 Cool? Okay cool. So let's try this one. If a gas occupies 10 liters at 273 kelvin with doubling the temperature to 546 kelvin, what is the final volume? So what are the two variables that are changing? Can you guys figure that out already? Volume and temperature. Okay when that happens it's called Charles law. Charles was some balloonist. Okay like when hot air balloons were all the rage back in like France in the 1800s you know and he was like some pioneer balloonist okay so he figured out that if you heat up a gas your balloon gets bigger okay that's essentially what Charles law is okay. If you cool it down it gets smaller too okay so we can start with pv equals nrt alright and we'll get Charles law and I'll show you what Charles law is. So pv, p1, v1, n1, rt1, p2, v2, n2, rt2 right so let's write down what we know from the problem. So v1 do we know that? 10 point of 100 liters right because it says if the gas occupies 10 liters at 273 kelvin so what is 273 kelvin? T1 right so everybody cool with it being T1 that's the initial temperature of it right it says if the gas occupies 10 liters at this temperature that means that's what it initially is okay then it says doubling the temperature to 546 kelvin so what does that mean we've done? T2 right we changed that temperature so 546 and then it's asking what is the final volume so what is that going to be? V2. So V2 is the variable we want to isolate right so did p change? No. Could v change? Yes. Did n change? No. And r never changes right so this is another way to write Charles law v1 over v2 equals T1 over T2 but a lot of times you'll see it written v1 divided by T1 equals v2 divided by T2 so it's the same thing though right try to mix that up okay so let's just use what we got from the ideal gap this pv equals nrt by the way it's called the ideal gas law it's cool because you can get all the other gas laws from okay so you don't have to memorize blah blah blah blah blah you know you can only memorize one thing so let's use this one that we got from the ideal gas law that's Charles law so we want to isolate v2 right let's use that flipping thing because it's easier when we have things on both sides to flip okay there's a easier or it's easier to just why we're doing okay so we want to get v2 on the top so we'll flip them both over okay so what do we get what's our equation going to be then v2 over v1 equals what T2 over T1 is the variable we're looking for isolated no so we're gonna have to do what multiply both sides by v1 right so once our new so that cancels our new equation is v2 equals what T2 v1 over T1 like that right it's much easier to do it this way with it instead of with the numbers you know so now what we do plug and chug right plug and chug yes exactly so what's our temperature take T2 546 Kelvin remember units and v1 10.0 liters and then T1 273 Kelvin so is there units that we can cancel here Kelvin what are the units that we get out leaders is that what we're looking for volume as a leader volume is good in leaders right that's what we're looking for okay so what do we do we can get our calculators out if you can't do this in your head this is to 2 divided by 1 essentially but so let's just do this together 546 times 10 and then divide that by 273 right and then what do we get 20.0 right why do we need three box around it you know that makes me happy so I know that your final is there a question okay I mean if you need to I flip that you'll flip you'll need to flip it when the isolate the variable you want to isolate is in the bottom okay so like if you have this form of the equation and you're looking for T1 right or flip it or look for T2 flip it you're looking if you have this form you're looking for v2 flip it what is your quick question are you sure you sure okay cool any more no okay