A 3-CHARACTERISTIC-PARAMETER CORRELATION MODEL FOR STRONG ELECTROLYTE-SOLUTIONS

In this study, a characteristic-parameter correlation model was develo ped for the aqueous strong electrolyte solutions. This correlation mod el consisted of the long-range ion-ion interaction described by Pitzer -Debye-Huckel model and short-range ion-solvent molecule interaction a ttributed to solvation effect. The proposed approach is based on our p revious paper of Lin et al. [C.-L. Lin, L.-S. Lee, H.-C.Tseng, Fluid P hase Equilibria, 90 (1993) 57-79.]. However, the significant improveme nt was made that the differential equation was solved analytically ins tead of numerically. This proposed model contains three parameters of physical significance and has been used to estimate the mean activity coefficients of electrolytes and osmotic coefficients of 144 aqueous s trong electrolyte solutions from literature. Comparisons were made to the models of Chen et al. [C.C. Chen, H.I. Britt, J.F. Boston, L.B. Ev ans, AIChE, 28 (1982) 588-596; C.C. Chen, L.B. Evans, AIChE, 32 (1986) 444-454.], Ananth and Ramachandran [M.S. Ananth, S. Ramachandran, AIC hE, 36 (1990) 370-386.], and Lin et al. [C.-L. Lin, L.-S. Lee, H.-C. T seng, Fluid Phase Equilibria, 90 (1993) 57-79.]. The results also show ed that the present model is at least as good as above models for 1-1 and 1-2 electrolyte solutions and improved very much for 2-1, 2-2, 3-1 , and 3-2 electrolyte solutions. (C) 1998 Elsevier Science B.V. All ri ghts reserved.