Vapour pressure of regular solution

To compare the excess Gibbs function of mixtures of carbon tetrachloride and cyclohexane with a simple formula for regular mixtures. 

The partial vapour pressures of mixtures of carbon tetrachloride and cyclohexane were measured by Scatchard, Wood, and Mochel (J. Amer. Chem. Soc. 1939, 61, 3206). They applied corrections to convert vapour pressures to fugacities and derived values for the excess Gibbs function G- by means of the formula 

Values thus obtained for G at 40 X are given in table 1, where x denotes the mole fraction of cyclohexane. 

The simplest type of formula relevant to regular solutions is G = (1 — x)w ( const.) 

We shall compare the experimental results with formula (2) by plotting G against a (1 — x). 

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