Page 72 - Corrosion Engineering Principles and Practice

52 C h a p t e r 4 C o r r o s i o n T h e r m o d y n a m i c s 53

Half-Reaction E 0
red
O (g) + 2 H + 2 e  O (g) + H O 2.07
+
−
3 2 2
+
H O + 2 H + 2 e  2 H O 1.776
−
2 2 2
−
Au + e  Au 1.68
+
PbO + 4 H + 2 e  Pb + 2 H O 1.467
−
+
2+
2 2
−
Cl (g) + 2 e  2 Cl − 1.3583
2
O + 4 H + 4 e  2 H O 1.229
+
−
2 2
Pt + 2 e  Pt 1.2
2+
−
H O + 2 e  2 OH 0.88
−
−
2 2
Hg + 2 e  Hg 0.851
−
2+
Ag + e  Ag 0.7996
+
−
Hg 2+ + 2 e  Hg 0.7961
−
2
Cu + e  Cu 0.522
+
−
−
O + 2 H O + 4 e  4 OH − 0.401
2 2
−
2+
Cu + 2 e  Cu 0.3402
2 H + 2 e  H 2 0.0000...
+
−
Fe + 3 e  Fe −0.036
3+
−
−
Pb + 2 e  Pb −0.1263
2+
Sn + 2 e  Sn −0.1364
2+
−
Ni + 2 e  Ni −0.23
2+
−
−
2+
Co + 2 e  Co −0.28
2+
−
Fe + 2 e  Fe −0.409
Cr + 3 e  Cr −0.74
3+
−
Zn + 2 e  Zn −0.7628
2+
−
Mn + 2 e  Mn −1.04
2+
−
Al + 3 e  Al −1.706
3+
−
Mg + 2 e  Mg −2.375
−
2+
+
Na + e  Na −2.7109
−
−
+
K + e  K −2.924
TABLE 4.2 Standard-State Reduction Half-Cell Potentials by Decreasing Order
of Potential