The binary excess Gibbs energies and excess enthalpies of liquid mixtures of alkanols and hydrocarbons, acetone, methyl acetate, acetonitrile, organic acid, etc., are simultaneously correlated with a new association model whose equilibrium constants are defined in terms of the modified segment fractions of chemical species. The model predicts ternary vapor-liquid, liquid-liquid equilibria and excess molar enthalpies of those mixtures well using only binary parameters.