| redox couple | half | reaction (reduction) | E°red (V) | |
|---|---|---|---|---|
| F2 / F– | F2(g) + 2e– | ⇌ | 2F–(aq) | +2.87 |
| O3 / O2 | O3(g) + 2H+(aq) + 2e– | ⇌ | O2(g) + H2O(l) | +2.07 |
| S2O82– / SO42– | S2O82–(aq) + 2e– | ⇌ | 2SO42–(aq) | +2.05 |
| H2O2 / H2O | H2O2(aq) + 2H+(aq) + 2e– | ⇌ | 2H2O(l) | +1.78 |
| PbO2 / PbSO4 | PbO2(s) + 3H+(aq) + HSO4–(aq) + 2e– | ⇌ | PbSO4(s) + 2H2O(l) | +1.69 |
| Au+ / Au | Au+(aq) + e– | ⇌ | Au(s) | +1.69 |
| Pb4+ / Pb2+ | Pb4+(aq) +2e– | ⇌ | Pb2+(aq) | +1.67 |
| HClO / Cl2 | 2HClO(aq) + 2H+(aq) + 2e– | ⇌ | Cl2(g) + 2H2O(l) | +1.63 |
| Ce4+ / Ce3+ | Ce4+(aq) + e– | ⇌ | Ce3+(aq) | +1.61 |
| MnO4– / Mn2+ | MnO4–(aq) + 8H+(aq) + 5e– | ⇌ | Mn2+(aq) + 4H2O(l) | +1.51 |
| Au3+ / Au | Au3+(aq) + 3e– | ⇌ | Au(s) | +1.40 |
| Cl2 / Cl– | Cl2(g) + 2e– | ⇌ | 2Cl–(aq) | +1.36 |
| Cr2O72– / Cr3+ | Cr2O72–(aq) + 14H+(aq) + 6e– | ⇌ | 2Cr3+(aq) + 7H2O(l) | +1.33 |
| O2 / H2O | O2(g) + 4H+(aq) + 4e– | ⇌ | 2H2O(l) | +1.23 |
| MnO2 / Mn2+ | MnO2(s) + 4H+(aq) + 2e– | ⇌ | Mn2+(aq) + 2H2O(l) | +1.21 |
| Pt2+ / Pt | Pt2+(aq) + 2e– | ⇌ | Pt(s) | +1.20 |
| Br2 / Br– | Br2(l) + 2e– | ⇌ | 2Br–(aq) | +1.09 |
| Pd2+ / Pd | Pd2+(aq) + 2e– | ⇌ | Pd(s) | +0.92 |
| Hg2+ / Hg22+ | 2Hg2+(aq) + 2e– | ⇌ | Hg22+(aq) | +0.92 |
| ClO– / Cl– | ClO–(aq) + H2O(l) + 2e– | ⇌ | Cl–(aq) + 2OH–(aq) | +0.89 |
| Ag+ / Ag | Ag+(aq) + e– | ⇌ | Ag(s) | +0.80 |
| Hg22+ / Hg | Hg22+(aq) + 2e– | ⇌ | 2Hg(l) | +0.79 |
| Fe3+ / Fe2+ | Fe3+(aq) + e– | ⇌ | Fe2+(aq) | +0.77 |
| MnO4– / MnO2 | MnO4–(aq) + 2H2O(l) + 3e– | ⇌ | MnO2(s) + 4OH–(aq) | +0.60 |
| I2 / I– | I2(s) + 2e– | ⇌ | 2I–(aq) | +0.54 |
| O2 / OH– | O2(g) + 2H2O(l) + 4e– | ⇌ | 4OH–(aq) | +0.40 |
| Cu2+ / Cu | Cu2+(aq) + 2e– | ⇌ | Cu(s) | +0.34 |
| Hg2Cl2 / Hg | Hg2Cl2(s) + 2e– | ⇌ | 2Hg(l) + 2Cl–(aq) | +0.27 |
| AgCl / Ag | AgCl(s) + e– | ⇌ | Ag(s) + Cl–(aq) | +0.22 |
| Bi3+ / Bi | Bi3+(aq) + e– | ⇌ | Bi(s) | +0.20 |
| NO3– / NO2– | NO3–(aq) + H2O(l) + 2e– | ⇌ | NO2–(aq) + 2OH–(aq) | +0.01 |
| H+ / H2 | 2H+(aq) + 2e– | ⇌ | H2(g) | +0.00 |
| Fe3+ / Fe | Fe3+(aq) + 3e– | ⇌ | Fe(s) | -0.04 |
| Pb2+ / Pb | Pb2+(aq) + 2e– | ⇌ | Pb(s) | -0.13 |
| Sn2+ / Sn | Sn2+(aq) + 2e– | ⇌ | Sn(s) | -0.14 |
| Ni2+ / Ni | Ni2+(aq) + 2e– | ⇌ | Ni(s) | -0.23 |
| V3+ / V2+ | V3+(aq) + e– | ⇌ | V2+(aq) | -0.26 |
| Co2+ / Co | Co2+(aq) + 2e– | ⇌ | Co(s) | -0.28 |
| In3+ / In | In3+(aq) + 3e– | ⇌ | In(s) | -0.34 |
| PbSO4 / Pb | PbSO4(s) + H+(aq) + 2e– | ⇌ | Pb(s) + HSO4–(aq) | -0.36 |
| Cd2+ / Cd | Cd2+(aq) + 2e– | ⇌ | Cd(s) | -0.40 |
| Cr3+ / Cr2+ | Cr3+(aq) + e– | ⇌ | Cr2+(aq) | -0.41 |
| Fe2+ / Fe | Fe2+(aq) + 2e– | ⇌ | Fe(s) | -0.44 |
| U4+ / U3+ | U4+(aq) + e– | ⇌ | U3+(aq) | -0.61 |
| FeCO3 / Fe | FeCO3(s) + 2e– | ⇌ | Fe(s) + CO32-(aq) | -0.76 |
| Zn2+ / Zn | Zn2+(aq) + 2e– | ⇌ | Zn(s) | -0.76 |
| H2O / H2 | 2H2O(l) + 2e– | ⇌ | H2(s) + 2OH–(aq) | -0.83 |
| Cr2+ / Cr | Cr2+(aq) + 2e– | ⇌ | Cr(s) | -0.91 |
| Mn2+ / Mn | Mn2+(aq) + 2e– | ⇌ | Mn(s) | -1.18 |
| V2+ / V | V2+(aq) + 2e– | ⇌ | V(s) | -1.19 |
| ZnS / Zn | ZnS(s) + 2e– | ⇌ | Zn(s) + S2–(aq) | -1.44 |
| Al3+ / Al | Al3+(aq) + 3e– | ⇌ | Al(s) | -1.66 |
| Mg2+ / Mg | Mg2+(aq) + 2e– | ⇌ | Mg(s) | -2.36 |
| Na+ / Na | Na+(aq) + e– | ⇌ | Na(s) | -2.71 |
| K+ / K | K+(aq) + e– | ⇌ | K(s) | -2.92 |
| Li+ / Li | Li+(aq) + e– | ⇌ | Li(s) | -3.05 |