Local thermodynamic consistency of vapor-liquid equilibrium data for binary and multicomponent systems

The Gibbs‐Duhem equation, integrated over specific concentration ranges, is used to determine local thermodynamic consistency of vapor‐liquid equilibrium data. Several specific applications of the test are given for binary systems, although the method is equally applicable to linear paths in multicomponent systems. The test is particularly useful for evaluating the consistency of incomplete data, that is, data measured over only part of the concentration range.