乙腈-水的液液、固液相平衡和过量Gibbs自由能

测制了xCH~3CN+(1-x)H~2O的液液、固液平衡相图, 此系液液分层的简单低共熔混合物类相图。低共熔点温度为227.44K, 组成x=0.955。最高临界溶解温度为271.0K, 临界组成x=0.35, 临界指数n=2.64。两液相与冰的平衡温度为263.07K。计算出体系在263.07K的过量Gibbs自由能G~m^E, 液液分层时G~m^E的最大值为1174J·mol^-^1。

Liquid-liquid and solid-liquid phase equilibria and excess Gibbs free energies for acetonitrile-water

Melting temperatures and liquid-liquid equilibrium temperatures have been measured, and the liquid-liquid, solid-liquid phase diagram was constructed for xCH~3CN+(1-x)H~2O. It is a simple eutectic system with the liquid separation. Eutectic temperature and composition are 227.44K and x=0.955, respectively. The upper critical temperature is 271.0K, the critical composition is x=0.35, the critical exponent n=2.64. The equilibrium temperature of two liquid phases with ice is 263.07K. Excess molar Gibbs free energies were calculated at 263.07K, the largest value of G~m^E is 1174J/mol when system separates into two liquid phases.