00:01
Hi, so we have three questions here.
00:02
First one, we're calculating molality, second, mole fraction, and then the last one is the mass percent of our salute, which is an acl.
00:14
So let's start with molality.
00:17
So what you have to remember is that molality is equivalent to the number of moles of the salute over the mass of the solvent in kilograms.
00:30
Okay, so that's the formula for molality.
00:32
And we're given here with the molarity of the solution so for malaria it's presented by capital letter m it is equivalent to the number of moles of salute over the volume of the solution which should be in liter so that's malaria so from this equation you could assume that we have we will assume that we have 100 grams of solution then use the formula for molarity to solve for the number of moles of solute so we have 2 .45 this is moles per liter solution and then here we have number of moles of solute which is an acl over the volume of the solution so we have 100 grams how do we convert grams to liters we will divide the given density of the solution which is given to 1 .1 this is then we have here ml and then we just need to convert them out to liters.
01:35
1000 ml is 1 liter.
01:39
Cancel some units.
01:40
We're able to cancel grams here in an ml.
01:45
And solving for the number of moles of salute will get 0.
01:52
This 2 .23.
01:54
This is moles of an acl.
01:58
And then if we are going to compute for the mass of the salute, we'll have 13 sorry we just rewrite this one it's 0 .2 .2 3 this is moles of nacl multiplied the molar mass of nacl which is equivalent to 58 .44 this is grams per mole so that means you could cancel this one and we'll get the mass of an acl that's going to be 13 .03 grams of an acl.
02:33
Now we could solve for molality.
02:37
Molality is represented by small letter m.
02:39
It is equivalent to the number of moles of the salute 0 .2 to 3 moles over what's the denominator for molality we have here kilogram solvent.
02:51
So for solvent we will subtract the mass of the solution and the i mean subtract the mass of the salute from the mass of the solution so the mass of our solution is 100 grams and then the mass of our salute is 13 .03.
03:07
This is in grams, so that means we need to convert this to kilograms because, again, molality is in terms of kilograms.
03:17
1 ,000 grams is 1 kilogram.
03:22
So we'll be able to cancel grams, and there are many units are moles in the numerator and kilograms in the denominator.
03:29
So our answer for this is 2 .56...