00:01
Hi everyone.
00:03
For this problem, we will be starting to use famous formula pv equals m r t.
00:15
This formula comes in everywhere.
00:19
And i think there will be lots of exercises so that we can get familiar with it.
00:25
So let's let's get into it.
00:31
P is for the pressure of a gas.
00:35
V is its volume, and t is its temperature.
00:41
Now the small n here is for number of particles in the gas expressed as moles.
00:52
But we don't actually need this n for this exercise.
00:55
So it will be a good example of an exercise where we don't need to use the whole equation and only part of it.
01:05
All right, so what is the problem? we have 3 .5 meters cube of a gas.
01:13
So let's draw a cube and imagine that there is gas in it.
01:21
3 .5 meters cube of it.
01:26
And it is placed at standard temperature and pressure, stp.
01:32
This means the pressure is 1 atm and the temperature is 273 kelvin.
01:44
Now, we place this volume of gas under a pressure of 3 .2 atm.
01:55
So something changes.
02:00
And now our cube will be different.
02:07
The pressure is now 3 .2 atm, which is a higher pressure.
02:15
And when we do that, we observe that the temperature of the gas rises up to the 38 degrees celsius.
02:26
38 degrees celsius in kelvin is 311.
02:36
So one thing will become very important when we use the ideal gas law, this one, is that temperature is always kelvin, always, always, kelvin in this equation.
03:05
And the thing we want to know is the volume in the final setting here.
03:14
I will write it vf for volume final.
03:21
Alright, so we have pressure, we have temperature, we want to know volume.
03:28
Looks like this equation is going to become handy, but we don't have the number of molecules of gas.
03:38
So we can't just use this equation directly...