Bảng giá trị thế điện cực chuẩn
Giá trị

| & | -9 |  |  |  |  |  |
| Zz | 9 |  |  |  |  |  |
| Sr | Sr+  +  e− | ⇌ | Sr(s) | -4.101 | 1 |  |
| Ca | Ca+  +  e− | ⇌ | Ca(s) | -3.8 | 1 |  |
| Th | Th4+ +  e− | ⇌ | Th3+  | -3.6 | 1 |  |
| Pr | Pr3+ +  e− | ⇌ | Pr2+  | -3.1 | 1 |  |
| N | 3N2(g) + 2 H+ + 2 e− | ⇌ | 2HN3(aq) | -3.09 | 2 |  |
| Li | Li+ +  e− | ⇌ | Li(s) | -3.0401 | 1 |  |
| N | N2(g) + 4 H2O + 2 e− | ⇌ | 2NH2OH(aq) + 2 OH− | -3.04 | 2 |  |
| Cs | Cs+ +  e− | ⇌ | Cs(s) | -3.026 | 1 |  |
| Ca | Ca(OH)2 + 2 e− | ⇌ | Ca(s) + 2 OH− | -3.02 | 2 |  |
| Er | Er3+ +  e− | ⇌ | Er2+  | -3 | 1 |  |
| Ba | Ba(OH)2 + 2 e− | ⇌ | Ba(s) + 2 OH− | -2.99 | 2 |  |
| Rb | Rb+ +  e− | ⇌ | Rb(s) | -2.98 | 1 |  |
| K | K+ +  e− | ⇌ | K(s) | -2.931 | 1 |  |
| Ba | Ba2+ + 2 e− | ⇌ | Ba(s) | -2.912 | 2 |  |
| La | La(OH)3(s) + 3 e− | ⇌ | La(s) + 3 OH− | -2.9 | 3 |  |
| Fr | Fr+ +  e− | ⇌ | Fr(s) | -2.9 | 1 |  |
| Sr | Sr2+ + 2 e− | ⇌ | Sr(s) | -2.899 | 2 |  |
| Sr | Sr(OH)2 + 2 e− | ⇌ | Sr(s) + 2 OH− | -2.88 | 2 |  |
| Ca | Ca2+ + 2 e− | ⇌ | Ca(s) | -2.868 | 2 |  |
| Li | Li+  + C 6(s) +  e− | ⇌ | LiC6(s) | -2.84 | 1 |  |
| Eu | Eu2+ + 2 e− | ⇌ | Eu(s) | -2.812 | 2 |  |
| Ra | Ra2+ + 2 e− | ⇌ | Ra(s) | -2.8 | 2 |  |
| Ho | Ho3+ +  e− | ⇌ | Ho2+ | -2.8 | 1 |  |
| Bk | Bk3+ +  e− | ⇌ | Bk2+  | -2.8 | 1 |  |
| Yb | Yb2+ + 2 e− | ⇌ | Yb(s) | -2.76 | 2 |  |
| Na | Na+ +  e− | ⇌ | Na(s) | -2.71 | 1 |  |
| Mg | Mg+ +  e− | ⇌ | Mg(s) | -2.7 | 1 |  |
| Nd | Nd3+ +  e− | ⇌ | Nd2+  | -2.7 | 1 |  |
| Mg | Mg(OH) 2 + 2 e− | ⇌ | Mg(s) + 2 OH− | -2.69 | 2 |  |
| Sm | Sm2+ + 2 e− | ⇌ | Sm(s) | -2.68 | 2 |  |
| Be | Be 2O2− 3 + 3 H2O + 4 e− | ⇌ | 2Be(s) + 6 OH− | -2.63 | 4 |  |
| Pm | Pm3+ +  e− | ⇌ | Pm2+  | -2.6 | 1 |  |
| Dy | Dy3+ +  e− | ⇌ | Dy2+  | -2.6 | 1 |  |
| No | No2+ + 2 e− | ⇌ | No | -2.5 | 2 |  |
| Hf | HfO(OH) 2 +  H2O + 4 e− | ⇌ | Hf(s) + 4 OH− | -2.5 | 4 |  |
| Th | Th(OH) 4 + 4 e− | ⇌ | Th(s) + 4 OH− | -2.48 | 4 |  |
| Md | Md2+  + 2 e− | ⇌ | Md | -2.4 | 2 |  |
| Tm | Tm2+  + 2 e− | ⇌ | Tm(s) | -2.4 | 2 |  |
| La | La3+ + 3 e− | ⇌ | La(s) | -2.379 | 3 |  |
| Y | Y3+ + 3 e− | ⇌ | Y(s) | -2.372 | 3 |  |
| Mg | Mg2+  + 2 e− | ⇌ | Mg(s) | -2.372 | 2 |  |
| Zr | ZrO(OH)2(s) +  H2O + 4 e− | ⇌ | Zr(s) + 4 OH− | -2.36 | 4 |  |
| Pr | Pr3+ + 3 e− | ⇌ | Pr(s) | -2.353 | 3 |  |
| Ce | Ce3+ + 3 e− | ⇌ | Ce(s) | -2.336 | 3 |  |
| Er | Er3+ + 3 e− | ⇌ | Er(s) | -2.331 | 3 |  |
| Ho | Ho3+ + 3 e− | ⇌ | Ho(s) | -2.33 | 3 |  |
| Al | H 2AlO− 3 +  H2O + 3 e− | ⇌ | Al(s) + 4 OH− | -2.33 | 3 |  |
| Nd | Nd3+ + 3 e− | ⇌ | Nd(s) | -2.323 | 3 |  |
| Tm | Tm3+ + 3 e− | ⇌ | Tm(s) | -2.319 | 3 |  |
| Al | Al(OH) 3(s) + 3 e− | ⇌ | Al(s) + 3 OH− | -2.31 | 3 |  |
| Sm | Sm3+ + 3 e− | ⇌ | Sm(s) | -2.304 | 3 |  |
| Fm | Fm2+ + 2 e− | ⇌ | Fm | -2.3 | 2 |  |
| Am | Am3+ +  e− | ⇌ | Am2+  | -2.3 | 1 |  |
| Dy | Dy3+ + 3 e− | ⇌ | Dy(s) | -2.295 | 3 |  |
| Lu | Lu3+ + 3 e− | ⇌ | Lu(s) | -2.28 | 3 |  |
| Tb | Tb3+ + 3 e− | ⇌ | Tb(s) | -2.28 | 3 |  |
| Gd | Gd3+ + 3 e− | ⇌ | Gd(s) | -2.279 | 3 |  |
| H | H2(g) + 2 e− | ⇌ | 2H−  | -2.23 | 2 |  |
| Es | Es2+  + 2 e− | ⇌ | Es(s) | -2.23 | 2 |  |
| Pm | Pm2+  + 2 e− | ⇌ | Pm(s) | -2.2 | 2 |  |
| Tm | Tm3+ +  e− | ⇌ | Tm2+ | -2.2 | 1 |  |
| Dy | Dy2+  + 2 e− | ⇌ | Dy(s) | -2.2 | 2 |  |
| Ac | Ac3+ + 3 e− | ⇌ | Ac(s) | -2.2 | 3 |  |
| Yb | Yb3+ + 3 e− | ⇌ | Yb(s) | -2.19 | 3 |  |
| Cf | Cf2+  + 2 e− | ⇌ | Cf(s) | -2.12 | 2 |  |
| Nd | Nd2+  + 2 e− | ⇌ | Nd(s) | -2.1 | 2 |  |
| Ho | Ho2+  + 2 e− | ⇌ | Ho(s) | -2.1 | 2 |  |
| Sc | Sc3+ + 3 e− | ⇌ | Sc(s) | -2.077 | 3 |  |
| Al | AlF3−6 + 3 e− | ⇌ | Al(s) + 6F−  | -2.069 | 3 |  |
| Am | Am3+ + 3 e− | ⇌ | Am(s) | -2.048 | 3 |  |
| Cm | Cm3+ + 3 e− | ⇌ | Cm(s) | -2.04 | 3 |  |
| Pu | Pu3+ + 3 e− | ⇌ | Pu(s) | -2.031 | 3 |  |
| Pr | Pr2+  + 2 e− | ⇌ | Pr(s) | -2 | 2 |  |
| Er | Er2+  + 2 e− | ⇌ | Er(s) | -2 | 2 |  |
| Eu | Eu3+ + 3 e− | ⇌ | Eu(s) | -1.991 | 3 |  |
| Lr | Lr3+ + 3 e− | ⇌ | Lr | -1.96 | 3 |  |
| Cf | Cf3+ + 3 e− | ⇌ | Cf(s) | -1.94 | 3 |  |
| Es | Es3+ + 3 e− | ⇌ | Es(s) | -1.91 | 3 |  |
| Pa | Pa4+  +  e− | ⇌ | Pa3+  | -1.9 | 1 |  |
| Am | Am2+  + 2 e− | ⇌ | Am(s) | -1.9 | 2 |  |
| Th | Th4+  + 4 e− | ⇌ | Th(s) | -1.899 | 4 |  |
| Fm | Fm3+ + 3 e− | ⇌ | Fm | -1.89 | 3 |  |
| Np | Np3+ + 3 e− | ⇌ | Np(s) | -1.856 | 3 |  |
| Be | Be2+  + 2 e− | ⇌ | Be(s) | -1.847 | 2 |  |
| P | H 2PO− 2 +  e− | ⇌ | P(s) + 2 OH− | -1.82 | 1 |  |
| U | U3+ + 3 e− | ⇌ | U(s) | -1.798 | 3 |  |
| Sr | Sr2+  + 2 e− | ⇌ | Sr(Hg) | -1.793 | 2 |  |
| B | H 2BO− 3 +  H2O + 3 e− | ⇌ | B(s) + 4 OH− | -1.79 | 3 |  |
| Th | ThO2 + 4 H+ + 4 e− | ⇌ | Th(s) + 2 H2O | -1.789 | 4 |  |
| Hf | HfO2+  + 2 H+ + 4 e− | ⇌ | Hf(s) +  H2O | -1.724 | 4 |  |
| P | HPO2− 3 + 2 H2O + 3 e− | ⇌ | P(s) + 5 OH− | -1.71 | 3 |  |
| Si | SiO2−3 + 3 H2O + 4 e− | ⇌ | Si(s) + 6 OH− | -1.697 | 4 |  |
| Al | Al3+ + 3 e− | ⇌ | Al(s) | -1.662 | 3 |  |
| Ti | Ti2+  + 2 e− | ⇌ | Ti(s) | -1.63 | 2 |  |
| Zr | ZrO 2(s) + 4 H+ + 4 e− | ⇌ | Zr(s) + 2 H2O | -1.553 | 4 |  |
| Zr | Zr4+  + 4 e− | ⇌ | Zr(s) | -1.45 | 4 |  |
| Ti | Ti3+  + 3 e− | ⇌ | Ti(s) | -1.37 | 3 |  |
| Ti | TiO(s) + 2 H+ + 2 e− | ⇌ | Ti(s) +  H2O | -1.31 | 2 |  |
| Ti | Ti2O3(s) + 2 H+ + 2 e− | ⇌ | 2TiO(s) +  H2O | -1.23 | 2 |  |
| Zn | Zn(OH)2− 4 + 2 e− | ⇌ | Zn(s) + 4 OH− | -1.199 | 2 |  |
| Mn | Mn2+  + 2 e− | ⇌ | Mn(s) | -1.185 | 2 |  |
| Fe | Fe(CN)4− 6 + 6 H+ + 2 e− | ⇌ | Fe(s) + 6HCN(aq) | -1.16 | 2 |  |
| Te | Te(s) + 2 e− | ⇌ | Te2−  | -1.143 | 2 |  |
| V | V2+  + 2 e− | ⇌ | V(s) | -1.13 | 2 |  |
| Nb | Nb3+ + 3 e− | ⇌ | Nb(s) | -1.099 | 3 |  |
| Sn | Sn(s) + 4 H+ + 4 e− | ⇌ | SnH 4(g) | -1.07 | 4 |  |
| Ti | TiO2+  + 2 H+ + 4 e− | ⇌ | Ti(s) +  H2O | -0.93 | 4 |  |
| Si | SiO 2(s) + 4 H+ + 4 e− | ⇌ | Si(s) + 2 H2O | -0.91 | 4 |  |
| B | B(OH)3(aq) + 3 H+ + 3 e− | ⇌ | B(s) + 3 H2O | -0.89 | 3 |  |
| Fe | Fe(OH) 2(s) + 2 e− | ⇌ | Fe(s) + 2 OH− | -0.89 | 2 |  |
| Fe | Fe 2O 3(s) + 3 H2O + 2 e− | ⇌ | 2Fe(OH) 2(s) + 2 OH− | -0.86 | 2 |  |
| H | 2 H2O + 2 e− | ⇌ | H 2(g) + 2 OH− | -0.8277 | 2 |  |
| Bi | Bi(s) + 3 H+ + 3 e− | ⇌ | BiH3 | -0.8 | 3 |  |
| Zn | Zn2+  + 2 e− | ⇌ | Zn(Hg) | -0.7628 | 2 |  |
| Zn | Zn2+  + 2 e− | ⇌ | Zn(s) | -0.7618 | 2 |  |
| Ta | Ta2O5(s) + 10 H+ + 10 e− | ⇌ | 2Ta(s) + 5 H2O | -0.75 | 10 |  |
| Cr | Cr3+ + 3 e− | ⇌ | Cr(s) | -0.74 | 3 |  |
| Ni | Ni(OH)2(s) + 2 e− | ⇌ | Ni(s) + 2 OH− | -0.72 | 2 |  |
| Ag | Ag2S(s) + 2 e− | ⇌ | 2Ag(s) + S2− (aq) | -0.69 | 2 |  |
| Au | [Au(CN) 2]−  +  e− | ⇌ | Au(s) + 2CN−  | -0.6 | 1 |  |
| Ta | Ta3+  + 3 e− | ⇌ | Ta(s) | -0.6 | 3 |  |
| Pb | PbO(s) +  H2O + 2 e− | ⇌ | Pb(s) + 2 OH− | -0.58 | 2 |  |
| Ti | 2TiO 2(s) + 2 H+ + 2 e− | ⇌ | Ti 2O 3(s) +  H2O | -0.56 | 2 |  |
| Ga | Ga3+ + 3 e− | ⇌ | Ga(s) | -0.53 | 3 |  |
| U | U4+  +  e− | ⇌ | U3+  | -0.52 | 1 |  |
| P | H3PO2(aq) +  H+ +  e− | ⇌ | P(white) + 2 H2O | -0.508 | 1 |  |
| P | H 3PO 3(aq) + 2 H+ + 2 e− | ⇌ | H 3PO 2(aq) +  H2O | -0.499 | 2 |  |
| Ni | NiO 2(s) + 2Bản mẫu:H2O-nl + 2 e− | ⇌ | Ni(OH)2(s) + 2 OH− | -0.49 | 2 |  |
| P | H3PO3(aq) + 3 H+ + 3 e− | ⇌ | P(red) + 3 H2O | -0.454 | 3 |  |
| Cu | Cu(CN)− 2 +  e− | ⇌ | Cu(s) + 2CN−  | -0.44 | 1 |  |
| Fe | Fe2+  + 2 e− | ⇌ | Fe(s) | -0.44 | 2 |  |
| C | 2CO2(g) + 2 H+ + 2 e− | ⇌ | HOOCCOOH(aq) | -0.43 | 2 |  |
| Cr | Cr3+  +  e− | ⇌ | Cr2+  | -0.42 | 1 |  |
| Cd | Cd2+  + 2 e− | ⇌ | Cd(s) | -0.4 | 2 |  |
| Ge | GeO2(s) + 2 H+ + 2 e− | ⇌ | GeO(s) +  H2O | -0.37 | 2 |  |
| Cu | Cu2O(s) +  H2O + 2 e− | ⇌ | 2Cu(s) + 2 OH− | -0.36 | 2 |  |
| Pb | PbSO4(s) + 2 e− | ⇌ | Pb(s) + SO2− 4 | -0.3588 | 2 |  |
| Pb | PbSO 4(s) + 2 e− | ⇌ | Pb(Hg) + SO2− 4 | -0.3505 | 2 |  |
| Eu | Eu3+  +  e− | ⇌ | Eu2+  | -0.35 | 1 |  |
| In | In3+ + 3 e− | ⇌ | In(s) | -0.34 | 3 |  |
| Tl | Tl+  +  e− | ⇌ | Tl(s) | -0.34 | 1 |  |
| Ge | Ge(s) + 4 H+ + 4 e− | ⇌ | GeH 4(g) | -0.29 | 4 |  |
| Co | Co2+  + 2 e− | ⇌ | Co(s) | -0.28 | 2 |  |
| P | H3PO4(aq) + 2 H+ + 2 e− | ⇌ | H 3PO 3(aq) +  H2O | -0.276 | 2 |  |
| V | V3+ +  e− | ⇌ | V2+  | -0.26 | 1 |  |
| Ni | Ni2+ + 2 e− | ⇌ | Ni(s) | -0.25 | 2 |  |
| As | As(s) + 3 H+ + 3 e− | ⇌ | AsH3(g) | -0.23 | 3 |  |
| Ag | AgI(s) +  e− | ⇌ | Ag(s) + I−  | -0.15224 | 1 |  |
| Mo | MoO2(s) + 4 H+ + 4 e− | ⇌ | Mo(s) + 2 H2O | -0.15 | 4 |  |
| Si | Si(s) + 4 H+ + 4 e− | ⇌ | SiH 4(g) | -0.14 | 4 |  |
| Sn | Sn2+  + 2 e− | ⇌ | Sn(s) | -0.13 | 2 |  |
| O | O2(g) +  H+ +  e− | ⇌ | HO• 2(aq) | -0.13 | 1 |  |
| Pb | Pb2+ + 2 e− | ⇌ | Pb(s) | -0.126 | 2 |  |
| W | WO2(s) + 4 H+ + 4 e− | ⇌ | W(s) + 2 H2O | -0.12 | 4 |  |
| P | P(red) + 3 H+ + 3 e− | ⇌ | PH3(g) | -0.111 | 3 |  |
| C | CO 2(g) + 2 H+ + 2 e− | ⇌ | HCOOH(aq) | -0.11 | 2 |  |
| Se | Se(s) + 2 H+ + 2 e− | ⇌ | H 2Se(g) | -0.11 | 2 |  |
| C | CO 2(g) + 2 H+ + 2 e− | ⇌ | CO(g) +  H2O | -0.11 | 2 |  |
| Cu | Cu(NH 3)+ 2 +  e− | ⇌ | Cu(s) + 2NH 3(aq) | -0.1 | 1 |  |
| Sn | SnO(s) + 2 H+ + 2 e− | ⇌ | Sn(s) +  H2O | -0.1 | 2 |  |
| Sn | SnO2(s) + 2 H+ + 2 e− | ⇌ | SnO(s) +  H2O | -0.09 | 2 |  |
| W | WO3(aq) + 6 H+ + 6 e− | ⇌ | W(s) + 3 H2O | -0.09 | 6 |  |
| Fe | Fe3O4(s) + 8 H+ + 8 e− | ⇌ | 3Fe(s) + 4 H2O | -0.085 | 8 |  |
| P | P(white) + 3 H+ + 3 e− | ⇌ | PH3(g) | -0.063 | 3 |  |
| Fe | Fe3+  + 3 e− | ⇌ | Fe(s) | -0.04 | 3 |  |
| C | HCOOH(aq) + 2 H+ + 2 e− | ⇌ | HCHO(aq) +  H2O | -0.03 | 2 |  |
| H | 2 H+ + 2 e− | ⇌ | H 2(g) | 0 | 2 |  |
| Ag | AgBr(s) +  e− | ⇌ | Ag(s) + Br−  | 0.07133 | 1 |  |
| S | S4O2−6 + 2 e− | ⇌ | 2S2O2−3 | 0.08 | 2 |  |
| N | N2(g) + 2 H2O + 6 H+ + 6 e− | ⇌ | 2NH4OH(aq) | 0.092 | 6 |  |
| Hg | HgO(s) +  H2O + 2 e− | ⇌ | Hg(l) + 2 OH− | 0.0977 | 2 |  |
| Cu | Cu(NH 3)2+ 4 +  e− | ⇌ | Cu(NH 3)+ 2 + 2NH 3(aq) | 0.1 | 1 |  |
| Ru | Ru(NH3)3+6 +  e− | ⇌ | Ru(NH 3)2+ 6 | 0.1 | 1 |  |
| N | N2H4(aq) + 4 H2O + 2 e− | ⇌ | 2NH+ 4 + 4 OH− | 0.11 | 2 |  |
| Mo | H2MoO4(aq) + 6 H+ + 6 e− | ⇌ | Mo(s) + 4 H2O | 0.11 | 6 |  |
| Ge | Ge4+  + 4 e− | ⇌ | Ge(s) | 0.12 | 4 |  |
| C | C(s) + 4 H+ + 4 e− | ⇌ | CH4(g) | 0.13 | 4 |  |
| C | HCHO(aq) + 2 H+ + 2 e− | ⇌ | CH3OH(aq) | 0.13 | 2 |  |
| S | S(s) + 2 H+ + 2 e− | ⇌ | H 2S(g) | 0.14 | 2 |  |
| Sn | Sn4+  + 2 e− | ⇌ | Sn2+  | 0.15 | 2 |  |
| Cu | Cu2+ +  e− | ⇌ | Cu+  | 0.159 | 1 |  |
| S | HSO− 4 + 3 H+ + 2 e− | ⇌ | SO 2(aq) + 2 H2O | 0.16 | 2 |  |
| U | UO2+2 +  e− | ⇌ | UO+ 2 | 0.163 | 1 |  |
| S | SO2− 4 + 4 H+ + 2 e− | ⇌ | SO 2(aq) + 2 H2O | 0.17 | 2 |  |
| Ti | TiO2+  + 2 H+ +  e− | ⇌ | Ti3+  +  H2O | 0.19 | 1 |  |
| Sb | SbO+  + 2 H+ + 3 e− | ⇌ | Sb(s) +  H2O | 0.2 | 3 |  |
| Fe | 3Fe2O3(s) + 2 H+ + 2 e− | ⇌ | 2Fe3O4(s) +  H2O | 0.22 | 2 |  |
| Ag | AgCl(s) +  e− | ⇌ | Ag(s) + Cl−  | 0.22233 | 1 |  |
| As | H3AsO3(aq) + 3 H+ + 3 e− | ⇌ | As(s) + 3 H2O | 0.24 | 3 |  |
| Ru | Ru3+ (aq) +  e− | ⇌ | Ru2+ (aq) | 0.249 | 1 |  |
| Ge | GeO(s) + 2 H+ + 2 e− | ⇌ | Ge(s) +  H2O | 0.26 | 2 |  |
| U | UO+ 2 + 4 H+ +  e− | ⇌ | U4+  + 2 H2O | 0.273 | 1 |  |
| Re | Re3+ + 3 e− | ⇌ | Re(s) | 0.3 | 3 |  |
| Bi | Bi3+  + 3 e− | ⇌ | Bi(s) | 0.308 | 3 |  |
| Cu | Cu2+  + 2 e− | ⇌ | Cu(s) | 0.337 | 2 |  |
| V | [VO]2+  + 2 H+ +  e− | ⇌ | V3+  +  H2O | 0.34 | 1 |  |
| Fe | [Fe(CN) 6]3−  +  e− | ⇌ | [Fe(CN) 6]4−  | 0.3704 | 1 |  |
| Fe | Fc+ +  e− | ⇌ | Fc(s) | 0.4 | 1 |  |
| O | O 2(g) + 2 H2O + 4 e− | ⇌ | 4 OH−(aq) | 0.401 | 4 |  |
| Mo | H 2MoO 4 + 6 H+ + 3 e− | ⇌ | Mo3+  + 4 H2O | 0.43 | 3 |  |
| Ru | Ru2+ (aq) + 2 e− | ⇌ | Ru | 0.455 | 2 |  |
| C | CH3OH(aq) + 2 H+ + 2 e− | ⇌ | CH4(g) +  H2O | 0.5 | 2 |  |
| S | SO 2(aq) + 4 H+ + 4 e− | ⇌ | S(s) + 2 H2O | 0.5 | 4 |  |
| Cu | Cu+  +  e− | ⇌ | Cu(s) | 0.52 | 1 |  |
| C | CO(g) + 2 H+ + 2 e− | ⇌ | C(s) +  H2O | 0.52 | 2 |  |
| I | I−3 + 2 e− | ⇌ | 3I−  | 0.53 | 2 |  |
| I | I2(s) + 2 e− | ⇌ | 2I−  | 0.54 | 2 |  |
| Au | [AuI 4]−  + 3 e− | ⇌ | Au(s) + 4I−  | 0.56 | 3 |  |
| As | H3AsO4(aq) + 2 H+ + 2 e− | ⇌ | H 3AsO 3(aq) +  H2O | 0.56 | 2 |  |
| Au | [AuI 2]−  +  e− | ⇌ | Au(s) + 2I−  | 0.58 | 1 |  |