HCl-NaCl-C_2H_6O_2-H_2O体系中HCl热力学  

THERMODYNAMICS OF HCl IN SYSTEM OF HCl-NaCl-C_2H_6O_2-H_2O

作　　者：王琴萍[1] 邢长宇[1] 陈洪涛[1] 周丽华[1] 吕殿祯[1] 

机构地区：[1]辽宁大学化学科学与工程学院,辽宁沈阳110036

出　　处：《化工学报》2004年第9期1406-1411,共6页CIESC Journal

摘　　要：在乙二醇和水为混合溶剂中加入HCl和NaCl组成四元系 ,在恒定溶液总离子强度I=1 0 0mol·kg-1,改变混合溶剂中乙二醇质量分数w (5 %、 15 %和 2 0 % )的条件下 ,组成下列电池Pt,H2 (10 5Pa )│HCl(m) ,C2 H6O2 (w) ,H2 O (1-w )│AgCl Ag (A)Pt,H2 (10 5Pa )│HCl(mA) ,NaCl(mB) ,C2 H6O2 (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AgCl Ag电极的标准电极电动势 ,讨论了HCl的迁移性质 .利用电池 (B)的电动势 ,计算出HCl的活度系数γA.结果表明 ,在溶液中总离子强度保持恒定 ,HCl的活度系数服从Harned规则 .在溶液组成恒定时 ,lgγA 是温度倒数 1/T的线性函数 ,进一步讨论了混合物中HCl的相对偏摩尔焓 .The thermodynamic property of HCl-NaCl-C 2H 6O 2-H 2O system were studied by means of emf measurement in the cells without liquid junction Pt,H 2 (10 5Pa )│HCl(m),C 3H 8O 3 (w), H 2O (1-w)│AgCl-Ag(A) Pt,H 2 (10 5Pa )│HCl(m A),NaCl(m B ), C 3H 8O 3 (w), H 2O (1-w)│AgCl-Ag(B) at a constant ionic strength I=1.00 mol·kg -1 and mass fraction of glycol in the mixed solvent, equating to w=5%,15% and 20%,respectively,at temperature ranging from 278.15 to 323.15 K.The standard electrode potential of Ag-AgCl in the mixed solvent were determined from cell (A).The activity coefficients of HCl γ A in the mixed solvent system were determined from cell(B).The results show that the activity coefficients of HCl in HCl-NaCl solutions still obey the Harned’s rule and lgγ A is a linear function of the reciprocal of the absolute temperature at constant composition of the mixture.Relative molar enthalpies of HCl L A are linear function of 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 solvent were calculated.

关 键 词：热力学 活度系数 离子强度 HARNED规则 电动势 

分 类 号：O646.23[理学—物理化学]