LIQUID-LIQUID AND SOLID-LIQUID PHASE-EQUI LIBRIA AND EXCESS GIBBS FREE-ENERGIES FOR ACETONITRILE-WATER

Melting temperatures and liquid-liquid equlibrium temperatures have be en measured, and the liquid-liquid,solid-liquid phase diagram was cons tructed for xCH(3)CN + (1 - x)H2O. It is a simple eutectic system with the liquid separation. Eutectic temperature and composition are 227.4 4 K and x = 0.955, respectively. The upper critical temperature is 271 .0 K, the critical composition is x = 0.35, the critical exponent n = 2.64. The equilibrium temperature of two liquid phases with ice is 263 .07 K. Excess molar Gibbs free energies were calculated at 263.07 K, t he largest value of G(m)(E) is 1174 J/mol when system separates into t wo liquid phases.