Thermodynamics of binary mixtures with n-mono and n-dibutyl phosphates

Thermodynamic properties of the binary mixtures of n-monobutyl phosphate and n-dibutyl phosphate with a number of diluents (water, benzene, hexane, cyclohexane, carbon tetrachloride, chloroform and ethanol) are considered. They were evaluated from the total vapour pressure measurements performed in the temperature range, 298.15-318.15 K. Activity coefficients and the excess Gibbs energies of mixing were calculated from the Gibbs-Duhem equation and the results obtained are discussed in terms of intermolecular hydrogen bond formation.