SURFACE DISSOCIATION-CONSTANTS FOR SOLID OXIDE AQUEOUS SOLUTION SYSTEMS

An equation for the surface potential ψ0 was used to define the surface dissociation constant of surface hydroxyls at a solid oxide/aqueous solution interface. Using the measurements of the surface charge, the Gouy-Chapman theory and crystallo-chemical data for oxides, the calculations of the surface dissociation constants have been carried out. The values of the acidic surface dissociation constants (in minus logarithmic scale) fall in range 8.7±0.8 at ionic strength 1 M and in the range 7.2±0.7 at 10-3 M KNO3 These constants exceed by 2 to 5 orders of magnitude the dissociation constants of M(OH)naq species in solution. © 1979 Dr. Dietrich Steinkopff Verlag.