 So yeah, so like I was saying time is never wasted if you're learning something. That's what I like to say now Okay, so did you wanted to do something PV equals inner T or something like that? Have a good one Alan You let me do this one and I'll get that for you. Okay, cool. Yeah so Is there a particular one of these that you want to do or all over this pretty much the same just different ways Pick one. Okay Okay, let's try this one It says 1.30 liter balloon is taken from room temperature 25 degrees Celsius and placed into a freezer at negative 11.5 degrees Celsius. What's the new volume? So you can like I was saying you can do all these PV equals in our T's or all these gas laws by using PV equals in our T So you just do PV equals in our T one one one one and you don't put the one on the R because it's constant and then you divided by PV equals in our T but P2 V2 and to our T2. Okay, so R is the same So it cancels out So let's just write down what the problem gives us now so T1 Is the initial temperature? And it says that's room temperature 25 degrees Celsius But you can't use degrees Celsius. What do you got to use? Kelvin and how do you get that from degrees? So 25 plus 273. What is that? 298. 298 Kelvin. Okay So it also gives us T2 which is cool and that says negative 11.5 degrees Celsius So 263, 262, 261.5, right? And it also gives it Gives us volume, initial volume, so V1 There's 1.30 liters and that's the units you want to do and then V2 is What we're looking for. It says what's the new volume? Okay, so notice the only things that changed are the temperature and the volume Does that make sense? Yeah So if that's the case did the pressure change? No, no, so P1 and P2 are the same is what it's saying Okay, did the volume change? So we did our V1 and V2 different. Yeah, so we got to leave that like that. So let's bring those down V1 divided by V2 equals did the number of moles change? No, no, so N1 equals N2, right? So we can cancel that and Did the temperature change? Yes So we got to bring that down. T1 does not equal T2 So we do that. Does that make sense? So there's a bunch of these gas laws you can do them all like this So all you really got to remember is that D equals N2 makes a lot easier Well, it we're looking for V2. Okay, so the easiest way for me to get there I like to get there just by flipping everything over, right? So if you flip one side, you can flip the other one. Okay, so we're going to turn this into a different equation V2 over V1 equals T2 over T1 So let's just erase up here for a second And remember we have to isolate the reason we did that why do we do that because we're trying to isolate the variable V2 Right? Okay, so we need that by itself. Yeah So in order to now do get V2 by itself We multiply both sides by V1, right? That'll cancel V1 out So if you can do anything to them, right? You just got to do it to both sides So if we cancel V1 out like there, what's our new equation? V2 equals T2 V1, right? Is this the right T1? Is that right? Yes So then we're going to erase that part and then now it's easy. Just plug and show So What's T2? T2 261.5 Kelvin. Why did I I left all of that just because the final answer I'm going to take to well 366 Okay, so V1 is Going to be 1.30 leaders divided by T1 Which is 298 Kelvin Notice Kelvin divided by Kelvin cancels and you're left with what? Leaders. Leaders. Is that what you want? Yes. Yeah, because you're looking for a volume. It's awesome So do leaders And then all we got to do now is take 261.5 multiply that by 1.3 divide that by 298 I got 1.14 that's the new volume of the Balloon So the other thing I want you to ask yourself is When you increase the temperature of a balloon does it get bigger or smaller? It's bigger. Did we increase or decrease the temperature here? We took it from room temperature put it in the freezer So what do we do? Decreased. Well think is that what happens when you put things in a freezer? So think didn't remember it's not all in the chemistry book. Okay, so if you put something in the freezer What happens to the temperature? It goes down goes down, right? So you would expect the balloon to get bigger or smaller smaller did it get smaller? 1.14 smaller than 1.30. Yeah, so that's your final check Okay, so make sure you May use your brain, you know not just your chemistry and cancelling units, you know because you know But in the freezer it's gonna get smaller Cool any questions?