A comparison of our electrolyte diffusion treatment with the conventional one

Abstract

We have now to compare our treatment of the mass flux, the electric current, and the excess mass and energy fluxes in inhomogeneous systems with the theory generally accepted and found in the literature1,2,3). We wish to give as simple an analysis as possible and therefore we consider a binary electrolyte-water system, for instance NaCl + H2O. Of course the NaCl concentration is not uniform throughout the system. In the conventional treatments the fluxes are the centre of interest, and thus we shall mainly discuss the interconnection between electric current density and mass flux on the one hand and the field properties determining the system on the other hand. Usually the mass fluxes are referred to the solvent fixed coordinate system and instead of the gradient of the solute particle density the gradient (or gradients) of the chemical potential are written in the equations. We assume that the electrodes in the conventional sense — if at all present — are remote and processes at the electrodes do not enter explicitly into the treatment. Comparison of the circumstances at the boundary metal/electrolyte will be postponed to the next chapter.