00:01
So distillation can be used to remove salts from the seawater.
00:07
And that is basically you boil the water off the container and you collect into another.
00:17
And the water will be transferred, will be a gas, of course, and then you have to condense that back into a liquid.
00:28
And it will not carry the salt that is dissolved with it.
00:34
So when it becomes a gas, it is freed from the salt, so you have pure water in the other side.
00:42
That's how you would use distillation.
00:45
Freezing would be about the same.
00:48
You wouldn't change container.
00:49
You would just lower the temperature until water starts to solidify.
00:56
And the solid will, if you do that very slowly, the solid will be pure, you won't have salt with it, but it's much harder to do that way.
01:07
So distillation is more popular.
01:12
But this is item a, okay, but most importantly, it's b, which talks about reverses masses.
01:22
And that's usually the way to go when you want to purify water in large scale because it's cheaper.
01:31
And also it's capable of removing gases, right? so distillation, you boil off the water.
01:38
And that is doing that you can remove solids.
01:43
They are dissolved in the water.
01:45
However, you cannot remove the gases, right? because the gases will just travel with the water to the new, to, the new container that you're going to collect.
01:55
Okay, so reverses models is cheaper and it can remove gases such as chlorine, which can be a problem in drinking water.
02:05
Okay, now let's look at this particular problem.
02:11
Say that we have this type of container where we have a membrane right here and in one side we have pure water right here and in this side, you have a solution of sodium chloride at 0 .5 molar.
02:34
Okay, obviously there is pressure...