起電力法によるBi-S融体中の硫黄の活量の測定

Abstract

An E.M.F. method using oxide solid electrolyte was applied to determine the sulfur activities in the liquid solution of bismuth and sulfur.The oxygen partial pressures over the melts equilibriated with nearly one atmospheric pressure of SO2 were measured by the following galvanic cell:(This article is not displayable. Please see full text pdf.) \ oindentFrom the measured oxygen partial pressures and the total pressure, the equilibrium sulfur pressures were calculated by using the published data on molar Gibbs energy of coexisting gas species.The sulfur activities of the melts were determined by this method for compositions up to 50 mol per cent of S over the temperature range 773 to 1073 K. The results were in good agreement with those reported by other authors based on the different methods.From these results the thermodynamic behaviors of the liquid solution of bismuth and sulfur were discussed. The standard molar Gibbs energy of formation of solid Bi2S3 was calculated from these thermodynamic functions over the temperature range 793 to 993 K as follows:(This article is not displayable. Please see full text pdf.)