 So let's start our discussion of thermochemistry here or at least start solving the problems in it. So you may see a thermochemical equation or basic thermochemical equation, something like this, so methane plus 2 oxygens goes to carbon dioxide plus 2 waters plus 802 kilojoules of air. So what is that saying? That's saying when you have one mole of methane and it reacts with two moles of oxygen, you're going to get one mole of carbon dioxide, two moles of water, and 802 kilojoules of energy out of it. Okay, so you can think of energy as a product of the reaction if you want to like that. You can also think of it like since you're getting it out of the reaction, right? It's being released by the reaction, so that means it's negative in energy, right? So you can think of, in this case, delta E being negative 802 kilojoules. Is everybody okay with that? You can also think of it like this. So remember for every one mole of methane you burn, you get 802 kilojoules of energy, right? So is everybody okay with that kind of logic process? So if we say one mole of methane equals negative 802 kilojoules like that, right? We have a conversion factor. Does everybody see that? So it's just like using the 1 to 2 ratio here in the chemical equation. So if we had three moles of methane, how much energy would be be making from this reaction? Could you guys help me with that? So how will we do it? Yeah, so the change in energy for the three moles of methane, what will we have to do? Well, we would say what, three moles of methane? Well, let's do a 3.00. And then what will we put on the bottom here? And at the top, negative 802 kilojoules. So for every one mole of methane, it makes 802 kilojoules. Cancel, cancel. So what'd you guys get? 2406. Is everybody okay with doing equations like that? Remember is this reaction going to happen spontaneously or not? Why? It's making it, right? So it's spontaneous. This one gives off a lot of you. Questions?