物理化学中焓是一个重要的物理量,各种教材中均讲它没有明确的物理意义,对于初学物理化学的同学来说,对焓的理解存在一定的难度。通过分析焓变的物理意义提出焓具有明确的物理意义,丰富了焓的内涵,对学习物理化学的同学透彻理解这个概念和恒压反应热与焓变的关系很有帮助。 Enthalpy in physical chemistry is an important physical quantity, all textbooks say it does not have a clear physical meaning, for beginners physical chemistry students, understanding of enthalpy there is a certain degree of difficulty. By analyzing the physical meaning of enthalpy change, it is pointed out that enthalpy has clear physical meaning and enriches the connotation of enthalpy. It is very helpful for students studying physics and chemistry to thoroughly understand the concept and the relationship between enthalpy and heat of constant pressure reaction.