DETERMINATION OF THERMODYNAMIC PROPERTIES IN AQUEOUS BINARY AND TERNARY ELECTROLYTE MIXTURES (ACTIVITIES COEFFICIENTS).

摘要

The understanding of the thermodynamic behavior of mixed electrolyte solutions is of fundamental importance in the study of chemistry and biochemistry, and may also lead to the development of important industrial processes.; A method has been developed to determine the contributions to the excess free energies of mixing due to pair, triplet and other higher order multiplet interactions if indeed such interactions occur in the mixed solution. This makes the assumption that the excess free energy of mixing is due solely to pairwise interactions unnecessary.; Osmotic coefficient data were obtained for the CdCl(,2)-ZnCl(,2)-H(,2)O system at 25(DEGREES)C and for the tetra n-butylammonium chloride-sodium chloride-water system at 25 and 60(DEGREES)C using a gravimetric isopiestic technique. These data, along with the EMF data reported by Leifer, Argersinger and Davidson for the CdCl(,2)-HCl-H(,2)O system at 25(DEGREES)C, were analyzed using modified Scatchard-Rush-Johnson (SRJ) equations. The osmotic coefficients, the activity coefficients of each solute component, the total excess free energies of mixing and the contributions to the excess free energies of mixing due to the various types of interactions occurring in the solution are determined over the entire range of ionic strength fraction and over a wide range of total ionic strengths. Friedman's interaction parameters were also determined as a function of total ionic strength.; This work demonstrates the importance of taking account of higher order multiplet interactions in ternary systems which exhibit complex behavior.