化学反应进度对Le Chatelier原理的热力学讨论

A Thermodynamic Discussion of Le Chatelier′s Principle in the Light of Degree of Reaction

体系反应进度的平衡值是反映化学平衡的一个严格又直观的概念,文章从化学反应进度的平衡值随温度或压力改变的角度,用图解法对Le Chatelier原理进行了热力学讨论,指出温度、压力恒定时,在G～ξ图中,ξe值有确定的位置,改变温度或压力,ξe位置发生移动.恒定温度增加压力时,ξe向体积缩小的方向移动;恒定压力升高温度时,ξe向体系吸热方向移动,从而证明了Le Chatelier原理.

The equilibrium value ξ_e of degree of reaction is a concept with ocular strictness that reflects the chemical equilibrium. In this paper we discuss about Le Chatelier′s principle with the graphic method in the light of the change of equilibrium value of degree of reaction with temperature or pressure. We also point out when the temperature and pressure is invariable, ξ_e value has definite position in G ～ξ_e picture, while temperature or pressure changing, the position is moved. When temperature is invariable but the pressure is increased, ξ_e is moved in the direction that the volume narrows; When the pressure is invariable but temperature is rised,ξ_e is moved toward the direction that system absorbs heat, thus Le Chatelier′s principle is proved.