00:01
In this problem, you're asked to determine the mass of glycerol c3h5 -oh3 that's required to form an aqueous solution with a mole fraction equal to 0 .093.
00:21
You're given 425 grams of h2o as the solvent.
00:27
You're also asked to find the molality of the resulting solution.
00:31
So let's start by finding the amount of glycerol that's required.
00:37
So in this case, our mole fraction, 0 .093, is going to be equal to the moles of glycerol over the total moles in solution, which is equal to the moles of h2o plus the moles of glycerol.
01:07
So in order to solve for moles of glycerol, we first have to determine moles of h2o, which we can do by using the mass of h -sh2o that's given, 425 grams, and dividing by the molar mass of water, which is 18 .015 grams per mole.
01:30
And doing this calculation yields the value of 23 .6 moles.
01:44
Now we can substitute that value into the equation that we came up with earlier, and that would be .093 is equal to we use x as a variable to represent the multiple glytheral over 23 .23 .23 .6 moles plus x.
02:21
So we can solve this equation first by multiplying both sides by the denominator here which gives us 2 .19 moles plus 0 .09x is equal to then we can subtract this to the other side, which gives us 2 .19 moles is equal to .907 x, and dividing by .907 gives us x is equal to 2 .42 moles of glycerol...