CONSISTENCY OF THE CONTINUOUS MODEL OF THE DIFFUSE LAYER WITH THE GIBBS ADSORPTION EQUATION

A continuous model of the diffuse layer (DL), which accounts for nonid eal nature of electrolytes and nonspecific adsorption of solvent molec ules in DL, is analyzed. The model is based on two traditional tin ter ms of the Gouy-Chapman model) requirements: (a) the source for a unidi mensional field of electric induction is the electric charges of ions and (b) the electrochemical potential of any particle is the same in a ny point within DL. The conditions are found at which the continuous m odel of DL is consistent with the Gibbs adsorption equation not only i n first order by the electrode charge, but in second order as well. Th e form of these conditions testifies that the equations of local therm odynamics may apply to DL, at least near the potential of zero charge.