汽—液平衡在溶液盐效应研究中的应用

<正> 盐对混合溶剂汽液平衡的影响,近几年来引起了较为广泛的重视。加盐于二元溶液可以改变溶剂的相对挥发度。此效应在以研究溶剂的分离为目的时是很重要的。另外,含盐溶液的汽——液平衡数据在了解和解释该溶液内部的结构特征和热力学性质是很重要和很有价值的。当从微观上来考察溶液中各组分之间所可能存在的相互作用,这样的数据可以提供出直接的或间接的信息,诸如盐在溶液中的溶剂化数、溶剂相对挥发度的改变、溶液恒沸组成的移动或破坏,每一组分的活度系数以及其它一些过量热力学函数等。这个课题迄今已发表了很多文章。本文中作者在对参考文献作一简单评述的同时,还在自己实验室中所得到的结果和工作的基础上,讨论和分析了以下几个主要方面: 1、利用盐对溶液汽——液平衡的影响来考察溶液的内部结构,盐的溶剂化以及溶液中存在的各种相互作用。 2、详细地分析二元溶液加盐前后溶剂相对挥发度的改变。正如题目的意思,本文的目的在于强调汽——浪平衡测定在研究溶液的盐效应是一个非常有效的方法之一。

THE APPLICATION OF VAPOR-LIQUID EQUILIBRIUM TO THE INVESTIGATION OF SALT EFFECT ON BINARY SOLUTIONS

The effect of salt on the vapor-liquid equilibrium of solvent mixtures has been of considerable interest in recent years.Introduction of a salt into a binary solvent mixture results in a change in the relative volatility of the solvents.This effect can be to better advantage when used in the separation of the solvents of interest. Moreover, the vaporliquid equilibrium data for the system containing two solvents and one salt are also important and valuable in understanding and interpreting the ther-modynamic Properties and structural characteristics of the solutions. with a view to microscopically investigating the possible interactions among the species Present, these data can provide direct cr indirect informations, such as solvaticn number of salt, change in the relative volatility of the solvents, movement or destruction of the azeotropic composition of the solution, the activity coefficient of each component, and some other excess thermonynamic functions. So far there are quite a number of papers have been published on this topic.while briefly reviewing the literature references, the author of this paper, on the basis o f the work and resul ts obtained in his laboratory, discusses and analyses the following Principal aspects: 1. Investigation into the internal structure of the solution, the salt solvation, and the various interactions present in solution by means of the effect of salt on the vapor-liquid equilibrium. 2. Detailed analysis of the change of the relative volatility of binary solutions bef—ore and after salt addition As the title implies, the purpose of this paper lies in emphasizing the importance of the vapor—liquid equilibrium determination as one of the most effective methods in studying the salt efflct of solution.