Analysis of coexistence-curve data for binary mixtures

Abstract

Earlier attempts by others to mathematically describe coexistence-curve data from binary mixtures are reviewed and the empirical nature of the functions is noted.

A statistically improved procedure to determine the quality of the fit of any particular function to a given set of experimental data is proposed. This procedure is then applied to determine the extent to which a number of empirical formulations accurately describe the partial miscibility observed in five experimental systems, namely: (1) isobutyric acid + water; (2)³He +⁴He; (3) neon + ammonia; (4) titanium tetrabromide + sulphur dioxide and (5) lead + zinc.

It is concluded that none of the functions examined can provide a close fit over a wide range of composition against temperature for all the systems examined.