preface to fifteenth edition

8.142 SECTION 8
TABLE 8.30
Half-Wave Potentialsof Inorganic Materials(Continued)
Element E 1/2 , volts Solvent system
2 to 0 1.54 1M KCl
2 to 3 0.40 1M KCl (anodic wave)
Cobalt
3 to 0 0.5; 1.3 1M NH 4 Cl plus1M NH 3 ;3 to 2 to 0
2 to 0 1.07 0.1M pyridine pluspyridinium chloride
1.03 Neutral 1M potassium thiocyanate
1.4 Co(H2O) 6
2 in noncomplexing systems
3 to 2 0.0 1M sodium oxalate in acetate buffer (pH 5); diffusion current
measured between 0 and 0.1 V
Copper
2 to 0 0.04 0.1M KNO 3 , 0.1M NH 4 ClO 4 ,or1M Na 2 SO 4
0.085 0.1M Na 4 P 2 O 7 plus0.2M Na acetate, pH 4.5
0.09 0.5M Na tartrate, pH 4.5
0.20 0.1M potassium oxalate, pH 5.7 to 10
0.22 0.5M potassium citrate, pH 7.5
0.4 0.5M Na tartrate plus0.1M NaOH (pH 12)
0.568 0.1M KNO 3 plus1M ethylenediamine
2 0.04; 0.22 1M KCl; consecutive waves: 2 to 1 to 0
0.02; 0.39 0.1M KSCN; consecutive waves: 2 to 1 to 0
0.05; 0.25 0.1M pyridine plus0.1M pyridinium chloride; consecutive
waves: 2 to 1 to 0
0.24; 0.50 1M NH 4 Cl plus1M NH 3 ; consecutive waves
Gallium
3 to 0 1.1 Not more than 0.001M HCl or wave masked by hydrogen
wave which immediately follows
Germanium
2 to 0 0.45 6M HCl; prior reduction with HPH 2 O 2 to 2
Gold
3 to 1 0 1M KCN; wave starts at 0 V
1 to 0 1.4
Au(CN) 2 wave best for analytical purposes
Indium
3 to 0 0.60 1M KCl
In Na acetate, pH 3.9 to 4.2
Iodine
IO 4 0.36 First wave at pH 0 (shifts to 0.08 at pH 12); second wave
corresponds to iodate reduction
IO 3 0.075 0.2M KNO 3 (shifts 0.13 V/pH unit increase)
0.305 0.1M hydrogen phthalate, pH 3.2
0.500 0.1M acetate plus0.1M KCl, pH 4.9
0.650 0.1M citrate, pH 5.95
1.050 0.2M phosphate, pH 7.10
1.20 0.05M borax 0.1M KCl, pH 9.2; or NaOH plus0.1M
KCl, pH 13.0
0to1 0.0 Wave starts from zero in acid media; Hg 2 I 2 formed
1 0.1 Oxidation of Hg to form Hg 2 I 2
Iron
3 0.44; 1.52 1M (NH 4 ) 2 CO 3 ; two waves; 3 to 2 to 0
0.17; 1.50 0.5M Na tartrate, pH 5.8; two waves; 3 to 2 to 0
0.9; 1.5 0.1 to 5M KOH plus8% mannitol; 3 to 2 to 0