Studies on thermodynamics of solution of scattered metal compounds I. The system of HCl+GaCl3+H2O

Activity coefficients of HCl in HCl+ GaCl3 + H2O at 5 different temperature s from 278. 15 to 318.15 K have been determined at total ionic strengths fr om 0.4 to 1.5 mol/kg using a cell of the type: Pt \H-2(101.325 kPa)\ HCl(m(A)), GaCl3(m(B)),H2O \ IAgCl \ Ag (A) The results for the 150 experimental emf data points have been used to dete rmine the variation of the activity coefficients of HCl with the change in molality of GaCl3 in the solution. It is found that the linear form of flam ed's rule is obeyed for HCl. Besides the ion - interaction model (Pitzer's electrolyte solution theory) has been applied to this system, the Pitzer's parameters of GaCl3: (beta ((0))(Ga,Cl) + theta (Ga,H)), beta (1)(Ga,Cl), C -Ga,C-Cl, Psi (Ga,H,Cl) Were obtained by the method of least squares. Accor ding to Yang and Fitter, the mixing parametes, theta (Ga,H) and beta ((0))( Ga,Cl) are obtained in terms of flamed coefficient of HCl, alpha (a), from the value of (beta ((0))(Ga,Cl) + theta (Ga,H)). The activity coefficients of GaCl3 in the system are calculated using Fitter equation. It is found th at the extensive Hamed equation is obeyed for GaCl3.