等压法测定Li_2SO_4-MgSO_4-H_2O体系的渗透和活度系数  

ISOPIESTIC DETERMINATION OF THE OSMOTIC AND ACTIVITY COEFFICIENTS OF AQUEOUS MIXTURES OF Li_2SO_4 AND MgSO_4

作　　者：张忠[1] 姚燕[1] 宋彭生[1] 陈敬清[1] 

机构地区：[1]中国科学院青海盐湖研究所,西宁810008

出　　处：《物理化学学报》1993年第3期366-373,共8页Acta Physico-Chimica Sinica

基　　金：国家自然科学基金

摘　　要：在25℃下,离子强度范围分别为0.2—8.7、0.6—12.7和1.4—13.5mol·kg^(-1)时,测定了纯Li_2SO_4、MgSO_4及Li_2SO_4-MgSO_4混盐水溶液的渗透系数.计算了Pitzer 方程和Scatchard 方程的离子作用参数.用上述两种方程及由热力学关系式直接推导出的Mckay-Perring 方程计算并比较了Li_2SO_4和MgSO_4在混合溶液中的平均活度系数,三者在实验误差范围内一致.利用获得的Pitzer 参数计算该体系的溶解度与文献值基本一致.The osmotic coefficients of aqueous mixtures of Li_2SO_4 and MgSO_4 have beenmeasured from 1.4 to 13.5 mol·(kg)^(-1) at 25℃ by using the isopiestic method.In the ranges of 0.2—8.7 and 0.6—12.7 mol·(kg)^(-1) the osmotic coefficients of Li_2SO_4 andMgSO_4 were also reported respectively.Ion interaction parameters of Pitzer modeland Scatchard model have been calculated from these measurements.In comparison withMckay-Perring method,the osmotic and activity coefficients for Li_2SO_4-MgSO_4 mixturesare fairly reliably represented by both Pitzer's equations and Scatchard's neutralelectrolyte equations.The predicted solubilities for this system using Pitzer's ap-proach show good agreement with experimental results.

关 键 词：硫酸锂 硫酸镁 水 热力学性质 

分 类 号：O642.542[理学—物理化学]