电动势法对LiCl-Li_2SO_4-H_2O体系25℃热力学性质研究  

Studies of Thermodynamlc Properties for LiCl-Li_2SO_4-H_2O System at 25℃ by EMF Method

作　　者：王瑞陵[1] 姚燕[1] 张忠[1] 吴国梁[1] 

机构地区：[1]中国科学院青海盐湖研究所,西宁810008

出　　处：《化学学报》1993年第6期534-542,共9页Acta Chimica Sinica

基　　金：国家自然科学基金

摘　　要：用自制的锂离子选择电极和经典Ag-AgCl电极,测定25℃时LiCl-Li_2SO_4-H_2O三元体系中离子强度0.01～6.0mol·kg^(-1)的LiCl的平均活度系数.由实验数据,用多元线性回归法求取Pitzer方程、Harned方程的离子作用参数和系数,并用上述方程计算LiCl在混合溶液中的平均活度系数,分别以In_(γ±LiCl)和log_(γ±LiCl)的形式与实验值进行比较,标准偏差均小于0.008.本工作测得的LiCl平均活度系数的自然对数与等压法测定的渗透系数拟合的Pitzer方程参数计算值比较,标准偏差为0.0097.同时计算了Li_2SO_4在该体系中的平均活度系数和混合溶液的渗透系数以及混合超额自由能.The mean activity coefficients of LiCl in LiCl-Li_2SO_4-H_2O system were determined at 25℃ in the total ionic strength range from 0.01 to 6.0mol·kg^(-1).The measurements were made using an electrochemical cell with a lithium ion-selective electrode against an Ag-AgCl electrode.The experimental mean activity coefficients of LiCl (In γ_(±LlCl) obey Harned's rule and Pitzer's equation very well and agree with the results obtained by isopiestic method with RMSD 0.0097.The mean activity coefficients of Li_2SO_4, the osmotic coefficients and excess free energies of mixing were also calculated.

关 键 词：氯化锂 硫酸锂 水 热力学 电动势 

分 类 号：O642.542[理学—物理化学]