Tables :  Standard Reduction Potentials

Standard Reduction Potentials
in Aqueous Solution at 25C

Half-reaction

 E (V)
Li+ + e- Li(s)

-3.05
Cs+ + e- Cs(s)

-2.92
K+ + e- K(s)

-2.92
Rb+ + e- Rb(s)

-2.92
Ba2+ + 2 e- Ba(s)

-2.90
Sr2+ 2 e- Sr(s)

-2.89
Ca2+ + 2 e- Ca(s)

-2.87
Na+ + e- Na(s)

-2.71
Mg2+ + 2 e- Mg(s)

-2.37
Be2+ + 2 e- Be(s)

-1.70
Al3+ + 3 e- Al(s)

-1.66
Mn2+ + 2 e- Mn(s)

-1.18
Zn2+ + 2 e- Zn(s)

-0.76
Cr3+ + 3 e- Cr(s)

-0.74
Fe2+ + 2 e- Fe(s)

-0.44
Cr3+ + e- Cr2+

-0.41
Cd2+ + 2 e- Cd(s)

-0.40
Tl+ + e- Tl(s)

-0.34
Co2+ + 2 e- Co(s)

-0.28
Ni2+ + 2 e- Ni(s)

-0.25
Sn2+ + 2e-  Sn(s)

-0.14
Pb2+ + 2 e- Pb(s)

-0.13
2 H+ + 2 e- H2(g)

0.00
S(s) + 2 H+ + 2 e- H2S (g)

0.14
Sn4+ + 2 e- Sn2+

0.15
Cu2+ + e- Cu+

0.15
Cu2+ + 2 e- Cu(s)

0.34
Cu+ + e- Cu(s)

0.52
I2(s) + 2 e- 2 I-

0.53
Fe3+ + e- Fe2+

0.77
Hg22+ + 2 e- 2 Hg(l)

0.79
Ag+ + e- Ag(s)

0.80
Hg2+ + 2 e- Hg(l)

0.85
2 Hg2+ + 2 e- Hg22+

0.92
Br2(l) + 2 e 2 Br-

1.07
O2(g) + 4 H+ + 4 e- 2 H2O(l)

1.23
Cl2(g) + 2 e- 2 Cl-

1.36
Au3+ + 3 e- Au(s)

1.50
Co3+ + e- Co2+

1.82
F2(g) + 2 e- 2 F-

2.87