CHAPTER 14
14.1 A = εcl
where the proportionality constant ε is the molar absorption coefficient, or extinction coefficient, the concentration of the absorber
is c, the pathlength of the sample is l, the intensity of the incident
light is I, and the intensity of the exiting light is I 0 .
14.2 (a)
(b)
(c)
14.3 (a)
(b)
(c)
14.4 (a) A = 0.27
(b)
14.5 (a) A = 0.0154
(b)
14.6
14.7 (a) A = cεl = (1 × 10
−6 M)(1 × 10
4 M
−1 cm
−1
)(1 cm) = 0.01
(b) A = cεl = (2 × 10
− 4 M)(1 × 10
4 M
−1 cm
−1
)(1 cm) = 2
14.8
14.9 w′ = B′ρ
[ ]
( ,
)( .
) (
)( .
Trp =
−
−
−
11 300
0 239
1500
0 71
1
1
M
M
7 7
11 300
5380
1500
1960
2
1
1
)
( ,
)(
) (
)(
)
.
M
M
−
−
−
= 8 81 10
5
×
− M
[ ]
(
) (.
) (
) (.
)
Tyr =
−
−
−
5380
0 717
1960
0 239
1
1
M
M
( ( ,
)(
) (
)(
)
.
11 300
5380
1500
1960
5 85
1
1
M
M
−
−
−
=
×
−
10
5 M
c
A
l
.
=
=
×
=
−
−
−
ε
10
10
1
0 1
1
3
1
1
M cm
cm
mM
c
A
l ( .
)(
)
.
=
=
×
=
−
−
−
ε
10
1 54 10
1
6
1
4
1
1
M cm
cm
5 5 10
6 5
6
.
×
=
− M
M
μ
c
.
. %
.
%
=
×
=
1
2 7
0 1
0 037
λ ν
= =
×
×
= ×
−
−
−
c
3 10
1 10
3 10
8
1
12
1
4
m s
s
m → infrared
λ ν
= =
×
×
= ×
→
−
−
c 3 10
1 10
3 10
8
1
6
1
2
m s
s
m
r radiowave
λ ν
= =
×
×
= ×
−
−
−
c
3 10
1 10
3 10
8
1
18
1
10
m s
s
m m
X-ray
→
ν λ
.
= =
×
×
=
×
−
−
c
3 10
3 10
1 0 10
8
1
2
10
m s
m
m → microwave
ν λ
.
= =
×
×
=
×
−
−
c 3 10
5 10
6 0 10
8
1
7
14
m s
m
m → → visible
ν λ
= =
×
×
= ×
→
−
−
c
3 10
1 10
3 10
8
1
9
17
m s
m
m
X-ray
ANSWERS TO PROBLEMS
473
9781405124362_5_end.qxd 4/29/08 9:17 Page 473