Solubilities and activity coefficients of silver sulphate in certain salt solutions

The Experimental Determination of Solubilities.

“…Generally a most satisfactory criterion of saturation is the observation that the system has reached a stable condition. Thus the attainment of a constant electrical potential (179) or a constant conductivity ( 20) is often useful in isosystic studies, while in many analytic determinations the fact that repeated analyses of the solution give constant results is frequently employed (36,44,181). In any case, the law governing the approach to saturation is necessarily a simple exponential one (1), whose parameters are determined by both the nature of the system and the temperature at which the study is made (136,191).…”

“…Among the filter media which one finds mentioned in the literature are cloth fabrics (68,190,195), cotton plugs (43), asbestos (92, 131), glass wool (12, 48,77,174), and mixed glass wool and cotton ( 236), all of which should be incorporated into removable filter tips for removal after the filtration is complete in order to obtain best results (25,194). In addition, filtration through an alundum disk has been found useful in studies of solubilities at very high pressures (191), while sintered-glass filters have also been used for filtration under pressure (36,70,136), in one case the filter having been made an integral part of the solubility cell by fusing it into the bottom of the vessel (155). The chief difficulty encountered with sintered filters is found in the removal of highly divided (colloidal-type) solids, but this trouble is common to most filter systems (70).…”

“…Chloupek and Danes (36) have designed a special pipet to facilitate this rejection by incorporating in the lower stem a bulb to receive the first few milliliters of solution withdrawn. When solubilities are studied at somewhat elevated temperatures, it is often necessary to take special precautions to avoid troublesome precipitations of solute during and immediately after sampling.…”

The Solution Thermochemistry of Polyvalent Electrolytes. II. Silver Sulfate

“…II. Silver Sulfate by Harry P. Hopkins, Jr., and Claus A. Wulff Department of Chemistry, Carnegie Institute of Technology, Pittsburgh, Pennsylvania (Received September 5,1964) Values for the thermodynamic functions characterizing the solution of silver sulfate have been obtained by utilizing data from the literature and newly determined values for the enthalpy of solution. It has been shown that previous evaluations of these quantities are in error, partially because of nonconsideration of the "weak" second ionization step.…”