Measurement and Modeling of Mean Ionic Activity Coefficient in Aqueous Solution Containing NaNO3 and Poly Ethylene Glycol

Abstract

<em>Potentiometric investigation on {H₂O+NaNO₃+PEG1500} mixtures were made at T=308.15K, using electrochemical cells with two ion-selective electrodes, (Na⁺ glass) as the cation ion-selective electrode against (NO₃^-solvent-polymer PVC) as the anion ion-selective electrode. The mean ionic activity coefficients of NaNO₃ were measured at different concentrations of NaNO₃ and PEG. Maximum concentration of electrolyte and PEG were 1 mol/kg and 0.12 mol/kg, respectively. The experimental data was modeled by utilizing the modified Pitzer equation and the activity coefficient ratio of PEG was evaluated by using Maxwell's cross differential relation. </em><em></em>