16.13: Standard Reduction Potentials
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\(\newcommand{\avec}{\mathbf a}\) \(\newcommand{\bvec}{\mathbf b}\) \(\newcommand{\cvec}{\mathbf c}\) \(\newcommand{\dvec}{\mathbf d}\) \(\newcommand{\dtil}{\widetilde{\mathbf d}}\) \(\newcommand{\evec}{\mathbf e}\) \(\newcommand{\fvec}{\mathbf f}\) \(\newcommand{\nvec}{\mathbf n}\) \(\newcommand{\pvec}{\mathbf p}\) \(\newcommand{\qvec}{\mathbf q}\) \(\newcommand{\svec}{\mathbf s}\) \(\newcommand{\tvec}{\mathbf t}\) \(\newcommand{\uvec}{\mathbf u}\) \(\newcommand{\vvec}{\mathbf v}\) \(\newcommand{\wvec}{\mathbf w}\) \(\newcommand{\xvec}{\mathbf x}\) \(\newcommand{\yvec}{\mathbf y}\) \(\newcommand{\zvec}{\mathbf z}\) \(\newcommand{\rvec}{\mathbf r}\) \(\newcommand{\mvec}{\mathbf m}\) \(\newcommand{\zerovec}{\mathbf 0}\) \(\newcommand{\onevec}{\mathbf 1}\) \(\newcommand{\real}{\mathbb R}\) \(\newcommand{\twovec}[2]{\left[\begin{array}{r}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\ctwovec}[2]{\left[\begin{array}{c}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\threevec}[3]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\cthreevec}[3]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\fourvec}[4]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\cfourvec}[4]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\fivevec}[5]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\cfivevec}[5]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\mattwo}[4]{\left[\begin{array}{rr}#1 \amp #2 \\ #3 \amp #4 \\ \end{array}\right]}\) \(\newcommand{\laspan}[1]{\text{Span}\{#1\}}\) \(\newcommand{\bcal}{\cal B}\) \(\newcommand{\ccal}{\cal C}\) \(\newcommand{\scal}{\cal S}\) \(\newcommand{\wcal}{\cal W}\) \(\newcommand{\ecal}{\cal E}\) \(\newcommand{\coords}[2]{\left\{#1\right\}_{#2}}\) \(\newcommand{\gray}[1]{\color{gray}{#1}}\) \(\newcommand{\lgray}[1]{\color{lightgray}{#1}}\) \(\newcommand{\rank}{\operatorname{rank}}\) \(\newcommand{\row}{\text{Row}}\) \(\newcommand{\col}{\text{Col}}\) \(\renewcommand{\row}{\text{Row}}\) \(\newcommand{\nul}{\text{Nul}}\) \(\newcommand{\var}{\text{Var}}\) \(\newcommand{\corr}{\text{corr}}\) \(\newcommand{\len}[1]{\left|#1\right|}\) \(\newcommand{\bbar}{\overline{\bvec}}\) \(\newcommand{\bhat}{\widehat{\bvec}}\) \(\newcommand{\bperp}{\bvec^\perp}\) \(\newcommand{\xhat}{\widehat{\xvec}}\) \(\newcommand{\vhat}{\widehat{\vvec}}\) \(\newcommand{\uhat}{\widehat{\uvec}}\) \(\newcommand{\what}{\widehat{\wvec}}\) \(\newcommand{\Sighat}{\widehat{\Sigma}}\) \(\newcommand{\lt}{<}\) \(\newcommand{\gt}{>}\) \(\newcommand{\amp}{&}\) \(\definecolor{fillinmathshade}{gray}{0.9}\)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. Data, 1989, 18, 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 | E (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 | E (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 | E (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 | E (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 | E (V) | Eo ́ (V) |
|---|---|---|
|
\(\text{Be}^{2+} + 2e^- \rightleftharpoons \text{Be}(s)\) |
–1.99 |
| Bismuth | E (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 | E (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 | E (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 | E (V) | Eo ́ (V) |
|---|---|---|
|
\(\text{Ca}^{2+} + 2e^- \rightleftharpoons \text{Ca}(s)\) |
–2.84 |
| Carbon | E (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 | E (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 | E (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 |
| Chlorine | E (V) | Eo ́ (V) |
|---|---|---|
|
\(\text{ClO}_3^- + 2\text{H}^+ + e^- \rightleftharpoons \text{ClO}_2(g) + \text{H}_2\text{O}(l)\) |
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 | E (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 | E (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 | E (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 | E (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 | E (V) | Eo ́ (V) |
|---|---|---|
|
\(\text{Ga}^{3+} + 3e^- \rightleftharpoons \text{Ga}(s)\) |
–0.529 |
| Gold | E (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 | E (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 | E (V) | Eo ́ (V) |
|---|---|---|
|
\(\text{I}_2(s) + 2e^- \rightleftharpoons 2\text{I}^-\) |
0.5355 |
| Iodine | E (V) | Eo ́ (V) |
|---|---|---|
|
\(\text{I}_3^- + 2e^- \rightleftharpoons 3\text{I}^-\) |
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 | E (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 | E (V) | Eo ́ (V) |
|---|---|---|
|
\(\text{La}^{3+} + 3e^- \rightleftharpoons \text{La}(s)\) |
–2.38 |
| Lead | E (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 | E (V) | Eo ́ (V) |
|---|---|---|
|
\(\text{Li}^+ + e^- \rightleftharpoons \text{Li}(s)\) |
–3.040 |
| Magnesium | E (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 | E (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 | E (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 |
| Mercury | E (V) | Eo ́ (V) |
|---|---|---|
|
\(\text{Hg}_2^{2+} + 2e^- \rightleftharpoons 2\text{Hg}(l)\) |
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 | E (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 | E (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 | E (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 | E (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 | E (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 | E (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 | E (V) | Eo ́ (V) |
|---|---|---|
|
\(\text{K}^+ + e^- \rightleftharpoons \text{K}(s)\) |
–2.924 |
| Ruthenium | E (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 | E (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 | E (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 | E (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 | E (V) | Eo ́ (V) |
|---|---|---|
|
\(\text{Na}^+ + e^- \rightleftharpoons \text{Na}(s)\) |
–2.713 |
| Strontium | E (V) | Eo ́ (V) |
|---|---|---|
|
\(\text{Sr}^{2+} + 2e^- \rightleftharpoons \text{Sr}(s)\) |
–2.89 |
| Sulfur | E (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 | E (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 | E (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 | E (V) | Eo ́ (V) |
|---|---|---|
|
\(\text{Ti}^{2+} + 2e^- \rightleftharpoons \text{Ti}(s)\) |
–0.163 |
|
|
\(\text{Ti}^{3+} + e^- \rightleftharpoons \text{Ti}^{2+}\) |
–0.37 |
| Tungsten | E (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 | E (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 | E (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 | E (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 |