The equations developed by us for the triple layer surface complexation approach, taking into account energetic heterogeneity of surface oxygens, are applied here to study the heterogeneity influences on the enthalpic effects accompanying ion adsorption at the silica/NaCl aqueous solution interface. That study is accompanied by the parallel experimental/theoretical study of the energetic heterogeneity of surface oxygens for adsorption of argon molecules which are known to interact practically only with surface oxygens. Such studies provide a simpler interpretation for information of the surface energetic heterogeneity. That additional study confirms a proper choice of the model of surface heterogeneity, accepted by us in our description of ion adsorption at the oxide/electrolyte interfaces. Our quantitative analysis also confirms quite different features of the silica/electrolyte interface, compared to those formed by other metal oxides. Namely, in the case of the silica/electrolyte interface, the adsorption of water molecules on the surface oxygens SO- is a process highly competitive with proton adsorption leading to that of formation of the neutral surface complexes SOHO.