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In-Depth Information
Table 2.3
Self-diffusion coefficients of ions in aqueous solution at 25
◦
C
a
D
0
(
dm
2
s
−
1
D
0
(
dm
2
s
−
1
Cations
Anions
×
10
−
7
)
×
10
−
7
)
H
3
O
+
OH
−
9.31
5.27
Li
+
F
−
1.03
1.47
Cl
−
Na
+
1.33
2.03
K
+
Br
−
1.96
2.08
Rb
+
I
−
2.06
2.04
Cs
+
HS
−
2.07
1.73
NH
4
+
SO
4
2
−
1.98
1.06
Mg
2
+
NO
2
−
0.70
1.91
Ca
2
+
NO
3
−
0.79
1.90
Sr
2
+
HCO
3
−
0.79
1.18
Ba
2
+
CO
3
2
−
0.85
0.92
Mn
2
+
H
2
PO
4
−
0.69
0.85
HPO
4
2
−
Fe
2
+
0.72
0.73
Ni
2
+
H
2
AsO
4
−
0.68
0.91
Cu
2
+
HCOO
−
b
0.73
1.45
CH
3
COO
−
b
Zn
2
+
0.72
1.09
Cd
2
+
CH
3
CH
2
COO
−
b
0.72
0.95
Pb
2
+
0.95
RT λ
0
|
a
Calculated with the relation
D
0
using values of the limiting equivalent conductivity,
λ
0
,
=
z
|
F
2
from Landolt
et al
. (1960).
b
Robinson and Stokes (1959).
2.5
Cs
+
Rb
+
Br
−
I
−
Cl
−
NH
4
+
2.0
K
+
1.5
Na
+
F
−
L
i
+
P
b
2
+
1.0
Fe
2
+
, Zn
2
+
Ca
2
+
Ni
2
+
Ba
2
+
Sr
2
+
Mg
2
+
Cd
2
+
Mn
2
+
Cu
2
+
0.5
0.0
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
|z|/r (nm
−
1
)
Figure 2.2
Self-diffusion coefficients at 25
◦
C plotted against ionic potential (after Li
and Gregory, 1974). Reprinted with permission from Elsevier Science
