That's the important message, delta H of formation of the products, minus delta H of formation of the reactants.

去反应物的生成焓，这,是个重要的信息，生成物的生成焓,减去反应物的生成焓。

麻省理工公开课 - 热力学与动力学课程节选

And from that, then you can look at enthalpies of reaction for countless numbers of reactions, right.

很多很多种化合物,利用这些你就可以研究,不计其数的反应的反应焓。

麻省理工公开课 - 热力学与动力学课程节选

And our heat of reaction or enthalpy of reaction is defined as the enthalpy at constant pressure.

我们的反应热，或反映,的焓被定义为恒压，等温。

麻省理工公开课 - 热力学与动力学课程节选

It's a state function. If we know the enthalpy of the products minus the enthalpy of the reactants, right. It's a state function.

如果我们知道生成物的焓减,去反应物的焓的值,它是个态函数，原则上我们可以做到。

麻省理工公开课 - 热力学与动力学课程节选

In other words, we choose a convention for the zero of entropy, so that then we can write entropies of products and reactants always referring to the same standard state.

换句话说，我们选择了一个,焓零点的约定，这样我们,就可以总是相对于同样的标准,状态写出生成物和反应物的焓。

麻省理工公开课 - 热力学与动力学课程节选

And if I do that then I can find out the change in enthalpy of this reaction. It's just going to be the heat of formation of these three moles of water, minus the heat of formation of the iron oxide. OK.

我就能得到这个,反应的焓的变化,它就是三摩尔水,的生成热，减去氧化铁的,生成热，好。

麻省理工公开课 - 热力学与动力学课程节选

It's delta H of formation of the products minus delta H of formation of the reactants.

反应的△H是多少？,它就是生成物的生成焓减。

麻省理工公开课 - 热力学与动力学课程节选