Standard Electrode Potentials for Oxidation and Reduction Reactions

Some Standard Reduction Potentials Oxidants   Reductants E0 (volts) Weakest Oxidant K++e K(s) -2.94 Strongest Reductant ↓ Ba2++2e Ba(s) -2.91 ↑ ↓ Ca2++2e Ca(s) -2.87 ↑ ↓ Na++e Na(s) -2.71 ↑ ↓ Mg2++2e Mg(s) -2.36 ↑ ↓ Al3++3e Al(s) -1.68 ↑ ↓ Mn2++2e Mn(s) -1.18 ↑ ↓ Zn2++2e Zn(s) -0.76 ↑ ↓ Fe2++2e Fe(s) -0.44 ↑ ↓ Ni2++2e Ni(s) -0.24 ↑ ↓ Sn2++2e Sn(s) -0.14 ↑ ↓ Pb2++2e Pb(s) -0.13 ↑ ↓ H++e ½H2(g) 0.00 ↑ ↓ Cu2++2e Cu(s) 0.34 ↑ ↓ Cu++e Cu(s) 0.52 ↑ ↓ ½I2(s)+e I- 0.54 ↑ ↓ ½I2(aq)+e I- 0.62 ↑ ↓ Fe3++e Fe2+ 0.77 ↑ ↓ Ag++e Ag(s) 0.80 ↑ ↓ ½Br2(l)+e Br- 1.08 ↑ ↓ ½Br2(aq)+e Br- 1.10 ↑ ↓ ½Cl2(g)+e Cl- 1.36 ↑ ↓ ½Cl2(aq)+e Cl- 1.40 ↑ Strongest Oxidant ½F2(g)+e F- 2.89 Weakest Reductant

Key Concepts A standard electrode potential* is a measure of the energy per electron in a given reaction. Eo is the symbol used for standard electrode potentials.** Eo is measured in volts (V). Values of standard electrode potentials are tabulated for reactions in which the reactants and products are in their standard states. Tables of Eo values are given for the reduction reaction Tabulated Eo values are referred to as standard reduction potentials, standard electrode potentials, standard redox potentials or, standard potentials. Eo for the oxidation reaction has the opposite sign to the Eo value for the reduction reaction. Eo values do not change if we change the stoichiometric coefficients of the reactants and products.

Examples: Determining the Standard Electrode Potential (E^o) for Oxidation and Reduction Reactions

AUS-e-TUTE Membership Advantages

^*If the reactants and products are not in their standard states, we use the term reduction potential, electrode potential, or redox potential.

^**If the reactants and products are not in their standard states, we use the symbol E.

^#The standard state for an ion in solution is the one for which the activity of the ion is defined as unity. For an ideal solution this occurs when its concentration is 1M

If the concentration of a solution is not 1M, you can use the Nernst Equation to find the value of E.

Search this Site

Subscribe to our Free Newsletter

AUS-e-NEWS is emailed out in
December, March, June, and September.

Ask Chris, the Chemist, a Question

Chris can also send you to the relevant
AUS-e-TUTE tutorial topic page.

Related AUS-e-TUTE Topics

Oxidation Numbers (States)

Displacement Reactions (Activity Series)

Calculating Electrochemical Cell EMF (voltage)

Corrosion

Electrolytic Cells

Writing cell half-equations

Faraday Laws of Electrolysis

Batteries

Fuel Cells

Nernst Equation

Become an AUS-e-TUTE Member

Bookmark AUS-e-TUTE