Vapor‐Liquid equilibrium: Part I. An appraisal of data reduction methods

Abstract
Correlations of the excess Gibbs function and the activity coefficients of a binary, liquid‐phase system at constant temperature depend on reduction of P‐x‐y data taken for the system in vapor‐liquid equilibrium. It is shown that use of a full P‐x‐y data set is for all practical purposes based on just the P‐y values. Alternative procedures require only P‐x or P‐y data. In any case, effective use of a full P‐x‐y data set can be made only if redundent experimental values of Px,y or P are compared for consistency with calculated values. This cannot be accomplished by means of the popular area test for thermodynamic consistency.