物理化学学报 >> 1993, Vol. 9 >> Issue (03): 366-373.doi: 10.3866/PKU.WHXB19930315

研究论文 上一篇    下一篇

等压法测定Li2SO4-MgSO4-H2O体系的渗透和活度系数

张忠; 姚燕; 宋彭生; 陈敬清   

  1. 中国科学院青海盐湖研究所,西宁 810008
  • 收稿日期:1991-10-11 修回日期:1992-07-20 发布日期:1993-06-15
  • 通讯作者: 姚燕

Isopiestic Determination of the Osmotic and Activity Coefficients of Aqueous Mixtures of Li2SO4 and MgSO4

Zhang Zhong; Yao Yan; Song Peng-Sheng; Chen Jing-Qing   

  1. Institute of Salt Lakes, Academia Sinica, Xining 810008
  • Received:1991-10-11 Revised:1992-07-20 Published:1993-06-15
  • Contact: Yao Yan

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—13.5 mol·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.

关键词: 渗透系数, 活度系数, Pitzer方程, Scatchard方程, 溶解度, 等压法

Abstract: The osmotic coefficients of aqueous mixtures of Li_2SO_4 and MgSO_4 have been measured 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 and MgSO_4 were also reported respectively. Ion interaction parameters of Pitzer model and Scatchard model have been calculated from these measurements. In comparison with Mckay-Perring method, the osmotic and activity coefficients for Li_2SO_4-MgSO_4 mixtures are fairly reliably represented by both Pitzer's equation and Scatchard's neutral electrolyte equation. The predicted solubilities for this system using Pitzer's approach show good agreement with experimental results.

Key words: Osmotic coefficient, Activity coefficient, Pitzer equation, Scatchard equation, Mckay-Perring method, Solubility