Measurement and modeling of mean activity coefficients in ternary electrolyte system (Nicl2/Triton X-100/H2O) at T=298.15 ± 0.1 K

Abstract

In this work, the results relating to the thermodynamic properties for the ternary electrolyte system of (NiCl2 + Triton X-100 + water) using the potentiometric method were reported at T = 298.15 K. The electromotive force measurements were carried out on the galvanic cell without liquid junction of the type: Ni2+-ISE | NiCl2 (m), Triton X-100 (%wt.), H2O (100-%wt.) | AgCl|Ag over total ionic strengths from 0.0010 to 6.0000 mol.kg-1 for different percentage mass fraction of Triton X-100 (%wt. = 0.0, 1.0, 2.5, 5.0, 7.5 and 10.0). The mean activity coefficients of NiCl2 were determined by using potentiometric data. Then, the mean activity coefficients of NiCl2 were correlated with Pitzer ion interaction model and TCPC model. The Pitzer ion-interaction parameters (βo, β1 and C^∅) and the adjustable parameters (b and S) of TCPC model were determined by correlating of data for the series under investigated system. The Pitzer ion interaction parameters were used to calculating of thermodynamic properties such as the osmotic coefficients and the excess Gibbs energy of solution. The result showed that the Pitzer ion interaction model could be used to investigation of the system, successfully.