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22.8: Standard Electrode (Half-Cell) Potentials

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    Standard Electrode (Half-Cell) Potentials
    Half-Reaction E° (V)
    \(\ce{Ag+ + e- ⟶Ag}\) +0.7996
    \(\ce{AgCl + e- ⟶Ag + Cl-}\) +0.22233
    \(\ce{[Ag(CN)2]- + e- ⟶Ag + 2CN-}\) −0.31
    \(\ce{Ag2CrO4 + 2e- ⟶2Ag + CrO4^2-}\) +0.45
    \(\ce{[Ag(NH3)2]+ + e- ⟶Ag + 2NH3}\) +0.373
    \(\ce{[Ag(S2O3)2]^3+ + e- ⟶Ag + 2S2O3^2-}\) +0.017
    \(\ce{[AlF6]^3- + 3e- ⟶Al + 6F-}\) −2.07
    \(\ce{Al^3+ + 3e- ⟶Al}\) −1.662
    \(\ce{Am^3+ + 3e- ⟶Am}\) −2.048
    \(\ce{Au^3+ + 3e- ⟶Au}\) +1.498
    \(\ce{Au+ + e- ⟶Au}\) +1.692
    \(\ce{Ba^2+ + 2e- ⟶Ba}\) −2.912
    \(\ce{Be^2+ + 2e- ⟶Be}\) −1.847
    \(\ce{Br2}(aq) + \ce{2e-} ⟶\ce{2Br-}\) +1.0873
    \(\ce{Ca^2+ + 2e- ⟶Ca}\) −2.868
    \(\ce{Ce^3 + 3e- ⟶Ce}\) −2.483
    \(\ce{Ce^4+ + e- ⟶Ce^3+}\) +1.61
    \(\ce{Cd^2+ + 2e- ⟶Cd}\) −0.4030
    \(\ce{[Cd(CN)4]^2- + 2e- ⟶Cd + 4CN-}\) −1.09
    \(\ce{[Cd(NH3)4]^2+ + 2e- ⟶Cd + 4NH3}\) −0.61
    \(\ce{CdS + 2e- ⟶Cd + S^2-}\) −1.17
    \(\ce{Cl2 + 2e- ⟶2Cl-}\) +1.35827
    \(\ce{ClO4- + H2O + 2e- ⟶ClO3- + 2OH-}\) +0.36
    \(\ce{ClO3- + H2O + 2e- ⟶ClO2- + 2OH-}\) +0.33
    \(\ce{ClO2- + H2O + 2e- ⟶ClO- + 2OH-}\) +0.66
    \(\ce{ClO- + H2O + 2e- ⟶Cl- + 2OH-}\) +0.89
    \(\ce{ClO4- + 2H3O+ + 2e- ⟶ClO3- + 3H2O}\) +1.189
    \(\ce{ClO3- + 3H3O+ + 2e- ⟶HClO2 + 4H2O}\) +1.21
    \(\ce{HClO + H3O+ + 2e- ⟶Cl- + 2H2O}\) +1.482
    \(\ce{HClO + H3O+ + e- ⟶\dfrac{1}{2}Cl2 + 2H2O}\) +1.611
    \(\ce{HClO2 + 2H3O+ + 2e- ⟶HClO + 3H2O}\) +1.628
    \(\ce{Co^3+ + e- ⟶Co^2+ \:(2\:mol\,//\,H2SO4)}\) +1.83
    \(\ce{Co^2+ + 2e- ⟶Co}\) −0.28
    \(\ce{[Co(NH3)6]^3+ + e- ⟶[Co(NH3)6]^2+}\) +0.1
    \(\ce{Co(OH)3 + e- ⟶Co(OH)2 + OH-}\) +0.17
    \(\ce{Cr^3 + 3e- ⟶Cr}\) −0.744
    \(\ce{Cr^3+ + e- ⟶Cr^2+}\) −0.407
    \(\ce{Cr^2+ + 2e- ⟶Cr}\) −0.913
    \(\ce{[Cu(CN)2]- + e- ⟶Cu + 2CN-}\) −0.43
    \(\ce{CrO4^2- + 4H2O + 3e- ⟶ Cr(OH)3 + 5OH-}\) −0.13
    \(\ce{Cr2O7^2- + 14H3O+ + 6e- ⟶2Cr^3+ + 21H2O}\) +1.232
    \(\ce{[Cr(OH)4]- + 3e- ⟶Cr + 4OH-}\) −1.2
    \(\ce{Cr(OH)3 + 3e- ⟶Cr + 3OH-}\) −1.48
    \(\ce{Cu^2+ + e- ⟶Cu+}\) +0.153
    \(\ce{Cu^2+ + 2e- ⟶Cu}\) +0.34
    \(\ce{Cu+ + e- ⟶Cu}\) +0.521
    \(\ce{F2 + 2e- ⟶2F-}\) +2.866
    \(\ce{Fe^2+ + 2e- ⟶Fe}\) −0.447
    \(\ce{Fe^3+ + e- ⟶Fe^2+}\) +0.771
    \(\ce{[Fe(CN)6]^3- + e- ⟶[Fe(CN)6]^4-}\) +0.36
    \(\ce{Fe(OH)2 + 2e- ⟶Fe + 2OH-}\) −0.88
    \(\ce{FeS + 2e- ⟶Fe + S^2-}\) −1.01
    \(\ce{Ga^3+ + 3e- ⟶Ga}\) −0.549
    \(\ce{Gd^3+ + 3e- ⟶Gd}\) −2.279
    \(\ce{\dfrac{1}{2}H2 + e- ⟶H- }\) −2.23
    \(\ce{2H2O + 2e- ⟶H2 + 2OH-}\) −0.8277
    \(\ce{H2O2 + 2H3O+ + 2e- ⟶4H2O}\) +1.776
    \(\ce{2H3O+ + 2e- ⟶H2 + 2H2O}\) 0.00
    \(\ce{HO2- + H2O + 2e- ⟶3OH-}\) +0.878
    \(\ce{Hf^4+ + 4e- ⟶Hf}\) −1.55
    \(\ce{Hg^2+ + 2e- ⟶Hg}\) +0.851
    \(\ce{2Hg^2+ + 2e- ⟶Hg2^2+}\) +0.92
    \(\ce{Hg2^2+ + 2e- ⟶2Hg}\) +0.7973
    \(\ce{[HgBr4]^2- + 2e- ⟶Hg + 4Br-}\) +0.21
    \(\ce{Hg2Cl2 + 2e- ⟶2Hg + 2Cl-}\) +0.26808
    \(\ce{[Hg(CN)4]^2- + 2e- ⟶Hg + 4CN-}\) −0.37
    \(\ce{[HgI4]^2- + 2e- ⟶Hg + 4I-}\) −0.04
    \(\ce{HgS + 2e- ⟶Hg + S^2-}\) −0.70
    \(\ce{I2 + 2e- ⟶2I-}\) +0.5355
    \(\ce{In^3+ + 3e- ⟶In}\) −0.3382
    \(\ce{K+ + e- ⟶K}\) −2.931
    \(\ce{La^3+ + 3e- ⟶La}\) −2.52
    \(\ce{Li+ + e- ⟶Li}\) −3.04
    \(\ce{Lu^3+ + 3e- ⟶Lu}\) −2.28
    \(\ce{Mg^2+ + 2e- ⟶Mg}\) −2.372
    \(\ce{Mn^2+ + 2e- ⟶Mn}\) −1.185
    \(\ce{MnO2 + 2H2O + 2e- ⟶Mn(OH)2 + 2OH-}\) −0.05
    \(\ce{MnO4- + 2H2O + 3e- ⟶MnO2 + 4OH-}\) +0.558
    \(\ce{MnO2 + 4H+ + 2e- ⟶Mn^2+ + 2H2O}\) +1.23
    \(\ce{MnO4- + 8H+ + 5e- ⟶Mn^2+ + 4H2O}\) +1.507
    \(\ce{Na+ + e- ⟶Na}\) −2.71
    \(\ce{Nd^3+ + 3e- ⟶Nd}\) −2.323
    \(\ce{Ni^2+ + 2e- ⟶Ni}\) −0.257
    \(\ce{[Ni(NH3)6]^2+ + 2e- ⟶Ni + 6NH3}\) −0.49
    \(\ce{NiO2 + 4H+ + 2e- ⟶Ni^2+ + 2H2O}\) +1.593
    \(\ce{NiO2 + 2H2O + 2e- ⟶Ni(OH)2 + 2OH-}\) +0.49
    \(\ce{NiS + 2e- ⟶Ni + S^2-}\) +0.76
    \(\ce{NO3- + 4H+ + 3e- ⟶NO + 2H2O}\) +0.957
    \(\ce{NO3- + 3H+ + 2e- ⟶HNO2 + H2O}\) +0.92
    \(\ce{NO3- + H2O + 2e- ⟶NO2- + 2OH-}\) +0.10
    \(\ce{Np^3+ + 3e- ⟶Np}\) −1.856
    \(\ce{O2 + 2H2O + 4e- ⟶4OH-}\) +0.401
    \(\ce{O2 + 2H+ + 2e- ⟶H2O2}\) +0.695
    \(\ce{O2 + 4H+ + 4e- ⟶2H2O}\) +1.229
    \(\ce{Pb^2+ + 2e- ⟶Pb}\) −0.1262
    \(\ce{PbO2 + SO4^2- + 4H+ + 2e- ⟶PbSO4 + 2H2O}\) +1.69
    \(\ce{PbS + 2e- ⟶Pb + S^2-}\) −0.95
    \(\ce{PbSO4 + 2e- ⟶Pb + SO4^2-}\) −0.3505
    \(\ce{Pd^2+ + 2e- ⟶Pd}\) +0.987
    \(\ce{[PdCl4]^2- + 2e- ⟶Pd + 4Cl-}\) +0.591
    \(\ce{Pt^2+ + 2e- ⟶Pt}\) +1.20
    \(\ce{[PtBr4]^2- + 2e- ⟶Pt + 4Br-}\) +0.58
    \(\ce{[PtCl4]^2- + 2e- ⟶Pt + 4Cl-}\) +0.755
    \(\ce{[PtCl6]^2- + 2e- ⟶[PtCl4]^2- + 2Cl-}\) +0.68
    \(\ce{Pu^3 + 3e- ⟶Pu}\) −2.03
    \(\ce{Ra^2+ + 2e- ⟶Ra}\) −2.92
    \(\ce{Rb+ + e- ⟶Rb}\) −2.98
    \(\ce{[RhCl6]^3- + 3e- ⟶Rh + 6Cl-}\) +0.44
    \(\ce{S + 2e- ⟶S^2-}\) −0.47627
    \(\ce{S + 2H+ + 2e- ⟶H2S}\) +0.142
    \(\ce{Sc^3+ + 3e- ⟶Sc}\) −2.09
    \(\ce{Se + 2H+ + 2e- ⟶H2Se}\) −0.399
    \(\ce{[SiF6]^2- + 4e- ⟶Si + 6F-}\) −1.2
    \(\ce{SiO3^2- + 3H2O + 4e- ⟶Si + 6OH-}\) −1.697
    \(\ce{SiO2 + 4H+ + 4e- ⟶Si + 2H2O}\) −0.86
    \(\ce{Sm^3+ + 3e- ⟶Sm}\) −2.304
    \(\ce{Sn^4+ + 2e- ⟶Sn^2+}\) +0.151
    \(\ce{Sn^2+ + 2e- ⟶Sn}\) −0.1375
    \(\ce{[SnF6]^2- + 4e- ⟶Sn + 6F-}\) −0.25
    \(\ce{SnS + 2e- ⟶Sn + S^2-}\) −0.94
    \(\ce{Sr^2+ + 2e- ⟶Sr}\) −2.89
    \(\ce{TeO2 + 4H+ + 4e- ⟶Te + 2H2O}\) +0.593
    \(\ce{Th^4+ + 4e- ⟶Th}\) −1.90
    \(\ce{Ti^2+ + 2e- ⟶Ti}\) −1.630
    \(\ce{U^3+ + 3e- ⟶U}\) −1.79
    \(\ce{V^2+ + 2e- ⟶V}\) −1.19
    \(\ce{Y^3+ + 3e- ⟶Y}\) −2.37
    \(\ce{Zn^2+ + 2e- ⟶Zn}\) −0.7618
    \(\ce{[Zn(CN)4]^2- + 2e- ⟶Zn + 4CN-}\) −1.26
    \(\ce{[Zn(NH3)4]^2+ + 2e- ⟶Zn + 4NH3}\) −1.04
    \(\ce{Zn(OH)2 + 2e- ⟶Zn + 2OH-}\) −1.245
    \(\ce{[Zn(OH)4]^2 + 2e- ⟶Zn + 4OH-}\) −1.199
    \(\ce{ZnS + 2e- ⟶Zn + S^2-}\) −1.40
    \(\ce{Zr^4 + 4e- ⟶Zr}\) −1.539

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