ISSN 1017-2548(Print)
ISSN 2234-8530(Online)
Volume 60, Number 2
JKCSEZ 60(2)
April 20, 2016 

In this article, new Gibbs free energy of mixing is derived when there are specific interactions between solvent- solute molecules and between solute-solute molecules in binary solutions. It is asssumed that a probability of specific interactions satisfies a binomial distribution. Using this Gibbs free energy of mixing, we investigate possible types of partial miscibilities and show that Ω-shaped temperature-composition phase diagrams can exist. We calculate Ω-shaped temperaturecomposition phase diagram of water-2-butanol system and compare that with result calculated by the method of Hino5 et al. and the experimental data.