物理化学系统过程不可逆性的量化

The quantification of irreversibility in physical and chemical process

从平衡态热力学的基本概念出发,分析了以热温商作为熵变算式对于包括不可逆过程在内的一切物化过程的普适性,但对于包含不可逆膨胀或压缩以及不可逆化学反应的过程,在计算熵变时,不仅考虑系统与环境的直接热交换,还考虑不可逆过程转化的能量.根据Clausius不等式代表的判据,分类讨论了二体间的不等温传热和不可逆膨胀或压缩,以及恒容绝热、恒压绝热、恒温恒容和恒温恒压条件下不可逆化学反应过程中熵增加在判据中的体现.发现以反应Gibbs自由能作为自发性判据,适用对象远不止于恒温恒压且不作非体积功的系统,这与化学势判据相吻合.

According to the basic conception of thermodynamics, by using the ration of heat to temperature the entropy increase is calculated, which is adapted for any infinitely small process including irrveversible expansion and chemical reaction, when the irreversible transform of energy and the heat exchange between sys- tem and environment are considered together. In term of the criterion in Clausius inequality, the entropy increase of isolated system is discussed in heat conducting is discussed between two non - isothermal bodies, irreversible expansion, and irreversible chemical reactions under some external conditions, including constant volume and pressure, constant temperature and volume, and constant temperature and pressure. The conclusion shows that the negative molar Gibbs change leads the spontaneity of reactions which dont involve the non - expansion work, no matter the reactions are at constant temperature and pressure or not. This is accordant with the criterion elucidated by the chemical potential.