THE ADSORPTION OF ARGON ON SOME VACUUM DEHYDRATED SALTS

Abstract

Isotherms for the adsorption of argon on amorphous products formed by the vacuum dehydration of several hydrated salts have been determined. These have shown that the adsorption is physical and that dehydration results in the formation of products of large capillary volume. The probable distribution of capillary diameters has been estimated and correlated with the effect of water vapor at low pressures in catalyzing the crystallization of the amorphous intermediates. Consideration of these findings, in the light of data for the heats of transition from the amorphous to the crystalline state, suggests that the X-ray amorphous character is not entirely due to the capillary structure but that other changes occur. The possible nature of these is discussed.