大学化学 >> 2019, Vol. 34 >> Issue (2): 55-60.doi: 10.3866/PKU.DXHX201807046

师生笔谈 上一篇    下一篇

关于等温循环方法推导开尔文公式的讨论

梁嘉树,郭东升*()   

  • 收稿日期:2018-07-27 发布日期:2019-02-26
  • 通讯作者: 郭东升 E-mail:dshguo@nankai.edu.cn

Discussion on the Derivation of Kelvin Formula by Isothermal Cycle Method

Jiashu LIANG,Dongsheng GUO*()   

  • Received:2018-07-27 Published:2019-02-26
  • Contact: Dongsheng GUO E-mail:dshguo@nankai.edu.cn

摘要:

等温循环方法是物理化学教材中推导开尔文公式的一个经典方法。本文从热力学基本原理出发,明确指出其中小液滴可逆相变为气体的吉布斯自由能变化值应由吉布斯自由能判据求解,并对温度恒定、两相压强分别恒定时的判据进行了重新推导。同时,本文还提出了一种对推导开尔文公式的等温循环法的新理解方式,该方式在建立的“箱管模型”辅助下,意义明确,便于理解,更适宜教学使用。

关键词: 开尔文公式, 等温循环, 吉布斯自由能判据, 新模型

Abstract:

Isothermal cycle is a classical method to solve thermodynamic problems in physical chemistry textbooks. In this paper, it is pointed out that The Gibbs free energy change of the reversible phase transformation of the droplet into the gas should be given by the criterion in the method. The Gibbs free energy criterion at constant temperature, gas and liquid pressures can be proven based on the basic principles of thermodynamics. At the same time, a new model and a new understanding of the isothermal cycle method are put forward, which is more straightforward, and thus suitable for teaching.

Key words: Kelvin formula, Isothermal cycle, Gibbs free energy criterion, New model

MSC2000: 

  • G64