Thermogalvanic Cells: Equations for Special States and Ionic Mobilities

Abstract

Linear phenomenological equations for processes in thermogalvanic cells are set up in two forms. One form is used for examining the nature of six special states: the thermal and shorted initial states, and the isothermal, thermal, shorted, and adiabatic steady states. With aqueous electrolytes the following are predicted: a large variation in the Soret effect and a moderate variation in the Peltier heat with changes in electrical state; a difference between electrical and thermal transference numbers; and a small temperature gradient set up by the flow of current under adiabatic conditions. The other form of the equations is used for examining the mobility of ions in a thermal field and a comparison with the mobility in an electrical field or a concentration gradient. Introduction of electrostatic potential as a variable suggests a way of measuring thermodynamic properties of individual ions.