Preferred Label : electrode reaction rate constants;
IUPAC definition : The electrode reaction rate constants are related to the partial currents by \[k_{\mathrm{ox}}
\frac{l_{{a}}}{n\ F\ A\ \Pi\: c_{i} {\nu _{i}}}\] \[k_{\mathrm{red}} \frac{l_{{c}}}{n\
F\ A\ \Pi\:c_{i} {\nu _{i}}}\] where kox 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 reaction rate constant at the conditional (formal) potential
of the electrode reaction. When α the transfer coefficient is independent of potential,
\[k_{{c}} \frac{k_{{ox}}}{{e} {\frac{\alpha _{{a}}\ (E- E_{{c}} {0'})\ n\ F}{\nu
\ R\ T}}} \frac{k_{{red}}}{{e} {\frac{-\alpha _{{c}}\ (E- E_{{c}} {0'})\ n\ F}{\nu
\ R\ T}}}\] where αa 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 concentrations
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.;
Origin ID : E01961;
See also
The electrode reaction rate constants are related to the partial currents by \[k_{\mathrm{ox}}
\frac{l_{{a}}}{n\ F\ A\ \Pi\: c_{i} {\nu _{i}}}\] \[k_{\mathrm{red}} \frac{l_{{c}}}{n\
F\ A\ \Pi\:c_{i} {\nu _{i}}}\] where kox 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 reaction rate constant at the conditional (formal) potential
of the electrode reaction. When α the transfer coefficient is independent of potential,
\[k_{{c}} \frac{k_{{ox}}}{{e} {\frac{\alpha _{{a}}\ (E- E_{{c}} {0'})\ n\ F}{\nu
\ R\ T}}} \frac{k_{{red}}}{{e} {\frac{-\alpha _{{c}}\ (E- E_{{c}} {0'})\ n\ F}{\nu
\ R\ T}}}\] where αa 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 concentrations
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.
