298.15K下LiCl-Li_(2)B_(4)O_(7)-H_(2)O体系中LiCl的活度系数和缔合平衡研究  

STUDIES OF ACTIVITY COEFFICIENTS OF LiCl AND ASSOCIATION EQUILIBRIUM IN LiCl LiCl-Li_(2)B_(4)O_(7)-H_(2)O SYSTEM AT 298.15K

作　　者：田海滨[1] 姚燕[1] 宋彭生[1] 

机构地区：[1]中国科学院盐湖研究所西安二部，陕西 西安 710043

出　　处：《化学研究与应用》2000年第4期403-408,共6页Chemical Research and Application

基　　金：国家自然科学基金资助项目(29871034) ;中科院基础局重点课题

摘　　要：用锂离子选择电极和 Ag-Ag Cl电极测定了 2 98.1 5K下 Li Cl-Li2 B4O7-H2 O体系中离子强度范围为 0 .0 1～ 2 .50 mol· kg- 1 、不同 Li2 B4O7离子强度分数的 Li Cl的平均活度系数。由实验数据 ,用迭代法及多元线性回归法 ,求取了 Li B4O- 7离子对的形成计量缔合平衡常数 Km 及 Pitzer离子作用参数 ,并与实验值比较 ,标准偏差为 0 .0 1 38。同时该实验结果与 2 98.1 5K下 Li Cl-Li2 SO4-H2 O体系 Li Cl平均活度系数的变化趋势进行了比较 ,得到在 0 .0 5～ 1 .0 mol· kg- 1 离子强度范围内 Li Cl在 Li2 B4O7介质中平均活度系数随 Yb的增大而增大 ,而在 Li2Mean activity coefficients of LiCl in LiCl Li 2B 4O 7 H 2O system have been determined in the ionic strength ranging from 0.01 to 2.50mol·kg -1 at 298.15K by the method of EMF using a pair of lithium ion selective electrode and Ag/AgCl electrode.Stoichiometric association equilibrium constant K m and Pitzer ion interaction parameters were evaluated from present measurements by using multiple regression and iterative method.The experimental activity coefficients were compared with those calculated by using Pitzer's equations with parameters obtained from this work and references,presenting reasonable agreement ,with a standard deviation of 0.0138.The actitity coefficients of LiCl in the medium of aq.Li 2B 4O 7 were compared with those in aq.Li 2SO 4.The results show that the activity coefficients of LiCl increase with increasing of Li 2B 4O 7 in the medium of aq.Li 2B 4O 7 and decrease with increasing of Li 2SO 4 in the medium of aq.Li 2SO 4 in the ionic strength range from 0.05 to 1.00 mol·kg -1 .

关 键 词：三元体系 氯化锂 硼酸锂 水 活度系数 

分 类 号：O614.111[理学—无机化学] O645.164[理学—化学]