Activity of Zinc and Cadmium in Liquid Solutions of Cd-Sb and Zn-Sb.

In order to determine the thermodynamic properties of cadmium-antimony and zinc-antimony liquid solutions, the authors employed a method of measuring electromotive forces of concentration cells in which the reference electrode, depending on the sort of system, was cadmium or zinc. The values of the electromotive forces were used to calculate the activities of zinc and cadmium in liquid solutions of Cd-Sb and Zn-Sb. In the first case, the solutions reveal a negative deviation from Raoult's law. For the Zn-Sb solutions, on the other hand, a similar deviation is observed, but at higher concentrations of zinc the activity coefficient exceeds unity. Such a behavior on the part of these solutions reveals a direct relation to phase equilibrium systems of Cd-Sb and Zn-Sb in which intermetallic phases are visible in the solid state.