Vapor–liquid equilibrium of ternary aqueous poly (ethylene glycol)+dipotassium tartrate at solutions at different temperatures

Abstract In this study, water activities for the ternary systems of {dipotassium tartrate (K 2 Tar)+PEG4000+H 2 O} have been measured using an improved isopiestic method at T =(298.15, 308.15, 318.15) K. From these measurements, values of the vapor pressure of solutions were also determined. The experimental data for the activity of water were accurately correlated with the Wilson model. Also, the performance of an empirical two parameter equation was also tested for representing the experimental water activity data.