00:02
Okay, so in this question, we have a gas mixture 1 % co2 by weight and 99 % o2 with a total pressure of 0 .97mospheres.
00:12
We're asked to find the partial pressure of the co2.
00:15
So the first thing we have to recognize is that these percentages are by weight.
00:20
And in order to apply dalton's law, we need to get them by mole instead.
00:26
So in order to get moles, we haven't been told how much gas we have.
00:31
So i'm just going to choose an arbitrary value that makes it easy.
00:35
So i'm going to start with one gram.
00:39
Let's get a different color there.
00:41
One gram of co2 and convert that to moles by dividing by the molar mass.
00:52
So the molar mass of co2 is 44 grams per mole because carbon is 12.
00:57
Oxygen is 16, but there are two of them.
01:00
Add those all together, we get 45.
01:07
And when we divide that out, we get 0 .022727.
01:15
We can do the same thing with the oxygen to figure out how many moles of oxygen there are in this hypothetical scenario.
01:23
So 32 grams per mole.
01:30
And that's going to be three, a little more than three.
01:33
Let's go ahead and do that on the calculator...