EXCESS ENTHALPY SURFACES FOR ALKANOL-ALKANE MIXTURES BY THE UNIQUAC MODEL

Temperature and composition dependences of excess enthalpy surfaces an d composition fluctuations were calculated using the UNIQUAC model and the Kirkwood-Buff theory of statistical mechanics for seven alkanol-a lkane mixtures. Surfaces of partial molar excess enthalpies and enthal py of dilution were also calculated. Temperature-dependent parameters of the UNIQUAC model in the range of 278.15-333.15 K were used in the calculations. The thermodynamic surfaces facilitate better understandi ng of thermodynamic properties of alkanol-alkane mixtures over the who le mole fraction range in a certain temperature interval. The UNIQUAC model is capable of representing the thermodynamic properties of assoc iating mixtures at low pressures.