Abstract: Excess enthalpies were measured by an isothermal dilution calorimeter for the binary mixtures of n-hexane + n-butanol, and n-hexane +ethyl acetate at 303. 15 K, 308. 15 K, and for the ternary mixture of n-butanol +ethyl acetate + n-hexane at 303. 15 K, respectively. Amathematical model was employed to correlate the excess enthalpies of binary systems for n-butanol-(-ethyl acetate, n-hexane+n-butano] and n-hexane+ethyl acetate at 303. 15 K. The excess enthalpies of the ternary system presented in this paper are well predicted according to the model. The average deviation between the experimental and predicted values is 6%.

Key words: Excess enthalpy, Mathematical model, Predicted values