Title: chronocoulometric constant
Long Title: IUPAC Gold Book - chronocoulometric constant
DOI: 10.1351/goldbook.09131
Status: current

Definition
Empirically-determined quantity defined by the equation \[{\cal Q} = (1/Ac)\Delta Q/\Delta (t^{1/2})\] where \(A\) is the electrode surface area, \(c\) is the bulk concentration of the electroactive substance, \(Q\) is the charge passed, and \(\Delta Q/\Delta(t^{1/2})\) is the slope of a plot of \(Q\) against \(t^{1/2}\).

Note
The SI unit of \(\cal Q\) is \(\pu{A s^{1/2} mol-1 m}\).

Related Term
- electrode surface area: https://goldbook.iupac.org/terms/view/09074

Source
- PAC, 2020, 92, 641. 'Terminology of Electrochemical Methods of Analysis (IUPAC Recommendations 2019)' on page 670 (https://doi.org/10.1515/pac-2018-0109)

Other Outputs
- html: https://goldbook.iupac.org/terms/view/09131/html
- json: https://goldbook.iupac.org/terms/view/09131/json
- xml: https://goldbook.iupac.org/terms/view/09131/xml

Citation: Citation: 'chronocoulometric constant' 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.09131
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Accessed: 2026-06-29T13:26:16+00:00