00:01
All right, so we have questions on gas laws here.
00:03
The first one, we're told that helium -fueled weather balloon has a volume v1.
00:09
Let's take a look at that.
00:09
V1 is 527 liters.
00:16
The pressure, p1, was 753 millimeters of mercury.
00:25
And the temperature, t1, was 25 .9, and add 273 to that, and you have, sorry, 21 .9, not 25.
00:35
And you would have 294 .9 kelvin.
00:41
Now, the question is, what is the volume at an altitude where the pressure is now, p2 is 487 millimeters of mercury, and the temperature is now minus 10 .1 degrees celsius.
01:05
So temperature, t2 is 273 minus 10 .1, and that's going to give you 262 .9 kelvin.
01:16
So to solve this, we use the combined gas equation, p1 v1 over t1 equals p2 v2 over t2, which means that v2 would be p1 v1 t2 divided by p2 t1.
01:35
And the v2, the volume, would be p1, we're told is 753.
01:41
So 753 multiplied by 527, 27 multiplied by 262 .9, divided by 487, multiplied by the initial temperature, which was 294 .9.
02:01
When you punch your calculator, this will give you 726 .4 liters.
02:09
That's what you have.
02:11
All right, let's look at b.
02:12
Then b says, a sample of nitrogen gas has a volume, v1 is 7 .9 liters, 97 liters.
02:24
T1, we're told the temperature was 44 degrees celsius, plus 273, and so that would give us 317 kelvin, and the pressure was one atmosphere.
02:44
All right, so the question now says, if it's desired to increase the volume, we want to v2, we want to increase it to 10 .8 liters, and the temperature, and the pressure is decreased, p2 is 0 .877 atm.
03:00
And the question says, what is the temperature of, at the new volume and pressure, what's the temperature? we're looking for t2.
03:13
Of course, we'll get that in kelvin spheres and then convert...