物理化学学报 >> 1993, Vol. 9 >> Issue (03): 357-365.doi: 10.3866/PKU.WHXB19930314

研究论文 上一篇    下一篇

电动势法对LiCl-MgCl2-H2O体系热力学性质的研究

王瑞陵; 姚燕; 吴国梁   

  1. 中国科学院青海盐湖研究所,西宁 810008
  • 收稿日期:1991-11-14 修回日期:1992-07-07 发布日期:1993-06-15
  • 通讯作者: 姚燕

Thermodynamic Properties of Electrolyte Solutions:An EMF Study of System LiCl-MgCl2-H2O

Wang Rui-Ling; Yao Yan; Wu Guo-Liang   

  1. Qinghai Institute of Salt Lakes, Academia Sinica, Xining 810008
  • Received:1991-11-14 Revised:1992-07-07 Published:1993-06-15
  • Contact: Yao Yan

摘要: 用自制的锂离子选择电极和经典的Ag-AgCl电极, 以电动势法测定了25 ℃时离子强度为0.05—6.0 mol·kg~(-1)范围的LiCl-MgCl_2-H_2O三元体系中LiCl的平均活度系数. 由实验数据, 求出了Pitzer方程、Harned方程和Scatchard方程的参数和系数. 用上述方程计算了LiCl 在该体系中的活度系数, 并与实验值进行比较, 标准偏差小于0.008. 与等压法测定的渗透系数拟合的Pitzer方程参数计算值比较在实验误差范围内. 同时计算了MgCl_2在该体系中的平均活度系数和混合溶液的渗透系数.

关键词: 三元体系LiCi-MgCl2-H2O, 活度系数, 锂离子选择电极, 电动势法

Abstract: The activity coefficients of aqueous LiCl in system LiCl-MgCl_2-H_2O were determined at 25 ℃ in the total ionic strength range from 0.05 to 6.0 mol·kg~(-1) by E.M.F. method using a lithium ion-selective electrode and Ag/AgCl electrode.
The electrode pairs used in present work were prepared in our laboratory and performance tests were carried out. linear near-Nernst response, good reproducibility, stability and selectivity were observed.
The Harned coefficients, Pitzer ternary interaction parameters and Scatchard parameters were evaluated from present measurement by using multiple regression. The whole range of the ionic strengths studied.
The experimental activity coefficients were compared with which calculated by Pitzer equation with known parameters from experimental osmotic coefficients.

Key words: Activity coefficients, Ternary system LiCl-MgCl2-H2O, Li sensitive electrode, E.M.F. method