ELECTROCHEMICAL SERIES
Petr Vanýsek
There are three tables for this electrochemical series. Each table lists standard reduction potentials, E° values, at 298.15 K (25°C), and at a pressure
of 101.325 kPa (1 atm). Table 1 is an alphabetical listing of the elements, according to the symbol of the elements. Thus, data for silver (Ag) precedes
those for aluminum (Al). Table 2 lists only those reduction reactions which have E° values positive in respect to the standard hydrogen electrode. In
Table 2, the reactions are listed in the order of increasing positive potential, and they range from 0.0000 V to + 3.4 V. Table 3 lists only those reduction
potentials which have E° negative with respect to the standard hydrogen electrode. In Table 3, the reactions are listed in the order of decreasing potential
and range from 0.0000 V to –4.10 V. The reliability of the potentials is not the same for all the data. Typically, the values with fewer significant figures
have lower reliability. The values of reduction potentials, in particular those of less common reactions, are not definite; they are subject to occasional
revisions.
Abbreviations: ac = acetate; bipy = 2,2′-dipyridine, or bipyridine; en = ethylenediamine; phen = 1,10-phenanthroline.
REFERENCES
1. G. Milazzo, S. Caroli, and V. K. Sharma, Tables of Standard Electrode Potentials, Wiley, Chichester, 1978.
2. A. J. Bard, R. Parsons, and J. Jordan, Standard Potentials in Aqueous Solutions, Marcel Dekker, New York, 1985.
3. S. G. Bratsch, J. Phys. Chem. Ref. Data, 18, 1—21, 1989.
TABLE 1
Alphabetical Listing
Reaction
Ac3+ + 3 e 1 Ac
Ag+ + e 1 Ag
Ag2+ + e 1 Ag+
Ag(ac) + e 1 Ag + (ac)–
AgBr + e 1 Ag + Br–
AgBrO3 + e 1 Ag + BrO3–
Ag2C2O4 + 2 e 1 2 Ag + C2O42–
AgCl + e 1 Ag + Cl–
AgCN + e 1 Ag + CN–
Ag2CO3 + 2 e 1 2 Ag + CO32–
Ag2CrO4 + 2 e 1 2 Ag + CrO42–
AgF + e 1 Ag + F–
Ag4[Fe(CN)6] + 4 e 1 4 Ag + [Fe(CN)6]4–
AgI + e 1 Ag + I–
AgIO3 + e 1 Ag + IO3–
Ag2MoO4 + 2 e 1 2 Ag + MoO42–
AgNO2 + e 1 Ag + 2 NO2–
Ag2O + H2O + 2 e 1 2 Ag + 2 OH–
Ag2O3 + H2O + 2 e 1 2 AgO + 2 OH–
Ag3+ + 2 e 1 Ag+
Ag3+ + e 1 Ag2+
Ag2O2 + 4 H+ + e 1 2 Ag + 2 H2O
2 AgO + H2O + 2 e 1 Ag2O + 2 OH–
AgOCN + e 1 Ag + OCN–
Ag2S + 2 e 1 2 Ag + S2–
Ag2S + 2 H+ + 2 e 1 2 Ag + H2S
AgSCN + e 1 Ag + SCN–
Ag2SeO3 + 2 e 1 2 Ag + SeO42–
Ag2SO4 + 2 e 1 2 Ag + SO42–
Ag2WO4 + 2 e 1 2 Ag + WO42–
Al3+ + 3 e 1 Al
Al(OH)3 + 3 e 1 Al + 3 OH–
© 2000 by CRC PRESS LLC
E°/V
–2.20
0.7996
1.980
0.643
0.07133
0.546
0.4647
0.22233
–0.017
0.47
0.4470
0.779
0.1478
–0.15224
0.354
0.4573
0.564
0.342
0.739
1.9
1.8
1.802
0.607
0.41
–0.691
–0.0366
0.08951
0.3629
0.654
0.4660
–1.662
–2.31
Reaction
Al(OH)4– + 3 e 1 Al + 4 OH–
H2AlO3– + H2O + 3 e 1 Al + 4 OH–
AlF63– + 3 e 1 Al + 6 F–
Am4+ + e 1 Am3+
Am2+ + 2 e 1 Am
Am3+ + 3 e 1 Am
Am3+ + e 1 Am2+
As + 3 H+ + 3 e 1 AsH3
As2O3 + 6 H+ + 6 e 1 2 As + 3 H2O
HAsO2 + 3 H+ + 3 e 1 As + 2 H2O
AsO2– + 2 H2O + 3 e 1 As + 4 OH–
H3AsO4 + 2 H+ + 2 e–1 HAsO2 + 2 H2O
AsO43– + 2 H2O + 2 e 1 AsO2– + 4 OH–
At2 + 2 e 1 2 At–
Au+ + e 1 Au
Au3+ + 2 e 1 Au+
Au3+ + 3 e 1 Au
Au2+ + e –1 Au+
AuOH2+ + H+ + 2 e 1 Au+ + H2O
AuBr2– + e 1 Au + 2 Br–
AuBr4– + 3 e 1 Au + 4 Br–
AuCl4– + 3 e 1 Au + 4 Cl–
Au(OH)3 + 3 H+ + 3 e 1 Au + 3 H2O
H2BO3– + 5 H2O + 8 e 1 BH4– + 8 OH–
H2BO3– + H2O + 3 e 1 B + 4 OH–
H3BO3 + 3 H+ + 3 e 1 B + 3 H2O
B(OH)3 + 7 H+ + 8 e 1 BH4– + 3 H2O
Ba2+ + 2 e 1 Ba
Ba2+ + 2 e 1 Ba(Hg)
Ba(OH)2 + 2 e 1 Ba + 2 OH–
Be2+ + 2 e 1 Be
Be2O32– + 3 H2O + 4 e 1 2 Be + 6 OH–
E°/V
–2.328
–2.33
–2.069
2.60
–1.9
–2.048
–2.3
–0.608
0.234
0.248
–0.68
0.560
–0.71
0.3
1.692
1.401
1.498
1.8
1.32
0.959
0.854
1.002
1.45
–1.24
–1.79
–0.8698
–0.481
–2.912
–1.570
–2.99
–1.847
–2.63
ELECTROCHEMICAL SERIES (continued)
TABLE 1
Alphabetical Listing (continued)
Reaction
p–benzoquinone + 2 H+ + 2 e 1 hydroquinone
Bi+ + e 1 Bi
Bi3+ + 3 e 1 Bi
Bi3+ + 2 e 1 Bi+
Bi + 3 H+ + 3 e 1 BiH3
BiCl4– + 3 e 1 Bi + 4 Cl–
Bi2O3 + 3 H2O + 6 e 1 2 Bi + 6 OH–
Bi2O4 + 4 H+ + 2 e 1 2 BiO+ + 2 H2O
BiO+ + 2 H+ + 3 e 1 Bi + H2O
BiOCl + 2 H+ + 3 e 1 Bi + Cl– + H2O
Bk4+ + e 1 Bk3+
Bk2+ + 2 e 1 Bk
Bk3+ + e 1 Bk2+
Br2(aq) + 2 e 1 2 Br–
Br2(l) + 2 e 1 2 Br–
HBrO + H+ + 2 e 1 Br– + H2O
HBrO + H+ + e 1 1/2 Br2(aq) + H2O
HBrO + H+ + e 1 1/2 Br2(l) + H2O
BrO– + H2O + 2 e 1 Br– + 2 OH–
BrO3– + 6 H+ + 5 e 1 1/2 Br2 + 3 H2O
BrO3– + 6 H+ + 6 e 1 Br– + 3 H2O
BrO3– + 3 H2O + 6 e 1 Br– + 6 OH–
(CN)2 + 2 H+ + 2 e 1 2 HCN
2 HCNO + 2 H+ + 2 e 1 (CN)2 + 2 H2O
(CNS)2 + 2 e 1 2 CNS–
CO2 + 2 H+ + 2 e 1 HCOOH
Ca+ + e 1 Ca
Ca2+ + 2 e 1 Ca
Ca(OH)2 + 2 e 1 Ca + 2 OH–
Calomel electrode, 1 molal KCl
Calomel electrode, 1 molar KCl (NCE)
Calomel electrode, 0.1 molar KCl
Calomel electrode, saturated KCl (SCE)
Calomel electrode, saturated NaCl (SSCE)
Cd2+ + 2 e 1 Cd
Cd2+ + 2 e 1 Cd(Hg)
Cd(OH)2 + 2 e 1 Cd(Hg) + 2 OH–
CdSO4 + 2 e 1 Cd + SO42–
Cd(OH)42– + 2 e 1 Cd + 4 OH–
CdO + H2O + 2 e 1 Cd + 2 OH–
Ce3+ + 3 e 1 Ce
Ce3+ + 3 e 1 Ce(Hg)
Ce4+ + e 1 Ce3+
CeOH3+ + H+ + e 1 Ce3+ + H2O
Cf4+ + e 1 Cf3+
Cf3+ + e 1 Cf2+
Cf3+ + 3 e 1 Cf
Cf2+ + 2 e 1 Cf
Cl2(g) + 2 e 1 2 Cl–
HClO + H + + e 1 1/2 Cl2 + H2O
HClO + H+ + 2 e 1 Cl– + H2O
ClO– + H2O + 2 e 1 Cl– + 2 OH–
ClO2 + H+ + e 1 HClO2
HClO2 + 2 H+ + 2 e 1 HClO + H2O
HClO2 + 3 H+ + 3 e 1 1/2 Cl2 + 2 H2O
© 2000 by CRC PRESS LLC
E°/V
0.6992
0.5
0.308
0.2
–0.8
0.16
–0.46
1.593
0.320
0.1583
1.67
–1.6
–2.8
1.0873
1.066
1.331
1.574
1.596
0.761
1.482
1.423
0.61
0.373
0.330
0.77
–0.199
–3.80
–2.868
–3.02
0.2800
0.2801
0.3337
0.2412
0.2360
–0.4030
–0.3521
–0.809
–0.246
–0.658
–0.783
–2.336
–1.4373
1.72
1.715
3.3
–1.6
–1.94
–2.12
1.35827
1.611
1.482
0.81
1.277
1.645
1.628
Reaction
HClO2 + 3 H+ + 4 e 1 Cl– + 2 H2O
ClO2– + H2O + 2 e 1 ClO– + 2 OH–
ClO2– + 2 H2O + 4 e 1 Cl– + 4 OH–
ClO2(aq) + e 1 ClO2–
ClO3– + 2 H+ + e 1 ClO2 + H2O
ClO3– + 3 H+ + 2 e 1 HClO2 + H2O
ClO3– + 6 H+ + 5 e 1 1/2 Cl2 + 3 H2O
ClO3– + 6 H+ + 6 e 1 Cl– + 3 H2O
ClO3– + H2O + 2 e 1 ClO2– + 2 OH–
ClO3– + 3 H2O + 6 e 1 Cl– + 6 OH–
ClO4– + 2 H+ + 2 e 1 ClO3– H2O
ClO4– + 8 H+ + 7 e 1 1/2 Cl2 + 4 H2O
ClO4– + 8 H+ + 8 e 1 Cl– + 4 H2O
ClO4– + H2O + 2 e 1 ClO3– + 2 OH–
Cm4+ + e 1 Cm3+
Cm3+ + 3 e 1 Cm
Co2+ + 2 e 1 Co
Co3+ + e 1 Co2+
[Co(NH3)6]3+ + e 1 [Co(NH3)6]2+
Co(OH)2 + 2 e 1 Co + 2 OH–
Co(OH)3 + e 1 Co(OH)2 + OH–
Cr2+ + 2 e 1 Cr
Cr3+ + e 1 Cr2+
Cr3+ + 3 e 1 Cr
Cr2O72– + 14 H+ + 6 e 1 2 Cr3+ + 7 H2O
CrO2– + 2 H2O + 3 e 1 Cr + 4 OH–
HCrO4– + 7 H+ + 3 e 1 Cr3+ + 4 H2O
CrO2 + 4 H+ + e 1 Cr3+ + 2H2O
Cr(V) + e 1 Cr(IV)
CrO42– + 4 H2O + 3 e 1 Cr(OH)3 + 5 OH–
Cr(OH)3 + 3 e 1 Cr + 3 OH–
Cs+ + e 1 Cs
Cu+ + e 1 Cu
Cu2+ + e 1 Cu+
Cu2+ + 2 e 1 Cu
Cu2+ + 2 e 1 Cu(Hg)
Cu3+ + e 1 Cu2+
Cu2O3 + 6 H+ + 2e 1 2Cu2+ + 3 H2O
Cu2+ + 2 CN– + e 1 [Cu(CN)2]–
CuI2– + e 1 Cu + 2 I–
Cu2O + H2O + 2 e 1 2 Cu + 2 OH–
Cu(OH)2 + 2 e 1 Cu + 2 OH–
2 Cu(OH)2 + 2 e 1 Cu2O + 2 OH– + H2O
2 D+ + 2 e 1 D2
Dy2+ + 2 e 1 Dy
Dy3+ + 3 e 1 Dy
Dy3+ + e 1 Dy2+
Er2+ + 2 e 1 Er
Er3+ + 3 e 1 Er
Er3+ + e 1 Er2+
Es3+ + e 1 Es2+
Es3+ + 3 e 1 Es
Es2+ + 2 e 1 Es
Eu2+ + 2 e 1 Eu
Eu3+ + 3 e 1 Eu
E°/V
1.570
0.66
0.76
0.954
1.152
1.214
1.47
1.451
0.33
0.62
1.189
1.39
1.389
0.36
3.0
–2.04
–0.28
1.92
0.108
–0.73
0.17
–0.913
–0.407
–0.744
1.232
–1.2
1.350
1.48
1.34
–0.13
–1.48
–3.026
0.521
0.153
0.3419
0.345
2.4
2.0
1.103
0.00
–0.360
–0.222
–0.080
–0.013
–2.2
–2.295
–2.6
–2.0
–2.331
–3.0
–1.3
–1.91
–2.23
–2.812
–1.991
ELECTROCHEMICAL SERIES (continued)
TABLE 1
Alphabetical Listing (continued)
Reaction
Eu3+ + e 1 Eu2+
F2 + 2 H+ + 2 e 1 2 HF
F2 + 2 e 1 2 F–
F2O + 2 H+ + 4 e 1 H2O + 2 F–
Fe2+ + 2 e 1 Fe
Fe3+ + 3 e 1 Fe
Fe3+ + e 1 Fe2+
2 HFeO4– + 8 H+ + 6 e 1 Fe2O3 + 5 H2O
HFeO4– + 4 H+ + 3 e 1 FeOOH + 2 H2O
HFeO4– + 7 H+ + 3 e 1 Fe3+ + 4 H2O
Fe2O3 + 4 H+ + 2 e 1 2 FeOH+ + H2O
[Fe(CN)6]3– + e 1 [Fe(CN)6]4–
FeO42– + 8 H+ + 3 e 1 Fe3+ + 4 H2O
[Fe(bipy)2]3+ + e 1 Fe(bipy)2]2+
[Fe(bipy)3]3+ + e 1 Fe(bipy)3]2+
Fe(OH)3 + e 1 Fe(OH)2 + OH–
[Fe(phen)3]3+ + e 1 [Fe(phen)3]2+
[Fe(phen)3]3+ + e 1 [Fe(phen)3]2+ (1 molar H2SO4)
[Ferricinium]+ + e 1 ferrocene
Fm3++ e 1 Fm2+
Fm3+ + 3 e 1 Fm
Fm2+ + 2 e 1 Fm
Fr+ + e 1 Fr
Ga3+ + 3 e 1 Ga
Ga+ + e 1 Ga
GaOH2+ + H+ + 3 e 1 Ga + H2O
H2GaO–3 + H2O + 3 e 1 Ga + 4 OH–
Gd3+ + 3 e 1 Gd
Ge2+ + 2 e 1 Ge
Ge4+ + 4 e 1 Ge
Ge4+ + 2 e 1 Ge2+
GeO2 + 2 H+ + 2 e 1 GeO + H2O
H2GeO3 + 4 H+ + 4 e 1 Ge + 3 H2O
2 H+ + 2 e 1 H2
H2 + 2 e 1 2 H–
HO2 + H+ + e 1 H2O2
2 H2O + 2 e 1 H2 + 2 OH–
H2O2 + 2 H+ + 2 e 1 2 H2O
Hf4+ + 4 e 1 Hf
HfO2+ + 2 H+ + 4 e 1 Hf + H2O
HfO2 + 4 H+ + 4 e 1 Hf + 2 H2O
HfO(OH)2 + H2O + 4 e 1 Hf + 4 OH–
Hg2+ + 2 e 1 Hg
2 Hg2+ + 2 e 1 Hg22+
Hg22+ + 2 e 1 2 Hg
Hg2(ac)2 + 2 e 1 2 Hg + 2(ac)–
Hg2Br2 + 2 e 1 2 Hg + 2 Br–
Hg2Cl2 + 2 e 1 2 Hg + 2 Cl–
Hg2HPO4 + 2 e 1 2 Hg + HPO42–
Hg2I2 + 2 e 1 2 Hg + 2 I–
Hg2O + H2O + 2 e 1 2 Hg + 2 OH–
HgO + H2O + 2 e 1 Hg + 2 OH–
Hg(OH)2 + 2 H+ + 2 e 1 Hg + 2 H2O
Hg2SO4 + 2 e 1 2 Hg + SO42–
Ho2+ + 2 e 1 Ho
© 2000 by CRC PRESS LLC
E°/V
–0.36
3.053
2.866
2.153
–0.447
–0.037
0.771
2.09
2.08
2.07
0.16
0.358
2.20
0.78
1.03
–0.56
1.147
1.06
0.400
–1.1
–1.89
–2.30
–2.9
–0.549
–0.2
–0.498
–1.219
–2.279
0.24
0.124
0.00
–0.118
–0.182
0.00000
–2.23
1.495
–0.8277
1.776
–1.55
–1.724
–1.505
–2.50
0.851
0.920
0.7973
0.51163
0.13923
0.26808
0.6359
–0.0405
0.123
0.0977
1.034
0.6125
–2.1
Reaction
Ho3+ + 3 e 1 Ho
Ho3+ + e 1 Ho2+
I2 + 2 e 1 2 I–
I3– + 2 e 1 3 I–
H3IO62– + 2 e 1 IO–3 + 3 OH–
H5IO6 + H+ + 2 e 1 IO3– + 3 H2O
2 HIO + 2 H+ + 2 e 1 I2 + 2 H2O
HIO + H+ + 2 e 1 I– + H2O
IO– + H2O + 2 e 1 I– + 2 OH–
2 IO3– + 12 H+ + 10 e 1 I2 + 6 H2O
IO3– + 6 H+ + 6 e 1 I– + 3 H2O
IO3– + 2 H2O + 4 e 1 IO– + 4 OH–
IO3– + 3 H2O + 6 e 1 IO– + 6 OH–
In+ + e 1 In
In2+ + e 1 In+
In3+ + e 1 In2+
In3+ + 2 e 1 In+
In3+ + 3 e 1 In
In(OH)3 + 3 e 1 In + 3 OH–
In(OH)4– + 3 e 1 In + 4 OH–
In2O3 + 3 H2O + 6 e 1 2 In + 6 OH–
Ir3+ + 3 e 1 Ir
[IrCl6]2– + e 1 [IrCl6]3–
[IrCl6]3– + 3 e 1 Ir + 6 Cl–
Ir2O3 + 3 H2O + 6 e 1 2 Ir + 6 OH–
K+ + e 1 K
La3+ + 3 e 1 La
La(OH)3 + 3 e 1 La + 3 OH–
Li+ + e 1 Li
Lr3+ + 3 e 1 Lr
Lu3+ + 3 e 1 Lu
Md3+ + e 1 Md2+
Md3+ + 3 e 1 Md
Md2+ + 2 e 1 Md
Mg+ + e 1 Mg
Mg2+ + 2 e 1 Mg
Mg(OH)2 + 2 e 1 Mg + 2 OH–
Mn2+ + 2 e 1 Mn
Mn3+ + 3e 1 Mn2+
MnO2 + 4 H+ + 2 e 1 Mn2+ + 2 H2O
MnO4– + e 1 MnO42–
MnO4– + 4 H+ + 3 e 1 MnO2 + 2 H2O
MnO4– + 8 H+ + 5 e 1 Mn2+ + 4 H2O
MnO4– + 2 H2O + 3 e 1 MnO2 + 4 OH–
MnO42– + 2 H2O + 2 e 1 MnO2 + 4 OH–
Mn(OH)2 + 2 e 1 Mn + 2 OH–
Mn(OH)3 + e 1 Mn(OH)2 + OH–
Mn2O3 + 6 H+ + e 1 2 Mn2+ + 3 H2O
Mo3+ + 3 e 1 Mo
MoO2 + 4 H+ + 4 e 1 Mo + 4 H2O
H3Mo7O243– + 45 H+ + 42 e 1 7 Mo + 24 H2O
MoO3 + 6 H+ + 6 e 1 Mo + 3 H2O
N2 + 2 H2O + 6 H+ + 6 e 1 2 NH4OH
3 N2 + 2 H+ + 2 e 1 2 HN3
N5+ + 3 H+ + 2 e 1 2 NH4+
E°/V
–2.33
–2.8
0.5355
0.536
0.7
1.601
1.439
0.987
0.485
1.195
1.085
0.15
0.26
–0.14
–0.40
–0.49
–0.443
–0.3382
–0.99
–1.007
–1.034
1.156
0.8665
0.77
0.098
–2.931
–2.379
–2.90
–3.0401
–1.96
–2.28
–0.1
–1.65
–2.40
–2.70
–2.372
–2.690
–1.185
1.5415
1.224
0.558
1.679
1.507
0.595
0.60
–1.56
0.15
1.485
–0.200
–0.152
0.082
0.075
0.092
–3.09
1.275
ELECTROCHEMICAL SERIES (continued)
TABLE 1
Alphabetical Listing (continued)
Reaction
N2O + 2
+ 2 e 1 N2 + H2O
H2N2O2 + 2 H+ + 2 e 1 N2 + 2 H2O
N2O4 + 2 e 1 2 NO2–
N2O4 + 2 H+ + 2 e 1 2 NHO2
N2O4 + 4 H+ + 4 e 1 2 NO + 2 H2O
2 NH3OH+ + H+ + 2 e 1 N2H5+ + 2 H2O
2 NO + 2 H+ + 2 e 1 N2O + H2O
2 NO + H2O + 2 e 1 N2O + 2 OH–
HNO2 + H+ + e 1 NO + H2O
2 HNO2 + 4 H+ + 4 e 1 H2N2O2 + 2 H2O
2 HNO2 + 4 H+ + 4 e 1 N2O + 3 H2O
NO2– + H2O + e 1 NO + 2 OH–
2 NO2– + 2 H2O + 4 e 1 N2O22– + 4 OH–
2 NO2– + 3 H2O + 4 e 1 N2O + 6 OH–
NO3– + 3 H+ + 2 e 1 HNO2 + H2O
NO3– + 4 H+ + 3 e 1 NO + 2 H2O
2 NO3– + 4 H+ + 2 e 1 N2O4 + 2 H2O
NO3– + H2O + 2 e 1 NO2– + 2 OH–
2 NO3– + 2 H2O + 2 e 1 N2O4 + 4 OH–
Na+ + e 1 Na
Nb3+ + 3 e 1 Nb
NbO2 + 2 H+ + 2 e 1 NbO + H2O
NbO2 + 4 H+ + 4 e 1 Nb + 2 H2O
NbO + 2 H+ + 2 e 1 Nb + H2O
Nb2O5 + 10 H+ + 10 e 1 2 Nb + 5 H2O
Nd3+ + 3 e 1 Nd
Nd2+ + 2 e 1 Nd
Nd3+ + e 1 Nd2+
Ni2+ + 2 e 1 Ni
Ni(OH)2 + 2 e 1 Ni + 2 OH–
NiO2 + 4 H+ + 2 e 1 Ni2+ + 2 H2O
NiO2 + 2 H2O + 2 e 1 Ni(OH)2 + 2 OH–
No3+ + e 1 No2+
No3+ + 3 e 1 No
No2+ + 2 e 1 No
Np3+ + 3 e 1 Np
Np4+ + e 1 Np3+
NpO2 + H2O + H+ + e 1 Np(OH)3
O2 + 2 H+ + 2 e 1 H2O2
O2 + 4 H+ + 4 e 1 2 H2O
O2 + H2O + 2 e 1 HO2– + OH–
O2 + 2 H2O + 2 e 1 H2O2 + 2 OH–
O2 + 2 H2O + 4 e 1 4 OH–
O3 + 2 H+ + 2 e 1 O2 + H2O
O3 + H2O + 2 e 1 O2 + 2 OH–
O(g) + 2 H+ + 2 e 1 H2O
OH + e 1 OH–
HO2– + H2O + 2 e 1 3 OH–
OsO4 + 8 H+ + 8 e 1 Os + 4 H2O
OsO4 + 4 H+ + 4 e 1 OsO2 + 2 H2O
[Os(bipy)2]3+ + e 1 [Os(bipy)2]2+
[Os(bipy)3]3+ + e 1 [Os(bipy)3]2+
P(red) + 3 H+ + 3 e 1 PH3(g)
P(white) + 3 H+ + 3 e 1 PH3(g)
P + 3 H2O + 3 e 1 PH3(g) + 3 OH–
H+
© 2000 by CRC PRESS LLC
E°/V
1.766
2.65
0.867
1.065
1.035
1.42
1.591
0.76
0.983
0.86
1.297
–0.46
–0.18
0.15
0.934
0.957
0.803
0.01
–0.85
–2.71
–1.099
–0.646
–0.690
–0.733
–0.644
–2.323
–2.1
–2.7
–0.257
–0.72
1.678
–0.490
1.4
–1.20
–2.50
–1.856
0.147
–0.962
0.695
1.229
–0.076
–0.146
0.401
2.076
1.24
2.421
2.02
0.878
0.838
1.02
0.81
0.80
–0.111
–0.063
–0.87
Reaction
+e 1 P+2
H3PO2 + H+ + e 1 P + 2 H2O
H3PO3 + 2 H+ + 2 e 1 H3PO2 + H2O
H3PO3 + 3 H+ + 3 e 1 P + 3 H2O
HPO32– + 2 H2O + 2 e 1 H2PO2– + 3 OH–
HPO32– + 2 H2O + 3 e 1 P + 5 OH–
H3PO4 + 2 H+ + 2 e 1 H3PO3 + H2O
PO43– + 2 H2O + 2 e 1 HPO32– + 3 OH–
Pa3+ + 3 e 1 Pa
Pa4+ + 4 e 1 Pa
Pa4+ + e 1 Pa3+
Pb2+ + 2 e 1 Pb
Pb2+ + 2 e 1 Pb(Hg)
PbBr2 + 2 e 1 Pb + 2 Br–
PbCl2 + 2 e 1 Pb + 2 Cl–
PbF2 + 2 e 1 Pb + 2 F–
PbHPO4 + 2 e 1 Pb + HPO42–
PbI2 + 2 e 1 Pb + 2 I–
PbO + H2O + 2 e 1 Pb + 2 OH–
PbO2 + 4 H+ + 2 e 1 Pb2+ + 2 H2O
HPbO2– + H2O + 2 e 1 Pb + 3 OH–
PbO2 + H2O + 2 e 1 PbO + 2 OH–
PbO2 + SO42– + 4 H+ + 2 e 1 PbSO4 + 2 H2O
PbSO4 + 2 e 1 Pb + SO42–
PbSO4 + 2 e 1 Pb(Hg) + SO42–
Pd2+ + 2 e 1 Pd
[PdCl4]2– + 2 e 1 Pd + 4 Cl–
[PdCl6]2– + 2 e 1 [PdCl4]2– + 2 Cl–
Pd(OH)2 + 2 e 1 Pd + 2 OH–
Pm2+ + 2 e 1 Pm
Pm3+ + 3 e 1 Pm
Pm3+ + e 1 Pm2+
Po4+ + 2 e 1 Po2+
Po4+ + 4 e 1 Po
Pr4+ + e 1 Pr3+
Pr2+ + 2 e 1 Pr
Pr3+ + 3 e 1 Pr
Pr3+ + e 1 Pr2+
Pt2+ + 2 e 1 Pt
[PtCl4]2– + 2 e 1 Pt + 4 Cl–
[PtCl6]2– + 2 e 1 [PtCl4]2– + 2 Cl–
Pt(OH)2 + 2 e 1 Pt + 2 OH–
PtO3 + 2 H+ + 2 e 1 PtO2 + H2O
PtO3 + 4 H+ + 2 e 1 Pt(OH)22+ + H2O
PtOH+ + H+ + 2 e 1 Pt + H2O
PtO2 + 2 H+ + 2 e 1 PtO + H2O
PtO2 + 4 H+ + 4 e 1 Pt + 2 H2O
Pu3+ + 3 e 1 Pu
Pu4+ + e 1 Pu3+
Pu5+ + e 1 Pu4+
PuO2(OH)2 + 2 H+ + 2 e 1 Pu(OH)4
PuO2(OH)2 + H+ + e 1 PuO2OH + H2O
Ra2+ + 2 e 1 Ra
Rb+ + e 1 Rb
Re3+ + 3 e 1 Re
H2P2–
OH–
E°/V
–1.82
–0.508
–0.499
–0.454
–1.65
–1.71
–0.276
–1.05
–1.34
–1.49
–1.9
–0.1262
–0.1205
–0.284
–0.2675
–0.3444
–0.465
–0.365
–0.580
1.455
–0.537
0.247
1.6913
–0.3588
–0.3505
0.951
0.591
1.288
0.07
–2.2
–2.30
–2.6
0.9
0.76
3.2
–2.0
–2.353
–3.1
1.18
0.755
0.68
0.14
1.7
1.5
1.2
1.01
1.00
–2.031
1.006
1.099
1.325
1.062
–2.8
–2.98
0.300
ELECTROCHEMICAL SERIES (continued)
TABLE 1
Alphabetical Listing (continued)
Reaction
ReO4– + 4 H+ + 3 e 1 ReO2 + 2 H2O
ReO2 + 4 H+ + 4 e 1 Re + 2 H2O
ReO4– + 2 H+ + e 1 ReO3 + H2O
ReO4– + 4 H2O + 7 e 1 Re + 8 OH–
ReO4– + 8 H+ + 7 e 1 Re + 4 H2O
Rh+ + e 1 Rh
Rh+ + 2e1 Rh
Rh3+ + 3 e 1 Rh
[RhCl6]3– + 3 e 1 Rh + 6 Cl–
RhOH2+ + H+ + 3 e 1 Rh + H2O
Ru2+ + 2 e 1 Ru
Ru3+ + e 1 Ru2+
RuO2 + 4 H+ + 2 e 1 Ru2+ + 2 H2O
RuO4– + e 1 RuO42–
RuO4 + e 1 RuO4–
RuO4 + 6 H+ + 4 e 1 Ru(OH)22+ + 2 H2O
RuO4 + 8 H+ + 8 e 1 Ru + 4 H2O
[Ru(bipy)3)3+ + e–1 [Ru(bipy)3]2+
[Ru(H2O)6]3+ + e–1 [Ru(H2O)6]2+
[Ru(NH3)6]3+ + e–1 [Ru(NH3)6]2+
[Ru(en)3]3+ + e –1 [Ru(en)3]2+
[Ru(CN)6]3– + e–1 [Ru(CN)6]4–
S + 2 e 1 S2–
S + 2H+ + 2 e 1 H2S(aq)
S + H2O + 2 e 1 SH– + OH–
2 S + 2 e 1 S22–
S2O62– + 4 H+ + 2 e 1 2 H2SO3
S2O82– + 2 e 1 2 SO42–
S2O82– + 2 H+ + 2 e 1 2 HSO4–
S4O62– + 2 e 1 2 S2O32–
2 H2SO3 + H+ + 2 e 1 HS2O4– + 2 H2O
H2SO3 + 4 H+ + 4 e 1 S + 3 H2O
2 SO32– + 2 H2O + 2 e 1 S2O42– + 4 OH–
2 SO32– + 3 H2O + 4 e 1 S2O32– + 6 OH–
SO42– + 4 H+ + 2 e 1 H2SO3 + H2O
2 SO42– + 4 H+ + 2 e 1 S2O62– + H2O
SO42– + H2O + 2 e 1 SO32– + 2 OH–
Sb + 3 H+ + 3 e 1 SbH3
Sb2O3 + 6 H+ + 6 e 1 2 Sb + 3 H2O
Sb2O5 (senarmontite) + 4 H+ + 4 e 1 Sb2O3 + 2 H2O
Sb2O5 (valentinite) + 4 H+ + 4 e 1 Sb2O3 + 2 H2O
Sb2O5 + 6 H+ + 4 e 1 2 SbO+ + 3 H2O
SbO+ + 2 H+ + 3 e 1 Sb + 2 H2O
SbO2– + 2 H2O + 3 e 1 Sb + 4 OH–
SbO3– + H2O + 2 e 1 SbO2– + 2 OH–
Sc3+ + 3 e 1 Sc
Se + 2 e 1 Se2–
Se + 2 H+ + 2 e 1 H2Se(aq)
H2SeO3 + 4 H+ + 4 e 1 Se + 3 H2O
Se + 2 H+ + 2 e 1 H2Se
SeO32– + 3 H2O + 4 e 1 Se + 6 OH–
SeO42– + 4 H+ + 2 e 1 H2SeO3 + H2O
SeO42– + H2O + 2 e 1 SeO32– + 2 OH–
SiF62– + 4 e 1 Si + 6 F–
SiO + 2 H+ + 2 e 1 Si + H2O
© 2000 by CRC PRESS LLC
E°/V
0.510
0.2513
0.768
–0.584
0.368
0.600
0.600
0.758
0.431
0.83
0.455
0.2487
1.120
0.59
1.00
1.40
1.038
1.24
0.23
0.10
0.210
0.86
–0.47627
0.142
–0.478
–0.42836
0.564
2.010
2.123
0.08
–0.056
0.449
–1.12
–0.571
0.172
–0.22
–0.93
–0.510
0.152
0.671
0.649
0.581
0.212
–0.66
–0.59
–2.077
–0.924
–0.399
0.74
–0.082
–0.366
1.151
0.05
–1.24
–0.8
Reaction
SiO2 (quartz) + 4 H+ + 4 e 1 Si + 2 H2O
SiO32– + 3 H2O + 4 e 1 Si + 6 OH–
Sm3+ + e 1 Sm2+
Sm3+ + 3 e 1 Sm
Sm2+ + 2 e 1 Sm
Sn2+ + 2 e 1 Sn
Sn4+ + 2 e 1 Sn2+
Sn(OH)3+ + 3 H+ + 2 e 1 Sn2+ + 3 H2O
SnO2 + 4 H+ + 2 e–1 Sn2+ + 2 H2O
SnO2 + 4 H+ + 4 e 1 Sn + 2 H2O
SnO2 + 3 H+ + 2 e 1 SnOH+ + H2O
SnO2 + 2 H2O + 4 e 1 Sn + 4 OH–
HSnO2– + H2O + 2 e 1 Sn + 3 OH–
Sn(OH)62– + 2 e 1 HSnO2– + 3 OH– + H2O
Sr+ + e 1 Sr
Sr2+ + 2 e 1 Sr
Sr2+ + 2 e 1 Sr(Hg)
Sr(OH)2 + 2 e 1 Sr + 2 OH–
Ta2O5 + 10 H+ + 10 e 1 2 Ta + 5 H2O
Ta3+ + 3 e 1 Ta
Tc2+ + 2 e 1 Tc
TcO4– + 4 H+ + 3 e 1 TcO2 + 2 H2O
Tc3+ + e 1 Tc2+
TcO4– + 8 H+ + 7 e 1 Tc + 4 H2O
Tb4+ + e 1 Tb3+
Tb3+ + 3 e 1 Tb
Te + 2 e 1 Te2–
Te + 2 H+ + 2 e 1 H2Te
Te4+ + 4 e 1 Te
TeO2 + 4 H+ + 4 e 1 Te + 2 H2O
TeO32– + 3 H2O + 4 e 1 Te + 6 OH–
TeO4– + 8 H+ + 7 e 1 Te + 4 H2O
H6TeO6 + 2 H+ + 2 e 1 TeO2 + 4 H2O
Th4+ + 4 e 1 Th
ThO2 + 4 H+ + 4 e 1 Th + 2 H2O
Th(OH)4 + 4 e 1 Th + 4 OH–
Ti2+ + 2 e 1 Ti
Ti3+ + e 1 Ti2+
TiO2 + 4 H+ + 2 e 1 Ti2+ + 2 H2O
Ti3+ + 3 e 1 Ti
TiOH3+ + H+ + e 1 Ti3+ + H2O
Tl+ + e 1 Tl
Tl+ + e 1 Tl(Hg)
Tl3+ + 2 e 1 Tl+
Tl3+ + 3 e 1 Tl
TlBr + e 1 Tl + Br–
TlCl + e 1 Tl + Cl–
TlI + e 1 Tl + I–
Tl2O3 + 3 H2O + 4 e 1 2 Tl+ + 6 OH–
TlOH + e 1 Tl + OH–
Tl(OH)3 + 2 e 1 TlOH + 2 OH–
Tl2SO4 + 2 e 1 Tl + SO42–
Tm3+ + e 1 Tm2+
Tm3+ + 3 e 1 Tm
Tm2+ + 2 e 1 Tm
E°/V
0.857
–1.697
–1.55
–2.304
–2.68
–0.1375
0.151
0.142
–0.094
–0.117
–0.194
–0.945
–0.909
–0.93
–4.10
–2.899
–1.793
–2.88
–0.750
–0.6
0.400
0.782
0.3
0.472
3.1
–2.28
–1.143
–0.793
0.568
0.593
–0.57
0.472
1.02
–1.899
–1.789
–2.48
–1.630
–0.9
–0.502
–1.37
–0.055
–0.336
–0.3338
1.252
0.741
–0.658
–0.5568
–0.752
0.02
–0.34
–0.05
–0.4360
–2.2
–2.319
–2.4
ELECTROCHEMICAL SERIES (continued)
TABLE 1
Alphabetical Listing (continued)
Reaction
U3+ + 3 e 1 U
U4+ + e 1 U3+
UO2+ + 4 H+ + e 1 U4+ + 2 H2O
UO22+ + e 1 UO+2
UO22+ + 4 H+ + 2 e 1 U4+ + 2 H2O
UO22+ + 4 H+ + 6 e 1 U + 2 H2O
V2+ + 2 e 1 V
V3+ + e 1 V2+
VO2+ + 2 H+ + e 1 V3+ + H2O
VO2+ + 2 H+ + e 1 VO2+ + H2O
V2O5 + 6 H+ + 2 e 1 2 VO2+ + 3 H2O
V2O5 + 10 H+ + 10 e 1 2 V + 5 H2O
V(OH)4+ + 2 H+ + e 1 VO2+ + 3 H2O
V(OH)4+ + 4 H+ + 5 e 1 V + 4 H2O
[V(phen)3]3+ + e 1 [V(phen)3]2+
W3+ + 3 e 1 W
W2O5 + 2 H+ + 2 e 1 2 WO2 + H2O
WO2 + 4 H+ + 4 e 1 W + 2 H2O
WO3 + 6 H+ + 6 e 1 W + 3 H2O
WO3 + 2 H+ + 2 e 1 WO2 + H2O
E°/V
–1.798
–0.607
0.612
0.062
0.327
–1.444
–1.175
–0.255
0.337
0.991
0.957
–0.242
1.00
–0.254
0.14
0.1
–0.031
–0.119
–0.090
0.036
Reaction
2 WO3 + 2 H+ + 2 e 1 W2O5 + H2O
H4XeO6 + 2 H+ + 2 e 1 XeO3 + 3 H2O
XeO3 + 6 H+ + 6 e 1 Xe + 3 H2O
XeF + e 1 Xe + F–
Y3+ + 3 e 1 Y
Yb3+ + e 1 Yb2+
Yb3+ + 3 e 1 Yb
Yb2+ + 2 e 1 Yb
Zn2+ + 2 e 1 Zn
Zn2+ + 2 e 1 Zn(Hg)
ZnO22– + 2 H2O + 2 e 1 Zn + 4 OH–
ZnSO4 ⋅ 7 H2O + 2 e = Zn(Hg) + SO42– + 7 H2O
(Saturated ZnSO4)
ZnOH+ + H+ + 2 e 1 Zn + H2O
Zn(OH)42– + 2 e 1 Zn + 4 OH–
Zn(OH)2 + 2 e 1 Zn + 2 OH–
ZnO + H2O + 2 e 1 Zn + 2 OH–
ZrO2 + 4 H+ + 4 e 1 Zr + 2 H2O
ZrO(OH)2 + H2O + 4 e 1 Zr + 4 OH–
Zr4+ + 4 e 1 Zr
E°/V
–0.029
2.42
2.10
3.4
–2.372
–1.05
–2.19
–2.76
–0.7618
–0.7628
–1.215
–0.7993
–0.497
–1.199
–1.249
–1.260
–1.553
–2.36
–1.45
TABLE 2
Reduction Reactions Having E° Values More Positive than that of the Standard Hydrogen Electrode
Reaction
2 H+ + 2 e 1 H2
CuI2– + e 1 Cu + 2 I–
Ge4+ + 2 e 1 Ge2+
NO3– + H2O + 2 e 1 NO2– + 2 OH–
Tl2O3 + 3 H2O + 4 e 1 2 Tl+ + 6 OH–
SeO42– + H2O + 2 e 1 SeO32– + 2 OH–
WO3 + 2 H+ + 2 e 1 WO2 + H2O
UO22+ + e = UO2+
Pd(OH)2 + 2 e 1 Pd + 2 OH–
AgBr + e 1 Ag + Br–
MoO3 + 6 H+ + 6 e 1 Mo + 3 H2O
S4O62– + 2 e 1 2 S2O32–
H3Mo7O243– + 45 H+ + 42 e 1 7 Mo + 24 H2O
AgSCN + e 1 Ag + SCN–
N2 + 2 H2O + 6 H+ + 6 e 1 2 NH4OH
HgO + H2O + 2 e 1 Hg + 2 OH–
Ir2O3 + 3 H2O + 6 e 1 2 Ir + 6 OH–
2 NO + 2 e 1 N2O22–
[Ru(NH3)6]3+ + e 1 [Ru(NH3)6]2+
W3+ + 3 e 1 W
[Co(NH3)6]3+ + e 1 [Co(NH3)6]2+
Hg2O + H2O + 2 e 1 2 Hg + 2 OH–
Ge4+ + 4 e 1 Ge
Hg2Br2 + 2 e 1 2 Hg + 2 Br–
Pt(OH)2 + 2 e 1 Pt + 2 OH–
[V(phen)3]3+ + e 1 [V(phen)3]2+
S + 2H+ + 2 e 1 H2S(aq)
© 2000 by CRC PRESS LLC
E°/V
0.00000
0.00
0.00
0.01
0.02
0.05
0.036
0.062
0.07
0.07133
0.075
0.08
0.082
0.8951
0.092
0.0977
0.098
0.10
0.10
0.1
0.108
0.123
0.124
0.13923
0.14
0.14
0.142
Reaction
Sn(OH)3+ + 3 H+ + 2 e 1 Sn2+ + 3 H2O
Np4+ + e 1 Np3+
Ag4[Fe(CN)6] + 4 e 1 4 Ag + [Fe(CN)6]4–
IO3– + 2 H2O + 4 e 1 IO– + 4 OH–
Mn(OH)3 + e 1 Mn(OH)2 + OH–
2 NO2– + 3 H2O + 4 e 1 N2O + 6 OH–
Sn4+ + 2 e 1 Sn2+
Sb2O3 + 6 H+ + 6 e 1 2 Sb + 3 H2O
Cu2+ + e 1 Cu+
BiOCl + 2 H+ + 3 e 1 Bi + Cl– + H2O
BiCl4– + 3 e 1 Bi + 4 Cl–
Fe2O3 + 4 H+ + 2 e 1 2 FeOH+ + H2O
Co(OH)3 + e 1 Co(OH)2 + OH–
SO42– + 4 H+ + 2 e 1 H2SO3 + H2O
Bi3+ + 2 e 1 Bi+
[Ru(en)3]3+ + e 1 [Ru(en)3]2+
SbO+ + 2 H+ + 3 e 1 Sb + 2 H2O
AgCl + e 1 Ag + Cl–
[Ru(H2O)6]3+ + e 1 [Ru(H2O)6]2+
As2O3 + 6 H+ + 6 e 1 2 As + 3 H2O
Calomel electrode, saturated NaCl (SSCE)
Ge2+ + 2 e 1 Ge
Ru3+ + e 1 Ru2+
Calomel electrode, saturated KCl
PbO2 + H2O + 2 e 1 PbO + 2 OH–
HAsO2 + 3 H+ + 3 e 1 As + 2 H2O
Ru3+ + e 1 Ru2+
E°/V
0.142
0.147
0.1478
0.15
0.15
0.15
0.151
0.152
0.153
0.1583
0.16
0.16
0.17
0.172
0.2
0.210
0.212
0.22233
0.23
0.234
0.2360
0.24
0.24
0.2412
0.247
0.248
0.2487
ELECTROCHEMICAL SERIES (continued)
TABLE 2
Reduction Reactions Having E° Values More Positive than that of the Standard Hydrogen Electrode
(continued)
Reaction
ReO2 + 4 H+ + 4 e 1 Re + 2 H2O
IO3– + 3 H2O + 6 e 1 I– + OH–
Hg2Cl2 + 2 e 1 2 Hg + 2 Cl–
Calomel electrode, 1 molal KCl
Calomel electrode, 1 molar KCl (NCE)
At2 + 2 e 1 2 At–
Re3+ + 3 e 1 Re
Tc3+ + e 1 Tc2+
Bi3+ + 3 e 1 Bi
BiO+ + 2 H+ + 3 e 1 Bi + H2O
UO22+ + 4 H+ + 2 e 1 U4+ + 2 H2O
ClO3– + H2O + 2 e 1 ClO2– + 2 OH–
2 HCNO + 2 H+ + 2 e 1 (CN)2 + 2 H2O
Calomel electrode, 0.1 molar KCl
VO2+ + 2 H+ + e 1 V3+ + H2O
Cu2+ + 2 e 1 Cu
Ag2O + H2O + 2 e 1 2 Ag + 2 OH–
Cu2+ + 2 e 1 Cu(Hg)
AgIO3 + e 1 Ag + IO3–
[Fe(CN)6]3– + e 1 [Fe(CN)6]4–
ClO4– + H2O + 2 e 1 ClO–3 + 2 OH–
Ag2SeO3 + 2 e 1 2 Ag + SeO32–
ReO4– + 8 H+ + 7 e 1 Re + 4 H2O
(CN)2 + 2 H+ + 2 e 1 2 HCN
[Ferricinium]+ + e 1 ferrocene
Tc2+ + 2 e 1 Tc
O2 + 2 H2O + 4 e 1 4 OH–
AgOCN + e 1 Ag + OCN–
[RhCl6]3– + 3 e 1 Rh + 6 Cl–
Ag2CrO4 + 2 e 1 2 Ag + CrO42–
H2SO3 + 4 H+ + 4 e 1 S + 3 H2O
Ru2+ + 2 e 1 Ru
Ag2MoO4 + 2 e 1 2 Ag + MoO42–
Ag2C2O4 + 2 e 1 2 Ag + C2O42–
Ag2WO4 + 2 e 1 2 Ag + WO42–
Ag2CO3 + 2 e 1 2 Ag + CO32–
TcO4– + 8 H+ + 7 e 1 Tc + 4 H2O
TeO4– + 8 H+ + 7 e 1 Te + 4 H2O
IO– + H2O + 2 e 1 I– + 2 OH–
NiO2 + 2 H2O + 2 e 1 Ni(OH)2 + 2 OH–
Bi+ + e 1 Bi
ReO4– + 4 H+ + 3 e 1 ReO2 + 2 H2O
Hg2(ac)2 + 2 e 1 2 Hg + 2(ac)–
Cu+ + e 1 Cu
I2 + 2 e 1 2 I–
I3– + 2 e 1 3 I–
AgBrO3 + e 1 Ag + BrO3–
MnO4– + e 1 MnO2–
H3AsO4 + 2 H+ + 2 e 1 HAsO2 + 2 H2O
S2O62– + 4 H+ + 2 e 1 2 H2SO3
AgNO2 + e 1 Ag + NO2–
Te4+ + 4 e 1 Te
Sb2O5 + 6 H+ + 4 e 1 2 SbO+ + 3 H2O
RuO4– + e 1 RuO42–
© 2000 by CRC PRESS LLC
E°/V
0.2513
0.26
0.26808
0.2800
0.2801
0.3
0.300
0.3
0.308
0.320
0.327
0.33
0.330
0.3337
0.337
0.3419
0.342
0.345
0.354
0.358
0.36
0.3629
0.368
0.373
0.400
0.400
0.401
0.41
0.431
0.4470
0.449
0.455
0.4573
0.4647
0.4660
0.47
0.472
0.472
0.485
0.490
0.5
0.510
0.51163
0.521
0.5355
0.536
0.546
0.558
0.560
0.564
0.564
0.568
0.581
0.59
Reaction
[PdCl4]2– + 2 e 1 Pd + 4 Cl–
TeO2 + 4 H+ + 4 e 1 Te + 2 H2O
MnO4– + 2 H2O + 3 e 1 MnO2 + 4 OH–
Rh2+ + 2 e 1 Rh
Rh+ + e 1 Rh
MnO42– + 2 H2O + 2 e 1 MnO2 + 4 OH–
2 AgO + H2O + 2 e 1 Ag2O + 2 OH–
BrO3– + 3 H2O + 6 e 1 Br– + 6 OH–
UO2+ + 4 H+ + e 1 U4+ + 2 H2O
Hg2SO4 + 2 e 1 2 Hg + SO42–
ClO3– + 3 H2O + 6 e 1 Cl– + 6 OH–
Hg2HPO4 + 2 e 1 2 Hg + HPO42–
Ag(ac) + e 1 Ag + (ac)–
Sb2O5(valentinite) + 4 H+ + 4 e 1 Sb2O3 + 2 H2O
Ag2SO4 + 2 e 1 2 Ag + SO42–
ClO2– + H2O + 2 e 1 ClO– + 2 OH–
Sb2O5(senarmontite) + 4 H+ + 4 e 1 Sb2O5 + 2 H2O
[PtCl6]2– + 2 e 1 [PtCl4]2– + 2 Cl–
O2 + 2 H+ + 2 e 1 H2O2
p–benzoquinone + 2 H+ + 2 e 1 hydroquinone
H3IO62– + 2 e 1 IO3– + 3 OH–
Ag2O3+ H2O + 2 e 1 2 AgO + 2 OH–
Tl3+ + 3 e 1 Tl
[PtCl4]2– + 2 e 1 Pt + 4 Cl–
Rh3+ + 3 e 1 Rh
ClO2– + 2 H2O + 4 e 1 Cl– + 4 OH–
2 NO + H2O + 2 e 1 N2O + 2 OH–
Po4+ + 4 e 1 Po
BrO– + H2O + 2 e 1 Br– + 2 OH–
ReO4– + 2 H+ +e1 ReO3 + H2O
(CNS)2 + 2 e 1 2 CNS–
[IrCl6]3– + 3 e 1 Ir + 6 Cl–
Fe3+ + e 1 Fe2+
AgF + e 1 Ag + F–
[Fe(bipy)2]3+ + e 1 [Fe(bipy)2]2+
TcO4– + 4 H+ + 3 e 1 TcO2 + 2 H2O
Hg22+ + 2 e 1 2 Hg
Ag+ + e 1 Ag
[Os(bipy)3]3+ + e 1 [Os(bipy)3]2+
2 NO3– + 4 H+ + 2 e 1 N2O4 + 2 H2O
[Os(bipy)2]3+ + e 1 [Os(bipy)2]2+
RhOH2+ + H + 3 e 1 Rh + H2O
OsO4 + 8 H+ + 8 e 1 Os + 4 H2O
ClO– + H2O + 2 e 1 Cl– + 2 OH–
Hg2+ + 2 e 1 Hg
AuBr4– + 3 e 1 Au + 4 Br–
SiO2(quartz) + 4 H+ + 4 e 1 Si + 2 H2O
2 HNO2 + 4 H+ + 4 e 1 H2N2O2 + H2O
[Ru(CN)6]3– + e–1 [Ru(CN)6]4–
[IrCl6]2– + e 1 [IrCl6]3–
N2O4 + 2 e 1 2 NO2–
HO2– + H2O + 2 e 1 3 OH–
Po4+ + 2 e 1 Po2+
2 Hg+ + 2 e 1 Hg22+
E°/V
0.591
0.593
0.595
0.600
0.600
0.60
0.607
0.61
0.612
0.6125
0.62
0.6359
0.643
0.649
0.654
0.66
0.671
0.68
0.695
0.6992
0.7
0.739
0.741
0.755
0.758
0.76
0.76
0.76
0.761
0.768
0.77
0.77
0.771
0.779
0.78
0.782
0.7973
0.7996
0.80
0.803
0.81
0.83
0.838
0.841
0.851
0.854
0.857
0.86
0.86
0.8665
0.867
0.878
0.9
0.920
ELECTROCHEMICAL SERIES (continued)
TABLE 2
Reduction Reactions Having E° Values More Positive than that of the Standard Hydrogen Electrode
(continued)
Reaction
NO3– + 3 H+ + 2 e 1 HNO2 + H2O
Pd2+ + 2 e 1 Pd
ClO2(aq) + e 1 ClO2–
NO3– + 4 H+ + 3 e 1 NO + 2 H2O
V2O5 + 6 H+ + 2 e 1 2 VO2+ + 3 H2O
AuBr2– + e 1 Au + 2 Br–
HNO2 + H+ + e 1 NO + H2O
HIO + H+ + 2 e 1 I– + H2O
VO2+ + 2 H+ + e 1 VO2+ + H2O
PtO2 + 4 H+ + 4 e 1 Pt + 2 H2O
RuO4 + e 1 RuO4–
V(OH)4+ + 2 H+ + e 1 VO2+ + 3 H2O
AuCl4– + 3 e 1 Au + 4 Cl–
Pu4+ + e 1 Pu3+
PtO2 + 2 H+ + 2 e 1 PtO + H2O
OsO4 + 4 H + 4 e 1 OsO2 + 2 H2O
H6TeO6 + 2 H+ + 2 e 1 TeO2 + 4 H2O
[Fe(bipy)3]3+ + e 1 [Fe(bipy)3]2+
Hg(OH)2 + 2 H+ + 2 e 1 Hg + 2 H2O
N2O4 + 4 H+ + 4 e 1 2 NO + 2 H2O
RuO4 + 8 H+ + 8 e 1 Ru + 4H2O
[Fe(phen)3]3+ + e 1 [Fe(phen)3]2+ (1 molar H2SO4)
PuO2(OH)2 + H+ + e 1 PuO2OH + H2O
N2O4 + 2 H+ + 2 e 1 2 HNO2
Br2(l) + 2 e 1 2Br–
IO3– + 6 H+ + 6 e 1 I– + 3 H2O
Br2(aq) + 2 e 1 2Br–
Pu5+ + e 1 Pu4+
Cu2+ + 2 CN– + e 1 [Cu(CN)2]–
RuO2 + 4 H+ + 2 e 1 Ru2+ + 2 H2O
[Fe(phen)3]3+ + e 1 [Fe(phen)3]2+
SeO42– + 4 H+ + 2 e 1 H2SeO3 + H2O
ClO3– + 2 H+ + e 1 ClO2 + H2O
Ir3+ + 3 e 1 Ir
Pt2+ + 2 e 1 Pt
ClO4– + 2 H+ + 2 e 1 ClO3– + H2O
2 IO3– + 12 H+ + 10 e 1 I2 + 6 H2O
PtOH+ + H+ + 2 e 1 Pt + H2O
ClO3– + 3 H+ + 2 e 1 HClO2 + H2O
MnO2 + 4 H+ + 2 e 1 Mn2+ + 2 H2O
O2 + 4 H+ + 4 e 1 2 H2O
Cr2O72– + 14 H+ + 6 e 1 2 Cr3+ + 7 H2O
O3 + H2O + 2 e 1 O2 + 2 OH–
[Ru(bipy)3]3+ + e 1 [Ru(bipy)3]2+
Tl3+ + 2 e 1 Tl+
N2H5+ + 3 H+ + 2 e 1 2 NH4+
ClO2 + H+ + e 1 HClO2
[PdCl6]2– + 2 e 1 [PdCl4]2– + 2 Cl–
2 HNO2 + 4 H+ + 4 e 1 N2O + 3 H2O
AuOH2+ + H+ + 2 e 1 Au+ + H2O
PuO2(OH)2 + 2 H– + 2 e 1 Pu(OH)4
HBrO + H+ + 2 e 1 Br– + H2O
Cr(V) + e 1 Cr(IV)
HCrO4– + 7 H+ + 3 e 1 Cr3+ + 4 H2O
© 2000 by CRC PRESS LLC
E°/V
0.934
0.951
0.954
0.957
0.957
0.959
0.983
0.987
0.991
1.00
1.00
1.00
1.002
1.006
1.01
1.02
1.02
1.03
1.034
1.035
1.038
1.06
1.062
1.065
1.066
1.085
1.0873
1.099
1.103
1.120
1.147
1.151
1.152
1.156
1.18
1.189
1.195
1.2
1.214
1.224
1.229
1.232
1.24
1.24
1.252
1.275
1.277
1.288
1.297
1.32
1.325
1.331
1.34
1.350
Reaction
Cl2(g) + 2 e 1 2Cl–
ClO4– + 8 H+ + 8 e 1 Cl– + 4 H2O
ClO4– + 8 H+ + 7 e 1 1/2 Cl2 + 4 H2O
No3+ + e 1 No2+
RuO4 + 6 H+ + 4 e 1 Ru(OH)22+ + 2 H2O
Au3+ + 2 e 1 Au+
2 NH3OH+ + H+ + 2 e 1 N2H5+ + 2 H2O
BrO3– + 6 H+ + 6 e 1 Br– + 3 H2O
2 HIO + 2 H+ + 2 e 1 I2 + 2 H2O
Au(OH)3 + 3 H+ + 3 e 1 Au– + 3 H2O
3IO3– + 6 H+ + 6 e 1 Cl– + 3 H2O
PbO2 +4 H+ + 2 e 1 Pb2+ + 2 H2O
ClO3– + 6 H+ + 5 e 1 1/2 Cl2 + 3 H2O
CrO2 + 4 H+ + e 1 Cr3+ + 2 H2O
BrO3– + 6 H+ + 5 e 1 1/2 Br2 + 3 H2O
HClO + H+ + 2 e 1 Cl– + H2O
Mn2O3 + 6 H+ + e 1 2 Mn2+ + 3 H2O
HO2 + H+ + e 1 H2O2
Au3+ + 3 e 1 Au
PtO3 + 4 H+ + 2 e 1 Pt(OH)22+ + H2O
MnO4– + 8 H+ + 5 e 1 Mn2+ + 4 H2O
Mn3+ + e 1 Mn2–
HClO2 + 3 H+ + 4 e 1 Cl– + 2 H2O
HBrO + H+ + e 1 1/2 Br2(aq) + H2O
2 NO + 2 H+ + 2 e 1 N2O + H2O
Bi2O4 + 4 H+ + 2 e 1 2 BiO+ + 2 H2O
HBrO + H+ + e 1 1/2 Br2(l) + H2O
H5IO6 + H+ + 2 e 1 IO3– + 3 H2O
HClO + H+ + e 1 1/2 Cl2 + H2O
HClO2 + 3 H+ + 3 e 1 1/2 Cl2 + 2 H2O
HClO2 + 2 H+ + 2 e 1 HClO + H2O
Bk4+ + e 1 Bk3+
NiO2 + 4 H+ + 2 e 1 Ni2+ + 2 H2O
MnO4– + 4 H+ + 3 e 1 MnO2 + 2 H2O
PbO2 + SO42– + 4 H+ + 2 e 1 PbSO4 + 2 H2O
Au+ + e 1 Au
PtO3 + 2 H+ + 2 e 1 PtO2 + H2O
CeOH3+ + H+ + e 1 Ce3+ + H2O
Ce4+ + e 1 Ce3+
N2O + 2 H+ + 2 e 1 N2 + H2O
H2O2 + 2 H+ + 2 e 1 2 H2O
Ag3+ + e 1 Ag2+
Au2+ + e–1 Au+
Ag2O2 + 4 H+ + e 1 2 Ag + 2 H2O
Co3+ + e 1 Co2–(2 molar H2SO4)
Ag3+ + 2 e 1 Ag+
Co3+ + e 1 Co2+
Ag2+ + e 1 Ag+
Cu2O3 + 6 H+ + 2 e 1 2 Cu2+ + 3 H2O
S2O82– + 2 e 1 2 SO42–
OH + e 1 OH–
HFeO4– + 7 H+ + 3 e 1 Fe3+ + 4 H2O
O3 + 2 H+ + 2 e 1 O2 + H2O
HFeO4– + 4 H+ + 3 e 1 FeOOH + 2 H2O
E°/V
1.35827
1.389
1.39
1.4
1.40
1.401
1.42
1.423
1.439
1.45
1.451
1.455
1.47
1.48
1.482
1.482
1.485
1.495
1.498
1.5
1.507
1.5415
1.570
1.574
1.591
1.593
1.596
1.601
1.611
1.628
1.645
1.67
1.678
1.679
1.6913
1.692
1.7
1.715
1.72
1.766
1.776
1.8
1.8
1.802
1.83
1.9
1.92
1.980
2.0
2.010
2.02
2.07
2.076
2.08
ELECTROCHEMICAL SERIES (continued)
TABLE 2
Reduction Reactions Having E° Values More Positive than that of the Standard Hydrogen Electrode
(continued)
Reaction
2 HFeO4– + 8 H+ + 6 e 1 Fe2O3 + 5 H2O
XeO3 + 6 H+ + 6 e 1 Xe + 3 H2O
S2O82– + 2 H+ + 2 e 1 2 HSO4–
F2O + 2 H+ + 4 e 1 H2O + 2 F–
FeO42– + 8 H+ + 3 e 1 Fe3+ + 4 H2O
Cu3+ + e 1 Cu2+
H4XeO6 + 2 H+ + 2 e 1 XeO3 + 3 H2O
O(g) + 2 H+ + 2 e 1 H2O
Am4+ + e 1 Am3+
E°/V
2.09
2.10
2.123
2.153
2.20
2.4
2.42
2.421
2.60
Reaction
H2N2O2 + 2 H+ + 2 e 1 N2 + 2 H2O
F2 + 2 e 1 2 F–
Cm4+ + e 1 Cm3+
F2 + 2 H+ + 2 e 1 2 HF
Tb4+ + e 1 Tb3+
Pr4+ + e 1 Pr3+
Cf4+ + e 1 Cf3+
XeF + e 1 Xe + F–
E°/V
2.65
2.866
3.0
3.053
3.1
3.2
3.3
3.4
TABLE 3
Reduction Reactions Having E° Values More Negative than that of the Standard Hydrogen Electrode
Reaction
2 H+ + 2 e 1 H2
2 D+ + 2 e 1 D2
AgCN + e 1 Ag + CN–
2 WO3 + 2 H+ + 2 e 1 W2O5 + H2O
W2O5 + 2 H+ + 2 e 1 2 WO2 + H2O
Ag2S + 2 H+ + 2 e 1 2 Ag + H2S
Fe3+ + 3 e 1 Fe
Hg2I2 + 2 e 1 2 Hg + 2 I–
Tl(OH)3 + 2 e 1 TlOH + 2 OH–
TiOH3+ + H+ + e 1 Ti3+ + H2O
2 H2SO3 + H+ + 2 e 1 HS2O4– + 2 H2O
P(white) + 3 H+ + 3 e 1 PH3(g)
O2 + H2O + 2 e 1 HO2– + OH–
2 Cu(OH)2 + 2 e 1 Cu2O + 2 OH– + H2O
Se + 2 H+ + 2 e 1 H2Se
WO3 + 6 H+ + 6 e 1 W + 3 H2O
SnO2 + 4 H+ + 2 e 1 Sn2+ + 2 H2O
Md3+ + e 1 Md2+
P(red) + 3 H+ + 3 e 1 PH3(g)
SnO2 + 4 H+ + 4 e 1 Sn + 2 H2O
GeO2 + 2 H+ + 2 e 1 GeO + H2O
WO2 + 4 H+ + 4 e 1 W + 2 H2O
Pb2+ + 2 e 1 Pb(Hg)
Pb2+ + 2 e 1 Pb
CrO42– + 4 H2O + 3 e 1 Cr(OH)3 + 5 OH–
Sn2– + 2 e 1 Sn
In+ + e 1 In
O2 + 2 H2O + 2 e 1 H2O2 + 2 OH–
MoO2 + 4 H+ + 4 e 1 Mo + 4 H2O
AgI + e 1 Ag + I–
2 NO2– + 2 H2O + 4 e 1 N2O22– + 4 OH–
H2GeO3 + 4 H+ + 4 e 1 Ge + 3 H2O
SnO2 + 3 H+ + 2 e 1 SnOH+ + H2O
CO2 + 2 H+ + 2 e 1 HCOOH
Mo3+ + 3 e 1 Mo
Ga+ + e 1 Ga
2 SO22– + 4 H+ + 2 e 1 S2O62– + H2O
© 2000 by CRC PRESS LLC
E°/V
0.00000
–0.013
–0.017
–0.029
–0.031
–0.0366
–0.037
–0.0405
–0.05
–0.055
–0.056
–0.063
–0.076
–0.080
–0.082
–0.090
–0.094
–0.1
–0.111
–0.117
–0.118
–0.119
–0.1205
–0.1262
–0.13
–0.1375
–0.14
–0.146
–0.152
–0.15224
–0.18
–0.182
–0.194
–0.199
–0.200
–0.2
–0.22
Reaction
Cu(OH)2 + 2 e 1 Cu + 2 OH–
V2O5 + 10 H+ + 10 e 1 2 V + 5 H2O
CdSO4 + 2 e 1 Cd + SO42–
V(OH)4+ + 4 H+ + 5 e 1 V + 4 H2O
V3+ + e 1 V2+
Ni2+ + 2 e 1 Ni
PbCl2 + 2 e 1 Pb + 2 Cl–
H3PO4 + 2 H+ + 2 e 1 H3PO3 + H2O
Co2+ + 2 e 1 Co
PbBr2 + 2 e 1 Pb + 2 Br–
Tl+ + e 1 Tl(Hg)
Tl+ + e 1 Tl
In3+ + 3 e 1 In
TlOH + e 1 Tl + OH–
PbF2 + 2 e 1 Pb + 2 F–
PbSO4 + 2 e 1 Pb(Hg) + SO42–
Cd2+ + 2 e 1 Cd(Hg)
PbSO4 + 2 e 1 Pb + SO42–
Cu2O + H2O + 2 e 1 2 Cu + 2 OH–
Eu3+ + e 1 Eu2+
PbI2 + 2 e 1 Pb + 2 I–
SeO32– + 3 H2O + 4 e 1 Se + 6 OH–
Se + 2 H+ + 2 e 1 H2Se(aq)
In2+ + e 1 In+
Cd2+ + 2 e 1 Cd
Cr3+ + e 1 Cr2+
2 S + 2 e 1 S22–
Tl2SO4 + 2 e 1 Tl + SO42–
In3+ + 2 e 1 In+
Fe2+ + 2 e 1 Fe
H3PO3 + 3 H+ + 3 e 1 P + 3 H2O
Bi2O3 + 3 H2O + 6 e 1 2 Bi + 6 OH–
NO2– + H2O + e 1 NO + 2 OH
PbHPO4 + 2 e 1 Pb + HPO42–
S + 2 e 1 S2–
S + H2O + 2 e 1 HS– + OH–
B(OH)3 + 7 H+ + 8 e 1 BH4– + 3 H2O
E°/V
–0.222
–0.242
–0.246
–0.254
–0.255
–0.257
–0.2675
–0.276
–0.28
–0.284
–0.3338
–0.336
–0.3382
–0.34
–0.3444
–0.3505
–0.3521
–0.3588
–0.360
–0.36
–0.365
–0.366
–0.399
–0.40
–0.4030
–0.407
–0.42836
–0.4360
–0.443
–0.447
–0.454
–0.46
–0.46
–0.465
–0.47627
–0.478
–0.481
ELECTROCHEMICAL SERIES (continued)
TABLE 3
Reduction Reactions Having E° Values More Negative than that of the Standard Hydrogen Electrode
(continued)
Reaction
In3+ + e 1 In2+
ZnOH+ + H+ + 2 e 1 Zn + H2O
GaOH2+ + H+ + 3 e 1 Ga + H2O
H3PO3 + 2 H+ + 2 e 1 H3PO2 + H2O
TiO2 + 4 H+ + 2 e 1 Ti2+ + 2 H2O
H3PO2 + H+ + e 1 P + 2 H2O
Sb + 3 H+ + 3 e 1 SbH3
HPbO2– + H2O + 2 e 1 Pb + 3 OH–
Ga3+ + 3 e 1 Ga
TlCl + e 1 Tl + Cl–
Fe(OH)3 + e 1 Fe(OH)2 + OH–
TeO32– + 3 H2O + 4 e 1 Te + 6 OH–
2 SO32– + 3 H2O + 4 e 1 S2O32– + 6 OH–
PbO + H2O + 2 e 1 Pb + 2 OH–
ReO2– + 4 H2O + 7 e 1 Re + 8 OH–
SbO3– + H2O + 2 e 1 SbO2– + 2 OH–
Ta3+ + 3 e 1 Ta
U4+ + e 1 U3+
As + 3 H+ + 3 e 1 AsH3
Nb2O5 + 10 H+ + 10 e 1 2 Nb + 5 H2O
NbO2 + 2 H+ + 2 e 1 NbO + H2O
Cd(OH)42– + 2 e 1 Cd + 4 OH–
TlBr + e 1 Tl + Br–
SbO2– + 2 H2O + 3 e 1 Sb + 4 OH–
AsO2– + 2 H2O + 3 e 1 As + 4 OH–
NbO2 + 4 H+ + 4 e 1 Nb + 2 H2O
Ag2S + 2 e 1 2 Ag + S2–
AsO43– + 2 H2O + 2 e 1 AsO2– + 4 OH–
Ni(OH)2 + 2 e 1 Ni + 2 OH–
Co(OH)2 + 2 e 1 Co + 2 OH–
NbO + 2 H+ + 2 e 1 Nb + H2O
H2SeO3 + 4 H+ + 4 e 1 Se + 3 H2O
Cr3+ + 3 e 1 Cr
Ta2O5 + 10 H+ + 10 e 1 2 Ta + 5 H2O
TlI + e 1 Tl + I–
Zn2+ + 2 e 1 Zn
Zn2+ + 2 e 1 Zn(Hg)
CdO + H2O + 2 e 1 Cd + 2 OH–
Te + 2 H+ + 2 e 1 H2Te
ZnSO4.7H2O + 2 e 1 Zn(Hg) + SO42– + 7 H2O
(Saturated ZnSO4)
Bi + 3 H+ + 3 e 1 BiH3
SiO + 2 H+ + 2 e 1 Si + H2O
Cd(OH)2 + 2 e 1 Cd(Hg) + 2 OH–
2 H2O + 2 e 1 H2 + 2 OH–
2 NO–3 + 2 H2O + 2 e 1 N2O4 + 4 OH–
H3BO3 + 3 H+ + 3 e 1 B + 3 H2O
P + 3 H2O + 3 e 1 PH3(g) + 3 OH–
Ti3+ + e 1 Ti2+
HSnO2– + H2O + 2 e 1 Sn + 3 OH–
Cr2+ + 2 e 1 Cr
Se + 2 e 1 Se2–
SO42– + H2O + 2 e 1 SO32– + 2 OH–
Sn(OH)62– + 2 e 1 HSnO2– + 3 OH– + H2O
© 2000 by CRC PRESS LLC
E°/V
–0.49
–0.497
–0.498
–0.499
–0.502
–0.508
–0.510
–0.537
–0.549
–0.5568
–0.56
–0.57
–0.571
–0.580
–0.584
–0.59
–0.6
–0.607
–0.608
–0.644
–0.646
–0.658
–0.658
–0.66
–0.68
–0.690
–0.691
–0.71
–0.72
–0.73
–0.733
–0.74
–0.744
–0.750
–0.752
–0.7618
–0.7628
–0.783
–0.793
–0.7993
–0.8
–0.8
–0.809
–0.8277
–0.85
–0.8698
–0.87
–0.9
–0.909
–0.913
–0.924
–0.93
–0.93
Reaction
SnO2 + 2 H2O + 4 e 1 Sn + 4 OH–
In(OH)3 + 3 e 1 In + 3 OH–
NpO2 + H2O + H+ + e 1 Np(OH)3
In(OH)4– + 3 e 1 In + 4 OH–
In2O3 + 3 H2O + 6 e 1 2 In + 6 OH–
PO43– + 2 H2O + 2 e 1 HPO32– + 3 OH–
Yb3+ + e 1 Yb2+
Nb3+ + 3 e 1 Nb
Fm3+ + e 1 Fm2+
2 SO32– + 2 H2O + 2 e 1 S2O42– + 4 OH–
Te + 2 e 1 Te2–
V2+ + 2 e 1 V
Mn2+ + 2 e 1 Mn
Zn(OH)42– + 2 e 1 Zn + 4 OH–
CrO2 + 2 H2O + 3 e 1 Cr + 4 OH–
No3+ + 3 e 1 No
ZnO2– + 2 H2O + 2 e 1 Zn + 4 OH–
H2GaO3– + H2O + 3 e 1 Ga + 4 OH–
H2BO3– + 5 H2O + 8 e 1 BH4– + 8 OH–
SiF62– + 4 e 1 Si + 6 F–
Zn(OH)2 + 2 e 1 Zn + 2 OH–
ZnO + H2O + 2 e 1 Zn + 2 OH–
Es3+ + e 1 Es2+
Pa3+ + 3 e 1 Pa
Ti3+ + 3 e 1 Ti
Ce3+ + 3 e 1 Ce(Hg)
UO22+ + 4 H+ + 6 e 1 U + 2 H2O
Zr4+ + 4 e 1 Zr
Cr(OH)3 + 3 e 1 Cr + 3 OH–
Pa4+ + 4 e 1 Pa
HfO2 + 4 H+ + 4 e 1 Hf + 2 H2O
Hf4+ + 4 e 1 Hf
Sm3+ + e 1 Sm2+
ZrO2 + 4 H+ + 4 e 1 Zr + 2 H2O
Mn(OH)2 + 2 e 1 Mn + 2 OH–
Ba2+ + 2 e 1 Ba(Hg)
Bk2+ + 2 e 1 Bk
Cf3+ + e 1 Cf2+
Ti2+ + 2 e 1 Ti
Md3+ + 3 e 1 Md
HPO32– + 2 H2O + 2 e 1 H2PO2– + 3 OH–
Al3+ + 3 e 1 Al
SiO32– + H2O + 4 e 1 Si + 6 OH–
HPO32– + 2 H2O + 3 e 1 P + 5 OH–
HfO2+ + 2 H+ + 4 e 1 Hf + H2O
ThO2 + 4 H+ + 4 e 1 Th + 2 H2O
H2BO3– + H2O + 3 e 1 B + 4 OH–
Sr2+ + 2 e 1 Sr(Hg)
U3+ + 3 e 1 U
H2PO–2 + e 1 P + 2 OH–
Be2+ + 2 e 1 Be
Np3+ + 3 e 1 Np
Fm3+ + 3 e 1 Fm
Th4+ + 4 e 1 Th
E°/V
–0.945
–0.99
–0.962
–1.007
–1.034
–1.05
–1.05
–1.099
–1.1
–1.12
–1.143
–1.175
–1.185
–1.199
–1.2
–1.20
–1.215
–1.219
–1.24
–1.24
–1.249
–1.260
–1.3
–1.34
–1.37
–1.4373
–1.444
–1.45
–1.48
–1.49
–1.505
–1.55
–1.55
–1.553
–1.56
–1.570
–1.6
–1.6
–1.630
–1.65
–1.65
–1.662
–1.697
–1.71
–1.724
–1.789
–1.79
–1.793
–1.798
–1.82
–1.847
–1.856
–1.89
–1.899
ELECTROCHEMICAL SERIES (continued)
TABLE 3
Reduction Reactions Having E° Values More Negative than that of the Standard Hydrogen Electrode
(continued)
Reaction
Am2+ + 2 e 1 Am
Pa4+ + e 1 Pa3+
Es3+ + 3 e 1 Es
Cf3+ + 3 e 1 Cf
Lr3+ + 3 e 1 Lr
Eu3+ + 3 e 1 Eu
Er2+ + 2 e 1 Er
Pr2+ + 2 e 1 Pr
Pu3+ + 3 e 1 Pu
Cm3+ + 3 e 1 Cm
Am3+ + 3 e 1 Am
AlF63– + 3 e 1 Al + 6 F–
Sc3+ + 3 e 1 Sc
Ho2+ + 2 e 1 Ho
Nd2+ + 2 e 1 Nd
Cf2+ + 2 e 1 Cf
Yb3+ + 3 e 1 Yb
Ac3+ + 3 e 1 Ac
Dy2+ + 2 e 1 Dy
Tm3+ + e 1 Tm2+
Pm2+ + 2 e 1 Pm
Es2+ + 2 e 1 Es
H2 + 2 e 1 2 H–
Gd3+ + 3 e 1 Gd
Tb3+ + 3 e 1 Tb
Lu3+ + 3 e 1 Lu
Dy3+ + 3 e 1 Dy
Am3+ + e 1 Am2+
Fm2+ + 2 e 1 Fm
Pm3+ + 3 e 1 Pm
Sm3+ + 3 e 1 Sm
Al(OH)3 + 3 e 1 Al + 3 OH–
Tm3+ + 3 e 1 Tm
Nd3+ + 3 e 1 Nd
Al(OH)– + 3 e 1 Al + 4 OH–
H2AlO3– + H2O + 3 e 1 Al + 4 OH–
Ho3+ + 3 e 1 Ho
Er3+ + 3 e 1 Er
Ce3+ + 3 e 1 Ce
Pr3+ + 3 e 1 Pr
© 2000 by CRC PRESS LLC
E°/V
–1.9
–1.9
–1.91
–1.94
–1.96
–1.991
–2.0
–2.0
–2.031
–2.04
–2.048
–2.069
–2.077
–2.1
–2.1
–2.12
–2.19
–2.20
–2.2
–2.2
–2.2
–2.23
–2.23
–2.279
–2.28
–2.28
–2.295
–2.3
–2.30
–2.30
–2.304
–2.31
–2.319
–2.323
–2.328
–2.33
–2.33
–2.331
–2.336
–2.353
Reaction
ZrO(OH)2 + H2O + 4 e 1 Zr + 4 OH–
Mg2+ + 2 e 1 Mg
Y3+ + 3 e 1 Y
La3+ + 3 e 1 La
Tm2+ + 2 e 1 Tm
Md2+ + 2 e 1 Md
Th(OH)4 + 4 e 1 Th + 4 OH–
HfO(OH)2 + H2O + 4 e 1 Hf + 4 OH–
No2+ + 2 e 1 No
Dy3+ + e 1 Dy2+
Pm3+ + e 1 Pm2+
Be2O32– + 3 H2O + 4 e 1 2 Be + 6 OH–
Sm2+ + 2 e 1 Sm
Mg(OH)2 + 2 e 1 Mg + 2 OH–
Nd3+ + e 1 Nd2+
Mg+ + e 1 Mg
Na+ + e 1 Na
Yb2+ + 2 e 1 Yb
Bk3+ + e 1 Bk2+
Ho3+ + e 1 Ho2+
Ra2+ + 2 e 1 Ra
Eu2+ + 2 e 1 Eu
Ca2+ + 2 e 1 Ca
Sr(OH)2 + 2 e 1 Sr + 2 OH–
Sr2+ + 2 e 1 Sr
Fr+ + e 1 Fr
La(OH)3 + 3 e 1 La + 3 OH–
Ba2+ + 2 e 1 Ba
K+ + e 1 K
Rb+ + e 1 Rb
Ba(OH)2 + 2 e 1 Ba + 2 OH–
Er3+ + e 1 Er2+
Ca(OH)2 + 2 e 1 Ca + 2 OH–
Cs+ + e 1 Cs
Li+ + e 1 Li
3 N2 + 2 H+ + 2 e 1 2 HN3
Pr3+ + e 1 Pr2+
Ca+ + e 1 Ca
Sr+ + e 1 Sr
E°/V
–2.36
–2.372
–2.372
–2.379
–2.4
–2.40
–2.48
–2.50
–2.50
–2.6
–2.6
–2.63
–2.68
–2.690
–2.7
–2.70
–2.71
–2.76
–2.8
–2.8
–2.8
–2.812
–2.868
–2.88
–2.89
–2.9
–2.90
–2.912
–2.931
–2.98
–2.99
–3.0
–3.02
–3.026
–3.0401
–3.09
–3.1
–3.80
–4.10