The Temperature Coefficients of Electrode Potentials

The temperature coefficient of the potential of an electrode can be defined experimentally by reference to (a) the potential of the SHE at the same temperature, (b) the potential of the same electrode at some fixed temperature. These two definitions give rise to the "isothermal" and "thermal" temperature coefficients of electrode potentials. The isothermal coefficient is where ΔS is the reaction entropy of the "SHE//Electrode" cell. The thermal coefficient is where is the entropy transported from the hot to the cold heat reservoir by the passage of n faradays of positive electricity through the cell from the cold to the hot electrode (before the onset of thermal diffusion). The entropy is divided into an entropy of electrochemical transport which determines the electrode temperature effect, and an entropy of migration transport which determines the thermal liquid junction potential.