The excess Gibbs free energy for organic acid$(1)-$water$(2)$ and organic acid$(1)-$hexane$(3)$ system is given by G$-80$x$,$x$,$ and $260$x$,$x$,$ respectively. Determine the equilibrium concentration of organic acid in hexane phase if it is contacted with the water phase containing $5$ mole percent organic acid. Hexane and water can be considered to be immiscible