Correlation and prediction of activity and osmotic coefficients of aqueous electrolytes at 298.15 K by the modified TCPC model
Correlation and prediction of activity and osmotic coefficients of aqueous electrolytes at 298.15 K by the modified TCPC model
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DOI：
10.1021/je060451k
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发表时间：
2007-03-01
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影响因子：
--
通讯作者：
Seetharaman, Seshadri
中科院分区：
文献类型：
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作者：
Ge, Xinlei;Wang, Xidong;Seetharaman, Seshadri
本文提出了一个用于计算298.15K下电解质水溶液热力学性质（包括渗透系数和平均活度系数）的三特征参数关联模型。该模型可以简化为两个参数：B，接近参数，和S，溶剂化参数。虽然该模型充分描述了这两个参数的热力学，第三个参数，n，这是有关的离子和溶剂分子之间的距离，也可以被视为一个可调参数。通过对实验值的回归，得到了283种单盐在饱和水溶液中的两组参数。用这两组参数计算了RbNO_2、MgCl_2、Sm（ClO_4）（3）和ZnSO_4的平均活度或渗透系数，并与平滑后的实验数据进行了比较，两者吻合较好。当采用三参数模型时，特别是在高浓度的情况下，它给出了更准确的结果。与Pitzer模型和原TCPC模型的比较也说明了改进模型的优良性能。
The modification and extension of a three-characteristic-parameter correlation model for calculating the thermodynamic properties including osmotic and mean activity coefficients of aqueous electrolytes at 298.15 K have been presented in this paper. The model can be reduced with two parameters: b, the approaching parameter, and S, the solvation parameter. Although the model adequately describes the thermodynamics with these two parameters, the third parameter, n, which is related to the distance between an ion and a solvent molecule, also can be regarded as an adjustable parameter. The two sets of parameters for 283 single salts in aqueous solutions up to saturation have been obtained from the regression of experimental values. Mean activity or osmotic coefficients of RbNO2, MgCl2, Sm(ClO4)(3), and ZnSO4, with these two sets of parameters, have been compared with the smoothed experimental data, which show good agreement. When the model with three parameters is employed, it gives a more accurate result, especially in case of high concentration. The comparison with Pitzer and the original TCPC model also illustrates the excellent performance of this modified model.