RbCl-H2O二元系和RbCl-RbNO3-H2O三元系作用浓度计算模型

Calculating models of mass action concentrations for RbCl-H2O binary system and RbCl-RbNO3-H2O ternary system

利用离子-分子共存理论建立温度为298．15K时强电解质水溶液二元系RbCl-H2O和三元系RbCl-RbNO3-H2O作用浓度计算热力学模型。热力学模型计算的以纯物质为标准态、以摩尔分数为浓度单位的RbCl-H2O二元系各组元作用浓度经过转换系数转换后，与文献报道的以无限稀为标准态、以质量摩尔浓度为浓度单位的组元活度吻合良好。RbCl-RbNO3-H2O三元系的RbCl和RbNO3转换后的作用浓度与文献报道的活度在总离子强度为0．01、0．05、0．1、0．5、1．0、1．5、2．0、3．0和3．5mol／kg时均良好吻合。这说明基于离子-分子共存理论建立的作用浓度计算热力学模型能反映强电解质水溶液RbCl-H2O和RbCl-RbNO3-H2O的结构特性；且组元的作用浓度在计算的浓度单位内严格遵守质量作用定律。

Thermodynamic models of calculating mass action concentrations of components in RbCl-H2O binary and RbCl-RbNO3-H2O ternary strong electrolyte aqueous solutions were developed based on the ion and molecule coexistence theory at 298.15 K. A transformation coefficient is needed to compare calculated mass action concentration with reported activity because they are obtained at different standard state and concentration unit. The results show that transformation coefficients between calculated mass action concentrations and reported activities of the same components change in a very narrow range. The transformed mass action concentrations of components in RbCl-H2O binary system are in good agreement with reported activities. The transformed mass action concentrations of RbCl and RbNO3 in RbCl-RbNO3-H2O ternary solution are in good agreement with reported activities αRbCl and αRbNO3 with different constant total ionic strengths as 0.01, 0.05, 0.1, 0.5, 1.0, 1.5, 2.0, 3.0 and 3.5 mol/kg, respectively. All those results mean that the developed thermodynamic model of strong electrolyte aqueous solutions can reflect structural characteristics of RbCl-H2O binary and RbCl-RbNO3-H2O ternary strong electrolyte aqueous solutions and the mass action concentration also strictly follows mass action law.