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
