00:01
Hi.
00:02
So we have here partial molar volumes of two liquids in a mixture and we're given with the mole fraction of a and it's partial molar volume and we also have the partial molar volume of b as well.
00:24
And we're given with the corresponding molar masses of a and b.
00:28
So first let's calculate the mole fraction of b.
00:36
Since we only have a and b in the mixture, that means the mole fraction of a plus the mole fraction of b is equivalent to 1.
00:46
So, mole fraction of b is 1 minus the mole fraction of a 0 .3713.
00:55
So before this, this is 0 .6287.
01:01
Next, we will use the given molar masses of a and b to determine the number of moles of a and b is.
01:07
The given mass of solution which is one kilogram.
01:12
Let's take note that mole fraction is number of moles over d.
01:17
For example, for a, number of moles of a over the total number of moles in the solution.
01:22
So that's sum of the number of moles of a and the number of moles of b.
01:26
And the mole fraction of b, this number of moles of b over total number of moles in the mixture.
01:40
So i'll just rearrange this equation to solve for the number of moles of a.
01:46
We have mole fraction of a multiplied by number of moles of a plus number of moles of b.
01:55
And number of moles of b is equivalent to the mole fraction of b multiplied by the number of most of a plus the number of moles of b.
02:04
Now using the given mass, one kilogram is equivalent to 1 ,000 grams.
02:09
So we will use the mass in terms of grams.
02:12
We're given with the molar mass in terms of grams per mole.
02:16
So if we multiply the number of moles of a with its molar mass, which is equivalent to 241 .1 grams per mole, it's 241 .1 grams per mole.
02:32
And then we'll add the number of moles of b multiplied by its molar mass, which is equivalent to 298 .2.
02:39
This would be equivalent to the mass of the solution, which is 1 kilograms.
02:47
So let's convert this to grams because, again, let's convert this to grams because the molar mass is in terms of grams.
02:58
Now this equation, we can rearrange this in a plus nb.
03:06
It would be equivalent to number of mals of a over a fraction of a...