 OK, so let's do this one. It says, at 34.1 degrees Celsius, the vapor pressure of water is 40.1 torr. What is the vapor pressure at 85.5 degrees Celsius? The change of heat of vaporization of water is 40.7 kilojoules per mole. So this one, again, we're going to have to use the Glossius-Slaperon equation. So again, hopefully, you can see that it's asking for a change, right? So change in temperature. So we're looking for what is that other pressure. So let's write down what the actual problem gives us. So T1 is 34.1 degrees C. So T2, that's what we're looking for. And it gives us T2, 85.5 degrees C. And it also gives us delta Hf of water at 40.7 kilojoules per mole. The other thing you have to remember, well, of course, the equation, which is ln P2 over P1 equals negative delta Hf over R times 1 divided by T2 over 1 divided by T1. And this R here is the ideal gas constant. So T1 equals 0.314 joules per mole. So hopefully, you guys can see that we need to do some conversions, right? So what do we need to convert from 2? Can anybody tell me? Tor? OK, so tor, you might think. It actually doesn't tell us what vapor pressure units it wants it in. So tor would be fun. But there's something more obvious. Yeah, degrees Celsius, right? How do I know what you've got to convert that to Kelvin, right? Why? Because Kelvin's down here, right? We've got to cancel that out, OK? Is there another unit that we need to cancel out? Kilojoules and joules, right? So we've got to convert one of them to either joules or kilojoules, OK? So the other thing you want to know about this, right, is this is the ln of P2 minus the ln of P1, OK? If you guys don't know how to break that thing, OK? And that's how to get P2 by itself, OK? So anyways, what I normally say is to isolate the variable. Well, let's just isolate the ln of P2 for a second, OK? So how do we do that? So we go ln of P2 minus ln P1 equals negative delta F1 T2 T1, OK? So we could, if we wanted to, take this over to the other side, right, and isolate it. Honestly, with these problems, if you start doing that, I've seen a lot of undergraduates kind of get mixed up. So why don't you just plug and chug with these ones? I know you guys like to do that anyways. So let's just go ahead and do it. So what do we got here? We've got the ln of P2, that's what we're looking for, minus the ln of P1 according to 0.1 for negative 0.7 kilojoules or 1 mole, OK? So 1 over R, OK? So we're going to multiply that by 1 over R, which would be 3, 1, 4 joules. Is everybody OK with me doing that? What about T2? We've got to convert those to Kelvin. So let's do that really quick, 273. So that is going to be negative 0.7 kilojoules by 1 mole to the negative 4 Kelvin, like that, OK? Is everybody OK with me doing that? And then, what do we have to do? We've got to convert kilojoules to joules. So cancel out both of them, 1 kilojoule, 1,000 kilojoules. Is everybody OK with that? So let's go ahead and cancel. So this again equals ln of P2 minus ln of 40.01. So let's go ahead and cancel our units. So kilojoules, cancels with kilojoules, moles, cancels with moles, kelvins, cancels with kelvins, and joules, cancels with joules, OK? So we don't have any of those units left, OK? So we're looking for the 4 over here. So let's go ahead and just multiply those out. 9,000 by 8.314 times 40.7 times negative 1. So now I get ln of P2 equals 2.2969. We're just going to go out with a bunch of figures, plus the ln of 40.01, or sorry, 40.1. And there's 4. We're just going to keep going for it now. So plus ln of 8 equals 5.988. In order to, can I erase the top up here? Is that OK with this? So in order to get rid of ln, how do you get rid of ln, guys? E, E, OK? So E to the 7 or whatever, OK? And 898.7, that's about that. So I know it's a long process, but really, it's all about plug and chip, OK? So once you know how to do everything, you should be able to stick them in and just go around with them, OK? So let's kill that one.