Surface Tension Model for Concentrated Electrolyte Aqueous Solutions by the Pitzer Equation

A new surface tension model based on a thermodynamic analysis on a vapor−liquid surface in an aqueous concentrated electrolyte solution has been proposed. The relation between the surface tensions and the osmotic coefficients of electrolyte solutions which are calculated by the Pitzer equation is established. The surface tensions of 46 single-electrolyte solutions are correlated with only one parameter and the overall average deviation is 1.22%. On the basis of the parameters obtained by correlating the surface tensions of single-electrolyte aqueous solutions, the surface tensions of mixed- and single-electrolyte solutions at different temperatures can also be predicted with deviations of 1.50%. In all cases investigated, good agreement is observed, even for the systems containing high concentrations of electrolytes.