Osmotic and activity coefficient investigation on the CsNO3 + methanol + water and CsNO3 + ethanol + water ternary systems at 298.15 K

Abstract

The mean ionic activity and osmotic coefficients of CsNO3 in methanol–water and ethanol–water mixed solvent at 298.15K have been determined herein utilizing the potentiometric method. The potential measurements were carried out on a cell, Cs-ISE/CsNO3 (m), ROH (w), H2O (1−w)/NO3-ISE, in the mixed solvent containing w=(0.00, 0.10, 0.20, and 0.30) mass fraction of alcohol. The activity coefficients were calculated from the experimental E value and fitted via the extended Debye–Hückel, Pitzer and the modified Pitzer model equations. The osmotic coefficients, the primary hydration number (nhydr), excess Gibbs free energy and standard Gibbs energies of transference of CsNO3 from the water to the methanol+water or ethanol+water mixtures have also been discussed.