11. Appendices

11.5. Standard reduction potentials in water at 25 °C

Based on the international convention that E0(H+/H2) \( \equiv \) 0 V at all temperatures.

 

Electrode                                     E0/V                Reaction

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Li+|Li                                        -3.040                Li+ + e- → Li

K+|K                                         -2.924                K+ + e- → K

Rb+|Rb                                     -2.924                Rb+ + e- → Rb

Na+|Na                                     -2.713                Na+ + e- → Na

Mg2+|Mg                                  -2.356                1/2 Mg2+ + e- → 1/2 Mg

Al3+|Al                                     -1.676                1/3 Al3+ + e- → 1/3 Al

OH-|H2|Pt                                -0.828                H2O + e- → 1/2 H2 + OH-

Zn2+|Zn                                    -0.7626              1/2 Zn2+ + e- → 1/2 Zn

S2-|Ag2S(s)|Ag                        -0.691                1/2 Ag2S + e- → Ag + 1/2 S2-

Br-|TlBr(s)|Tl                           -0.658                TlBr + e-→ Tl + Br-

Fe2+|Fe                                     -0.44                  1/2 Fe2+ + e- → 1/2 Fe

Cr3+, Cr2+|Pt                             -0.424                Cr3+ + e- → Cr2+

Cd2+|Cd                                   -0.403                1/2 Cd2+ + e- → 1/2 Cd

I-|PbI2(s)|Pb                             -0.365                1/2 PbI2 + e- → 1/2 Pb + I-

SO4-|PbSO4(s)|Pb                    -0.359                1/2 PbSO4 + e- → 1/2 Pb + 1/2 SO4-

F-|PbF2(s)|Pb                           -0.344                1/2 PbF2 + e- → 1/2 Pb + F-

Tl+|Tl                                        -0.3363              Tl+ + e- → Tl

Br-|PbBr2(s)|Pb                        -0.280                1/2 PbBr2 + e- →  1/2 Pb + Br

Co2+|Co                                    -0.277                1/2 Co2+ + e- → 1/2 Co

Cl-|PbCl2(s)|Pb                        -0.268                1/2 PbCl2 + e- → 1/2 Pb + Cl-

Ni2+|Ni                                     -0.257                1/2 Ni2+ + e- → 1/2 Ni

I-|AgI(s)|Ag                             -0.1522              AgI + e- → Ag + I-

Sn2+|Sn                                     -0.136                1/2 Sn2+ + e- → 1/2 Sn

Pb2+|Pb                                     -0.1251              1/2 Pb2+ + e- → 1/2 Pb

H+|H2|Pt                                  0                      H+ + e- → 1/2 H2

 
 

 


TiO2+. Ti3+|Pt                           0.10                    TiO2+ + 2H+ + e- → Ti3++ H2O

Br-|AgBr(s)|Ag                        0.0711                AgBr + e- → Ag + Br-

Sn4+, Sn2+|Pt                            0.15                    1/2 Sn4+ + e- → 1/2 Sn2+

Cu2+, Cu+|Pt                             0.159                  Cu2+ + e- → Cu+

Cl-|AgCl(s)|Ag                        0.2223                AgCl + e- → Ag + Cl-

Cl-|Hg2Cl2(s)|Hg                     0.2682*              1/2Hg2Cl2 + e- → Hg + Cl-

Cu2+|Cu                                    0.340                  1/2 Cu2+ + e- → 1/2 Cu

OH-|O2|Pt                                0.401                  1/2 O2 + H2O + 2e- → 2 OH-

CO3-|Ag2CO3(s)|Ag                0.47                    1/2 Ag2CO3 + e- → Ag + 1/2 CO3-

Cu+|Cu                                     0.520                  Cu+ + e- → Cu

I-|I2(s)|Pt                                  0.5355                1/2 I2 + e- → I-

SO4-|Hg2SO4(s)|Hg                 0.613                  1/2 Hg2SO4 + e- → Hg + 1/2 SO4-

SO4-|Ag2SO4(s)|Ag                 0.654                  1/2 Ag2SO4 + e- → Ag + 1/2 SO4-

H+|quinhydrone(s)|Pt                  0.6996                1/2 C6H4O2 + H+ + e- → 1/2 C6H6O2

Fe3+, Fe2+|Pt                             0.771                  Fe3+ + e- → Fe2+

Hg22  +|Hg                                   0.796                  1/2 Hg22  + + e- → Hg

Ag+|Ag                                     0.799                  Ag+ + e- → Ag

Hg2+, Hg22  +|Pt                            0.911                  Hg2+ + e- → 1/2 Hg22  +

Br-|Br2(l)|Pt                             1.065                  1/2 Br2(l) + e- → Br-

H+|O2|Pt                                   1.229                  1/2 O2 + 2 H+ + 2 e- → H2O

Tl3+, Tl+|Pt                               1.25                    1/2 Tl3+ + e- → 1/2 Tl+

Cl-|Cl2(g)|Pt                             1.3583                1/2 Cl2(g) + e- → Cl-

Pb2+|PbO2|Pb                           1.468                  1/2 PbO2(s) +  2H++ e- → 1/2 Pb2+ + H2O

Au3+|Au                                   1.52                    1/3 Au3+ + e- → 1/3 Au

SO4-|PbO2(s)|PbSO4(s)|Pb       1.698                  PbO2 + SO4- + 4 H+ + 2 e- → PbSO4 + 2 H2O

Ce4+, Ce3+|Pt                            1.72                    Ce4+ + e- → Ce3+

Co3+, Co2+|Pt                           1.92                    Co3+ + e- → Co2+

F-|F2(g)|Pt                                2.87                    1/2 F2(g) + e- → F-

HF(aq)|F2(g)|Pt                        3.053                  H+ + 1/2 F2(g) + e- → HF(aq)


 



* With 1 M KCl calomel electrode the potential is 0.281 V and with saturated KCl 0.242 V.