Osmotic and activity coefficients of { yNaH 2PO 4+(1− y)Na 2SO 4}(aq) at the temperature 298.15 K

Abstract

The osmotic coefficients of the mixed electrolyte solution { yNaH 2PO 4+(1− y)Na 2SO 4}(aq) have been measured by the isopiestic method, at the temperature T=298.15 K. The activity coefficients of NaH 2PO 4 and Na 2SO 4 were calculated by Scatchard's neutral-electrolyte method and by Pitzer and Kim's treatment for mixed-electrolyte solutions. The Scatchard interaction parameters are used for calculation of the excess Gibbs energy as a function of ionic strength and ionic-strength fraction of NaH 2PO 4. Also, the Zdanovskii's rule of linearity is tested.