Thermodynamic consistency of low pressure equilibrium data of water + congener mixtures using a versatile equation of state

•A general thermodynamic consistency test is applied to analyze phase equilibrium data.•Binary water + congener mixtures were considered.•The Gibbs–Duhem equation is used to check consistency.•The test combines the Peng–Robinson equation of state modified by Kwak and Mansoori.•The results are in agreement with information from the literature.