Term: redox potential
https://doi.org/10.1351/goldbook.RT06783

Definition:
Any oxidation-reduction (redox) reaction can be divided into two half-reactions: one in which a chemical species undergoes oxidation and one in which another chemical species undergoes reduction. If a half-reaction is written as a reduction, the driving force is the reduction potential. If the half-reaction is written as oxidation, the driving force is the oxidation potential related to the reduction potential by a sign change. So the redox potential is the reduction/oxidation potential of a compound measured under standards conditions against a standard reference half-cell. In biological systems the standard redox potential is defined at pH – 7.0 versus the hydrogen electrode and partial pressure of hydrogen = 1 bar.

Related Terms:
1) electrode potential (http://doi.org/10.1351/goldbook.E01956).
2) oxidation (http://doi.org/10.1351/goldbook.O04362).
3) partial pressure (http://doi.org/10.1351/goldbook.P04420).
4) bar (http://doi.org/10.1351/goldbook.B00596).

Source: PAC, 1997, 69, 1251. 'Glossary of terms used in bioinorganic chemistry (IUPAC Recommendations 1997)' on page 1294 (https://doi.org/10.1351/pac199769061251)

Citation: 'redox potential' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. https://doi.org/10.1351/goldbook.RT06783

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