对范德瓦耳斯气体引力势能的一种谬论的深入分析

摘要

对范德瓦耳斯气体引力势能理解中的一种错误进行深入分析，根据统计的思想，用两种方法证明了范氏气体摩尔引力势能的表达式，并指出它的适用条件是短程弱引力分子气体；通过对比范氏固体和范氏气体引力势能的计算过程，揭示了谬论的错误所在；从概率论的角度分析了膨胀时气体引力势能变化量有别于固体的根本原因。%In this text, an intensive talk about a sort of misunderstanding of the attractive energy in van der waals gas was given. Based on the thought of statistics, two methods to prove the expression of molar attractive energy in van der Waals gas were presented, and its applicable condition of weak short range attraction in molecular gas was pointed out. At the same time, the author revealed the mistakes in the misunderstanding by contrasting the calculating processes of attractive energy in van der Waals gas and in van der Waals solid. In addition, the author analysed the ultimate reasons in view of probability that increment of attractive energy in gas is distinguished from solid when they expand.