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

Studies of Activity Coefficients and Dissociation Equilibrium for 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] 龙光明[1] 王鲁英[1] 

机构地区：[1]中国科学院青海盐湖研究所西安二部,陕西 西安 710043

出　　处：《盐湖研究》2000年第4期29-36,共8页Journal of Salt Lake Research

基　　金：国家自然科学基金资助项目(29871034);中国科学院基础局重点课题(J-05-02)

摘　　要：用锂离子选择电极和经典 Ag- Ag Cl电极测定了 2 98.15K下 L i Cl- Li2 B4 O7- H2 O体系中离子强度范围为 0 .0 1～ 2 .50 mol· kg-1,不同 Li2 B4 O7离子强度分数的 L i 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 L i2 B4 O7的化学计量离解平衡常数 Km,热力学离解平衡常数 K及 Pitzer离子作用参数 ,并与实验值比较标准偏差为 0 .0 50 0。同时该实验结果在 0 .0 1- 0 .50 mol·kg-1离子强度范围内与 2 98.15K下 L i Cl- L i2 SO4 - H2 O体系 L i Cl平均活度系数的变化趋势进行了比较 ,得到 L i Cl在 Li2 B4 O7介质中平均活度系数随 Yb的增大而增大 ,而在 L i2 SO4Mean activity coefficients of LiCl for LiCI Li 2B 4O 7 H 2O system have been deteminated in the ionic strength range 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 equilibrium constant(K m), Thermodynamic constant(K) and Pitzer ion interaction parameters were evaluated from present measurement using multiple regression and iterative method. The experimental activity coefficients were compared with those calculated by Pitzer equations from this work and references, presenting reasonable agreement. The activity 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 rang from 0.01 to 0.50mol·kg -1 .

关 键 词：硼 锂 多组分水盐体系 活度系数 离解平衡 

分 类 号：O645.1[理学—物理化学] O614.111[理学—化学]