00:01
Okay, so in this question, we have to compute the vapor pressure of a solution.
00:06
To do that, we use raululah.
00:09
That says that the pressure of some species a is going to be equal the pressure of that species when it's pure.
00:17
So say the pure solvent times the molar ratio of that particular species, the molar fraction.
00:26
So we have the pressure of the water when it's pure.
00:30
31 .8 tor or millimeters of mercury.
00:35
And we have the masses of both water and sugar.
00:40
So we can compute the molar ratio and then we can multiply both to get the vapor pressure of our solution.
00:49
So let's go ahead and do that.
00:50
So let's start by computing the number of moles of the sucrose, which is the sugar, which is our solute.
01:00
And we have 396 grams.
01:06
So we use the molar mass to convert that to moles.
01:10
The molar mass of sucrose is 342 grams.
01:16
So when you compute that, you will get 1 .16 mole.
01:24
Cool.
01:25
Now we can go and do the same for water.
01:28
So number of moles of water is going to be equal.
01:36
624 grams that was given in the question so we convert that to moles using the more mass again the molar mass of water is 18 grams so cancel the units here sanity check and then the value should be 34 .7 great so now we have all the malls they are needed so we can compute the total and therefore the molar ratio...