Measurement and Modeling of Mean Activity Coefficients in Ternary Electrolyte System (Nicl2/Triton X-100/H2O) at T=298.15 ± 0.1 K

In this work, the results relating to the thermodynamic properties of 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 a 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 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 the Pitzer ion interaction model and TCPC model. The Pitzer ion-interaction parameters (βo, β1 and CØ) and the adjustable parameters (b and S) of TCPC model were determined by correlating data for the series under-investigated system. The Pitzer ion interaction parameters were used to calculate thermodynamic properties such as the osmotic coefficients and the excess Gibbs energy of the solution. The result showed that the Pitzer ion interaction model could be used to investigate the system, successfully.