An electromotive force study of solutions of bismuth in bismuth(III) chloride At 240°

Abstract

Melts of BiCl 3 containing 0.2 to 20 mole % metal have been studied in sealed concentration cells without fixed reference at 240°. The marked nonideality required by the EMF data above about 1% Bi contrasts with the substantially ideal solutions of Bi + and Bi 3 + (vice Bi 4 4+) previously established at higher temperatures and lower metal concentrations. Combination of the EMF results with published cryoscopic data allows some limits to be placed on the activity coefficients of these species; in particular, positive deviation is required for the low-field Bi 3 + over much of the range. Other thermodynamic measurements on the concentrated solutions at higher temperatures are also considered briefly.