Emf measurements were made on the cell without liquid junction: Pt;H2(g,1 atm)|HCl(m1),CoCl2(m2)|AgCl,Ag (A). Activity coefficients of HCl and CoCl2 for the system H+-Co2+-Cl--H2O have been investigated at temperatures ranging from 278.15 to 318.15 K at 10 K intervals and at constant total ionic strengths from 0.1 to 4.0 mol kg-1. The results have been interpreted using Harned's empirical equations and the comprehensive treatment of Pitzer, including the contributions of higher order electrostatic terms. The Pitzer mixing parameters SθH,Co and ψH,Co,Cl as well as the temperature derivatives of the mixing coefficients have been well represented by linear equations. These results may be used to calculate the relative apparent molal enthalpy for H+, Co2+, and Cl- aqueous solutions. The activity coefficients and excess enthalpies for HCl and CoCl2 are reported at 298.15 K.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry