Electrochemical Series

Transcription

1 Electrochemical Series Petr Vanýsek There are three tables for this electrochemical series. Each table lists standard reduction potentials, E values, at K (25 C), and at a pressure of kpa (1 atm). Table 1 is an alphabetical listing of the elements, according to the symbol of the elements. Thus, data for silver (Ag) precede those for aluminum (Al). Table 2 lists only those reduction reactions that 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 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 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, Bard, A. J., Parsons, R., and Jordan, J. Standard Potentials in Aqueous Solutions, Marcel Dekker, New York, Bratsch, S. G. J. Phys. Chem. Ref. Data, 18, 121, TABLE 1. Alphabetical Listing Ac 3 3 e Ac 2.20 Ag e Ag e Ag Ag(ac) e Ag (ac) AgBr e Ag Br AgBr e Ag Br C 2 2 e 2 Ag C AgCl e Ag Cl AgCN e Ag CN C 2 e 2 Ag C Cr 2 e 2 Ag Cr AgF e Ag F Ag 4 [Fe(CN ] 4 e 4 Ag [Fe(CN ] AgI e Ag I AgI e Ag I Mo 2 e 2 Ag Mo AgN e Ag 2 N O O 2 e 2 Ag 2 OH O 2 e 2 AgO 2 OH Ag 3 2 e Ag 1.9 Ag 3 e H e 2 Ag O AgO O 2 e O 2 OH AgOCN e Ag OCN 0.41 S 2 e 2 Ag S 2 H 2 e 2 Ag S AgSCN e Ag SCN Se 2 e 2 Ag Se S 2 e 2 Ag S W 2 e 2 Ag W Al 3 3 e Al Al(OH) 3 3 e Al 3 OH 2.31 Al(OH) 4 3 e Al 4 OH Al O 3 e Al 4 OH AlF 6 3 e Al 6 F Am 4 e Am Am 2 2 e Am 1.9 Am 3 3 e Am Am 3 e Am As 3 H 3 e As As 2 6 H 6 e 2 As O HAs 3 H 3 e As O As O 3 e As 4 OH 0.68 As 2 H 2 e HAs O As O 2 e As 4 OH 0.71 At 2 2 e 2 At 0.3 Au e Au Au 3 2 e Au Au 3 3 e Au Au 2 e Au 1.8 AuO H 2 e Au O 1.32 Au e Au 2 Br AuBr 4 3 e Au 4 Br AuCl 4 3 e Au 4 Cl Au(OH) 3 3 H 3 e Au O 1.45 B 5 O 8 e BH 4 8 OH 1.24 B O 3 e B 4 OH 1.79 B 3 H 3 e B O B(OH) 3 7 H 8 e BH 4 O Ba 2 2 e Ba Ba 2 2 e Ba(Hg) Ba(OH) 2 2 e Ba 2 OH 2.99 Be 2 2 e Be Be 2 O 4 e 2 Be 6 OH 2.63 pbenzoquinone 2 H 2 e hydroquinone Bi e Bi 0.5 Bi 3 3 e Bi Bi 3 2 e Bi 0.2 Bi 3 H 3 e Bi 0.8 BiCl 4 3 e Bi 4 Cl 0.16 Bi 2 O 6 e 2 Bi 6 OH 0.46 Bi 2 4 H 2 e 2 BiO O BiO 2 H 3 e Bi O BiOCl 2 H 3 e Bi Cl O Bk 4 e Bk Bk 2 2 e Bk 1.6 Bk 3 e Bk

2 Electrochemical Series 5-81 (aq) 2 e 2 Br (l) 2 e 2 Br HBrO H 2 e Br O HBrO H e 1/2 (aq) O HBrO H e 1/2 (l) O BrO O 2 e Br 2 OH Br 6 H 5 e 1/2 O Br 6 H 6 e Br O Br O 6 e Br 6 OH 0.61 (CN) 2 2 H 2 e 2 HCN HCNO 2 H 2 e (CN) 2 O (CNS) 2 2 e 2 CNS 0.77 C 2 H 2 e HCOOH Ca e Ca 3.80 Ca 2 2 e Ca Ca(OH) 2 2 e Ca 2 OH 3.02 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) Cd 2 2 e Cd Cd 2 2 e Cd(Hg) Cd(OH) 2 2 e Cd(Hg) 2 OH CdS 2 e Cd S Cd(OH) 4 2 e Cd 4 OH CdO O 2 e Cd 2 OH Ce 3 3 e Ce Ce 3 3 e Ce(Hg) Ce 4 e Ce CeO H e Ce 3 O Cf 4 e Cf Cf 3 e Cf Cf 3 3 e Cf 1.94 Cf 2 2 e Cf 2.12 Cl 2 (g) 2 e 2 Cl HClO H e 1/2 Cl 2 O HClO H 2 e Cl O ClO O 2 e Cl 2 OH 0.81 Cl H e HCl HCl 2 H 2 e HClO O HCl 3 H 3 e 1/2 Cl 2 O HCl 3 H 4 e Cl O Cl O 2 e ClO 2 OH 0.66 Cl O 4 e Cl 4 OH 0.76 Cl (aq) e Cl Cl 2 H e Cl O Cl 3 H 2 e HCl O Cl 6 H 5 e 1/2 Cl 2 O 1.47 Cl 6 H 6 e Cl O Cl O 2 e Cl 2 OH 0.33 Cl O 6 e Cl 6 OH 0.62 Cl 2 H 2 e Cl O Cl 8 H 7 e 1/2 Cl 2 4 O 1.39 Cl 8 H 8 e Cl 4 O Cl O 2 e Cl 2 OH 0.36 Cm 4 e Cm Cm 3 3 e Cm 2.04 Co 2 2 e Co 0.28 Co 3 e Co [Co(N ] 3 e [Co(N ] Co(OH) 2 2 e Co 2 OH 0.73 Co(OH) 3 e Co(OH) 2 OH 0.17 Cr 2 2 e Cr Cr 3 e Cr Cr 3 3 e Cr Cr 2 O 7 14 H 6 e 2 Cr 3 7 O 1.36 Cr O 3 e Cr 4 OH 1.2 HCr 7 H 3 e Cr 3 4 O Cr 4 H e Cr 3 2 O 1.48 Cr(V) e Cr(IV) Cr 4 O 3 e Cr(OH) 3 5 OH 0.13 Cr(OH) 3 3 e Cr 3 OH 1.48 Cs e Cs Cu e Cu Cu 2 e Cu Cu 2 2 e Cu Cu 2 2 e Cu(Hg) Cu 3 e Cu Cu 2 6 H 2e 2Cu 2.0 Cu 2 2 CN e [Cu(CN) 2 ] CuI 2 e Cu 2 I 0.00 Cu 2 O O 2 e 2 Cu 2 OH Cu(OH) 2 2 e Cu 2 OH Cu(OH) 2 2 e Cu 2 O 2 OH O D 2 e D Dy 2 2 e Dy 2.2 Dy 3 3 e Dy Dy 3 e Dy Er 2 2 e Er 2.0 Er 3 3 e Er Er 3 e Er Es 3 e Es Es 3 3 e Es 1.91 Es 2 2 e Es 2.23 Eu 2 2 e Eu Eu 3 3 e Eu Eu 3 e Eu H 2 e 2 HF e 2 F O 2 H 4 e O 2 F Fe 2 2 e Fe Fe 3 3 e Fe Fe 3 e Fe HFe 8 H 6 e Fe HFe 4 H 3 e FeOOH.08 HFe 7 H 3 e Fe Fe 2 4 H 2 e 2 FeOH O 0.16 [Fe(CN ] 3 e [Fe(CN ] Fe 8 H 3 e Fe [Fe(bipy) 2 ] 3 e Fe(bipy) 2 ] [Fe(bipy) 3 ] 3 e Fe(bipy) 3 ] Fe(OH) 3 e Fe(OH) 2 OH 0.56 [Fe(phen) 3 ] 3 e [Fe(phen) 3 ] [Fe(phen) 3 ] 3 e [Fe(phen) 3 ] 2 (1 molar S ) 1.06 [Ferricinium] e ferrocene Fm 3 e Fm Fm 3 3 e Fm 1.89 Fm 2 2 e Fm 2.30

3 5-82 Electrochemical Series Fr e Fr 2.9 Ga 3 3 e Ga Ga e Ga 0.2 GaO H 3 e Ga O GaO H O 3 e Ga OH Gd 3 3 e Gd Ge 2 2 e Ge 0.24 Ge 4 4 e Ge Ge 4 2 e Ge Ge 2 H 2 e GeO O Ge 4 H 4 e Ge O H 2 e e 2 H 2.23 H H e O 2 e 2 OH H 2 e 2 O Hf 4 4 e Hf 1.55 Hf 2 H 4 e Hf O Hf 4 H 4 e Hf O HfO(OH) 2 O 4 e Hf 4 OH e Hg e e 2 Hg (ac) 2 2 e 2 Hg 2(ac) e 2 Hg 2 Br Cl 2 2 e 2 Hg 2 Cl HP 2 e 2 Hg HP I 2 2 e 2 Hg 2 I O O 2 e 2 Hg 2 OH HgO O 2 e Hg 2 OH Hg(OH) 2 2 H 2 e Hg O S 2 e 2 Hg S Ho 2 2 e Ho 2.1 Ho 3 3 e Ho 2.33 Ho 3 e Ho I 2 2 e 2 I I 3 2 e 3 I I 2 e IO 3 3 OH 0.7 H 5 I H 2 e I O HIO 2 H 2 e I 2 O HIO H 2 e I O IO O 2 e I 2 OH I 12 H 10 e I 2 6 O I 6 H 6 e I O I O 4 e IO 4 OH 0.15 I O 6 e IO 6 OH 0.26 In e In 0.14 In 2 e In 0.40 In 3 e In In 3 2 e In In 3 3 e In In(OH) 3 3 e In 3 OH 0.99 In(OH) 4 3 e In 4 OH In 2 O 6 e 2 In 6 OH Ir 3 3 e Ir [IrCl 6 ] 2 e [IrCl 6 ] [IrCl 6 ] 3 3 e Ir 6 Cl 0.77 Ir 2 O 6 e 2 Ir 6 OH K e K La 3 3 e La La(OH) 3 3 e La 3 OH 2.90 Li e Li Lr 3 3 e Lr 1.96 Lu 3 3 e Lu 2.28 Md 3 e Md Md 3 3 e Md 1.65 Md 2 2 e Md 2.40 Mg e Mg 2.70 Mg 2 2 e Mg Mg(OH) 2 2 e Mg 2 OH Mn 2 2 e Mn Mn 3 e Mn Mn 4 H 2 e Mn 2 O Mn e Mn Mn 4 H 3 e Mn O Mn 8 H 5 e Mn 2 4 O Mn O 3 e Mn 4 OH Mn O 2 e Mn 4 OH 0.60 Mn(OH) 2 2 e Mn 2 OH 1.56 Mn(OH) 3 e Mn(OH) 2 OH 0.15 Mn 2 6 H e 2 Mn 2 O Mo 3 3 e Mo Mo 4 H 4 e Mo 4 O Mo H 42 e 7 Mo 24 O Mo 6 H 6 e Mo O O 6 H 6 e 2 NH 4 OH H 2 e 2 HN N 5 3 H 2 e 2 NH O 2 H 2 e O H 2 e.65 2 e 2 N H 2 e 2 NH H 4 e 2 NO O N OH H 2 e H 5 O NO 2 H 2 e O O NO O 2 e O 2 OH 0.76 HN H e NO O HN 4 H 4 e O HN 4 H 4 e O O N O e NO 2 OH N O 4 e 4 OH N O 4 e O 6 OH 0.15 N 3 H 2 e HN O N 4 H 3 e NO O N 4 H 2 e O N O 2 e N 2 OH N O 2 e 4 OH 0.85 Na e Na 2.71 Nb 3 3 e Nb Nb 2 H 2 e NbO O Nb 4 H 4 e Nb O NbO 2 H 2 e Nb O Nb 2 10 H 10 e 2 Nb 5 O Nd 3 3 e Nd Nd 2 2 e Nd 2.1 Nd 3 e Nd Ni 2 2 e Ni Ni(OH) 2 2 e Ni 2 OH 0.72 Ni 4 H 2 e Ni 2 O Ni O 2 e Ni(OH) 2 2 OH 0.490

4 Electrochemical Series 5-83 No 3 e No No 3 3 e No 1.20 No 2 2 e No 2.50 Np 3 3 e Np Np 4 e Np Np O H e Np(OH) H 2 e H 4 e 2 O O 2 e H OH O 2 e 2 OH O 4 e 4 OH H 2 e.076 O 2 e 2 OH 1.24 O(g) 2 H 2 e.421 OH e OH 2.02 H O 2 e 3 OH Os 8 H 8 e Os 4 O Os 4 H 4 e Os O 1.02 [Os(bipy) 2 ] 3 e [Os(bipy) 2 ] [Os(bipy) 3 ] 3 e [Os(bipy) 3 ] P(red) 3 H 3 e P (g) P(white) 3 H 3 e P (g) P O 3 e P (g) 3 OH 0.87 P 2 e P 2 OH 1.82 P H e P O P 2 H 2 e P O P 3 H 3 e P O HP O 2 e P 3 OH HP O 3 e P 5 OH 1.71 P 2 H 2 e P O P O 2 e HP 3 OH 1.05 Pa 3 3 e Pa 1.34 Pa 4 4 e Pa 1.49 Pa 4 e Pa Pb 2 2 e Pb Pb 2 2 e Pb(Hg) Pb 2 e Pb 2 Br PbCl 2 2 e Pb 2 Cl Pb 2 e Pb 2 F PbHP 2 e Pb HP PbI 2 2 e Pb 2 I PbO O 2 e Pb 2 OH Pb 4 H 2 e Pb 2 O HPb O 2 e Pb 3 OH Pb O 2 e PbO 2 OH Pb S 4 H 2 e PbS O PbS 2 e Pb S PbS 2 e Pb(Hg) S Pd 2 2 e Pd [PdCl 4 ] 2 2 e Pd 4 Cl [PdCl 6 ] 2 2 e [PdCl 4 ] 2 2 Cl Pd(OH) 2 2 e Pd 2 OH 0.07 Pm 2 2 e Pm 2.2 Pm 3 3 e Pm 2.30 Pm 3 e Pm Po 4 2 e Po Po 4 4 e Po 0.76 Pr 4 e Pr Pr 2 2 e Pr 2.0 Pr 3 3 e Pr Pr 3 e Pr Pt 2 2 e Pt 1.18 [PtCl 4 ] 2 2 e Pt 4 Cl [PtCl 6 ] 2 2 e [PtCl 4 ] 2 2 Cl 0.68 Pt(OH) 2 2 e Pt 2 OH 0.14 Pt 2 H 2 e Pt O 1.7 Pt 4 H 2 2 e Pt(OH) 2 O 1.5 PtOH H 2 e Pt O 1.2 Pt 2 H 2 e PtO O 1.01 Pt 4 H 4 e Pt O 1.00 Pu 3 3 e Pu Pu 4 e Pu Pu 5 e Pu Pu (OH) 2 2 H 2 e Pu(OH) Pu (OH) 2 H e Pu OH O Ra 2 2 e Ra 2.8 Rb e Rb 2.98 Re 3 3 e Re Re 4 H 3 e Re O Re 4 H 4 e Re O Re 2 H e Re O Re 4 O 7 e Re 8 OH Re 8 H 7 e Re 4 O Rh e Rh Rh 3 3 e Rh [RhCl 6 ] 3 3 e Rh 6 Cl RhO H 3 e Rh O 0.83 Ru 2 2 e Ru Ru 3 e Ru Ru 4 H 2 e Ru 2 O Ru e Ru 0.59 Ru e Ru 1.00 Ru 6 H 2 4 e Ru(OH) 2 O 1.40 Ru 8 H 8 e Ru 4 O [Ru(bipy) 3 ) 3 e [Ru(bipy) 3 ] [Ru( O ] 3 e [Ru( O ] [Ru(N ] 3 e [Ru(N ] [Ru(en) 3 ] 3 e [Ru(en) 3 ] [Ru(CN ] 3 e [Ru(CN ] S 2 e S 2H 2 e S(aq) S O 2 e SH OH S 2 e H 2 e 2 S O 8 2 e 2 S O 8 2 H 2 e 2 HS S 4 2 e S H 2 e H O S 4 H 4 e S O S O 2 e 4 OH S O 4 e 6 OH S 4 H 2 e S O S 4 H 2 2 e O S O 2 e S 2 OH 0.93 Sb 3 H 3 e Sb H 6 e 2 Sb O (senarmontite) 4 H 4 e O (valentinite) 4 H 4 e O

5 5-84 Electrochemical Series 6 H 4 e 2 SbO O SbO 2 H 3 e Sb O Sb O 3 e Sb 4 OH 0.66 Sb O 2 e Sb 2 OH 0.59 Sc 3 3 e Sc Se 2 e Se Se 2 H 2 e Se(aq) Se 4 H 4 e Se O 0.74 Se 2 H 2 e Se Se O 4 e Se 6 OH Se 4 H 2 e Se O Se O 2 e Se 2 OH SiF 6 4 e Si 6 F 1.24 SiO 2 H 2 e Si O 0.8 Si (quartz) 4 H 4 e Si O Si O 4 e Si 6 OH Sm 3 e Sm Sm 3 3 e Sm Sm 2 2 e Sm 2.68 Sn 2 2 e Sn Sn 4 2 e Sn Sn(OH) 3 3 H 2 e Sn 2 O Sn 4 H 2 e Sn 2 O Sn 4 H 4 e Sn O Sn 3 H 2 e SnOH O Sn O 4 e Sn 4 OH HSn O 2 e Sn 3 OH Sn(OH 2 e HSn 3 OH O 0.93 Sr e Sr 4.10 Sr 2 2 e Sr Sr 2 2 e Sr(Hg) Sr(OH) 2 2 e Sr 2 OH 2.88 Ta 2 10 H 10 e 2 Ta 5 O Ta 3 3 e Ta 0.6 Tc 2 2 e Tc Tc 4 H 3 e Tc O Tc 3 e Tc Tc 8 H 7 e Tc 4 O Tb 4 e Tb Tb 3 3 e Tb 2.28 Te 2 e Te Te 2 H 2 e Te Te 4 4 e Te Te 4 H 4 e Te O Te O 4 e Te 6 OH 0.57 Te 8 H 7 e Te 4 O H 6 Te 2 H 2 e Te 4 O 1.02 Th 4 4 e Th Th 4 H 4 e Th O Th(OH) 4 4 e Th 4 OH 2.48 Ti 2 2 e Ti Ti 3 e Ti Ti 4 H 2 e Ti 2 O Ti 3 3 e Ti 1.37 TiO H e Ti 3 O Tl e Tl Tl e Tl(Hg) Tl 3 2 e Tl Tl 3 3 e Tl TlBr e Tl Br TlCl e Tl Cl TlI e Tl I Tl 2 O 4 e 2 Tl 6 OH 0.02 TlOH e Tl OH 0.34 Tl(OH) 3 2 e TlOH 2 OH Tl 2 S 2 e Tl S Tm 3 e Tm Tm 3 3 e Tm Tm 2 2 e Tm 2.4 U 3 3 e U U 4 e U U 4 H e U 4 O U e UO U 4 H 2 e U 4 O U 4 H 6 e U O V 2 2 e V V 3 e V V 2 H e V 3 O V 2 H e V O V 2 6 H 2 e 2 V O V 2 10 H 10 e 2 V 5 O V(OH) 4 2 H e V O 1.00 V(OH) 4 4 H 5 e V 4 O [V(phen) 3 ] 3 e [V(phen) 3 ] W 3 3 e W 0.1 W 2 2 H 2 e 2 W O W 4 H 4 e W O W 6 H 6 e W O W 2 H 2 e W O W 2 H 2 e W 2 O H 4 Xe 2 H 2 e Xe.42 Xe 6 H 6 e Xe.10 XeF e Xe F 3.4 Y 3 3 e Y Yb 3 e Yb Yb 3 3 e Yb 2.19 Yb 2 2 e Yb 2.76 Zn 2 2 e Zn Zn 2 2 e Zn(Hg) Zn O 2 e Zn 4 OH ZnS 7 O 2 e = Zn(Hg) S O (Saturated ZnS ) ZnOH H 2 e Zn O Zn(OH) 4 2 e Zn 4 OH Zn(OH) 2 2 e Zn 2 OH ZnO O 2 e Zn 2 OH Zr 4 H 4 e Zr O ZrO(OH) 2 O 4 e Zr 4 OH 2.36 Zr 4 4 e Zr 1.45

6 Electrochemical Series 5-85 TABLE 2. Reduction s Having E Values More Positive than That of the Standard Hydrogen Electrode 2 H 2 e CuI 2 e Cu 2 I 0.00 Ge 4 2 e Ge N O 2 e N 2 OH 0.01 Tl 2 O 4 e 2 Tl 6 OH Se O 2 e Se 2 OH 0.05 W 2 H 2 e W O U e = U Pd(OH) 2 2 e Pd 2 OH 0.07 AgBr e Ag Br Mo 6 H 6 e Mo O S 4 2 e Mo H 42 e 7 Mo 24 O AgSCN e Ag SCN O 6 H 6 e 2 NH 4 OH HgO O 2 e Hg 2 OH Ir 2 O 6 e 2 Ir 6 OH NO 2 e 0.10 [Ru(N ] 3 e [Ru(N ] W 3 3 e W 0.1 [Co(N ] 3 e [Co(N ] O O 2 e 2 Hg 2 OH Ge 4 4 e Ge e 2 Hg 2 Br Pt(OH) 2 2 e Pt 2 OH 0.14 [V(phen) 3 ] 3 e [V(phen) 3 ] S 2H 2 e S(aq) Sn(OH) 3 3 H 2 e Sn 2 O Np 4 e Np Ag 4 [Fe(CN ] 4 e 4 Ag [Fe(CN ] I O 4 e IO 4 OH 0.15 Mn(OH) 3 e Mn(OH) 2 OH N O 4 e O 6 OH 0.15 Sn 4 2 e Sn H 6 e 2 Sb O Cu 2 e Cu BiOCl 2 H 3 e Bi Cl O BiCl 4 3 e Bi 4 Cl 0.16 Fe 2 4 H 2 e 2 FeOH O 0.16 Co(OH) 3 e Co(OH) 2 OH S 4 H 2 e S O Bi 3 2 e Bi 0.2 [Ru(en) 3 ] 3 e [Ru(en) 3 ] SbO 2 H 3 e Sb O AgCl e Ag Cl [Ru( O ] 3 e [Ru( O ] As 2 6 H 6 e 2 As O Calomel electrode, saturated NaCl (SSCE) Ge 2 2 e Ge 0.24 Ru 3 e Ru Calomel electrode, saturated KCl Pb O 2 e PbO 2 OH HAs 3 H 3 e As O Ru 3 e Ru Re 4 H 4 e Re O I O 6 e I OH 0.26 Cl 2 2 e 2 Hg 2 Cl Calomel electrode, 1 molal KCl Calomel electrode, 1 molar KCl (NCE) At 2 2 e 2 At 0.3 Re 3 3 e Re Tc 3 e Tc Bi 3 3 e Bi BiO 2 H 3 e Bi O U 4 H 2 e U 4 O Cl O 2 e Cl 2 OH HCNO 2 H 2 e (CN) 2 O Calomel electrode, 0.1 molar KCl V 2 H e V 3 O Cu 2 2 e Cu O O 2 e 2 Ag 2 OH Cu 2 2 e Cu(Hg) AgI e Ag I [Fe(CN ] 3 e [Fe(CN ] Cl O 2 e ClO 2 3 OH Se 2 e 2 Ag Se Re 8 H 7 e Re 4 O (CN) 2 2 H 2 e 2 HCN [Ferricinium] e ferrocene Tc 2 2 e Tc O 4 e 4 OH AgOCN e Ag OCN 0.41 [RhCl 6 ] 3 3 e Rh 6 Cl Cr 2 e 2 Ag Cr S 4 H 4 e S O Ru 2 2 e Ru Mo 2 e 2 Ag Mo C 2 2 e 2 Ag C W 2 e 2 Ag W C 2 e 2 Ag C 0.47 Tc 8 H 7 e Tc 4 O Te 8 H 7 e Te 4 O IO O 2 e I 2 OH Ni O 2 e Ni(OH) 2 2 OH Bi e Bi 0.5 Re 4 H 3 e Re O (ac) 2 2 e 2 Hg 2(ac) Cu e Cu I 2 2 e 2 I I 3 2 e 3 I AgBr e Ag Br Mn e Mn As 2 H 2 e HAs O H 2 e 2 S AgN e Ag N Te 4 4 e Te H 4 e 2 SbO O Ru e Ru 0.59 [PdCl 4 ] 2 2 e Pd 4 Cl Te 4 H 4 e Te O Mn O 3 e Mn 4 OH Rh 2 2 e Rh 0.600

7 5-86 Electrochemical Series Rh e Rh Mn O 2 e Mn 4 OH AgO O 2 e O 2 OH Br O 6 e Br 6 OH 0.61 U 4 H e U 4 O S 2 e 2 Hg S Cl O 6 e Cl 6 OH HP 2 e 2 Hg HP Ag(ac) e Ag (ac) (valentinite) 4 H 4 e O S 2 e 2 Ag S Cl O 2 e ClO 2 OH 0.66 (senarmontite) 4 H 4 e 2 O [PtCl 6 ] 2 2 e [PtCl 4 ] 2 2 Cl H 2 e pbenzoquinone 2 H 2 e hydroquinone I 2 e I 3 OH 0.7 O 2 e 2 AgO 2 OH Tl 3 3 e Tl [PtCl 4 ] 2 2 e Pt 4 Cl Rh 3 3 e Rh Cl O 4 e Cl 4 OH NO O 2 e O 2 OH 0.76 Po 4 4 e Po 0.76 BrO O 2 e Br 2 OH Re 2 H e Re O (CNS) 2 2 e 2 CNS 0.77 [IrCl 6 ] 3 3 e Ir 6 Cl 0.77 Fe 3 e Fe AgF e Ag F [Fe(bipy) 2 ] 3 e [Fe(bipy) 2 ] Tc 4 H 3 e Tc O e 2 Hg Ag e Ag [Os(bipy) 3 ] 3 e [Os(bipy) 3 ] N 4 H 2 e O [Os(bipy) 2 ] 3 e [Os(bipy) 2 ] RhO H 3 e Rh O 0.83 Os 8 H 8 e Os 4 O ClO O 2 e Cl 2 OH e Hg AuBr 4 3 e Au 4 Br Si (quartz) 4 H 4 e Si O HN 4 H 4 e O 0.86 [Ru(CN ] 3 e [Ru(CN ] [IrCl 6 ] 2 e [IrCl 6 ] e 2 N H O 2 e 3 OH Po 4 2 e Po e N 3 H 2 e HN O Pd 2 2 e Pd Cl (aq) e Cl N 4 H 3 e NO O V 2 6 H 2 e 2 V O Au e Au 2 Br HN H e NO O HIO H 2 e I O V 2 H e V O Pt 4 H 4 e Pt O 1.00 Ru e Ru 1.00 V(OH) 4 2 H e V O 1.00 AuCl 4 3 e Au 4 Cl Pu 4 e Pu Pt 2 H 2 e PtO O 1.01 Os 4 H 4 e Os O 1.02 H 6 Te 2 H 2 e Te 4 O 1.02 [Fe(bipy) 3 ] 3 e [Fe(bipy) 3 ] Hg(OH) 2 2 H 2 e Hg O H 4 e 2 NO O Ru 8 H 8 e Ru 4 O [Fe(phen) 3 ] 3 e [Fe(phen) 3 ] 2 (1 molar S ) 1.06 Pu (OH) 2 H e Pu OH O H 2 e 2 HN (l) 2 e 2Br I 6 H 6 e I O (aq) 2 e 2Br Pu 5 e Pu Cu 2 2 CN e [Cu(CN) 2 ] Ru 4 H 2 e Ru 2 O [Fe(phen) 3 ] 3 e [Fe(phen) 3 ] Se 4 H 2 e Se O Cl 2 H e Cl O Ir 3 3 e Ir Pt 2 2 e Pt 1.18 Cl 2 H 2 e Cl O I 12 H 10 e I 2 6 O PtOH H 2 e Pt O 1.2 Cl 3 H 2 e HCl O Mn 4 H 2 e Mn 2 O H 4 e 2 O O 2 e 2 OH 1.24 [Ru(bipy) 3 ] 3 e [Ru(bipy) 3 ] Tl 3 2 e Tl H 5 3 H 2 e 2 NH Cl H e HCl [PdCl 6 ] 2 2 e [PdCl 4 ] 2 2 Cl HN 4 H 4 e O O AuO H 2 e Au O 1.32 Pu (OH) 2 2 H 2 e Pu(OH) HBrO H 2 e Br O Cr(V) e Cr(IV) 1.34 HCr 7 H 3 e Cr 3 4 O Cl 2 (g) 2 e 2Cl Cr 2 O 7 14 H 6 e 2 Cr 3 7 O 1.36 Cl 8 H 8 e Cl 4 O Cl 8 H 7 e 1/2 Cl 2 4 O 1.39 No 3 e No Ru 6 H 2 4 e Ru(OH) 2 O 1.40 Au 3 2 e Au N OH H 2 e H 5 O 1.42 Br 6 H 6 e Br O HIO 2 H 2 e I 2 O Au(OH) 3 3 H 3 e Au O 1.45

8 Electrochemical Series I 6 H 6 e Cl O Pb 4 H 2 e Pb 2 O Cl 6 H 5 e 1/2 Cl 2 O 1.47 Cr 4 H e Cr 3 O 1.48 Br 6 H 5 e 1/2 O HClO H 2 e Cl O Mn 2 6 H e 2 Mn 2 O H H e Au 3 3 e Au Pt 4 H 2 2 e Pt(OH) 2 O 1.5 Mn 8 H 5 e Mn 2 4 O Mn 3 e Mn HCl 3 H 4 e Cl O HBrO H e 1/2 (aq) O NO 2 H 2 e O O Bi 2 4 H 2 e 2 BiO O HBrO H e 1/2 (l) O H 5 I H 2 e I O HClO H e 1/2 Cl 2 O HCl 3 H 3 e 1/2 Cl 2 O HCl 2 H 2 e HClO O Bk 4 e Bk Ni 4 H 2 e Ni 2 O Mn 4 H 3 e Mn O Pb S 4 H 2 e PbS O Au e Au Pt 2 H 2 e Pt O 1.7 CeO H e Ce 3 O Ce 4 e Ce O 2 H 2 e O H 2 e 2 O Ag 3 e 1.8 Au 2 e Au H e 2 Ag O Co 3 e Co 2 (2 molar S ) 1.83 Ag 3 2 e Ag 1.9 Co 3 e Co e Ag Cu 2 6 H 2 e 2 Cu O 8 2 e 2 S OH e OH 2.02 HFe 7 H 3 e Fe H 2 e.076 HFe 4 H 3 e FeOOH.08 2 HFe 8 H 6 e Fe Xe 6 H 6 e Xe.10 2 O 8 2 H 2 e 2 HS O 2 H 4 e O 2 F Fe 8 H 3 e Fe Cu 3 e Cu H 4 Xe 2 H 2 e Xe.42 O(g) 2 H 2 e.421 Am 4 e Am H 2 e.65 2 e 2 F Cm 4 e Cm H 2 e 2 HF Tb 4 e Tb Pr 4 e Pr Cf 4 e Cf XeF e Xe F 3.4 TABLE 3. Reduction s Having E Values More Negative than That of the Standard Hydrogen Electrode 2 H 2 e D 2 e D AgCN e Ag CN W 2 H 2 e W 2 O W 2 2 H 2 e 2 W O S 2 H 2 e 2 Ag S Fe 3 3 e Fe I 2 2 e 2 Hg 2 I Tl(OH) 3 2 e TlOH 2 OH 0.05 TiO H e Ti 3 O S H 2 e H O P(white) 3 H 3 e P (g) O 2 e H OH Cu(OH) 2 2 e Cu 2 O 2 OH O Se 2 H 2 e Se W 6 H 6 e W O Sn 4 H 2 e Sn 2 O Md 3 e Md P(red) 3 H 3 e P (g) Sn 4 H 4 e Sn O Ge 2 H 2 e GeO O W 4 H 4 e W O Pb 2 2 e Pb(Hg) Pb 2 2 e Pb Cr 4 O 3 e Cr(OH) 3 5 OH 0.13 Sn 2 2 e Sn In e In 0.14 O 2 e 2 OH Mo 4 H 4 e Mo 4 O AgI e Ag I N O 4 e 4 OH 0.18 Ge 4 H 4 e Ge O Sn 3 H 2 e SnOH O C 2 H 2 e HCOOH Mo 3 3 e Mo Ga e Ga S 4 H 2 2 e O 0.22 Cu(OH) 2 2 e Cu 2 OH V 2 10 H 10 e 2 V 5 O CdS 2 e Cd S V(OH) 4 4 H 5 e V 4 O V 3 e V

9 5-88 Electrochemical Series Ni 2 2 e Ni PbCl 2 2 e Pb 2 Cl P 2 H 2 e P O Co 2 2 e Co 0.28 Pb 2 e Pb 2 Br Tl e Tl(Hg) Tl e Tl In 3 3 e In TlOH e Tl OH 0.34 Pb 2 e Pb 2 F PbS 2 e Pb(Hg) S Cd 2 2 e Cd(Hg) PbS 2 e Pb S Cu 2 O O 2 e 2 Cu 2 OH Eu 3 e Eu PbI 2 2 e Pb 2 I Se O 4 e Se 6 OH Se 2 H 2 e Se(aq) In 2 e In 0.40 Cd 2 2 e Cd Cr 3 e Cr S 2 e Tl 2 S 2 e Tl S In 3 2 e In Fe 2 2 e Fe P 3 H 3 e P O Bi 2 O 6 e 2 Bi 6 OH 0.46 N O e NO 2 OH PbHP 2 e Pb HP S 2 e S O 2 e HS OH B(OH) 3 7 H 8 e BH 4 O In 3 e In ZnOH H 2 e Zn O GaO H 3 e Ga O P 2 H 2 e P O Ti 4 H 2 e Ti 2 O P H e P O Sb 3 H 3 e Sb HPb O 2 e Pb 3 OH Ga 3 3 e Ga TlCl e Tl Cl Fe(OH) 3 e Fe(OH) 2 OH Te O 4 e Te 6 OH S O 4 e 6 OH PbO O 2 e Pb 2 OH Re 4 O 7 e Re 8 OH Sb O 2 e Sb 2 OH 0.59 Ta 3 3 e Ta 0.6 U 4 e U As 3 H 3 e As Nb 2 10 H 10 e 2 Nb 5 O Nb 2 H 2 e NbO O Cd(OH) 4 2 e Cd 4 OH TlBr e Tl Br Sb O 3 e Sb 4 OH 0.66 As O 3 e As 4 OH 0.68 Nb 4 H 4 e Nb O S 2 e 2 Ag As O 2 e As 4 OH 0.71 Ni(OH) 2 2 e Ni 2 OH 0.72 Co(OH) 2 2 e Co 2 OH 0.73 NbO 2 H 2 e Nb O Se 4 H 4 e Se O 0.74 Cr 3 3 e Cr Ta 2 10 H 10 e 2 Ta 5 O TlI e Tl I Zn 2 2 e Zn Zn 2 2 e Zn(Hg) CdO O 2 e Cd 2 OH Te 2 H 2 e Te ZnS. 7 O 2 e Zn(Hg) S 7 O (Saturated ZnS ) Bi 3 H 3 e Bi 0.8 SiO 2 H 2 e Si O 0.8 Cd(OH) 2 2 e Cd(Hg) 2 OH O 2 e 2 OH NO 2 H O 2 e N O OH 0.85 B 3 H 3 e B O P O 3 e P (g) 3 OH 0.87 Ti 3 e Ti HSn O 2 e Sn 3 OH Cr 2 2 e Cr Se 2 e Se S O 2 e S 2 OH Sn(OH 2 e HSn 3 OH O 0.93 Sn O 4 e Sn 4 OH In(OH) 3 3 e In 3 OH 0.99 Np O H e Np(OH) In(OH) 4 3 e In 4 OH In 2 O 6 e 2 In 6 OH P O 2 e HP 3 OH 1.05 Yb 3 e Yb Nb 3 3 e Nb Fm 3 e Fm S O 2 e 4 OH 1.12 Te 2 e Te V 2 2 e V Mn 2 2 e Mn Zn(OH) 4 2 e Zn 4 OH Cr O 3 e Cr 4 OH 1.2 No 3 3 e No 1.20 Zn O 2 e Zn 4 OH Ga O 3 e Ga 4 OH B 5 O 8 e BH 4 8 OH SiF 6 4 e Si 6 F 1.24 Zn(OH) 2 2 e Zn 2 OH ZnO O 2 e Zn 2 OH Es 3 e Es Pa 3 3 e Pa 1.34 Ti 3 3 e Ti 1.37 Ce 3 3 e Ce(Hg) U 4 H 6 e U O Zr 4 4 e Zr 1.45

10 Electrochemical Series 5-89 Cr(OH) 3 3 e Cr 3 OH 1.48 Pa 4 4 e Pa 1.49 Hf 4 H 4 e Hf O Hf 4 4 e Hf 1.55 Sm 3 e Sm Zr 4 H 4 e Zr O Mn(OH) 2 2 e Mn 2 OH 1.56 Ba 2 2 e Ba(Hg) Bk 2 2 e Bk 1.6 Cf 3 e Cf Ti 2 2 e Ti Md 3 3 e Md HP O 2 e P 3 OH 1.65 Al 3 3 e Al Si O 4 e Si 6 OH HP O 3 e P 5 OH 1.71 Hf 2 H 4 e Hf O Th 4 H 4 e Th O B O 3 e B 4 OH 1.79 Sr 2 2 e Sr(Hg) U 3 3 e U PO e P 2 2 OH 1.82 Be 2 2 e Be Np 3 3 e Np Fm 3 3 e Fm 1.89 Th 4 4 e Th Am 2 2 e Am 1.9 Pa 4 e Pa Es 3 3 e Es 1.91 Cf 3 3 e Cf 1.94 Lr 3 3 e Lr 1.96 Eu 3 3 e Eu Er 2 2 e Er 2.0 Pr 2 2 e Pr 2.0 Pu 3 3 e Pu Cm 3 3 e Cm 2.04 Am 3 3 e Am AlF 6 3 e Al 6 F Sc 3 3 e Sc Ho 2 2 e Ho 2.1 Nd 2 2 e Nd 2.1 Cf 2 2 e Cf 2.12 Yb 3 3 e Yb 2.19 Ac 3 3 e Ac 2.20 Dy 2 2 e Dy 2.2 Tm 3 e Tm Pm 2 2 e Pm 2.2 Es 2 2 e Es e 2 H 2.23 Gd 3 3 e Gd Tb 3 3 e Tb 2.28 Lu 3 3 e Lu 2.28 Dy 3 3 e Dy Am 3 e Am Fm 2 2 e Fm 2.30 Pm 3 3 e Pm 2.30 Sm 3 3 e Sm Al(OH) 3 3 e Al 3 OH 2.31 Tm 3 3 e Tm Nd 3 3 e Nd Al(OH) 3 e Al 4 OH Al O 3 e Al 4 OH 2.33 Ho 3 3 e Ho 2.33 Er 3 3 e Er Ce 3 3 e Ce Pr 3 3 e Pr ZrO(OH) 2 O 4 e Zr 4 OH 2.36 Mg 2 2 e Mg Y 3 3 e Y La 3 3 e La Tm 2 2 e Tm 2.4 Md 2 2 e Md 2.40 Th(OH) 4 4 e Th 4 OH 2.48 HfO(OH) 2 O 4 e Hf 4 OH 2.50 No 2 2 e No 2.50 Dy 3 e Dy Pm 3 e Pm Be 2 O 4 e 2 Be 6 OH 2.63 Sm 2 2 e Sm 2.68 Mg(OH) 2 2 e Mg 2 OH Nd 3 e Nd Mg e Mg 2.70 Na e Na 2.71 Yb 2 2 e Yb 2.76 Bk 3 e Bk Ho 3 e Ho Ra 2 2 e Ra 2.8 Eu 2 2 e Eu Ca 2 2 e Ca Sr(OH) 2 2 e Sr 2 OH 2.88 Sr 2 2 e Sr Fr e Fr 2.9 La(OH) 3 3 e La 3 OH 2.90 Ba 2 2 e Ba K e K Rb e Rb 2.98 Ba(OH) 2 2 e Ba 2 OH 2.99 Er 3 e Er Ca(OH) 2 2 e Ca 2 OH 3.02 Cs e Cs Li e Li H 2 e 2 HN Pr 3 e Pr Ca e Ca 3.80 Sr e Sr 4.10