The Peng-Robinson equation of state las modified by Stryjek and Vera), comb
ined with the Wong-Sandler mixing rule, was used for the prediction of exce
ss enthalpies of highly nonideal mixtures at both low and high pressures, a
nd with supercritical components included. In this work, the model paramete
rs were fitted only to experimental vapor-liquid equilibrium data and were
then used to obtain simultaneous representation of both vapor-liquid equili
bria and excess enthalpy data. The results show that this equation of state
model is able to yield not only qualitative, but also reasonably quantitat
ive, predictions of the thermodynamic properties of nonideal systems of var
ying complexity.