Skip to main content
Chemistry LibreTexts

16.13: Standard Reduction Potentials

  • Page ID
    220810
  • \( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \) \( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash {#1}}} \)\(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\) \(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\)\(\newcommand{\AA}{\unicode[.8,0]{x212B}}\)

    The following table provides Eo and Eo ́ values for selected reduction reactions. Values are from the following sources (primarily the first two):

    • Bard, A. J.; Parsons, B.; Jordon, J., eds. Standard Potentials in Aqueous Solutions, Dekker: New York, 1985
    • Milazzo, G.; Caroli, S.; Sharma, V. K. Tables of Standard Electrode Potentials, Wiley: London, 1978;
    • Swift, E. H.; Butler, E. A. Quantitative Measurements and Chemical Equilibria, Freeman: New York, 1972.
    • Bratsch, S. G. "Standard Electrode Potentials and Temperature Coefficients in Water at 298.15K, J. Phys. Chem. Ref. Data198918, 1–21.
    • Latimer, W. M. Oxidation Potentials, 2nd. Ed., Prentice-Hall: Englewood Cliffs, NJ, 1952

    Solids, gases, and liquids are identified; all other species are aqueous. Reduction reactions in acidic solution are written using H+ in place of H3O+. You may rewrite a reaction by replacing H+ with H3O+ and adding to the opposite side of the reaction one molecule of H2O per H+; thus 

    H3AsO4 + 2H+ +2e \(\rightleftharpoons\) HAsO2 +2H2O

    becomes

    H3AsO4 + 2H3O+ +2e \(\rightleftharpoons\) HAsO2 +4H2O

    Conditions for formal potentials (Eo ́) are listed next to the potential.

    For most of the reduction half-reactions gathered here, there are minor differences in values provided by the references above. In most cases, these differences are small and will not affect calculations. In a few cases the differences are not insignificant and the user may find discrepancies in calculations. For example, Bard, Parsons, and Jordon report an Eo value of –1.285 V for 

    \[\text{Zn(OH)}_4^{2-} + 2e^- \rightleftharpoons \text{Zn}(s) + 4\text{OH}^-\nonumber\] 

    while Milazzo, Caroli, and Sharma report the value as –1.214 V, Swift reports the value as –1.22, Bratsch reports the value as –1.199 V, and Latimer reports the value as –1.216 V.

    Aluminum (V) Eo ́ (V)

    \(\text{Al}^{3+} + 3e^- \rightleftharpoons \text{Al}(s)\)

    –1.676  
    \(\text{Al(OH)}_4^- + 3e^- \rightleftharpoons \text{Al}(s) + 4\text{OH}^-\) –2.310  

    \(\text{AlF}_6^{3-} + 3e^- \rightleftharpoons \text{Al}(s) + 6\text{F}^-\)

    –2.07  
    Antimony (V) Eo ́ (V)
    \(\text{Sb} + 3\text{H}^+ + 3e^- \rightleftharpoons \text{SbH}_3(g)\) –0.510  
    \(\text{Sb}_2\text{O}_5 + 6\text{H}^+ + 4e^- \rightleftharpoons 2\text{SbO}^+ + 3\text{H}_2\text{O}(l)\)  0.605  
    \(\text{SbO}^+ + 2\text{H}^+ + 3e^- \rightleftharpoons \text{Sb}(s) + \text{H}_2\text{O}(l)\) 0.212  
    Arsenic (V) Eo ́ (V)
    \(\text{As}(s) + 3\text{H}^+ + 3e^- \rightleftharpoons \text{AsH}_3(g)\) –0.225  
    \(\text{H}_3\text{AsO}_4 + 2\text{H}^+ + 2e^- \rightleftharpoons \text{HAsO}_2 + 2\text{H}_2\text{O}(l)\) 0.560  
    \(\text{HAsO}_2 + 3\text{H}^+ + 3e^- \rightleftharpoons \text{As}(s) + 2\text{H}_2\text{O}(l)\) 0.240  
    Barium (V) Eo ́ (V)

    \(\text{Ba}^{2+} + 2e^- \rightleftharpoons \text{Ba}(s)\)

    –2.92  

    \(\text{BaO}(s) + 2\text{H}^+ + 2e^- \rightleftharpoons \text{Ba}(s) + \text{H}_2\text{O}(l)\)

    –2.166  
    Beryllium (V) Eo ́ (V)

    \(\text{Be}^{2+} + 2e^- \rightleftharpoons \text{Be}(s)\)

    –1.99  
    Bismuth (V) Eo ́ (V)

    \(\text{Bi}^{3+} + 3e^- \rightleftharpoons \text{Bi}(s)\)

    0.317

     
    \(\text{BiCl}_4^- + 3e^- \rightleftharpoons \text{Bi}(s) + 4\text{Cl}^-\)

    0.199

     
    Boron (V) Eo ́ (V)

    \(\text{B(OH)}_3 + 3\text{H}^+ + 3e^- \rightleftharpoons \text{B}(s) + 3\text{H}_2\text{O}(l)\)

    –0.890

     

    \(\text{B(OH)}_4^- + 3e^- \rightleftharpoons \text{B}(s) + 4\text{OH}^-\)

    –1.811

     
    Bromine E (V) Eo ́ (V)
    \(\text{Br}_2(l) + 2e^- \rightleftharpoons 2\text{Br}^-\)

    1.087

     

    \(\text{HOBr} + \text{H}^+ + 2e^- \rightleftharpoons \text{Br}^- + \text{H}_2\text{O}(l)\)

    1.341

     

    \(\text{HOBr} + \text{H}^+ + e^- \rightleftharpoons \frac{1}{2} \text{Br}_2 + \text{H}_2\text{O}(l)\)

    1.604

     

    \(\text{BrO}^- + \text{H}_2\text{O}(l) + 2e^- \rightleftharpoons \text{Br}^- + 2\text{OH}^-\)

     

    0.76 in 1 M NaOH

    \(\text{BrO}_3^- +6\text{H}^+ + 5e^- \rightleftharpoons \frac{1}{2} \text{Br}_2(l) + 3\text{H}_2\text{O}(l)\)

    1.5

     

    \(\text{BrO}_3^- + 6\text{H}^+ +6e^- \rightleftharpoons \text{Br}^- + 3\text{H}_2\text{O}(l)\)

    1.478

     
    Cadmium (V) Eo ́ (V)

    \(\text{Cd}^{2+} + 2e^- \rightleftharpoons \text{Cd}(s)\)

    –0.4030

     

    \(\text{Cd(CN)}_4^{2-} + 2e^- \rightleftharpoons \text{Cd}(s) + 4\text{CN}^-\)

    –0.943

     

    \(\text{Cd(NH}_3)_4^{2+} + 2e^- \rightleftharpoons \text{Cd}(s) + 4\text{NH}_3\)

    –0.622

     
    Calcium (V) Eo ́ (V)

    \(\text{Ca}^{2+} + 2e^- \rightleftharpoons \text{Ca}(s)\)

    –2.84

     
    Carbon (V) Eo ́ (V)

    \(\text{CO}_2(g) + 2\text{H}^+ + 2e^- \rightleftharpoons \text{CO}(g) + \text{H}_2\text{O}(l)\)

    –0.106

     

    \(\text{CO}_2(g) + 2\text{H}^+ +2e^- \rightleftharpoons \text{HCO}_2\text{H}\)

    –0.20

     

    \(2\text{CO}_2(g) + 2\text{H}^+ +2e^- \rightleftharpoons \text{H}_2\text{C}_2\text{O}_4\)

    –0.481

     

    \(\text{HCHO} + 2\text{H}^+ + 2e^- \rightleftharpoons \text{CH}_3\text{OH}\)

    0.2323

     
    Cerium (V) Eo ́ (V)

    \(\text{Ce}^{3+} + 3e^- \rightleftharpoons \text{Ce}(s)\)

    –2.336

     

    \(\text{Ce}^{4+} + e^- \rightleftharpoons \text{Ce}^{3+}\)

    1.72

    1.70 in 1 M HClO4

    1.44 in 1 M H2SO4

    1.61 in 1 M HNO3

    1.28 in 1 M HCl

    Chlorine (V) Eo ́ (V)

    \(\text{Cl}_2(g) + 2e^- \rightleftharpoons 2\text{Cl}^-\)

    1.396

     

    \(\text{ClO}^- + \text{H}_2\text{O}(l) + e^- \rightleftharpoons \frac{1}{2} \text{Cl}_2(g) + 2\text{OH}^-\)

     

    0.421 in 1 M NaOH

    \(\text{ClO}^- + \text{H}_2\text{O}(l) + 2e^- \rightleftharpoons \text{Cl}^- + 2\text{OH}^-\)

     

    0.890 in 1 M NaOH

    \(\text{HClO}_2 + 2\text{H}^+ + 2e^- \rightleftharpoons \text{HOCl} + \text{H}_2\text{O}(l)\)

    1.64

     

    \(\text{ClO}_3^- + 2\text{H}^+ + e^- \rightleftharpoons \text{ClO}_2(g) + \text{H}_2\text{O}(l)\)

    1.175

     

    \(\text{ClO}_3^- + 3\text{H}^+ + 2e^- \rightleftharpoons \text{HClO}_2 + \text{H}_2\text{O}(l)\)

    1.181

     

    \(\text{ClO}_4^- + 2\text{H}^+ +2e^- \rightleftharpoons \text{ClO}_3^- + \text{H}_2\text{O}(l)\)

    1.201

     
    Chromium (V) Eo ́ (V)

    \(\text{Cr}^{3+} + 3e^- \rightleftharpoons \text{Cr}(s)\)

    –0.424

     

    \(\text{Cr}^{2+} + 2e^- \rightleftharpoons \text{Cr}(s)\)

    –0.90

     

    \(\text{Cr}_2\text{O}_7^{2-} + 14\text{H}^+ + 6e^- \rightleftharpoons 2\text{Cr}^{3+} + 7\text{H}_2\text{O}(l)\)

    1.36

     

    \(\text{CrO}_4^{2-} + 4\text{H}_2\text{O}(l) + 3e^- \rightleftharpoons \text{Cr(OH)}_4^- + 4\text{OH}^-\)

      –0.13 in 1 M NaOH
    Cobalt (V) Eo ́ (V)

    \(\text{Co}^{2+} + 2e^- \rightleftharpoons \text{Co}(s)\)

    –0.277

     

    \(\text{Co}^{3+} + 3e^- \rightleftharpoons \text{Co}(s)\)

    1.92

     

    \(\text{Co(NH}_3)_6^{3+} + e^- \rightleftharpoons \text{Co(NH}_3)_6^{2+}\)

    0.1

     

    \(\text{Co(OH)}_3(s) + e^- \rightleftharpoons \text{Co(OH)}_2(s) + \text{OH}^-\)

    0.17

     

    \(\text{Co(OH)}_2(s) + 2e^- \rightleftharpoons \text{Co}(s) + 2\text{OH}^-\)

    –0.746

     
    Copper (V) Eo ́ (V)

    \(\text{Cu}^+ + e^- \rightleftharpoons \text{Cu}(s)\)

    0.520

     

    \(\text{Cu}^{2+} + e^- \rightleftharpoons \text{Cu}^+\)

    0.159

     

    \(\text{Cu}^{2+} + 2e^- \rightleftharpoons \text{Cu}(s)\)

    0.3419

     

    \(\text{Cu}^{2+} + \text{I}^- + e^- \rightleftharpoons \text{CuI}(s)\)

    0.86

     

    \(\text{Cu}^{2+} + \text{Cl}^- + e^- \rightleftharpoons \text{CuCl}(s)\)

    0.559

     
    Fluorine (V) Eo ́ (V)

    \(\text{F}_2(g) + 2\text{H}^+ + 2e^- \rightleftharpoons 2\text{HF}(g)\)

    3.053

     

    \(\text{F}_2(g) + 2e^- \rightleftharpoons 2\text{F}^-\)

    2.87

     
    Gallium (V) Eo ́ (V)

    \(\text{Ga}^{3+} + 3e^- \rightleftharpoons \text{Ga}(s)\)

    –0.529  
    Gold (V) Eo ́ (V)

    \(\text{Au}^+ + e^- \rightleftharpoons \text{Au}(s)\)

    1.83

     

    \(\text{Au}^{3+} + 2e^- \rightleftharpoons \text{Au}^+\)

    1.36

     

    \(\text{Au}^{3+} + 3e^- \rightleftharpoons \text{Au}(s)\)

    1.52

     

    \(\text{AuCl}_4^- + 3e^- \rightleftharpoons \text{Au}(s) + 4\text{Cl}^-\)

    1.002

     
    Hydrogen (V) Eo ́ (V)

    \(2\text{H}^+ + 2e^- \rightleftharpoons \text{H}_2 (g)\)

    0.00000

     

    \(\text{H}_2\text{O}(l) + e^- \rightleftharpoons \frac{1}{2} \text{H}_2(g) + \text{OH}^-\)

    –0.828

     
    Iodine (V) Eo ́ (V)

    \(\text{I}_2(s) + 2e^- \rightleftharpoons 2\text{I}^-\)

    0.5355

     

    \(\text{I}_3^- + 2e^- \rightleftharpoons 3\text{I}^-\)

    0.536

     

    \(\text{HIO} + \text{H}^+ + 2e^- \rightleftharpoons \text{I}^- + \text{H}_2\text{O}(l)\)

    0.985

     

    \(\text{IO}_3^- + 6\text{H}^+ + 5e^- \rightleftharpoons \frac{1}{2} \text{I}_2(s) + 3\text{H}_2\text{O}(l)\)

    1.195

     

    \(\text{IO}_3^- + 3\text{H}_2\text{O}(l) + 6e^- \rightleftharpoons \text{I}^- +6\text{OH}^-\)

    0.257

     
    Iron (V) Eo ́ (V)

    \(\text{Fe}^{2+} + 2e^- \rightleftharpoons \text{Fe}(s)\)

    –0.44

     

    \(\text{Fe}^{3+} + 3e^- \rightleftharpoons \text{Fe}(s)\)

    –0.037

     

    \(\text{Fe}^{3+} + e^- \rightleftharpoons \text{Fe}^{2+}\)

    0.771

    0.70 in 1 M HCl

    0.767 in 1 M HClO4

    0.746 in 1 M HNO3

    0.68 in 1 M H2SO4

    0.44 in 0.3 M H3PO4

    \(\text{Fe(CN)}_6^{3-} + e^- \rightleftharpoons \text{Fe(CN)}_6^{4-}\)

    0.356

     

    \(\text{Fe(phen)}_3^{3+} + e^- \rightleftharpoons \text{Fe(phen)}_3^{2+}\)

    1.147

     
    Lanthanum (V) Eo ́ (V)

    \(\text{La}^{3+} + 3e^- \rightleftharpoons \text{La}(s)\)

    –2.38

     
    Lead (V) Eo ́ (V)

    \(\text{Pb}^{2+} + 2e^- \rightleftharpoons \text{Pb}(s)\)

    –0.126

     

    \(\text{PbO}_2(s) + 4\text{H}^+ + 2e^- \rightleftharpoons \text{Pb}^{2+} + 2\text{H}_2\text{O}(l)\)

    1.46

     

    \(\text{PbO}_2(s) + \text{SO}_4^{2-} + 4\text{H}^+ + 2e^- \rightleftharpoons \text{PbSO}_4(s) + 2\text{H}_2\text{O}(l)\)

    1.690

     

    \(\text{PbSO}_4(s) + 2e^- \rightleftharpoons \text{Pb}(s) + \text{SO}_4^{2-}\)

    –0.356

     
    Lithium (V) Eo ́ (V)

    \(\text{Li}^+ + e^- \rightleftharpoons \text{Li}(s)\)

    –3.040

     
    Magnesium (V) Eo ́ (V)

    \(\text{Mg}^{2+} + 2e^- \rightleftharpoons \text{Mg}(s)\)

    –2.356

     

    \(\text{Mg(OH)}_2(s) + 2e^- \rightleftharpoons \text{Mg}(s) + 2\text{OH}^-\)

    –2.687

     
    Manganese (V) Eo ́ (V)

    \(\text{Mn}^{2+} + 2e^- \rightleftharpoons \text{Mn}(s)\)

    –1.17

     

    \(\text{Mn}^{3+} + e^- \rightleftharpoons \text{Mn}^{2+}\)

    1.5

     

    \(\text{MnO}_2(s) + 4\text{H}^+ + 2e^- \rightleftharpoons \text{Mn}^{2+} + 2\text{H}_2\text{O}(l)\)

    1.23

     

    \(\text{MnO}_4^- + 4\text{H}^+ +3e^- \rightleftharpoons \text{MnO}_2(s) + 2\text{H}_2\text{O}(l)\)

    1.70

     

    \(\text{MnO}_4^- + 8\text{H}^+ + 5e^- \rightleftharpoons \text{Mn}^{2+} + 4\text{H}_2\text{O}(l)\)

    1.51

     

    \(\text{MnO}_4^- + 2\text{H}_2\text{O}(l) + 3e^- \rightleftharpoons \text{MnO}_2(s) + 4\text{OH}^-\)

    0.60

     
    Mercury (V) Eo ́ (V)

    \(\text{Hg}^{2+} + 2e^- \rightleftharpoons \text{Hg}(l)\)

    0.8535

     

    \(2\text{Hg}^{2+} +2e^- \rightleftharpoons \text{Hg}_2^{2+}\)

    0.911

     

    \(\text{Hg}_2^{2+} + 2e^- \rightleftharpoons 2\text{Hg}(l)\)

    0.7960

     

    \(\text{Hg}_2\text{Cl}_2(s) + 2e^- \rightleftharpoons 2\text{Hg}(l) + 2\text{Cl}^-\)

    0.2682

     

    \(\text{HgO}(s) + 2\text{H}^+ + 2e^- \rightleftharpoons \text{Hg}(l) + \text{H}_2\text{O}(l)\)

    0.926

     

    \(\text{Hg}_2\text{Br}_2(s) + 2e^- \rightleftharpoons 2\text{Hg}(l) + 2\text{Br}^-\)

    1.392

     

    \(\text{Hg}_2\text{I}_2(s) + 2e^- \rightleftharpoons 2\text{Hg}(l) + 2\text{I}^-\)

    –0.0405

     
    Molybdenum (V) Eo ́ (V)

    \(\text{Mo}^{3+} + 3e^- \rightleftharpoons \text{Mo}(s)\)

    –0.2

     

    \(\text{MoO}_2(s) + 4\text{H}^+ + 4e^- \rightleftharpoons \text{Mo}(s) + 2\text{H}_2\text{O}(l)\)

    –0.152

     

    \(\text{MoO}_4^{2-} + 4\text{H}_2\text{O}(l) + 6e^- \rightleftharpoons \text{Mo}(s) + 8\text{OH}^-\)

    –0.913

     
    Nickel (V) Eo ́ (V)

    \(\text{Ni}^{2+} + 2e^- \rightleftharpoons \text{Ni}(s)\)

    –0.257

     

    \(\text{Ni(OH)}_2(s) + 2e^- \rightleftharpoons \text{Ni}(s) + 2\text{OH}^-\)

    –0.72

     

    \(\text{Ni(NH}_3)_6^{2+} + 2e^- \rightleftharpoons \text{Ni}(s) + 6\text{NH}_3\)

    –0.49

     
    Nitrogen (V) Eo ́ (V)

    \(\text{N}_2(g) + 5\text{H}^+ + 4e^- \rightleftharpoons \text{N}_2\text{H}_5^+\)

    –0.23

     

    \(\text{N}_2\text{O}(g) + 2\text{H}^+ + 2e^- \rightleftharpoons \text{N}_2(g) + \text{H}_2\text{O}(l)\)

    1.77

     

    \(2\text{NO}(g) + 2\text{H}^+ + 2e^- \rightleftharpoons \text{N}_2\text{O}(g) + \text{H}_2\text{O}(l)\)

    1.59

     

    \(\text{HNO}_2 + \text{H}^+ + e^- \rightleftharpoons \text{NO}(g) + \text{H}_2\text{O}(l)\)

    0.996

     

    \(2\text{HNO}_2 + 4\text{H}^+ + 4e^- \rightleftharpoons \text{N}_2\text{O}(g) + 3\text{H}_2\text{O}(l)\)

    1.297

     

    \(\text{NO}_3^- + 3\text{H}^+ + 2e^- \rightleftharpoons \text{HNO}_2 + \text{H}_2\text{O}(l)\)

    0.94

     
    Oxygen (V) Eo ́ (V)

    \(\text{O}_2(g) + 2\text{H}^+ + 2e^- \rightleftharpoons \text{H}_2\text{O}_2\)

    0.695

     

    \(\text{O}_2(g) + 4\text{H}^+ + 4e^- \rightleftharpoons 2\text{H}_2\text{O}(l)\)

    1.229

     

    \(\text{H}_2\text{O}_2 + 2\text{H}^+ + 2e^- \rightleftharpoons 2\text{H}_2\text{O}(l)\)

    1.763

     

    \(\text{O}_2(g) + 2\text{H}_2\text{O}(l) + 4e^- \rightleftharpoons 4\text{OH}^-\)

    0.401

     

    \(\text{O}_3(g) + 2\text{H}^+ + 2e^- \rightleftharpoons \text{O}_2(g) + \text{H}_2\text{O}(l)\)

    2.07

     
    Phosphorous (V) Eo ́ (V)

    \(\text{P}(s, white) + 3\text{H}^+ + 3e^- \rightleftharpoons \text{PH}_3(g)\)

    –0.063

     

    \(\text{H}_3\text{PO}_3 + 2\text{H}^+ + 2e^- \rightleftharpoons  \text{H}_3\text{PO}_2 + \text{H}_2\text{O}(l)\)

    –0.499

     

    \(\text{H}_3\text{PO}_4 + 2\text{H}^+ + 2e^- \rightleftharpoons \text{H}_3\text{PO}_3 + \text{H}_2\text{O}(l)\)

    –0.276

     
    Platinum (V) Eo ́ (V)

    \(\text{Pt}^{2+} + 2e^- \rightleftharpoons \text{Pt}(s)\)

    1.188

     

    \(\text{PtCl}_4^{2-} + 2e^- \rightleftharpoons \text{Pt}(s) + 4\text{Cl}^-\)

    0.758

     
    Potasium (V) Eo ́ (V)

    \(\text{K}^+ + e^- \rightleftharpoons \text{K}(s)\)

    –2.924

     
    Ruthenium (V) Eo ́ (V)

    \(\text{Ru}^{3+} + 3e^- \rightleftharpoons \text{Ru}(s)\)

    0.249

     

    \(\text{RuO}_2(s) + 4\text{H}^+ + 4e^- \rightleftharpoons \text{Ru}(s) + 2\text{H}_2\text{O}(l)\)

    0.68

     

    \(\text{Ru(NH}_3)_6^{3+} + e^- \rightleftharpoons \text{Ru(NH}_3)_6^{2+}\)

    0.10

     

    \(\text{Ru(CN)}_6^{3-} + e^- \rightleftharpoons \text{Ru(CN)}_6^{4-}\)

    0.86

     
    Selenium (V) Eo ́ (V)

    \(\text{Se}(s) + 2e^- \rightleftharpoons \text{Se}^{2-}\)

     

    –0.67 in 1 M NaOH

    \(\text{Se}(s) + 2\text{H}^+ + 2e^- \rightleftharpoons \text{H}_2\text{Se}(g)\)

    –0.115

     

    \(\text{H}_2\text{SeO}_3 + 4\text{H}^+ + 4e^- \rightleftharpoons \text{Se}(s) + 3\text{H}_2\text{O}(l)\)

    0.74

     

    \(\text{SeO}_4^{3-} + 4\text{H}^+ + e^- \rightleftharpoons  \text{H}_2\text{SeO}_3 + \text{H}_2\text{O}(l)\)

    1.151

     
    Silicon (V) Eo ́ (V)

    \(\text{SiF}_6^{2-} + 4e^- \rightleftharpoons \text{Si}(s) + 6\text{F}^-\)

    –1.37

     

    \(\text{SiO}_2(s) + 4\text{H}^+ + 4e^- \rightleftharpoons \text{Si}(s) + 2\text{H}_2\text{O}(l)\)

    –0.909

     

    \(\text{SiO}_2(s) + 8\text{H}^+ + 8e^- \rightleftharpoons \text{SiH}_4(g) + 2\text{H}_2\text{O}(l)\)

    –0.516

     
    Silver (V) Eo ́ (V)

    \(\text{Ag}^+ + e^- \rightleftharpoons \text{Ag}(s)\)

    0.7996

     

    \(\text{AgBr}(s) + e^- \rightleftharpoons \text{Ag}(s) + \text{Br}^-\)

    0.071

     

    \(\text{Ag}_2\text{C}_2\text{O}_4(s) + 2e^- \rightleftharpoons 2\text{Ag}(s) + \text{C}_2\text{O}_4^{2-}\)

    0.47

     

    \(\text{AgCl}(s) + e^- \rightleftharpoons \text{Ag}(s) + \text{Cl}^-\)

    0.2223

     

    \(\text{AgI}(s) + e^- \rightleftharpoons \text{Ag}(s) + \text{I}^-\)

    –0.152

     

    \(\text{Ag}_2\text{S}(s) + 2e^- \rightleftharpoons 2\text{Ag}(s) + \text{S}^{2-}\)

    –0.71

     

    \(\text{Ag(NH}_3)_2^+ + e^- \rightleftharpoons \text{Ag}(s) + 2\text{NH}_3\)

    –0.373

     
    Sodium (V) Eo ́ (V)

    \(\text{Na}^+ + e^- \rightleftharpoons \text{Na}(s)\)

    –2.713

     
    Strontium (V) Eo ́ (V)

    \(\text{Sr}^{2+} + 2e^- \rightleftharpoons \text{Sr}(s)\)

    –2.89

     
    Sulfur (V) Eo ́ (V)

    \(\text{S}(s) + 2e^- \rightleftharpoons \text{S}^{2-}\)

    –0.407

     

    \(\text{S}(s) + 2\text{H}^+ + 2e^- \rightleftharpoons \text{H}_2\text{S}(g)\)

    0.144

     

    \(\text{S}_2\text{O}_6^{2-} + 4\text{H}^+ + 2e^- \rightleftharpoons 2\text{H}_2\text{SO}_3\)

    0.569

     

    \(\text{S}_2\text{O}_8^{2-} + 2e^- \rightleftharpoons 2\text{SO}_4^{2-}\)

    1.96

     

    \(\text{S}_4\text{O}_6^{2-} + 2e^- \rightleftharpoons 2\text{S}_2\text{O}_3^{2-}\)

    0.080

     

    \(2\text{SO}_3^{2-} + 2\text{H}_2\text{O}(l) + 2e^- \rightleftharpoons \text{S}_2\text{O}_4^{2-} + 4\text{OH}^-\)

    –1.13

     

    \(2\text{SO}_3^{2-} + 3\text{H}_2\text{O}(l) + 4e^- \rightleftharpoons \text{S}_2\text{O}_3^{2-} + 6\text{OH}^-\)

     

    –0.576 in 1 M NaOH

    \(2\text{SO}_4^{2-} + 4\text{H}^+ + 2e^- \rightleftharpoons \text{S}_2\text{O}_6^{2-} + 2\text{H}_2\text{O}(l)\)

    –0.25

     

    \(\text{SO}_4^{2-} + \text{H}_2\text{O}(l) + 2e^- \rightleftharpoons \text{SO}_3^{2-} + 2\text{OH}^-\)

    –0.936

     

    \(\text{SO}_4^{2-} + 4\text{H}^+ + 2e^- \rightleftharpoons \text{H}_2\text{SO}_3 + \text{H}_2\text{O}(l)\)

    0.172

     
    Thallium (V) Eo ́ (V)

    \(\text{Tl}^{3+} + 2e^- \rightleftharpoons \text{Tl}^+\)

     

    1.25 in 1 M HClO4

    0.77 in 1 M HCl

    \(\text{Tl}^{3+} + 3e^- \rightleftharpoons \text{Tl}(s)\)

    0.742

     

    Tin (V) Eo ́ (V)

    \(\text{Sn}^{2+} + 2e^- \rightleftharpoons \text{Sn}(s)\)

     

    –0.19 in 1 M HCl

    \(\text{Sn}^{4+} + 2e^- \rightleftharpoons \text{Sn}^{2+}\)

    0.154

    0.139 in 1 M HCl

    Titanium (V) Eo ́ (V)

    \(\text{Ti}^{2+} + 2e^- \rightleftharpoons \text{Ti}(s)\)

    –0.163

     

    \(\text{Ti}^{3+} + e^- \rightleftharpoons \text{Ti}^{2+}\)

    –0.37

     
    Tungsten (V) Eo ́ (V)

    \(\text{WO}_2(s) + 4\text{H}^+ + 4e^- \rightleftharpoons \text{W}(s) + 2\text{H}_2\text{O}(l)\)

    –0.119

     

    \(\text{WO}_3(s) + 6\text{H}^+ + 6e^- \rightleftharpoons \text{W}(s) + 3\text{H}_2\text{O}(l)\)

    –0.090

     
    Uranium (V) Eo ́ (V)

    \(\text{U}^{3+} + 3e^- \rightleftharpoons \text{U}(s)\)

    –1.66

     

    \(\text{U}^{4+} + e^- \rightleftharpoons \text{U}^{3+}\)

    –0.52

     

    \(\text{UO}_2^+ + 4\text{H}^+ + e^- \rightleftharpoons \text{U}^{4+} + 2\text{H}_2\text{O}(l)\)

    0.27

     

    \(\text{UO}_2^{2+} + e^- \rightleftharpoons \text{UO}_2^+\)

    0.16

     

    \(\text{UO}_2^{2+} + 4\text{H}^+ + 2e^- \rightleftharpoons \text{U}^{4+} + 2\text{H}_2\text{O}(l)\)

    0.327

     
    Vanadium (V) Eo ́ (V)

    \(\text{V}^{2+} + 2e^- \rightleftharpoons \text{V}(s)\)

    –1.13

     

    \(\text{V}^{3+} + e^- \rightleftharpoons \text{V}^{2+}\)

    –0.255

     

    \(\text{VO}^{2+} + 2\text{H}^+ + e^- \rightleftharpoons \text{V}^{3+} + \text{H}_2\text{O}(l)\)

    0.337

     

    \(\text{VO}_2^{+} + 2\text{H}^+ + e^- \rightleftharpoons \text{VO}^{2+} + \text{H}_2\text{O}(l)\)

    1.000

     
    Zinc (V) Eo ́ (V)

    \(\text{Zn}^{2+} + 2e^- \rightleftharpoons \text{Zn}(s)\)

    –0.7618

     

    \(\text{Zn(OH)}_4^{2-} + 2e^- \rightleftharpoons \text{Zn}(s) + 4\text{OH}^-\)

    –1.285

     

    \(\text{Zn(NH}_3)_4^{2+} + 2e^- \rightleftharpoons \text{Zn}(s) + 4\text{NH}_3\)

    –1.04

     

    \(\text{Zn(CN)}_4^{2-} + 2e^- \rightleftharpoons \text{Zn}(s) + 4\text{CN}^-\)

    –1.34

     

    This page titled 16.13: Standard Reduction Potentials is shared under a CC BY-NC-SA 4.0 license and was authored, remixed, and/or curated by David Harvey.

    • Was this article helpful?