Title: thickness of reaction layer
Long Title: IUPAC Gold Book - thickness of reaction layer
DOI: 10.1351/goldbook.T06344
Status: current

Definition
When a kinetic current flows, the concentrations of the electroactive substance B and its precursor C at very small distances from the electrode surface are influenced both by mass transfer and by the finite rate of establishment of the chemical equilibrium. As the distance from the electrode surface increases, the chemical equilibrium is more and more nearly attained. The thickness of the reaction layer is the distance from the electrode surface beyond which deviations from the chemical equilibrium between C and B are taken to be negligibly small.

Related Terms
- chemical equilibrium: https://goldbook.iupac.org//terms/view/C01023
- electroactive substance: https://goldbook.iupac.org//terms/view/E01940
- kinetic current: https://goldbook.iupac.org//terms/view/K03399

Source
- PAC, 1985, 57, 1491. 'Recommended terms, symbols, and definitions for electroanalytical chemistry (Recommendations 1985)' on page 1504 (https://doi.org/10.1351/pac198557101491)

Other Outputs
- html: https://goldbook.iupac.org/terms/view/T06344/html
- json: https://goldbook.iupac.org/terms/view/T06344/json
- xml: https://goldbook.iupac.org/terms/view/T06344/xml

Citation: Citation: 'thickness of reaction layer' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. 10.1351/goldbook.T06344
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Accessed: 2026-04-18T11:05:44+00:00