{"term":{"id":"01961","doi":"10.1351\/goldbook.E01961","code":"E01961","status":"current","longtitle":"IUPAC Gold Book - electrode reaction rate constants","title":"electrode reaction rate constants","contains":"conditional rate constant of an electrode reaction, standard rate constant of an electrode reaction","termversion":"2.3.3","lastupdated":"2014-02-24","definitions":[{"id":"1","text":"The electrode reaction rate constants are related to the partial currents by kox = la\/n.F.A.Π.ci^νi and kred are the rate constants for the oxidizing (anodic) and reducing (cathodic) reactions respectively, n is the charge number of the cell reaction, F is the Faraday constant and A is the geometric area of the electrode, the product Π c i ν i includes all the species i which take part in the partial reaction, ci is the volume concentration of species i and ν i is the order of the reaction with respect to species i. The conditional rate constant of an electrode reaction is the value of the electrode reactionrate constant at the conditional (formal) potential of the electrode reaction. When α the transfer coefficient is independent of potential, kc = kox\/(e^(αc(E - Ec0').n.F\/ν.R.T)) = kred\/(e^(-αa(E - Ec0').n.F\/ν.R.T)) and αc are the anodic and cathodic transfer coefficients respectively, E is the electric potential difference, E c is the conditional (formal) potential, ν is the stoichiometric number, R is the gas constant and T is the thermodynamic temperature. Similar rate constants can be defined using activities in place of concen trations in the first two equations, and the standard electrode potential in place of the conditional potential in the latter two equations. This type of rate constant is called the standard rate constant of the electrode reaction. The observable electrode rate constant is the constant of proportionality expressing the dependence of the rate of the electrode reaction on the interfacial concentration of the chemical species involved in the reaction.","links":[{"title":"electrode reaction","type":"goldify","url":"https:\/\/dev.goldbook.iupac.org\/terms\/view\/E01960"},{"title":"charge number","type":"goldify","url":"https:\/\/dev.goldbook.iupac.org\/terms\/view\/C00993"},{"title":"Faraday constant","type":"goldify","url":"https:\/\/dev.goldbook.iupac.org\/terms\/view\/F02325"},{"title":"rate constant","type":"goldify","url":"https:\/\/dev.goldbook.iupac.org\/terms\/view\/O04322"},{"title":"coefficient","type":"goldify","url":"https:\/\/dev.goldbook.iupac.org\/terms\/view\/C01124"},{"title":"electric potential","type":"goldify","url":"https:\/\/dev.goldbook.iupac.org\/terms\/view\/E01935"},{"title":"conditional (formal) potential","type":"goldify","url":"https:\/\/dev.goldbook.iupac.org\/terms\/view\/C01240"},{"title":"gas constant","type":"goldify","url":"https:\/\/dev.goldbook.iupac.org\/terms\/view\/G02579"},{"title":"thermodynamic temperature","type":"goldify","url":"https:\/\/dev.goldbook.iupac.org\/terms\/view\/T06321"},{"title":"standard electrode potential","type":"goldify","url":"https:\/\/dev.goldbook.iupac.org\/terms\/view\/S05912"},{"title":"stoichiometric number","type":"internal","url":"https:\/\/dev.goldbook.iupac.org\/terms\/view\/S06025"},{"title":"interfacial concentration (in electrochemistry)","type":"internal","url":"https:\/\/dev.goldbook.iupac.org\/terms\/view\/I03083"}],"math":[{"meaning":"Oxidizing reaction rate constant","type":"equation","alttext":"kox = la\/n.F.A.Π.ci^νi","latex":"k_{\\mathrm{ox}}=\\frac{l_{\\text{a}}}{n\\ F\\ A\\ \\Pi\\: c_{i}^{\\nu _{i}}}"},{"meaning":"Reducing reaction rate constant","type":"equation","alttext":"kred = lc\/(n.F.A.Π.ci^νi)","latex":"k_{\\mathrm{red}}=\\frac{l_{\\text{c}}}{n\\ F\\ A\\ \\Pi\\:c_{i}^{\\nu _{i}}}"},{"meaning":"Oxidizing reaction rate constant","type":"quantity","alttext":"kox","latex":"k_{\\mathrm{ox}}"},{"meaning":"Reducing reaction rate constant","type":"quantity","alttext":"kred","latex":"k_{\\mathrm{red}}"},{"alttext":"n","latex":"n"},{"alttext":"F","latex":"F"},{"alttext":"A","latex":"A"},{"alttext":"Π c i ν i","latex":"\\Pi\\:c_{i}^{\\nu _{i}}"},{"alttext":"i","latex":"i"},{"alttext":"ci","latex":"c_{i}"},{"alttext":"i","latex":"i"},{"alttext":"ν i","latex":"\\nu _{i}"},{"alttext":"i","latex":"i"},{"type":"symbol","alttext":"α","latex":"\\alpha "},{"meaning":"Conditional rate constants (at electrodes)","type":"equation","alttext":"kc = kox\/(e^(αc(E - Ec0').n.F\/ν.R.T)) = kred\/(e^(-αa(E - Ec0').n.F\/ν.R.T))","latex":"k_{\\text{c}} = \\frac{k_{\\text{ox}}}{\\text{e}^{\\frac{\\alpha _{\\text{a}}\\ (E- E_{\\text{c}}^{0'})\\ n\\ F}{\\nu \\ R\\ T}}} = \\frac{k_{\\text{red}}}{\\text{e}^{\\frac{-\\alpha _{\\text{c}}\\ (E- E_{\\text{c}}^{0'})\\ n\\ F}{\\nu \\ R\\ T}}}"},{"type":"symbol","alttext":"αa","latex":"\\alpha _{\\text{a}}"},{"alttext":"αc","latex":"\\alpha _{\\text{c}}"},{"alttext":"E","latex":"E"},{"alttext":"E c","latex":"E_{\\text{c}}"},{"alttext":"ν","latex":"\\nu "},{"alttext":"R","latex":"R"},{"alttext":"T","latex":"T"}],"sources":["PAC, 1974, 37, 499. 'Electrochemical nomenclature' on page 515 (https:\/\/doi.org\/10.1351\/pac197437040499)","PAC, 1980, 52, 233. 'Electrode Reaction Orders, Transfer Coefficients and Rate Constants. Amplification of Definitions and Recommendations for Publication of Parameters' on page 236 (https:\/\/doi.org\/10.1351\/pac198052010233)"]}],"links":{"html":"https:\/\/dev.goldbook.iupac.org\/terms\/view\/E01961\/html","json":"https:\/\/dev.goldbook.iupac.org\/terms\/view\/E01961\/json","xml":"https:\/\/dev.goldbook.iupac.org\/terms\/view\/E01961\/xml","plain":"https:\/\/dev.goldbook.iupac.org\/terms\/view\/E01961\/plain","pdf":"https:\/\/dev.goldbook.iupac.org\/terms\/view\/E01961\/pdf"},"citation":"Citation: 'electrode reaction rate constants' in IUPAC Compendium of Chemical Terminology, 3rd ed. International Union of Pure and Applied Chemistry; 2006. Online version 3.0.1, 2019. 10.1351\/goldbook.E01961","license":"The IUPAC Gold Book is licensed under Creative Commons Attribution-ShareAlike CC BY-SA 4.0 International (https:\/\/creativecommons.org\/licenses\/by-sa\/4.0\/) for individual terms.","collection":"If you are interested in licensing the Gold Book for commercial use, please contact the IUPAC Executive Director at executivedirector@iupac.org .","disclaimer":"The International Union of Pure and Applied Chemistry (IUPAC) is continuously reviewing and, where needed, updating terms in the Compendium of Chemical Terminology (the IUPAC Gold Book). Users of these terms are encouraged to include the version of a term with its use and to check regularly for updates to term definitions that you are using.","accessed":"2023-12-06T04:17:03+00:00"}}