Table of standard electrode potentials

The values below are standard electrode potentials taken at 25°C in aqueous solution.

Cathode (Reduction) Half-Reaction Standard Potential E° (volts)
Li+(aq) + e- → Li(s) -3.04
Rb+ + e- → Rb (s) -2.98
K+(aq) + e- → K(s) -2.93
Cs+(aq) + e- → Cs(s) -2.92
Ba2+(aq) + 2e- → Ba(s) -2.91
Sr2+(aq) + 2e- → Sr(s) -2.89
Ca2+(aq) + 2e- → Ca(s) -2.76
Na+(aq) + e- → Na(s) -2.71
Mg2+(aq) + 2e- → Mg(s) -2.38
Al3+(aq) + 3e- → Al(s) -1.66
Mn2+(aq) + 2e- → Mn(s) -1.19
2H2O(l) + 2e- → H2(g) + 2OH-(aq) -0.83
Zn2+(aq) + 2e- → Zn(s) -0.76
Cr3+(aq) + 3e- → Cr(s) -0.74
Fe2+(aq) + 2e- → Fe(s) -0.41
Cd2+(aq) + 2e- → Cd(s) -0.40
Co2+(aq) + 2e- → Co(s) -0.28
Ni2+(aq) + 2e- → Ni(s) -0.23
Sn2+(aq) + 2e- → Sn(s) -0.14
Pb2+(aq) + 2e- → Pb(s) -0.13
Fe3+(aq) + 3e- → Fe(s) -0.04
2H+(aq) + 2e- → H2(g) 0.00
Sn4+(aq) + 2e- → Sn2+(aq) 0.15
Cu2+(aq) + 2e- → Cu+(aq) 0.16
ClO4-(aq) +

H2O(l) + 2e- → ClO3-(aq) +

2OH-(aq)
0.17
AgCl(s) + e- → Ag(s) + Cl-(aq) 0.22
Cu2+(aq) + 2e- → Cu(s) 0.34
ClO3-(aq) +

H2O(l) + 2e-

ClO2-(aq) + 2OH-(aq)
0.35
O-(aq) + H2O(l) + 2e-I-(aq) + 2OH-(aq) 0.49
Cu+(aq) + e- → Cu(s) 0.52
I2(s) + 2e- → 2I-(aq) 0.54
ClO2-(aq) +

H2O(l) + 2e- → ClO-(aq) +

2OH-(aq)
0.59
Fe3+(aq) + e- → Fe2+(aq) 0.77
Hg22+(aq) + 2e- → 2Hg(l) 0.80
Ag+(aq) + e- → Ag(s) 0.80
Hg2+(aq) + 2e- → Hg(l) 0.85
ClO-(aq) + H2O(l) + 2e- → Cl-(aq) + 2OH-(aq) 0.90
2Hg2+(aq) + 2e- → Hg22+(aq) 0.90
NO3-(aq) +

4H+(aq) + 3e- → NO(g) +

2H2O(l)
0.96
Br2(l) + 2e- → 2Br-(aq) 1.07
O2(g) + 4H+(aq) + 4e- → 2H2O(l) 1.23
Cr2O72-(aq) +

14H+(aq) + 6e- → 2Cr3+(aq) +

7H2O(l)
1.33
Cl2(g) + 2e- → 2Cl-(aq) 1.36
Ce4+(aq) + e- → Ce3+(aq) 1.44
MnO4-(aq) +

8H+(aq) + 5e- → Mn2+(aq) +

4H2O(l)
1.49
H2O2(aq) + 2H+(aq) + 2e- → 2H2O(l) 1.78
Co3+(aq) + e- → Co2+(aq) 1.82
S2O82-(aq) + 2e- → 2SO42-(aq) 2.01
O3(g) + 2H+(aq) + 2e- → O2(g) + H2O(l) 2.07
F2(g) + 2e- → 2F-(aq) 2.87

See also: electrochemical potential

See also: Table of standard electrode potentials, Electrochemical potential, Standard electrode potential