甲醇-苯混合溶剂中NaI活度系数的测定与计算

Measurement and Calculation for the Activity Coefficients of NaI in Methanol-benzene System

测定了甲醇-苯-NaI体系在恒压条件下的汽液平衡数据,采用双标准检验法对数据进行检验,检验结果全部合格.应用P itzer强电解质在水溶液中的活度系数模型,采用全部合格的汽液平衡数据拟合出方程中的维利系数,从而获得在双液比固定条件下盐在甲醇-苯混合溶剂中的活度系数.计算结果表明,正常泡点温度下在具有固定双液比的甲醇-苯混合溶剂中,NaI的平均活度系数随盐浓度的增加先减小,经过一个极小值后又增加.

By measuring the vapor-liquid equilibrium of methanol （1） - benzene（2） -NaI and testing the data using the ternary Gibbs-Duhem equation, the experimental results of the vapor-liquid equilibrium with thermodynamics consistency were obtained. Applying the Pitzer equation of the activity coefficients of 1-1 type electrolyte to non-aqueous mixed solvents, each parameter of the equation was obtained by the method of least squares. The calculation results show that the activity coefficients of NaI in methanol- benzene system with constant composition decrease at first then pass a minimum and increase gradually again as its concentration increases.