Emf studies of a ternary molten AgNO 3KNO 3NaNO 3 system

Abstract

The excess chemical potentials of AgNO 3 have been measured using a suitable formation cell over a wide composition range of the ternary AgNO 3KNO 3NaNO 3 system. The coefficients of series expansions in the composition variables of ▪ and x AgNO 3 for isothermal excess chemical potential of AgNO 3 were determined. The experimental data show a minimum at t = 0.500 for all the temperatures and mole fractions of silver nitrate. Such an anomalous phenomenon in a ternary AgNO 3KNO 3NaNO 3 molten system is explained on the basis of the behavior of the subsidiary binary systems, as well as by change in the quasi-lattice structure of the melt, as a consequence of increasing the mole fraction of AgNO 3 in the mixture. The conformal ionic solution (CIS) theory has been tested with respect to its capability to predict the excess chemical potential in a ternary AgNO 3KNO 3NaNO 3 molten system. From the linear temperature dependence of emf values in pure AgNO 3 and in ternary molten salt mixtures, the partial excess enthalpies and partial excess entropies of silver nitrate in the AgNO 3KNO 3NaNO 3 melts were calculated.