Taula de potencials estàndards de reducció
El potencial de reducció s'utilitza per determinar el potencial electroquímic o el potencial d'un elèctrode d'una cel·la electroquímica o d'una cel·la galvànica.
Aquests potencials de reducció venen donats en volts respecte d'un elèctrode estàndard d'hidrògen. Els valors dels potencials estàndards de reducció que es presenten a la taula han estat presos a una temperatura de 298 K, una pressió de 100 KPa i en una solució aquosa amb una concentració d'1 mol.[1][2][3][4]
| Mitja reacció | E |
|---|---|
| Li+(aq) + e− → Li(s) | −3.05 |
| Rb+(aq) + 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 |
| H₂ + 2e− → 2H− | −2.25 |
| Be2+(aq) + 2e− → Be(s) | −1.85 |
| Al3+(aq) + 3e− → Al(s) | −1.68 |
| Ti2+(aq) + 2e− → Ti(s) | −1.63 |
| TiO(s) + 2H+ + 2e− → Ti(s) + H₂O | −1.31 |
| Ti₂O₃(s) + 2H+ + 2e− → 2TiO(s) + H₂O | −1.23 |
| Ti3+(aq) + 3e− → Ti(s) | −1.21 |
| Mn2+(aq) + 2e− → Mn(s) | −1.18 |
| V2+(aq) + 2e− → V(s) | −1.13 |
| Sn(s) + 4H+ + 4e− → SnH₄(g) | −1.07 |
| SiO₂(s) + 4H+ + 4e− → Si(s) + 2H₂O | −0.91 |
| B(OH)₃(aq) + 3H+ + 3e− → B(s) + 3H₂O | −0.89 |
| TiO2+(aq) + 2H+ + 4e− → Ti(s) + H₂O | −0.86 |
| 2 H₂O(l) + 2e– → H₂(g) + 2 OH–(aq) | −0.83 |
| Zn2+(aq) + 2e− → Zn(s) | −0.76 |
| Cr3+(aq) + 3e− → Cr(s) | −0.74 |
| Au(CN)₂–(aq) + e– → Au(s) +2 CN–(aq) | −0.60 |
| 2TiO₂(s) + 2H+ + 2e− → Ti₂O₃(s) + H₂O | −0.56 |
| Ga3+(aq) + 3e− → Ga(s) | −0.53 |
| H₃PO₂(aq) + H+ + e− → P(s) + 2H₂O | −0.51 |
| H₃PO₃(aq) + 3H+ + 3e− → P(s) + 3H₂O | −0.50 |
| H₃PO₃(aq) + 2H+ + 2e− → H₃PO₂(aq) + H₂O | −0.50 |
| Fe2+(aq) + 2e− → Fe(s) | −0.44 |
| 2CO₂(g) + 2H+(aq) + 2e– → HOOCCOOH(aq) | −0.43 |
| Cr3+(aq) + e− → Cr2+(aq) | −0.42 |
| 2H+ + 2e− → H₂ | −0.41 |
| Cd2+(aq) + 2e− → Cd(s) | −0.40 |
| PbSO₄(s) + 2e– → Pb(s) +SO₄2-(aq) | −0.36 |
| GeO₂(s) + 2H+ + 2e− → GeO(s) + H₂O | −0.37 |
| In3+(aq) + 3e− → In(s) | −0.34 |
| Tl+(aq) + e− → Tl(s) | −0.34 |
| Ge(s) + 4H+ + 4e− → GeH₄(g) | −0.29 |
| Co2+(aq) + 2e → Co(s) | −0.28 |
| H₃PO₄(aq) + 2H+ + 2e− → H₃PO₃(aq) + H₂O | −0.28 |
| V3+(aq) + e− → V2+(aq) | −0.26 |
| Ni2+(aq) + 2e− → Ni(s) | −0.25 |
| As(s) + 3H+ + 3e− → AsH₃(g) | −0.23 |
| MoO₂(s) + 4H+ + 4e− → Mo(s) + 2H₂O | −0.15 |
| Si(s) + 4H+ + 4e− → SiH₄(g) | −0.14 |
| Sn2+(aq) + 2e− → Sn(s) | −0.13 |
| O₂(g) + H+ + e− → HO₂•(aq) | −0.13 |
| Pb2+(aq) + 2e− → Pb(s) | −0.13 |
| WO₂(s) + 4H+ + 4e− → W(s) | −0.12 |
| CO₂(g) + 2H+ + 2e− → HCOOH(aq) | −0.11 |
| Se(s) + 2H+ + 2e− → H₂Se(g) | −0.11 |
| CO₂(g) + 2H+ + 2e− → CO(g) + H₂O | −0.11 |
| SnO(s) + 2H+ + 2e− → Sn(s) + H₂O | −0.10 |
| SnO₂(s) + 2H+ + 2e− → SnO(s) + H₂O | −0.09 |
| WO₃(aq) + 6H+ + 6e− → W(s) | −0.09 |
| P(s) + 3H+ + 3e− → PH₃(g) | −0.06 |
| HCOOH(aq) + 2H+ + 2e− → HCHO(aq) + H₂O | −0.03 |
| 2H+(aq) + 2e− → H₂(g) | 0.00 |
| H₂MoO₄(aq) + 6H+ + 6e− → Mo(s) + 4H₂O | +0.11 |
| Ge4+(aq) + 4e− → Ge(s) | +0.12 |
| C(s) + 4H+ + 4e− → CH₄(g) | +0.13 |
| HCHO(aq) + 2H+ + 2e− → CH₃OH(aq) | +0.13 |
| S(s) + 2H+ + 2e− → H₂S(g) | +0.14 |
| Sn4+(aq) + 2e− → Sn2+(aq) | +0.15 |
| Cu2+(aq) + e− → Cu+(aq) | +0.16 |
| HSO₄−(aq) + 3H+ + 2e− → 2H₂O(l) + SO₂(aq) | +0.16 |
| SO₄2−(aq) + 4H+ + 2e− → 2H₂O(l) + SO₂(aq) | +0.17 |
| SbO+ + 2H+ + 3e− → Sb(s) + H₂O | +0.20 |
| H₃AsO₃(aq) + 3H+ + 3e− → As(s) + 3H₂O | +0.24 |
| GeO(s) + 2H+ + 2e− → Ge(s) + H₂O | +0.26 |
| Bi3+(aq) + 3e− → Bi(s) | +0.32 |
| VO2+(aq) + 2H+ + e− → V3+(aq) | +0.34 |
| Cu2+(aq) + 2e− → Cu(s) | +0.34 |
| [Fe(CN)₆]3−(aq) + e− → [Fe(CN)₆]4−(aq) | +0.36 |
| O₂(g) + 2H₂O(l) + 4e– → 4OH–(aq) | +0.40 |
| H₂MoO₄ + 6H+ + 3e− → Mo3+(aq) | +0.43 |
| CH₃OH(aq) + 2H+ + 2e− → CH₄(g) + H₂O | +0.50 |
| SO₂(aq) + 4H+ + 4e− → S(s) + 2H₂O | +0.50 |
| Cu+(aq) + e− → Cu(s) | +0.52 |
| CO(g) + 2H+ + 2e− → C(s) + H₂O | +0.52 |
| I₂(s) + 2e− → 2I−(aq) | +0.54 |
| I₃−(aq) + 2e− → 3I−(aq) | +0.54 |
| [AuI₄]−(aq) + 3e− → Au(s) + 4I−(aq) | +0.56 |
| H3AsO₄(aq) + 2H+ + 2e− → H₃AsO₃(aq) + H₂O | +0.56 |
| [AuI₂]−(aq) + e− → Au(s) + 2I−(aq) | +0.58 |
| MnO₄–(aq) + 2H₂O(l) + 3e– → MnO₂(s) + 4 OH–(aq) | +0.59 |
| S₂O₃2− + 6H+ + 4e− → 2S(s) + 3H₂O | +0.60 |
| H₂MoO₄(aq) + 2H+ + 2e− → MoO₂(s) + 2H₂O | +0.65 |
| O₂(g) + 2H+ + 2e− → H₂O₂(aq) | +0.70 |
| Tl3+(aq) + 3e− → Tl(s) | +0.72 |
| H₂SeO₃(aq) + 4H+ + 4e− → Se(s) + 3H₂O | +0.74 |
| Fe3+(aq) + e− → Fe2+(aq) | +0.77 |
| Hg₂2+(aq) + 2e− → 2Hg(l) | +0.80 |
| Ag+(aq) + e− → Ag(s) | +0.80 |
| NO₃–(aq) + 2H+(aq) +e– → NO₂(g) + H₂O(l) | +0.80 |
| [AuBr₄]−(aq) + 3e− → Au(s) + 4Br−(aq) | +0.85 |
| Hg2+(aq) + 2e− → Hg(l) | +0.85 |
| MnO₄−(aq) + H+ + e− → HMnO₄−(aq) | +0.90 |
| 2Hg2+(aq) + 2e− → Hg₂2+(aq) | +0.91 |
| [AuCl₄]−(aq) + 3e− → Au(s) + 4Cl−(aq) | +0.93 |
| MnO₂(s) + 4H+ + e− → Mn3+(aq) + 2H₂O | +0.95 |
| [AuBr₂]−(aq) + e− → Au(s) + 2Br−(aq) | +0.96 |
| Br₂(l) + 2e− → 2Br−(aq) | +1.07 |
| Br₂(aq) + 2e− → 2Br−(aq) | +1.09 |
| IO₃−(aq) + 5H+ + 4e− → HIO(aq) + 2H₂O | +1.13 |
| [AuCl₂]−(aq) + e− → Au(s) + 2Cl−(aq) | +1.15 |
| HSeO₄−(aq) + 3H+ + 2e− → H₂SeO₃(aq) + H₂O | +1.15 |
| Ag₂O(s) + 2H+ + 2e− → 2Ag(s) | +1.17 |
| ClO₃−(aq) + 2H+ + e− → ClO₂(g) + H₂O | +1.18 |
| ClO₂(g) + H+ + e− → HClO₂(aq) | +1.19 |
| 2IO₃−(aq) + 12H+ + 10e− → I₂(s) + 6H₂O | +1.20 |
| ClO₄−(aq) + 2H+ + 2e− → ClO₃−(aq) + H₂O | +1.20 |
| O₂(g) + 4H+ + 4e− → 2H₂O | +1.23 |
| MnO₂(s) + 4H+ + 2e− → Mn2+(aq) + 2H₂O | +1.23 |
| Tl3+(aq) + 2e− → Tl+(s) | +1.25 |
| Cl₂(g) + 2e− → 2Cl−(aq) | +1.36 |
| Cr₂O₇2−(aq) + 14H+ + 6e− → 2Cr3+(aq) + 7H₂O | +1.36 |
| CoO₂(s) + 4H+ + e− → Co3+(aq) + 2H₂O | +1.42 |
| 2HIO(aq) + 2H+ + 2e− → I₂(s) + 2H₂O | +1.44 |
| BrO₃−(aq) + 5H+ + 4e− → HBrO(aq) + 2H₂O | +1.45 |
| 2BrO₃− + 12H+ + 10e− → Br₂(l) + 6H₂O | +1.48 |
| 2ClO₃− + 12H+ + 10e− → Cl₂(g) + 6H₂O | +1.49 |
| MnO₄−(aq) + 8H+ + 5e− → Mn2+(aq) + 4H₂O | +1.51 |
| HO₂• + H+ + e− → H₂O₂(aq) | +1.51 |
| Au3+(aq) + 3e− → Au(s) | +1.52 |
| NiO₂(s) + 4H+ + 2e− → Ni2+(aq) | +1.59 |
| 2HClO(aq) + 2H+ + 2e− → Cl₂(g) + 2H₂O | +1.63 |
| Ag₂O₃(s) + 6H+ + 4e− → 2Ag+(aq) + 3H₂O | +1.67 |
| HClO₂(aq) + 2H+ + 2e− → HClO(aq) + H₂O | +1.67 |
| Pb4+(aq) + 2e− → Pb2+(aq) | +1.69 |
| MnO₄−(aq) + 4H+ + 3e− → MnO₂(s) + 2H₂O | +1.70 |
| H₂O₂(aq) + 2H+ + 2e− → 2H₂O | +1.76 |
| AgO(s) + 2H+ + e− → Ag+(aq) + H₂O | +1.77 |
| Au+(aq) + e− → Au(s) | +1.83 |
| BrO₄−(aq) + 2H+ + 2e− → BrO₃−(aq) + H₂O | +1.85 |
| Co3+(aq) + e− → Co2+(aq) | +1.92 |
| Ag2+(aq) + e− → Ag+(aq) | +1.98 |
| S₂O₈2- + 2e– → 2SO₄2- | +2.07 |
| HMnO₄−(aq) + 3H+ + 2e− → MnO₂(s) + 2H₂O | +2.09 |
| F₂(g) + 2e− → 2F−(aq) | +2.87 |
| F₂(g) + 2H+ + 2e− → 2HF(aq) | +3.05 |
Referències
modifica- ↑ Milazzo, G., Caroli, S., and Sharma, V. K. (1978). Tables of Standard Electrode Potentials (Wiley, Chichester).
- ↑ Bard, A. J., Parsons, R., and Jordan, J. (1985). Standard Potentials in Aqueous Solutions (Marcel Dekker, New York).
- ↑ Bratsch, S. G. (1989). Journal of Physical Chemistry Reference Data Vol. 18, p. 1–21.
- ↑ Vanysek, Petr (2006). "Electrochemical Series," in Handbook of Chemistry and Physics: 87th Edition Arxivat 2017-07-24 a Wayback Machine. (Chemical Rubber Company).