Thermodynamic properties of binary systems containing hexafluorobenzene. Part 1.—Phase diagrams

Abstract

Experimental phase diagrams have been obtained for binary mixtures of hexafluorobenzene with six hydrocarbons, benzene, toluene, p-xylene, mesitylene, cyclohexane and n-hexane. The first four systems all form well-defined 1:1 molecular complexes with congruent melting points. The mixture containing cyclohexane forms three much weaker complexes with incongruent melting points and compositions corresponding to a molar ratio of hexafluorobenzene to cyclohexane of 3:1, 5:1 and probably 6:1. Hexafluorobenzene forms a simple eutectic with n-hexane and an analysis of the experimental phase diagram indicates that the system exhibits a considerable positive deviation from ideality.