Abstract: The modified mean spherical approximation(MSA)model is used to predict the mean ionic activity coefficients for 32 aqueous mixed electrolyte solutions at 298.15K without any mixing parameters. The results show that the model gives a better representation of mixture properties in terms ofpure component parameters than Pitzers equation without mixing parameters. The mean standard deviation between the calculated and experimental values of 1n γ± is 0.0113. It is close to that of Pitzers equation with mixing parameters. The mean ionic activity coefficients in four mixed electrolyte solutions at saturated concentration and various temperatures have also been calculated by using the parameters obtained from single electrolyte solutions at 298.15K. The agreement between the calculated results and the experimental data is satisfactory over a wide range of temperatures. It shows that the present model has a powerfull capability for predicting the thermodynamic properties of aqueous mixed electrolyte solutions.

摘要： 用(I)报中所得到的阳离子有效直径参数,用平均球近似(MSA)法,在不用混合参数的条件下,预测了32个混合电解质水溶液的离子平均活度系教.预测的Inγ_± 与实验值的平均标准偏差为0.0113.文中还用Pitzer方程作了计算.结果表明本文预测结果比无混合参数的Pitzer方程好得多,接近于带混合参数的Pitzer方程的关联结果,作者还分别预测了各温度下4个混合电解质水溶液饱和浓度时的活度系数,结果令人满意.