide is less sterically hindered than the secondary alkyl halide.
10.
A protic solvent has a hydrogen bonded to an oxygen or to a nitrogen, whereas an aprotic solvent does not
have a hydrogen bonded to an oxygen or to a nitrogen.
a.
aprotic
b.
aprotic
c.
protic
d.
aprotic
11.
a.
RO
-
, because ROH is a weaker acid than RSH since the hydrogen is attached to a smaller atom.
b.
RS
-
, because it is less well solvated by water and sulfur is more polarizable than oxygen.
c.
RO
-
, because, although they differ in size, they are in an aprotic solvent. Remember that the stronger
base is always the better nucleophile in an aprotic solvent.
12.
Remember that the stronger base is always the better nucleophile unless they differ in size
and
they are in a
protic solvent.
a.
They differ in size, and because they are in a protic solvent, the larger one
1
Br
-
2
is the better
nucleophile.
b.
They differ in size, and because they are in an aprotic solvent, the stronger base
1
Cl
-
2
is the better
nucleophile.
c.
Because the oxygen is negatively charged,
CH
3
O
-
is the better nucleophile.
d.
Because the oxygen is negatively charged,
CH
3
O
-
is the better nucleophile.
e.
Because
H
2
O
is a stronger acid than
NH
3
,
-
NH
2
is the stronger base and the better nucleophile.
f.
Because
H
2
O
is a stronger acid than
NH
3
,
-
NH
2
is the stronger base and the better nucleophile.
g.
They differ in size and, because they are in a protic solvent, the larger one
1
I
-
2
is the better nucleophile.
h.
They differ in size and, because they are in an aprotic solvent, the stronger base
1
Br
-
2
is the better
nucleophile.