The
electrode reaction rate constants are related to the partial currents by
where
and
are the rate constants for the oxidizing (anodic) and reducing (cathodic) reactions
respectively,
is the
charge number of the cell reaction,
is the
Faraday constant
and
is the geometric area of the electrode,
the product
includes all the species
which take part in the partial reaction,
is the volume concentration of species
and
is the order of the reaction with respect to species
.
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
the transfer
coefficient is independent of potential,
where
and
are the anodic and cathodic transfer coefficients respectively,
is the
electric potential difference,
is the
conditional (formal) potential,
is the
stoichiometric number,
is the
gas constant
and
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.
Source:
PAC, 1980, 52, 233
(Electrode reaction orders, transfer coefficients and rate constants. Amplification
of definitions and recommendations for publication of parameters)
on page 236
Cite as:
IUPAC. Compendium of Chemical Terminology, 2nd ed. (the "Gold Book"). Compiled by
A. D. McNaught and A. Wilkinson. Blackwell Scientific Publications, Oxford (1997).
XML on-line corrected version: http://goldbook.iupac.org (2006-) created by M. Nic,
J. Jirat, B. Kosata; updates compiled by A. Jenkins. ISBN 0-9678550-9-8.
https://doi.org/10.1351/goldbook.