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【知识脉络】一、正确理解“三热”概念1.反应热:在化学反应过程中反应本身放出或吸收的热量。在恒温恒压条件下的反应热用ΔH表示,单位是kJ/mol,并规定放热反应的ΔH<0,吸热反应的ΔH>0。2.标准燃烧热与热值:燃烧热是反应热的一种形式,使用燃烧热的概念时要理解下列要点。(1)规定是在101kPa压强下测出热量。书中提供的燃烧热数据都是在101kPa下测定出来的。因为压强不同,反应热有所不同。(2)规定可燃物的物质的量为1mol(这样
【First】, a correct understanding of the “three hot” concept 1. Reaction heat: the reaction itself in the chemical reaction release or absorption of heat. The reaction heat at constant temperature and constant pressure is expressed by ΔH in kJ / mol and specifies the ΔH of the exothermic reaction <0 and the ΔH of the endothermic reaction> 0.2. Standard heat of combustion and calorific value: The heat of combustion is a reaction A form of heat, use the concept of heat of combustion to understand the following points. (1) provides that the heat is measured at a pressure of 101 kPa. The heat of combustion data provided in the book is measured at 101kPa. Because of the different pressures, the heat of reaction varies. (2) The amount of substance that provides combustible material is 1 mol (so