You could run the reaction, take solid iron gaseous oxygen, form iron oxide, measure the heat of formation of it, tabulate it.

你可以进行一个反应,用固态铁和氧气生成氧化铁，测量它的生成热，列成表格。

麻省理工公开课 - 热力学与动力学课程节选

Something I can measure and I can tabulate, and when I turn my dT knob here I know what's going to happen to the enthalpy.

----热容，我们可以用实验，测出热容并成表,当我知道这里的变量。

麻省理工公开课 - 热力学与动力学课程节选

Iron as an element is a solid. That's it's most stable state at room temperature and pressure, right, and so on. And then we can figure out heats of formation.

铁单质是固态,这是他在室温和常压下,最稳定的状态，然后我们,可以算出生成热，现在这个。

麻省理工公开课 - 热力学与动力学课程节选

We can tabulate them. We can know them, and then when we have reactions that inter-convert different compounds, we can calculate the heat of reaction is just the difference between the heat of formation of the reactants, and the heat of formation of the products, right.

种化合物的生成热，可以把它们列成表,可以认知它们，而当我们要处理，在不同化合物间转变的反应时,我们只要计算反应物和,生成物的生成热之间的不同,就能计算出反应热。

麻省理工公开课 - 热力学与动力学课程节选

So here, I'm going to have delta H, is just the sum for all the products of delta heat of formation right? Here I'm going to put together all the products. So this is a positive heat of formation.

所以这里△H就是所有生成物的,生成热的和,对吧？这里,我要把元素组合成所有这些,生成物，所以这里是正的生成热。

麻省理工公开课 - 热力学与动力学课程节选