Standard electrode potential (data page)
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Main article: standard electrode potential
The values of standard electrode potentials are given in the table below in volts relative to the standard hydrogen electrode and are for the following conditions:
- A temperature of 298.15 K (25 °C);
- An effective concentration of 1 mol/L for each aqueous species or a species in a mercury amalgam;
- A partial pressure of 101.325 kPa (absolute) (1 atm, 1.01325 bar) for each gaseous reagent. This pressure is used because most literature data are still given for this value rather than for the current standard of 100 kPa.
- An activity of unity for each pure solid, pure liquid, or for water (solvent).
Legend: (s) – solid; (l) – liquid; (g) – gas; (aq) – aqueous (default for all charged species); (Hg) – amalgam.
| Half-reaction | E° (V)[note 1] | Ref. |
|---|---|---|
3⁄2 N2(g) + H+ + e−  HN3(aq) |
−3.09 | [1][2] |
| Li+ + e− Li(s) |
−3.0401 | [2] |
| N2(g) + 4 H2O + 2 e− 2 NH2OH(aq) + 2 OH− |
−3.04 | [1] |
| Cs+ + e− Cs(s) |
−3.026 | [2] |
| Rb+ + e− Rb(s) |
−2.98 | [2] |
| K+ + e− K(s) |
−2.931 | [2] |
| Ba2+ + 2 e− Ba(s) |
−2.912 | [2] |
| La(OH)3(s) + 3 e− La(s) + 3 OH− |
−2.90 | [2] |
| Sr2+ + 2 e− Sr(s) |
−2.899 | [2] |
| Ca2+ + 2 e− Ca(s) |
−2.868 | [2] |
| Eu2+ + 2 e− Eu(s) |
−2.812 | [2] |
| Ra2+ + 2 e− Ra(s) |
−2.8 | [2] |
| Na+ + e− Na(s) |
−2.71 | [2][3] |
| La3+ + 3 e− La(s) |
−2.379 | [2] |
| Y3+ + 3 e− Y(s) |
−2.372 | [2] |
| Mg2+ + 2 e− Mg(s) |
−2.372 | [2] |
| ZrO(OH)2(s) + H2O + 4 e− Zr(s) + 4 OH− |
−2.36 | [2] |
| Al(OH)4− + 3 e− Al(s) + 4 OH− |
−2.33 | |
| Al(OH)3(s) + 3 e− Al(s) + 3 OH− |
−2.31 | |
| H2(g) + 2 e− 2 H− |
−2.25 | |
| Ac3+ + 3 e− Ac(s) |
−2.20 | |
| Be2+ + 2 e− Be(s) |
−1.85 | |
| U3+ + 3 e− U(s) |
−1.66 | [4] |
| Al3+ + 3 e− Al(s) |
−1.66 | [3] |
| Ti2+ + 2 e− Ti(s) |
−1.63 | [3] |
| ZrO2(s) + 4 H+ + 4 e− Zr(s) + 2 H2O |
−1.553 | [5] |
| Zr4+ + 4 e− Zr(s) |
−1.45 | [5] |
| Ti3+ + 3 e− Ti(s) |
−1.37 | [6] |
| TiO(s) + 2 H+ + 2 e− Ti(s) + H2O |
−1.31 | |
| Ti2O3(s) + 2 H+ + 2 e− 2 TiO(s) + H2O |
−1.23 | |
| Zn(OH)42− + 2 e− Zn(s) + 4 OH− |
−1.199 | [5] |
| Mn2+ + 2 e− Mn(s) |
−1.185 | [5] |
| Fe(CN)64− + 6 H+ + 2 e− Fe(s) + 4HCN(aq) |
−1.16 | [7] |
| Te(s) + 2 e− Te2− |
−1.143 | [8] |
| V2+ + 2 e− V(s) |
−1.13 | [8] |
| Nb3+ + 3 e− Nb(s) |
−1.099 | |
| Sn(s) + 4 H+ + 4 e− SnH4(g) |
−1.07 | |
| SiO2(s) + 4 H+ + 4 e− Si(s) + 2 H2O |
−0.91 | |
| B(OH)3(aq) + 3 H+ + 3 e− B(s) + 3 H2O |
−0.89 | |
| Fe(OH)2(s) + 2 e− Fe(s) + 2 OH− |
−0.89 | [7] |
| Fe2O3(s) + 3 H2O + 2 e− 2Fe(OH)2(s) + 2 OH− |
−0.86 | [7] |
| TiO2+ + 2 H+ + 4 e− Ti(s) + H2O |
−0.86 | |
| 2 H2O + 2 e− H2(g) + 2 OH− |
−0.8277 | [5] |
| Bi(s) + 3 H+ + 3 e− BiH3 |
−0.8 | [5] |
| Zn2+ + 2 e− Zn(Hg) |
−0.7628 | [5] |
| Zn2+ + 2 e− Zn(s) |
−0.7618 | [5] |
| Ta2O5(s) + 10 H+ + 10 e− 2 Ta(s) + 5 H2O |
−0.75 | |
| Cr3+ + 3 e− Cr(s) |
−0.74 | |
| [Au(CN)2]− + e− Au(s) + 2 CN− |
−0.60 | |
| Ta3+ + 3 e− Ta(s) |
−0.6 | |
| PbO(s) + H2O + 2 e− Pb(s) + 2 OH− |
−0.58 | |
| 2 TiO2(s) + 2 H+ + 2 e− Ti2O3(s) + H2O |
−0.56 | |
| Ga3+ + 3 e− Ga(s) |
−0.53 | |
| U4+ + e− U3+ |
−0.52 | [4] |
| H3PO2(aq) + H+ + e− P(white)[note 2] + 2 H2O |
−0.508 | [5] |
| H3PO3(aq) + 2 H+ + 2 e− H3PO2(aq) + H2O |
−0.499 | [5] |
| H3PO3(aq) + 3 H+ + 3 e− P(red)[note 2] + 3 H2O |
−0.454 | [5] |
| Fe2+ + 2 e− Fe(s) |
−0.44 | [3] |
| 2 CO2(g) + 2 H+ + 2 e− HOOCCOOH(aq) |
−0.43 | |
| Cr3+ + e− Cr2+ |
−0.42 | |
| Cd2+ + 2 e− Cd(s) |
−0.40 | [3] |
| GeO2(s) + 2 H+ + 2 e− GeO(s) + H2O |
−0.37 | |
| Cu2O(s) + H2O + 2 e− 2 Cu(s) + 2 OH− |
−0.360 | [5] |
| PbSO4(s) + 2 e− Pb(s) + SO42− |
−0.3588 | [5] |
| PbSO4(s) + 2 e− Pb(Hg) + SO42− |
−0.3505 | [5] |
| Eu3+ + e− Eu2+ |
−0.35 | [4] |
| In3+ + 3 e− In(s) |
−0.34 | [8] |
| Tl+ + e− Tl(s) |
−0.34 | [8] |
| Ge(s) + 4 H+ + 4 e− GeH4(g) |
−0.29 | |
| Co2+ + 2 e− Co(s) |
−0.28 | [5] |
| H3PO4(aq) + 2 H+ + 2 e− H3PO3(aq) + H2O |
−0.276 | [5] |
| V3+ + e− V2+ |
−0.26 | [3] |
| Ni2+ + 2 e− Ni(s) |
−0.25 | |
| As(s) + 3 H+ + 3 e− AsH3(g) |
−0.23 | [8] |
| AgI(s) + e− Ag(s) + I− |
−0.15224 | [5] |
| MoO2(s) + 4 H+ + 4 e− Mo(s) + 2 H2O |
−0.15 | |
| Si(s) + 4 H+ + 4 e− SiH4(g) |
−0.14 | |
| Sn2+ + 2 e− Sn(s) |
−0.13 | |
| O2(g) + H+ + e− HO2•(aq) |
−0.13 | |
| Pb2+ + 2 e− Pb(s) |
−0.13 | [3] |
| WO2(s) + 4 H+ + 4 e− W(s) + 2 H2O |
−0.12 | |
| P(red) + 3 H+ + 3 e− PH3(g) |
−0.111 | [5] |
| CO2(g) + 2 H+ + 2 e− HCOOH(aq) |
−0.11 | |
| Se(s) + 2 H+ + 2 e− H2Se(g) |
−0.11 | |
| CO2(g) + 2 H+ + 2 e− CO(g) + H2O |
−0.11 | |
| SnO(s) + 2 H+ + 2 e− Sn(s) + H2O |
−0.10 | |
| SnO2(s) + 2 H+ + 2 e− SnO(s) + H2O |
−0.09 | |
| WO3(aq) + 6 H+ + 6 e− W(s) + 3 H2O |
−0.09 | [8] |
| P(white) + 3 H+ + 3 e− PH3(g) |
−0.063 | [5] |
| Fe3+ + 3 e− Fe(s) |
−0.04 | [7] |
| HCOOH(aq) + 2 H+ + 2 e− HCHO(aq) + H2O |
−0.03 | |
| 2 H+ + 2 e− H2(g) |
0.0000 | ≡ 0 |
| AgBr(s) + e− Ag(s) + Br− |
+0.07133 | [5] |
| S4O62− + 2 e− 2 S2O32− |
+0.08 | |
| Fe3O4(s) + 8 H+ + 8 e− 3 Fe(s) + 4 H2O |
+0.085 | [9] |
| N2(g) + 2 H2O + 6 H+ + 6 e− 2 NH4OH(aq) |
+0.092 | |
| HgO(s) + H2O + 2 e− Hg(l) + 2 OH− |
+0.0977 | |
| Cu(NH3)42+ + e− Cu(NH3)2+ + 2 NH3 |
+0.10 | [8] |
| Ru(NH3)63+ + e− Ru(NH3)62+ |
+0.10 | [4] |
| N2H4(aq) + 4 H2O + 2 e− 2 NH4+ + 4 OH− |
+0.11 | [1] |
| H2MoO4(aq) + 6 H+ + 6 e− Mo(s) + 4 H2O |
+0.11 | |
| Ge4+ + 4 e− Ge(s) |
+0.12 | |
| C(s) + 4 H+ + 4 e− CH4(g) |
+0.13 | [8] |
| HCHO(aq) + 2 H+ + 2 e− CH3OH(aq) |
+0.13 | |
| S(s) + 2 H+ + 2 e− H2S(g) |
+0.14 | |
| Sn4+ + 2 e− Sn2+ |
+0.15 | |
| Cu2+ + e− Cu+ |
+0.159 | [8] |
| HSO4− + 3 H+ + 2 e− SO2(aq) + 2 H2O |
+0.16 | |
| UO22+ + e− UO2+ |
+0.163 | [4] |
| SO42− + 4 H+ + 2 e− SO2(aq) + 2 H2O |
+0.17 | |
| TiO2+ + 2 H+ + e− Ti3+ + H2O |
+0.19 | |
| SbO+ + 2 H+ + 3 e− Sb(s) + H2O |
+0.20 | |
| AgCl(s) + e− Ag(s) + Cl− |
+0.22233 | [5] |
| H3AsO3(aq) + 3 H+ + 3 e− As(s) + 3 H2O |
+0.24 | |
| GeO(s) + 2 H+ + 2 e− Ge(s) + H2O |
+0.26 | |
| UO2+ + 4 H+ + e− U4+ + 2 H2O |
+0.273 | [4] |
| Re3+ + 3 e− Re(s) |
+0.300 | |
| Bi3+ + 3 e− Bi(s) |
+0.308 | [5] |
| VO2+ + 2 H+ + e− V3+ + H2O |
+0.34 | |
| Cu2+ + 2 e− Cu(s) |
+0.340 | [8] |
| [Fe(CN)6]3− + e− [Fe(CN)6]4− |
+0.36 | |
| O2(g) + 2 H2O + 4 e− 4 OH−(aq) |
+0.40 | [3] |
| H2MoO4 + 6 H+ + 3 e− Mo3+ + 2 H2O |
+0.43 | |
| CH3OH(aq) + 2 H+ + 2 e− CH4(g) + H2O |
+0.50 | |
| SO2(aq) + 4 H+ + 4 e− S(s) + 2 H2O |
+0.50 | |
| Cu+ + e− Cu(s) |
+0.520 | [8] |
| CO(g) + 2 H+ + 2 e− C(s) + H2O |
+0.52 | |
| I3− + 2 e− 3 I− |
+0.53 | [3] |
| I2(s) + 2 e− 2 I− |
+0.54 | [3] |
| [AuI4]− + 3 e− Au(s) + 4 I− |
+0.56 | |
| H3AsO4(aq) + 2 H+ + 2 e− H3AsO3(aq) + H2O |
+0.56 | |
| [AuI2]− + e− Au(s) + 2 I− |
+0.58 | |
| MnO4− + 2 H2O + 3 e− MnO2(s) + 4 OH− |
+0.59 | |
| S2O32 − + 6 H+ + 4 e− 2 S(s) + 3 H2O |
+0.60 | |
| Fc+ + e− Fc(s) |
+0.641 | [10] |
| H2MoO4(aq) + 2 H+ + 2 e− MoO2(s) + 2 H2O |
+0.65 | |
 + 2 H+ + 2 e−  |
+0.6992 | [5] |
| O2(g) + 2 H+ + 2 e− H2O2(aq) |
+0.70 | |
| Tl3+ + 3 e− Tl(s) |
+0.72 | |
| PtCl62− + 2 e− PtCl42− + 2 Cl− |
+0.726 | [4] |
| H2SeO3(aq) + 4 H+ + 4 e− Se(s) + 3 H2O |
+0.74 | |
| PtCl42− + 2 e− Pt(s) + 4 Cl− |
+0.758 | [4] |
| Fe3+ + e− Fe2+ |
+0.77 | |
| Ag+ + e− Ag(s) |
+0.7996 | [5] |
| Hg22+ + 2 e− 2 Hg(l) |
+0.80 | |
| NO3−(aq) + 2 H+ + e− NO2(g) + H2O |
+0.80 | |
| FeO42− + 5 H2O + 6 e− Fe2O3(s) + 10 OH− |
+0.81 | [7] |
| [AuBr4]− + 3 e− Au(s) + 4 Br− |
+0.85 | |
| Hg2+ + 2 e− Hg(l) |
+0.85 | |
| MnO4− + H+ + e− HMnO4− |
+0.90 | |
| 2 Hg2+ + 2 e− Hg22+ |
+0.91 | [8] |
| Pd2+ + 2 e− Pd(s) |
+0.915 | [4] |
| [AuCl4]− + 3 e− Au(s) + 4 Cl− |
+0.93 | |
| MnO2(s) + 4 H+ + e− Mn3+ + 2 H2O |
+0.95 | |
| [AuBr2]− + e− Au(s) + 2 Br− |
+0.96 | |
| [HXeO6]3− + 2 H2O + 2 e− + [HXeO4]− + 4 OH− |
+0.99 | [11] |
| H6TeO6(aq) + 2 H+ + 2 e− TeO2(s) + 4 H2O |
+1.02 | [12] |
| Br2(l) + 2 e− 2 Br− |
+1.066 | [5] |
| Br2(aq) + 2 e− 2 Br− |
+1.0873 | [5] |
| IO3− + 5 H+ + 4 e− HIO(aq) + 2 H2O |
+1.13 | |
| [AuCl2]− + e− Au(s) + 2 Cl− |
+1.15 | |
| HSeO4− + 3 H+ + 2 e− H2SeO3(aq) + H2O |
+1.15 | |
| Ag2O(s) + 2 H+ + 2 e− 2 Ag(s) + H2O |
+1.17 | |
| ClO3− + 2 H+ + e− ClO2(g) + H2O |
+1.18 | |
| [HXeO6]3− + 5 H2O + 8 e− Xe(g) + 11 OH− |
+1.18 | [11] |
| Pt2+ + 2 e− Pt(s) |
+1.188 | [4] |
| ClO2(g) + H+ + e− HClO2(aq) |
+1.19 | |
| 2 IO3− + 12 H+ + 10 e− I2(s) + 6 H2O |
+1.20 | |
| ClO4− + 2 H+ + 2 e− ClO3− + H2O |
+1.20 | |
| O2(g) + 4 H+ + 4 e− 2 H2O |
+1.229 | [3] |
| MnO2(s) + 4 H+ + 2 e− Mn2+ + 2 H2O |
+1.23 | |
| [HXeO4]− + 3 H2O + 6 e− Xe(g) + 7 OH− |
+1.24 | [11] |
| Tl3+ + 2 e− Tl+ |
+1.25 | |
| Cr2O72− + 14 H+ + 6 e− 2 Cr3+ + 7 H2O |
+1.33 | |
| Cl2(g) + 2 e− 2 Cl− |
+1.36 | [3] |
| CoO2(s) + 4 H+ + e− Co3+ + 2 H2O |
+1.42 | |
| 2 NH3O H+ + H+ + 2 e− N2H5+ + 2 H2O |
+1.42 | [1] |
| 2 HIO(aq) + 2 H+ + 2 e− I2(s) + 2 H2O |
+1.44 | |
| Ce4+ + e− Ce3+ |
+1.44 | |
| BrO3− + 5 H+ + 4 e− HBrO(aq) + 2 H2O |
+1.45 | |
| β-PbO2(s) + 4 H+ + 2 e− Pb2+ + 2 H2O |
+1.460 | [8] |
| α-PbO2(s) + 4 H+ + 2 e− Pb2+ + 2 H2O |
+1.468 | [8] |
| 2 BrO3− + 12 H+ + 10 e− Br2(l) + 6 H2O |
+1.48 | |
| 2ClO3− + 12 H+ + 10 e− Cl2(g) + 6 H2O |
+1.49 | |
| MnO4− + 8 H+ + 5 e− Mn2+ + 4 H2O |
+1.51 | |
| HO2• + H+ + e− H2O2(aq) |
+1.51 | |
| Au3+ + 3 e− Au(s) |
+1.52 | |
| NiO2(s) + 4 H+ + 2 e− Ni2+ + 2 OH− |
+1.59 | |
| 2 HClO(aq) + 2 H+ + 2 e− Cl2(g) + 2 H2O |
+1.63 | |
| Ag2O3(s) + 6 H+ + 4 e− 2 Ag+ + 3 H2O |
+1.67 | |
| HClO2(aq) + 2 H+ + 2 e− HClO(aq) + H2O |
+1.67 | |
| Pb4+ + 2 e− Pb2+ |
+1.69 | [8] |
| MnO4− + 4 H+ + 3 e− MnO2(s) + 2 H2O |
+1.70 | |
| AgO(s) + 2 H+ + e− Ag+ + H2O |
+1.77 | |
| H2O2(aq) + 2 H+ + 2 e− 2 H2O |
+1.78 | |
| Co3+ + e− Co2+ |
+1.82 | |
| Au+ + e− Au(s) |
+1.83 | [8] |
| BrO4− + 2 H+ + 2 e− BrO3− + H2O |
+1.85 | |
| Ag2+ + e− Ag+ |
+1.98 | [8] |
| S2O82− + 2 e− 2 SO42− |
+2.010 | [5] |
| O3(g) + 2 H+ + 2 e− O2(g) + H2O |
+2.075 | [4] |
| HMnO4− + 3 H+ + 2 e− MnO2(s) + 2 H2O |
+2.09 | |
| XeO3(aq) + 6 H+ + 6 e− Xe(g) + 3 H2O |
+2.12 | [11] |
| H4XeO6(aq) + 8 H+ + 8 e− Xe(g) + 6 H2O |
+2.18 | [11] |
| FeO42− + 3 e− + 8 H+ Fe3+ + 4 H2O |
+2.20 | [13] |
| XeF2(aq) + 2 H+ + 2 e− Xe(g) + 2HF(aq) |
+2.32 | [11] |
| H4XeO6(aq) + 2 H+ + 2 e− XeO3(aq) + H2O |
+2.42 | [11] |
| F2(g) + 2 e− 2 F− |
+2.87 | [8][3] |
| F2(g) + 2 H+ + 2 e− 2 HF(aq) |
+3.05 | [8] |
- ^ Clicking on this column to re-sort by potential didn’t work in the Safari web browser in v. 4.0.3 or earlier (but works in v. 4.0.5). In this case just reload the page to restore the original order.
- ^ a b Not specified in the indicated reference, but assumed due to the difference between the value −0.454 and that computed by (2×−0.499 + −0.508)/3 = −0.502 exactly matching the difference between the values for white (−0.063) and red (−0.111) phosphorus in equilibrium with PH3.
[edit] In oxidative phosphorylation
Further information: Oxidative phosphorylation#Eukaryotic electron transport chains
Oxidative phosphorylation is the means by which organism generate energy, and is driven by differences in electrode potential between intermediaries in a chain of reactions.
The following values are calculated for pH 7, which is more biologically realistic, but makes the values incompatible with the values in the table above with standard criteria.
| Respiratory enzyme | Redox pair | Midpoint potential
(Volts) |
|---|---|---|
| NADH dehydrogenase | NAD+ / NADH | −0.32[14] |
| Succinate dehydrogenase | FMN or FAD / FMNH2 or FADH2 | −0.20[14] |
| Cytochrome bc1 complex | Coenzyme Q10ox / Coenzyme Q10red | +0.06[14] |
| Cytochrome bc1 complex | Cytochrome box / Cytochrome bred | +0.12[14] |
| Complex IV | Cytochrome cox / Cytochrome cred | +0.22[14] |
| Complex IV | Cytochrome aox / Cytochrome ared | +0.29[14] |
| Complex IV | O2 / HO− | +0.82[14] |
[edit] References
- http://www.jesuitnola.org/upload/clark/Refs/red_pot.htm
- http://hyperphysics.phy-astr.gsu.edu/Hbase/tables/electpot.html#c1
- ^ a b c d Greenwood, N. N.; Earnshaw, A. (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 0080379419.
- ^ a b c d e f g h i j k l m n o p Vanýsek, Petr (2011). “Electrochemical Series”, in Handbook of Chemistry and Physics: 92nd Edition (Chemical Rubber Company).
- ^ a b c d e f g h i j k l m Peter Atkins (1997). Physical Chemistry, 6th edition (W.H. Freeman and Company, New York).
- ^ a b c d e f g h i j k Bard, A.J., Faulkner, L.R.(2001). Electrochemical Methods. Fundamentals and Applications, 2nd edition (John Wiley and Sons Inc).
- ^ a b c d e f g h i j k l m n o p q r s t u v w x y z aa Vanýsek, Petr (2007). “Electrochemical Series”, in Handbook of Chemistry and Physics: 88th Edition (Chemical Rubber Company).
- ^ Gordon Aylward & Tristan Findlay (2008). "SI Chemical Data", 6th edition (John Wiley & Sons, Australia), ISBN 9780470816387.
- ^ a b c d e WebElements Periodic Table of the Elements | Iron | compounds information
- ^ a b c d e f g h i j k l m n o p q r s Bard, A. J., Parsons, R., and Jordan, J. (1985). Standard Potentials in Aqueous Solutions (Marcel Dekker, New York).
- ^ Marcel Pourbaix (1966). Atlas of Electrochemical Equilibria in Aqueous Solutions (NACE International, Houston, Texas; Cebelcor, Brussels).
- ^ Connelly, Neil G.; Geiger, William E. (1 January 1996). "Chemical Redox Agents for Organometallic Chemistry". Chemical Reviews 96 (2): 877–910. doi:10.1021/cr940053x. PMID 11848774.
- ^ a b c d e f g WebElements Periodic Table of the Elements | Xenon | compounds information
- ^ Cotton, F. Albert; Wilkinson, Geoffrey; Murillo, Carlos A.; Bochmann, Manfred (1999), Advanced Inorganic Chemistry (6th ed.), New York: Wiley-Interscience, ISBN 0-471-19957-5
- ^ Redox Reactions, Western Oregon University website
- ^ a b c d e f g Medical CHEMISTRY Compendium. By Anders Overgaard Pedersen and Henning Nielsen. Aarhus University. 2008
