In order to prediction surface tension of binary mixtures based on thermodynamic models, surface molar area and partial surface molar area of component are required. There are several approaches that have been proposed to determine surface molar area of component.This includes UNIFAC [1], Rasmussen [2],and Paquette molar surface area [3]. It should be mentioned that, in more models for prediction of surface tension is assumed surface molar area and partial surface molar area is equal[4,5]. But in this study, an approach based on experimental density of solution is developed in order to provide a generally more accurate prediction for the surface molar area. This method is subsequently utilized to predict the surface tensions of several binary systems organic–organic and aneotropic mixtures. The surface tension obtained are compared to those to those calculated using other predictive models. The results show that the present modified model provides surface tension predictions which are equal to, and in some cases are better than those provided by other models. In general, the results demonstrate the usefulness of including a ‘‘real” surface molar area approximation in the surface tension calculations.
