92
Chemical Oceanography, 4th Edition
Here we discuss the various inorganic complexes of the d 0 metal ions that are the major
components of seawater.
3.1.2 d 10 Cations
Cations with an outer shell of 18 electrons include Ag + , Zn 2+ , Ga 3+ , and Sc 4+ . The univalent
d 10 metal ions behave in a different way from the d 0 metals. For these ions, the halide complexes are quite strong and increase in stability with increasing atomic weight or size of
the ligand. This is shown as follows for the stability constants for the formation of silver
and copper(I) halide complexes as a function of the radius of the halide ion:
Complex
CuX
AgX
Radius (Å)
MF
—
–0.3
1.36
MCl
2.7
3.0
1.81
MBr
3.2
4.3
1.95
MI
7.2
8.1
2.16
Ia IIa
Trace
< 50 pM
Minor
0.5–50 µM
IIIa IVa Va
VIIa
VIa
4
Be
5
B
6
C
7
N
8
O
9
F
14
Si
15
P
16
S
17
Cl
3
Li
Trace
0.5–50 nM
Major
0.5–50 mM
Major
>50 mM
12
Mg
13
Al
11
Na
IIIb IVb Vb VIb VIIb
VIIIb
Ib IIb
19
K
20
Ca
21
Sc
22
Ti
23
V
24
Cr
25
Mn
26
Fe
27
Co
28
Ni
29
Cu
30
Zn
31
Ga
32
Ge
33
As
34
Se
35
Br
38
Sr
39
Y
40
Zr
41
Nb
42
Mo
43
Tc
44
Ru
45
Rh
46
Pd
47
Ag
48
Cd
49
In
50
Sn
51
Sb
56
Ba
57
La
72
Hf
73
Ta
74
W
75
Re
76
Os
77
Ir
78
Pt
79
Au
80
Hg
81
Tl
82
Pb
60
Nd
61
Pm
62
Sm
63
Eu
64
Gd
65
Tb
66
Dy
67
Ho
68
Er
69
Tm
70
Yb
71
Lu
83
Bi
52
Te
53
I
37
Rb
55
Cs
58
Ce
59
Pr
Figure 3.1
Classification of elements in ocean waters.