Calculation of thermodynamic acid-base equilibrium constants at oxide-electrolyte interfaces from experimental electrokinetic potential versus pH data

A procedure is described for determining the parameters of the electrical double layer and acid-base equilibrium constants at oxide-electrolyte interfaces from the pH dependence of the electrokinetic potential when there is no specific adsorption of ions. The procedure is used to calculate the parameters of the electrical double layer and acid-base equilibrium constants for 20 oxides. At a given background electrolyte concentration, the dependence of the calculated parameters on the difference pH - pH(0) is insensitive to the nature of the oxide