混合电解质中HCl热力学性质——HCl-C_3H_8O_3-NaCl-H_2O体系  

On the Thermodynamic Properties of HCl in the System HCl-C_3H_8O_3-NaCl-H_2O

作　　者：王琴萍[1] 吕殿祯[1] 孙雪丽[1] 

机构地区：[1]辽宁大学化学系,沈阳110036

出　　处：《应用化学》2003年第2期149-154,共6页Chinese Journal of Applied Chemistry

基　　金：辽宁省自然科学基金资助项目 ( 9810 30 0 90 2 )

摘　　要：在恒定溶液总离子强度I=1 0 0mol/kg ,改变甘油在混合溶剂中的质量分数为 5、1 5和 2 0的条件下 ,测定了无液体接界电池 (A)和电池 (B)的电动势。Pt,H2 (1 0 5Pa)│HCl(c) ,C3H8O3(w) ,H2 O(1 -w)│AgCl-Ag (A)Pt,H2 (1 0 5Pa)│HCl(cA) ,NaCl(cB) ,C3H8O3(w) ,H2 O(1 -w)│AgCl-Ag (B)根据测得电池 (A)的电动势 ,确定混合溶剂中Ag AgCl电极的标准电极电势 ,讨论了HCl的迁移性质。利用测得电池 (B)的电动势 ,计算了混合溶液中HCl的活度系数γA。结果表明 ,在溶液中总离子强度保持恒定为I=1 0 0 0mol/kg时 ,HCl的活度系数服从Harned规则。在溶液组成恒定时 ,logγA对热力学温度的倒数 1 /T作图 ,是一条直线。The thermodynamic property of HCl-C 3H 8O 3-NaCl-H 2O system has been studied by emf measurement in the cells without liquid junction at 5 to 45 ℃:Pt,H 2(10 5 Pa)HCl(c),C 3H 8O 3(w),H 2O(1-w)AgCl-Ag(A) Pt,H 2(10 5 Pa)HCl(c A),NaCl(c B),C 3H 8O 3(w),H 2O(1-w)AgCl-Ag(B)with the mass fraction of glycerol ω(C 3H 8O 3)=5%, 15% and 20% at a total ionic strength I=1.00 mol/kg. The standard electrode potential of Ag-AgCl in the mixed solvent was determined for cell(A). The activity coefficient γ A of HCl in the mixed solvent system was determined from cell(B).The results show that the acti-vity coefficient of HCl in HCl-NaCl solutions still obeys Harned′s rule and lg γ A is linear to the reciprocal of the absolute temperature at constant composition of the mixture. Relative molar enthalpies L A of HCl are in linear function with the ionic strength fraction of NaCl at constant total ionic strength and temperature. The standard transfer Gibbs free energies of HCl from water to mixed sovents were calculated. The primary, secondary and total medium effect of HCl were calculated and discussed.

关 键 词：混合电解质 HCL 热力学性质 HCl-C3H8O3-NaCl-H2O体系 活度系数 电动势 电极电势 无液接电池 盐酸 氯化钠 

分 类 号：O646.2[理学—物理化学]