Calculating models of mass action concentrations for structural units or
ion couples in RbCl-H2O binary system and RbCl-RbNO3-H2O ternary system
ion couples in RbCl-H2O binary system and RbCl-RbNO3-H2O ternary system
(1. School of Metallurgical and Ecological Engineering,
University of Science and Technology Beijing, Beijing 100083, China;
2. State Key Laboratory of Multiphase Complex System, Institute of Process Engineering,
Chinese Academy of Sciences, Beijing 100190, China)
University of Science and Technology Beijing, Beijing 100083, China;
2. State Key Laboratory of Multiphase Complex System, Institute of Process Engineering,
Chinese Academy of Sciences, Beijing 100190, China)
Abstract: Thermodynamic models of calculating mass action concentrations for structural units or ion couples 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 the calculated mass action concentration and the reported activity because they are obtained at different standard states and concentration units. The results show that the transformation coefficients between the calculated mass action concentrations and the reported activities of the same structural units or ion couples in RbCl-H2O binary and RbCl-RbNO3-H2O ternary strong electrolyte aqueous solutions change in a very narrow range. The transformed mass action concentrations of structural units or ion couples in RbCl-H2O binary system are in good agreement with the reported activities. The transformed mass action concentrations of RbCl and RbNO3 in RbCl-RbNO3-H2O ternary solution are also in good agreement with the reported activities, aRbCl and , with different 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 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 the mass action law.
Key words: mass action concentration; activity; ion and molecule coexistence theory; RbCl-H2O; RbCl-RbNO3-H2O; structural unit; ion couple