OBSERVABLE ELECTRIC-POTENTIAL IN NONEQUILIBRIUM ELECTROLYTE-SOLUTIONSWITH A COMMON ION

The electric potential in a nonequilibrium electrolyte solution with a common ion is studied. We have used an observable electric potential (that measured in the metallic phase of an electrode in equilibrium wi th the solution) instead of the unmeasurable electric potential usuall y invoked. The phenomenological equations deduced from the dissipation function of irreversible thermodynamics describe the system in a prec ise, clear, and simple manner when we consider this observable electri c potential. An interesting property of this formalism is the distinct ion between distribution equilibrium and electric equilibrium. The phe nomenological coefficients are related to well-known variables such as the specific electric conductance, transference numbers, and diffusio n coefficients. The utility of this new formalism is shown by evaluati ng the profile of the electric potential in a liquid junction.