Warburg coefficient
The Warburg coefficient (or Warburg constant; denoted AWScript error: No such module "Check for unknown parameters". or Template:Mvar) is the diffusion coefficient of ions in solution, associated to the Warburg element, ZWScript error: No such module "Check for unknown parameters".. The Warburg coefficient has units of
The value of AWScript error: No such module "Check for unknown parameters". can be obtained by the gradient of the Warburg plot, a linear plot of the real impedance (Template:Mvar) against the reciprocal of the square root of the frequency (). This relation should always yield a straight line, as it is unique for a Warburg.
Alternatively, the value of AWScript error: No such module "Check for unknown parameters". can be found by:
where
- Template:Mvar is the ideal gas constant;
- Template:Mvar is the thermodynamic temperature;
- Template:Mvar is the Faraday constant;
- Template:Mvar is the valency;
- Template:Mvar is the diffusion coefficient of the species, where subscripts OScript error: No such module "Check for unknown parameters". and RScript error: No such module "Check for unknown parameters". stand for the oxidized and reduced species respectively;
- Template:Mvar is the concentration of the OScript error: No such module "Check for unknown parameters". and RScript error: No such module "Check for unknown parameters". species in the bulk;
- Template:Mvar is the concentration of the electrolyte;
- Template:Mvar denotes the surface area;
- ΘScript error: No such module "Check for unknown parameters". denotes the fraction of the OScript error: No such module "Check for unknown parameters". and RScript error: No such module "Check for unknown parameters". species present.
The equation for AWScript error: No such module "Check for unknown parameters". applies to both reversible and quasi-reversible reactions for which both halves of the couple are soluble.
References
- Script error: No such module "citation/CS1".