摘要
本文用分光光度法测定了25℃下邻、间、对位二甲苯分别在Na_2SO_4、K_2SO_4、(NH_4)_2SO_4、MgSO_4及MgCl_2五种高价盐水溶液中的活度系数f,所作lgf—c_S(盐浓度)图均呈直线,并基本通过原点,符合Setschenow盐效应经验公式。得到的三种二甲苯的盐析次序均为:Na_2SO_4>K_2SO_4>(NH_4)_2SO_4>MgSO_4>MgCl_2。本文还用Debye-MacAulay和Conway-Desnoyers-Smith两种静电理论、Masterton-Lee定标粒子理论、McDevit-Long内压力理论以及改进后的内压力理论(XIPT)对研究体系进行了计算,结果表明;XIPT计算值比其它理沦计算值更符合实际,且具有方法简单、适用体系广,误差小,盐析常数符号与实际一致等显著优点。
The activity coefficients and sahing-out constants of o-,m-,p-xylenes in six aqueous salt solutions at 25℃ are determined by spectrophotometric method. The salts used are Na_2SO_4, K_2SO_4, (NH_4)_2SO_4, MgSO_4 and MgCl_2. The relations logf-c_s are found to he all straight lines through the origin, in agreement with the Setschenow empirical formula. The order of salting-out ability is Na_2SO_4>K_2SO_4>(NH_4)_2SO_4>MgSO_4>MgCl_2
The experimental results of three xylenes are compared respectively with the calculated resuhs of Debye-MacAulay and Conway-Desnoyers-Smith electrostatic theories, Masterton-Lee scaled particle theory and McDevit-Long internal pressure theory and internal pressure theory modified by Xie. The numerical calculation of the modified internal pressure theory agrees with experimental data better.
出处
《物理化学学报》
SCIE
CAS
CSCD
北大核心
1991年第6期688-693,共6页
Acta Physico-Chimica Sinica
关键词
二甲苯
盐效应
盐析
活度系数
Salt effect, Salting-out, Activity coefficicnt, Xylene
