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Selected Standard Reduction Potentials at 298 K

Reduction half-reactions E°(V)
Li1+(aq) + e1– Li(s) –3.04
K1+ (aq)+ e1– K(s) –2.92
Ba2+(aq) + 2 e1– Ba(s) –2.92
Ca2+(aq) + 2 e1– Ca(s) –2.84
Na1+(aq) + e1– Na(s) –2.71
Mg2+(aq) + 2 e1– Mg(s) –2.36
Al3+(aq) + 3 e1– Al(s) –1.66
U3+(aq) + 3 e1– U(s) –1.66
Ti2+(aq) + 2 e1– Ti(s) –1.63
Mn2+(aq) + 2 e1– Mn(s) –1.18
2 H2O + 2 e1– H2(g) + 2 OH1–(aq) –0.83
Zn2+(aq) + 2 e1– Zn(s) –0.76
Cr3+(aq) + 3 e1– Cr(s) –0.74
HCHO(aq) + 2 H2O + 2 e1– CH3OH(aq) + 2 OH1–(aq) –0.59
Fe2+(aq) + 2 e1– Fe(s) –0.44
2 H2O + 2 e1– H2(g) + 2 OH1–(aq) –0.41*
Cd2+(aq) + 2 e1– Cd(s) –0.40
PbSO4(s) + 2 e1– Pb(s) + SO42–(aq) –0.36
In3+(aq) + 3 e1– In(s) –0.34
Co2+(aq) + 2 e1– Co(s) –0.28
Ni2+(aq) + 2 e1– Ni(s) –0.23
Sn2+(aq) + 2 e1– Sn(s) –0.14
Pb2+(aq) + 2 e1– Pb(s) –0.13
2 H1+(aq) + 2 e1– H2(g)   0.00
Sn4+(aq) + 2 e1– Sn2+(aq) +0.15
Cu2+(aq) + e1– Cu1+(aq) +0.16
ClO41–(aq) + H2O(l) + 2 e1– ClO31–(aq) + 2 OH1–(aq) +0.17
AgCl(s) + e1– Ag(s) + Cl1–(aq) +0.22
PbO2(s) + 2 H1+(aq) + 2 e1– PbO(s) + H2O +0.28
Cu2+(aq) + 2 e1– Cu(s) +0.34
Ag2O(s) +H2O + 2 e1– 2 Ag(s) + 2 OH1–(aq) +0.34
ClO31–(aq) + H2O(l) + 2 e1– ClO21–(aq) + 2 OH1–(aq) +0.35
O2(g) + 2 H2O + 4 e1– 4 OH1–(aq) +0.40
I2(s) + 2 e1– 2 I1–(aq) +0.54
ClO21–(aq) + H2O(l) + 2 e1– ClO1–(aq) + 2 OH1–(aq) +0.59
2 AgO(s) + H2O + 2 e1– Ag2O(s) + 2 OH1–(aq) +0.60
O2(g) + 2 H1+(aq) + 2 e1– H2O2(aq) +0.70
Fe3+(aq) + e1– Fe2+(aq) +0.77
BrO1–(aq) + H2O + 2 e1– Br1–(aq) + 2 OH1–(aq) +0.77
Ag1+(aq) + e1– Ag(s) +0.80
O2(g)+ 4 H1+(aq) + 4 e1– 2 H2O +0.82*
H2O2(aq) + 2 e1– 2 OH1–(aq) +0.88
ClO1–(aq) + H2O + 2 e1– Cl1–(aq) + 2 OH1–(aq) +0.89
Hg2+(aq) + 2 e1– Hg(l) +0.85
NO31–(aq) + 4 H1+(aq) + 3 e1– NO(g) + 2 H2O +0.96
VO21+(aq) + 2 H1+(aq) + e1– VO2+(aq) + H2O +1.00
Br2(l) + 2 e1– 2 Br1–(aq) +1.09
ClO41–(aq) + 2 H1+(aq) + 2 e1– ClO31–(aq) + H2O(l) +1.19
O2(g)+ 4 H1+(aq) + 4 e1– 2 H2O +1.23
Cr2O72–(aq)+ 14 H1+(aq) + 6 e1– 2 Cr3+(aq) + 7 H2O +1.33
Cl2(g) + 2 e1– 2 Cl1–(aq) +1.36
Au3+(aq) + 3 e1– Au(s) +1.50
MnO41–(aq) + 8 H1+(aq)+ 5 e1– Mn2+(aq) + 4 H2O +1.51
PbO2(s) + 4 H1+(aq) + SO42–(aq) + 2 e1– PbSO4(s) + 2 H2O +1.69
H2O2(aq) + 2 H1+(aq) + 2 e1– 2 H2O(l) +1.76
S2O82–(aq) + 2 e1– 2 SO42–(aq) +2.01
O3(g) + 2 H1+(aq) + 2 e1– O2(g) + H2O +2.07
F2(g) + 2 e1– 2 F1–(aq) +2.87

* The half-cell potentials for the O2/H2O and the H2O/H2 systems are for neutral (pH = 7) water and are not standard reduction potentials where [OH1–] or [H1+] = 1.0 M.