 Okay, so let's try this one. It says how much energy would it take to boil 36 grams of water at a hundred degrees Celsius? And then it gives us the heat of vaporization as plus 40.7 kilojoules per mole, so Let's write that down So, for water plus 40.7 kilojoules per mole. So, if we've got, what does it say? We've got the mass of the water at 36.0 grams. So, how would we know how much energy we would need? How would we do this? Anybody help me? So, what is, will this help us? This grams? We've got to convert it to moles, right? Why do we got to do that? Because we got this thing over here, that's a what? The conversion factor, very good guys, right? And so that's going to convert for us what? moles to kilojoules, right? And kilojoules is a form of what? Energy, and we're looking for what? Energy, okay? So, it's just these two conversion factors on top of each other, okay? So, 36.0 grams of water We know the molar mass of water 18.02 grams of water for one mole. We have this conversion factor up here. So, one mole of water is plus 40.7 kilojoules. So, we should be able to cancel, cancel, cancel, cancel, cancel, giving us energy up there. Is everybody okay with that? Oh, and this is no longer the mass of water, right? This is going to be, you want to think about it that way, energy or something. Now I need to find my calculator, which is somewhere, can I just, thank you, confiscate that for a second. 36 divided by 18.02 times 40.7 And it doesn't tell us what energy units it wants it, but it does say three sig figs, right? So, I mean that 36.0 gives us three sig figs. So, I got 81.3 kilojoules This is going to be positive, 81.3. So, if you want to put the plus, that's fine with me, kilojoules of energy. So, what do we need to do? We've got to pump energy into this system, right? So, and two questions I guess, maybe would be the better way.