Term: isotope effect
https://doi.org/10.1351/goldbook.I03327

Definition:
The effect on the rate or equilibrium constant of two reactions that differ only in the isotopic composition of one or more of their otherwise chemically identical components is referred to as a kinetic isotope effect or a thermodynamic (or equilibrium) isotope effect, respectively.

Related Terms:
1) equilibrium constant (http://doi.org/10.1351/goldbook.E02177).
2) kinetic isotope effect (http://doi.org/10.1351/goldbook.K03405).
3) thermodynamic (http://doi.org/10.1351/goldbook.T06319).

Source: PAC, 1994, 66, 1077. 'Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994)' on page 1130 (https://doi.org/10.1351/pac199466051077)

Citation: 'isotope effect' 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.I03327

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