by Jules Bruno
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in this video, we take a look at the technique off extraction. Now we're gonna say, under extraction, we have the separation of a solid Add a liquid. Now we're gonna say we have the removal of a component from a mixture by selective precipitation and a new solvent. So here what we have is a secretary funnel. And in this Secretary funnel, we have two different types of liquids Were going to say here that this is the mawr dense mawr dense layer. And usually this more dense layer represents water. So we'll say that this is our acquis layer. And up here is our less dense layer, which is why it's floating on top. And usually that's something that's organic, meaning it has carbons within it. So we'll say that this is our organic later. Now, the way extraction works is we have different types of precipitates within our organic clear. And what we're gonna do here is we're gonna react the organic layer. Um, in the traditional type of extraction is acid base extraction. So we'll react the organic layer with either an acid or base and transform that Saul you particle into an ion and want to get to charge. It becomes polar, and therefore it will go down into the acquis layer. And in that way we can then drain out by opening up this stop cock. We open it up, and then the acquis layer just pours down into here with our salute. And then we re make it into a neutral form of itself, and then it will solidify within the quickest slayer. And once it solidifies in the Equus layer, we can just go in and physically remove that solid from the liquid. So that's how extraction works now here. Like I said, the most common type of extraction is acid base extraction. Okay, so here we're gonna say the pH of the system is selectively varied by adding strong or weak base. Usually sometimes even strong, a weak acid, depending on what our initial components are now, depending on the peak a of the component, it's soluble it, Ian. Equus organic layer will change. So we're gonna stay here if we have the formation of an eye on. Like I said, it will increase. Saw you bility in the acquis layer. And then if we have the non ionic or neutral form, it will be more favorable within the organic layer. So an example of this is we could have ammonia. Now. Ammonia is a weak base and then with ammonia weaken, also have acetic acid, which can be written to different ways. Either this way or or this way. Both are technically correct. So we'll have both of them within our secretary Funnel. Right. So here in our secretary funnel, we have our acquis layer here, and then we have or organically you're here. Well, say here that ammonia is a acetic acid is be so they're both neutral right now, so they're both found in the organic layer. So what I would do here is we can add a base because that's customer what we do. First, we add some base so I would drop some bass drop by drop into here. The base would react with the acid, the acetic acid. So if you don't recall this or haven't gotten there yet, just remember when it comes to acid base reactions, the acid donates on H plus ion. So one of its hydrogen gets donated to the base so this H plus or this H plus gets donated to the base. As a result, we create C two h 30 to minus or ch three c 00 minus the fact that it gains a charge in whichever form you're writing. It gained a charge, so it'll slowly go into the acquis layer because water is polar. If you have a charge is a compound you're also polar likes. Dissolve likes So the newly formed acetate ions going to the acquis later. So now they have been physically separated. They're both founded different liquid layers. So once the acetate ion is in this layer, we drain this layer into this beaker. So my acetate ion is now in this speaker. But I wanna isolated solid form. How do I isolated solid form? Well, water is polar. It has a charge currently. So it's polar. To make it become a sound again, I need to make it non polar because once it becomes non polar again, it will no longer dissolved within the water. So it took a base to remove an H plus from it to make it a charge to form. So what I'm gonna do now is I'm gonna add some acid when I add that acid the ass is gonna donated H plus two acetate ion recreating my acetic acid. And now that I have acetic acid and it's neutral, it's gonna be insoluble in my a quay slayer. So it's gonna form a little solid here on the bottom, which I can then go in and pluck out. And in that way, I've just separated my solid from the liquid. This is how extraction works. Now the thing is, because we're dealing with acid base extractions, we have to add the base right drop by drop to the to the organic layer. But you can't just let it go drop by, drop in weight, forward to react. What you need to do here is you need toe. Make sure this thing mixes so that the base gets into contact with the acetic acid. So what you would do is you would put ah cork on top of here and then you would take the secretary funnel and you would you would mix it So you go this way to get a thorough mix. So the base would basically mix all in here. Okay, going like this. But the problem with an acid based reaction is that it will build up pressure. So we would take this and you would invert. It's that the this portion here is pointing up and you kind of angle it up some, and then you would open it up slightly to relieve the pressure that comes out because the pressure would build as you're mixing acid and base together, because that's a very reactive process. Okay, so if you don't vent out the gas that's being created as a result, it has the potential to erupt. So the secretary fund could actually, um, crack. Or it could just open up itself and some of the acid and base would spill on it, which you don't want. Okay, so you would mix it by inverting it to make sure mixes and then air out, vent out some of the gas that forms to relieve pressure and then go back. Then you will leave it alone. The two layers would eventually reform again, and we make sure now because we've added that base, the acetic acid has become acetate ion, and it's now on the acquis layer, and you contest this by using a litmus, a piece of litmus paper and checking to see is the organic layer basic enough. If the organic layer is basic enough, that means that it has basically neutralized all the acetic acid in the organic layer. And in that way, we can then separate the acetic acid portion from the that's now in the Equus. Lay weaken, separate that out and isolate that acetic acid at the end. Now this is just a simplified view of what's going on in terms of acid based extractions. We'll talk about it more detail. What if we had multiple compounds and we wanted to separate each one of them from a solution through the use of acid base extraction?