Selected Standard Reduction Potentials at 298 K
| Reduction half-reactions | E°(V) | ||
|---|---|---|---|
| Li1+(aq) + e1– | ⇌ | Li(s) | –3.04 |
| K1+ (aq)+ e1– | ⇌ | K(s) | –2.92 |
| Ba2+(aq) + 2 e1– | ⇌ | Ba(s) | –2.92 |
| Ca2+(aq) + 2 e1– | ⇌ | Ca(s) | –2.84 |
| Na1+(aq) + e1– | ⇌ | Na(s) | –2.71 |
| Mg2+(aq) + 2 e1– | ⇌ | Mg(s) | –2.36 |
| Al3+(aq) + 3 e1– | ⇌ | Al(s) | –1.66 |
| U3+(aq) + 3 e1– | ⇌ | U(s) | –1.66 |
| Ti2+(aq) + 2 e1– | ⇌ | Ti(s) | –1.63 |
| Mn2+(aq) + 2 e1– | ⇌ | Mn(s) | –1.18 |
| 2 H2O + 2 e1– | ⇌ | H2(g) + 2 OH1–(aq) | –0.83 |
| Zn2+(aq) + 2 e1– | ⇌ | Zn(s) | –0.76 |
| Cr3+(aq) + 3 e1– | ⇌ | Cr(s) | –0.74 |
| HCHO(aq) + 2 H2O + 2 e1– | ⇌ | CH3OH(aq) + 2 OH1–(aq) | –0.59 |
| Fe2+(aq) + 2 e1– | ⇌ | Fe(s) | –0.44 |
| 2 H2O + 2 e1– | ⇌ | H2(g) + 2 OH1–(aq) | –0.41* |
| Cd2+(aq) + 2 e1– | ⇌ | Cd(s) | –0.40 |
| PbSO4(s) + 2 e1– | ⇌ | Pb(s) + SO42–(aq) | –0.36 |
| In3+(aq) + 3 e1– | ⇌ | In(s) | –0.34 |
| Co2+(aq) + 2 e1– | ⇌ | Co(s) | –0.28 |
| Ni2+(aq) + 2 e1– | ⇌ | Ni(s) | –0.23 |
| Sn2+(aq) + 2 e1– | ⇌ | Sn(s) | –0.14 |
| Pb2+(aq) + 2 e1– | ⇌ | Pb(s) | –0.13 |
| 2 H1+(aq) + 2 e1– | ⇌ | H2(g) | 0.00 |
| Sn4+(aq) + 2 e1– | ⇌ | Sn2+(aq) | +0.15 |
| Cu2+(aq) + e1– | ⇌ | Cu1+(aq) | +0.16 |
| ClO41–(aq) + H2O(l) + 2 e1– | ⇌ | ClO31–(aq) + 2 OH1–(aq) | +0.17 |
| AgCl(s) + e1– | ⇌ | Ag(s) + Cl1–(aq) | +0.22 |
| PbO2(s) + 2 H1+(aq) + 2 e1– | ⇌ | PbO(s) + H2O | +0.28 |
| Cu2+(aq) + 2 e1– | ⇌ | Cu(s) | +0.34 |
| Ag2O(s) +H2O + 2 e1– | ⇌ | 2 Ag(s) + 2 OH1–(aq) | +0.34 |
| ClO31–(aq) + H2O(l) + 2 e1– | ⇌ | ClO21–(aq) + 2 OH1–(aq) | +0.35 |
| O2(g) + 2 H2O + 4 e1– | ⇌ | 4 OH1–(aq) | +0.40 |
| I2(s) + 2 e1– | ⇌ | 2 I1–(aq) | +0.54 |
| ClO21–(aq) + H2O(l) + 2 e1– | ⇌ | ClO1–(aq) + 2 OH1–(aq) | +0.59 |
| 2 AgO(s) + H2O + 2 e1– | ⇌ | Ag2O(s) + 2 OH1–(aq) | +0.60 |
| O2(g) + 2 H1+(aq) + 2 e1– | ⇌ | H2O2(aq) | +0.70 |
| Fe3+(aq) + e1– | ⇌ | Fe2+(aq) | +0.77 |
| BrO1–(aq) + H2O + 2 e1– | ⇌ | Br1–(aq) + 2 OH1–(aq) | +0.77 |
| Ag1+(aq) + e1– | ⇌ | Ag(s) | +0.80 |
| O2(g)+ 4 H1+(aq) + 4 e1– | ⇌ | 2 H2O | +0.82* |
| H2O2(aq) + 2 e1– | ⇌ | 2 OH1–(aq) | +0.88 |
| ClO1–(aq) + H2O + 2 e1– | ⇌ | Cl1–(aq) + 2 OH1–(aq) | +0.89 |
| Hg2+(aq) + 2 e1– | ⇌ | Hg(l) | +0.85 |
| NO31–(aq) + 4 H1+(aq) + 3 e1– | ⇌ | NO(g) + 2 H2O | +0.96 |
| VO21+(aq) + 2 H1+(aq) + e1– | ⇌ | VO2+(aq) + H2O | +1.00 |
| Br2(l) + 2 e1– | ⇌ | 2 Br1–(aq) | +1.09 |
| ClO41–(aq) + 2 H1+(aq) + 2 e1– | ⇌ | ClO31–(aq) + H2O(l) | +1.19 |
| O2(g)+ 4 H1+(aq) + 4 e1– | ⇌ | 2 H2O | +1.23 |
| Cr2O72–(aq)+ 14 H1+(aq) + 6 e1– | ⇌ | 2 Cr3+(aq) + 7 H2O | +1.33 |
| Cl2(g) + 2 e1– | ⇌ | 2 Cl1–(aq) | +1.36 |
| Au3+(aq) + 3 e1– | ⇌ | Au(s) | +1.50 |
| MnO41–(aq) + 8 H1+(aq)+ 5 e1– | ⇌ | Mn2+(aq) + 4 H2O | +1.51 |
| PbO2(s) + 4 H1+(aq) + SO42–(aq) + 2 e1– | ⇌ | PbSO4(s) + 2 H2O | +1.69 |
| H2O2(aq) + 2 H1+(aq) + 2 e1– | ⇌ | 2 H2O(l) | +1.76 |
| S2O82–(aq) + 2 e1– | ⇌ | 2 SO42–(aq) | +2.01 |
| O3(g) + 2 H1+(aq) + 2 e1– | ⇌ | O2(g) + H2O | +2.07 |
| F2(g) + 2 e1– | ⇌ | 2 F1–(aq) | +2.87 |
* The half-cell potentials for the O2/H2O and the H2O/H2 systems are for neutral (pH = 7) water and are not standard reduction potentials where [OH1–] or [H1+] = 1.0 M.