Modeling of the Ternary NH₄Cl + ROH + Water Electrolyte Systems (with R = Me, Et, 1-Pr, and 2-Pr) by the Pitzer−Simonson−Clegg Approach and Its Modified Forms

Abstract

Literature data on electrolyte modeling in nonaqueous and in mixed solvent systems are still relatively scarce. In addition, contrary to the currently used Pitzer ion-interaction approach, modeling of the ternary systems containing electrolyte, nonelectrolyte, and water by the more refined Pitzer−Simonson−Clegg (PSC) ion-interaction approach is limited only to the work of three research groups. In this context, we have recently reported the use of Pitzer and Pitzer−Simonson−Clegg (PSC) ion-interaction approaches for modeling the ternary HCl + ROH + water electrolyte systems (with R = Me, Et, 1-Pr, and 2-Pr). The present investigation describes also the results obtained by the application of the simplified PSC, original PSC, and previously reported modified PSC, as well as another proposed modified PSC approach (presented in this work), for modeling the nonideal behavior of the ternary NH4Cl + ROH + water mixture. The calculations were achieved based on the experimental potentiometric data previously obtained in our laboratory. Accordingly, the present calculations were performed for NH4Cl electrolyte molalities ranging from 0.01 up to about 4 mol·kg−1 in several alcohols (ROH) with different percent mass fractions, x = (10, 20, 30, 40, and 50) %, for R = Me, Et, 1-Pr, and up to 30 % for 2-Pr, at (298.15 ± 0.05) K.