ISOPIESTIC STUDIES OF AQUEOUS-SOLUTIONS AT ELEVATED-TEMPERATURES .10. ((1-Y)NACL+YCSCL)(AQ)

The mixed electrolyte system {(1- y)NaCl + yCsCl}(aq) has been studied with the isopiestic technique over the temperature range 383.19-523.17 K. NaCl(aq) served as the reference electrolyte. The ion-interaction model, as applied to mixed electrolytes, gave an excellent description of the experimental results, requiring only a binary mixing parameter in addition to the pure electrolyte properties. As with previously studied mixtures of the alkali metal chlorides, the excess thermodynamic properties are relatively simple in that the mixing parameter is a linear function of reciprocal temperature. Relative behavior of the alkali metal chloride mixtures is independent of temperatures over the range of 298-523 K. All of the results are qualitatively consistent with the relative strength of the cation-water interaction involved. © 1990 American Chemical Society.