00:01
So what is the difference between a mixture and a solution? it's a very distinct one that chemists have to worry about all the time.
00:12
A mixture, the components are not dissolved, which means, okay, i might say, okay, that makes sense.
00:27
But what it means is that they can be separated.
00:45
In a solution, there's complete combining.
00:48
Of the substance of the solute with the solvent.
00:57
And so it is very difficult to separate the two, unless you do something, maybe chemical.
01:06
But usually you use a physical process, not always, but there's usually a physical process that you can find to separate the components in a mixture.
01:40
Okay, so we'll take a look at some examples.
01:42
Of the separation processes, and i am going to also include an example from the kitchen, because usually people really get into the chemistry in the kitchen.
01:57
So examples from cooking.
02:06
So we'll take a look at some processes, and the first one is, what do we do to an insoluble substance that goes into a liquid, and we try to get that substance back through using a filter paper.
02:24
Okay, so this is filtration, and there's a little slight difference between filtering and sieving, but this is filtration.
02:36
An example that many people are familiar with is using a coffee filter in your coffee maker.
02:52
So you put in your grounds, okay, this is kind of a silly picture, but you put all the coffee grounds into that filter, in comes hot water, and you have coffee coming out, hot coffee, but the grounds stay put.
03:13
So we're separating those grounds from the liquid.
03:22
Okay, a method of separating excess liquid from food by heating would be evaporation.
03:34
An example of that, i don't know if you're familiar with dehydrating, a lot of people will buy a special device called a hydrator, dehydrator.
03:50
And it's simply a set of trays that you can stack one on the other.
03:55
And you put typically fruits and vegetables, but you can put meat in there as well.
03:59
So strawberries, zucchini, i don't know, getting creative bananas.
04:08
So you can put slices of fruits and vegetables.
04:11
And then there's usually a fan in the bottom that blows air over the pieces, and that air is hot air.
04:27
And as you wait over time, the usually takes at least a day for reasonably sized slices, but you're removing the water from the fruit and vegetables.
04:48
And as a result of that, the dehydrated vegetables and fruits can be kept for a very long time, even outside the refrigerator.
04:58
So it's a method of food storage that allows preserving foods for long times.
05:07
Decantation, which of the following mixture can be separated by decantation? in decantation, what you're hoping is that two liquids do not dissolve in one another, and they will separate due to gravity.
05:37
And in fact, that's what a centrifuge does.
05:42
But in the absence of a centrifuge, you put your two liquids in a bottle.
05:48
I think those are called decanters.
05:51
And you wait, and you wait, and you wait.
05:54
And you'll get the lighter liquid floating to the top, the heavier one on the bottom.
06:09
So an example of this is oil and water.
06:16
They do not mix.
06:19
Yeah, like they say, oil and water do not mix...