00:01
To calculate, first of all, the more fraction of each component and valerity and molality in the concentration in ppm.
00:08
So let's first of all start from the first one.
00:13
If you want to calculate the more fraction of each component, let's assume that it has one liter of the solution because you go by percentage.
00:22
So the density of the solution is 1 .18 gram per liter and the mass of the solution equals the density multiplied by volume.
00:41
Now from here as again we assume that the volume is one liter.
00:48
So the density is 1 .18 gram per millimeter and the volume we assume 1 liter 1 ,000 millimeter.
01:07
That would give you 11a 0 gram.
01:13
Now let's calculate the mass of magnesium chloride because we know the magnesium chloride as marked as 20 % by mass.
01:24
So the mass of magnesium chloride is going to be 11a0, the solution multiplied by 20%, which is 0 .2.
01:39
That is 236.
01:42
The next step, the calculate the mass of the water.
01:48
So the mass of the water is going to be the total solution, 1 180 gram, minus the mass of magnesium, which is 236.
02:06
So that is 944.
02:16
All right, so then let's calculate the mole of the magnesium.
02:25
That is going to be the mass divided by the 1st, by the molecular weight.
02:31
And you can always find out the molecular weight of magnesium is online 95 .21 gram per mole.
02:45
So the mass we know is 236 gram.
02:51
This is around 2 .48 mole.
02:56
All right, so the next step, you want to calculate the more of the water, 944 gram, divide by molecular weight or mass of water which is 18 again you can find this information online that is 52 .44 mole all right so now let's calculate the mole fraction the mole fraction is going to be the more of magnesium fluoride divided by total mole which is the mole of magnesium chloride plus water so so we can actually do our math.
03:58
Mole of magnesium is 2 .48 mole, and the total is 2 .48 plus 52 .44.
04:11
This is water.
04:15
And then you can actually calculate.
04:21
This is around 0 .045.
04:28
So this is the mole fraction of magnesium.
04:34
And of course, if you want to do the more fraction of water, this is going to be the opposite.
04:48
The mole fraction of water is 1 minus 0 .0 .05.
05:10
So the rest of the mole is going to made up water.
05:13
So 0 .955.
05:23
So this is actually the moor fraction of water.
05:27
All right, so now let's calculate the second.
05:30
The second is molarity.
05:33
A molarity of magnesium can be calculated by mole of magnesium, divide by the volume of the solution...