Extension of a model for solutions of non-metals in liquid alkali-metals; calculation of the enthalpy of solution

Abstract

An extension to a previously proposed model for the solution of non-metals as negative ions in liquid alkali-metals is obtained by introducing an extra term representing the direct Coulomb interaction between the dissolved ions and the metal ion cores. A method for calculating this interaction for screened potentials around the ions in a free-electron gas using the Fourier convolution theorem is given.

The results of this calculation show in most cases an improved agreement with the experimental values, in particular for fluorine and oxygen. Only in the case of solutions in sodium did the agreement not improve. Possible explanations for this behaviour are proposed.