Why enthalpy change is different from heat, even though they turn out to be pretty much the same anyway.

为什么焓变与热不同， 尽管事实证明它们几乎是一样的。

And I'm very happy the inventors knew how to calculate the enthalpy change of chemical reactions.

我很高兴发明者知道如何计算化学反应的焓变。

First, we'll find the enthalpy change using Hess's Law and standard enthalpies of formation.

首先， 我们将使用赫斯定律和标准生成焓求出焓变。

As long as you start with the same reactants and end with the same products, the enthalpy change is the same.

只要您从相同的反应物开始并以相同的产物结束， 焓变就相同。

Hess's law says that the total enthalpy change for a reaction doesn't depend on the pathway it takes, but only on its initial and final states.

赫斯定律说反应的总焓变不取决于它所采用的路径，而只取决于它的初始和最终状态。

So there you go, the calorimetry formula gave an absolute enthalpy change of 6.2 kJ, while Hess's Law gives a change of 5.67 kJ. So, why the difference?

所以你走了，量热法公式给出了 6. 2 kJ 的绝对焓变， 而赫斯定律给出了 5. 67 kJ 的变化。 那么，为什么不同？

The enthalpy change for a reaction is equal to the sum of the standard enthalpies of formation of the products, minus the sum of the standard enthalpies of formation of the reactants.

反应的焓变等于产物的标准生成焓之和减去反应物的标准生成焓之和。