 This one says the work done in kilojoules during a synthesis of ammonia in which the volume contracts from 8.6 liters to 4.3 liters at a constant external pressure of 44 ATM. In which direction does the work flow? So let's figure out how to do this problem. So the thing I need to first is my calculator. So how would we go about setting this thing up? So what would you need to know? Okay, the change in volume. So we know some things. We know the initial volume, right? What is that? 8.6 liters. And we know the final volume, which is 4.3 liters. So the change in volume is going to be VF minus VI. So 4.3 liters minus 8.6 liters. So when we do that, what do we get? Negative 4.3 liters. So what does that mean? It went kind of sucked in by 4.3 liters, right? So what else do we know? We know the external pressure, right? So what is that? The external 44 ATM. What else do we know? Okay, we know that conversion factor, right? 1 liter ATM equals 101.3 joules. And the last thing we need to know for this one is the work equation, right? So work PV equals negative P external times delta P, like that, okay? So in order to do this, just plug in chug, 44 ATM. And we've already done the calculation for the volume. So ATM leader, we can already, if we want to convert to joules, so 1 liter ATM is 101.3 joules. But it asks us to do it to kilojoules, right? So we've got to do one more. So 1,000 joules, 1 kilojoule. So cancel, cancel, cancel, cancel, cancel, cancel. And that should give us the same kilojoules, right? So let's just do it. So negative 4.3 times negative 44 times 101.3 divided by 1,000. So what do you guys get? Did anybody do it besides me? Not a single one? Okay, Valenti's doing it, right? So you can confirm. Did you get 19 kilojoules as well? Yeah. Okay. Yes. So the thing you want to probably remember to do is put a positive 19, so that'll tell you that whether work is flowing into or out of, what is, is work flowing into or out of the system? Into, right? Why? Because it's positive. So into. So work. Or energy, if you want to think of it that way. In this case it's work. Into. Is there any questions on that one? Pretty straightforward.