Modeling the variation of surface tension with composition for binary liquid mixtures

We study the variation of surface tension of a solution with concentration via dimensionless variables and an identity. The behavior at the extremities are analyzed critically via a perturbative route that generates the natural indices of non-ideality. A Padé interpolation leads finally to a general form for the concerned variation. It nicely accounts for the salient features and correlates the change of surface tension with mole fraction in a variety of completely miscible, binary aqueous solutions. The workability of a few prevalent equations are also scrutinized in the light of the present endeavor.