The Representation of Electrical Conductances for Polyvalent Electrolytes by the Quint–Viallard Conductivity Equation

Abstract

Electrical conductivities of dilute aqueous solutions of aluminum sulfate were determined and analyzed in terms of a strongly associated electrolyte of the 3:2 type. The conductivities reported here were determined from 15 to 35 °C. Representation of conductances, in the framework of the ion association model, was performed using the Quint–Viallard conductivity equations for highly charged electrolytes and the Debye–Huckel expression for activity coefficients. Determined apparent association constants K a(T) were considered as adjustable parameters. The determined limiting conductances of the trivalent aluminum ion λ0((1/3)Al3+) are considerably higher than those reported in the literature. Available specific conductivities in concentrated aqueous solutions of aluminum sulfate were fitted by a new empirical equation with only three adjustable parameters.