Thermodynamics of dissociation of strontium, barium and nickel caproates in water

Abstract

The critical micellar concentration (CMC) and thermodynamic parameters (heat $Delta H_d$, free energy $Delta G_d$, and entropy $Delta S_d$, of dissociation) of aqueous solutions of strontium, barium and nickel caproates were determined by conductivity measurements. A Kraus and Bray-type expression was used to evaluate molecular conductance at infinite dilution and theromdynamic parameters. The results confirm that CMC remains unaffected by temperature in the range of $25-55^circ C$, and show that the dissociation of soaps is an exothermic reaction and nonspontaneous.