这个反应的能量变化是-349千焦每摩尔。

The change in energy for this reaction is negative 349 kilojoules per mole.

youdao

你可以让原子粉碎原子，产生连锁反应，产生能量，那是一个非常惊人的发明。

You can get atoms to smash atoms and create a chain reaction and create power, that's a pretty amazing invention.

youdao

你看，原来某些微生物是化学合成的——它们不需要阳光，因为它们从化学反应中获取能量。

You see, it turns out that certain microorganisms are chemosynthetic—they don't need sunlight because they take their energy from chemical reactions.

youdao

So if we have a negative change in energy for any reaction as it's written, what that actually means is we're giving off energy as the reaction proceeds.

如果我们像这里写的这样,在任何一个反应过后，得，到的能量变化为负值,这就意味着我们在这个过程中放出了能量。

麻省理工公开课 - 化学原理课程节选

And we haven't talked about reactions at all yet, so you don't need to worry about the specifics of that exactly, but just that if you have this negative change in energy, you have a more stable product than you do reactant.

当然我们还没有开始讨论反应，所以你不用担心它的细节是怎么样的，你只需要知道，如果能量的变化是负值，那么你将得到一个比反应物更稳定的生成物。

麻省理工公开课 - 化学原理课程节选

Hess' Law states that for any chemical reaction, the energy change is path independent.

盖斯定律表明，对于任意化学反应，能量变化并非是路径依赖的。

麻省理工公开课 - 固态化学导论课程节选