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. Milazzo, G., Caroli, S., and Sharma, V. K. Tables of Standard Electrode Potentials, Wiley, Chichester, 1978. 2. Bard, A. J., Parsons, R., and Jordan, J. Standard Potentials in Aqueous Solutions, Marcel Dekker, New York, 1985. 3. Bratsch, S. G. J. Phys. Chem. Ref. Data, 18, 1–21, 1989.
TABLE 1. Alphabetical Listing Reaction Ac3+ + 3 e ⇌ Ac Ag+ + e ⇌ Ag Ag2+ + e ⇌ Ag+ Ag(ac) + e ⇌ Ag + (ac)– AgBr + e ⇌ Ag + Br– AgBrO3 + e ⇌ Ag + BrO3– Ag2C2O4 + 2 e ⇌ 2 Ag + C2O42– AgCl + e ⇌ Ag + Cl– AgCN + e ⇌ Ag + CN– Ag2CO3 + 2 e ⇌ 2 Ag + CO32– Ag2CrO4 + 2 e ⇌ 2 Ag + CrO42– AgF + e ⇌ Ag + F– Ag4[Fe(CN)6] + 4 e ⇌ 4 Ag + [Fe(CN)6]4– AgI + e ⇌ Ag + I– AgIO3 + e ⇌ Ag + IO3– Ag2MoO4 + 2 e ⇌ 2 Ag + MoO42– AgNO2 + e ⇌ Ag + 2 NO2– Ag2O + H2O + 2 e ⇌ 2 Ag + 2 OH– Ag2O3 + H2O + 2 e ⇌ 2 AgO + 2 OH– Ag3+ + 2 e ⇌ Ag+ Ag3+ + e ⇌ Ag2+ Ag2O2 + 4 H+ + e ⇌ 2 Ag + 2 H2O 2 AgO + H2O + 2 e ⇌ Ag2O + 2 OH– AgOCN + e ⇌ Ag + OCN– Ag2S + 2 e ⇌ 2 Ag + S2– Ag2S + 2 H+ + 2 e ⇌ 2 Ag + H2S AgSCN + e ⇌ Ag + SCN– Ag2SeO3 + 2 e ⇌ 2 Ag + SeO42– Ag2SO4 + 2 e ⇌ 2 Ag + SO42– Ag2WO4 + 2 e ⇌ 2 Ag + WO42– Al3+ + 3 e ⇌ Al Al(OH)3 + 3 e ⇌ Al + 3 OH– Al(OH)4– + 3 e ⇌ Al + 4 OH– H2AlO3– + H2O + 3 e ⇌ Al + 4 OH– AlF63– + 3 e ⇌ Al + 6 F– Am4+ + e ⇌ Am3+ Am2+ + 2 e ⇌ Am Am3+ + 3 e ⇌ Am Am3+ + e ⇌ Am2+
8-20
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 –2.328 –2.33 –2.069 2.60 –1.9 –2.048 –2.3
Reaction As + 3 H+ + 3 e ⇌ AsH3 As2O3 + 6 H+ + 6 e ⇌ 2 As + 3 H2O HAsO2 + 3 H+ + 3 e ⇌ As + 2 H2O AsO2– + 2 H2O + 3 e ⇌ As + 4 OH– H3AsO4 + 2 H+ + 2 e– ⇌ HAsO2 + 2 H2O AsO43– + 2 H2O + 2 e ⇌ AsO2– + 4 OH– At2 + 2 e ⇌ 2 At– Au+ + e ⇌ Au Au3+ + 2 e ⇌ Au+ Au3+ + 3 e ⇌ Au Au2+ + e – ⇌ Au+ AuOH2+ + H+ + 2 e ⇌ Au+ + H2O AuBr2– + e ⇌ Au + 2 Br– AuBr4– + 3 e ⇌ Au + 4 Br– AuCl4– + 3 e ⇌ Au + 4 Cl– Au(OH)3 + 3 H+ + 3 e ⇌ Au + 3 H2O H2BO3– + 5 H2O + 8 e ⇌ BH4– + 8 OH– H2BO3– + H2O + 3 e ⇌ B + 4 OH– H3BO3 + 3 H+ + 3 e ⇌ B + 3 H2O B(OH)3 + 7 H+ + 8 e ⇌ BH4– + 3 H2O Ba2+ + 2 e ⇌ Ba Ba2+ + 2 e ⇌ Ba(Hg) Ba(OH)2 + 2 e ⇌ Ba + 2 OH– Be2+ + 2 e ⇌ Be Be2O32– + 3 H2O + 4 e ⇌ 2 Be + 6 OH– p–benzoquinone + 2 H+ + 2 e ⇌ hydroquinone Bi+ + e ⇌ Bi Bi3+ + 3 e ⇌ Bi Bi3+ + 2 e ⇌ Bi+ Bi + 3 H+ + 3 e ⇌ BiH3 BiCl4– + 3 e ⇌ Bi + 4 Cl– Bi2O3 + 3 H2O + 6 e ⇌ 2 Bi + 6 OH– Bi2O4 + 4 H+ + 2 e ⇌ 2 BiO+ + 2 H2O BiO+ + 2 H+ + 3 e ⇌ Bi + H2O BiOCl + 2 H+ + 3 e ⇌ Bi + Cl– + H2O Bk4+ + e ⇌ Bk3+ Bk2+ + 2 e ⇌ Bk Bk3+ + e ⇌ Bk2+
E°/V –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 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