Hello and welcome back to another video with ItsDrDan, and today we're going to be looking at the hydrolysis of esters for introductory organic chemistry. So what is that all about? Well, try to think of the word, right? Hydro. If you think of hydro, what's the first thing that comes to your mind? Well, hopefully it is water, right? So whenever we have hydro, the entire idea should be water. Now, When we look at the rest of the word, lysis, well, if you're someone that maybe has taken physiology or microbiology or any type of intro to bio, lysis is all about destroying or getting rid of, well, lysis in particular stands for to cut, so what we are going to be doing is we're going to be cutting with water. So instead, if you remember from esterification videos, that was all about removing water. Hydrolysis is the opposite process where this time we're going to be cutting with water. Now, depending on how we can cut with water, this is something that can exist in two different ways. Now, so we have acid catalyzed hydrolysis. And then we also have base catalyzed hydrolysis, also known as saponification, so, which is making soap. So, we're going to be diving into both of those different reactions in this video, starting with acid catalyzed, going through trying to understand that, and then going through many examples along the way. Acid hydrolysis is when water reacts with an ester in the presence of a strong acid like HCl, H2SO4, or or HNO3. And when it does that, it's going to make it into the original components that made the ester in the first place, which is an alcohol and a carboxylic acid. So as I mentioned earlier, this is the opposite of esterification. So with this, we're going to be cutting our bond. So when we are looking at this, well, how exactly are we going to be cutting it? What are the different parts of this? Well, it's going to be similar to a lot of reactions that we had before, especially if you think of hydration reactions back during addition. Now with a hydration. The big thing is here is that you were adding an -H and an -OH component to this. And it's gonna be very similar here. 'cause the whole goal is to get our original components. So when I cut this particular bond, right, so if I put my little scissors here and we cut this, we're going to be adding our two parts. Now keep in mind what is our goal is we want an alcohol. and a carboxylic acid. So the first one is if I want an alcohol, well the most likely candidate for that is going to be the part on the right, and it's going to be putting our little puzzle piece of an H attached to that. So if I add my part here where I have an H connected to O R, Right, we have an alcohol that is formed. Now on the other part, well, for our OH, that's going to make our carboxylic acid. So when we put all those pieces back together, we have our R C O, double, our C double bond O, with an OH component, which are our two pieces from our water molecule put together. So we have alcohol and then a carboxylic acid As our two components here and that's the general idea is that whenever we have an acid with heat We can cut the bond and completely change what it is before right? So when this happens the pH is going to change Because now you have an acid as one of your properties So you should see results and a change in how it behaves and how it smells too Okay, let's go through some different examples of this. Alright, our first type of example. So here what we're going to be doing is predicting the following reaction. Meaning we're going to go through hydrolysis by adding an acid to the following different compounds. So commonly the way that you will see an acid introduced is whenever you have an H plus written, because if you think of an acid, it's something that donates a proton in a reaction. And if acids and bases are something that aren't as memorable, go over to my acids and bases video and then I'll help you remember that concept. So, with this one, right, the whole idea is that we have this ester and we're going to be cutting it with water. So when we are cutting this, we do it between the carbon and the O, so it's between the two different parts of the functional group here. So when we cut, right, we're going to be adding H and OH to our two different pieces. making a carboxylic acid and an alcohol. Now the portion that is the ether side, right, so if I were to kind of label these, the ether is going to go towards the alcohol. And the more, the C double bond O is going to turn into a carboxylic acid. If you were to kind of break apart the ester into what components does it have. So the carbonyl will feed the carboxylic acid. When we do that, we are going to be, we are going to take our C double bond O, that will have our OH component to make the carboxylic acid. And then on the other part, the alcohol is going to be our HO with our 2 propanol on the other structure. So then we have the two different products that you're going to have and you have to list out all the products that are being made in these reactions. Or you did not predict the products correctly, right? You have to list them all. Now on the next one, it's going to be the same general idea, right? We're going to cut our bond. right between the two oxygens. Now we're going to add our two components, right? So we have H and OH are what's going to be added here. So we're going to redraw our carbons, which that's another thing to mention as you're going through these, make sure you still have all of your carbons accounted for at the end of the reaction, right? So in this particular one, we have eight carbons going in, we should have eight coming out of it in the end as well. So make sure you check, right? So you have the benzene ring, which is six, the C double bond O, which makes a seventh carbon. Then we will add our OH to this. And then on our other part, we have a methanol, which is our eighth carbon. So you can see that everything is accounted for in this reaction. So we, this is your acid base catalyzed reactions. Let's go on to our base hydrolysis type reactions. Okay. Now we're going to be looking at saponification. also known as base hydrolysis, which is really similar to the concept of actually making soap or how soap works. Um, so with this one, we're going to see when an ester is going to undergo hydrolysis, but this is in the presence of a strong base. Um, Mark particularly might see sodium hydroxide, which is NaOH or potentially potassium hydroxide. which is KOH now the products for this are a carboxylate salt which we'll go over what that show it looks like and an alcohol so with this particular reaction I'm going to try to explain it in like the I would think it's like the easier way just to kind of memorize it for yourself and how the reaction happens not the exact actual like mechanism behind it because it's a little more complicated than the acid hydrolysis. But if you think of it in terms of trading charges, it actually will make a little bit more sense if you remember it this way. So what exactly is it? So let's take a look. So when we have, let's say an Esther with a base, so we have the Esther on the left hand side, uh, which is right here. And then we have our strong base. Now remember this whole entire thing, it's going to be under heat and involving water because that's, what's going to be doing the cutting. Now for this one, the easiest way to think about it is let's look more at the charges here. Um, and I know these are not ionic, entirely ionic species, but it's something that it makes them make a little bit more sense. So if you have the first one, which let's say if we look at the sodium hydroxide, right, we have a plus and then we have a minus on the two portions of that, right? Because it's an ionic species. Now, the whole idea here is that we want to trade positives, okay, so that's what we're going to say. Trade positives, because we always like being positive around here, right? So when we are being positive, we want to trade positivity. So how can we label that on our ester? Well, if you remember from hydrolysis, the main part of hydrolysis is going to be happening right kind of around this oxygen. In particular, this one's going to be more on the right hand side for this particular one, just so it makes sense. We're going to trade positives. So it, what is negative in this case? Is it the oxygen or would it be the R group? Well, if you think of. oxygen. It's on that top right hand side of the periodic table. So it's more electronegative. So I'm going to label that with a negative. Now with the R group, this is going to be R positive. We're going to trade the two positives. Okay. So we're going to do a little bit of a swappy, swappy. and trade the two different portions, right? So kind of like a double replacement reaction. So when that happens, now we are going to be making on the left hand side of this reaction is our carboxylate salt. Now, why is it referred to as a carboxylate salt? Well, if you think of a salt compound, that is whenever we have ionic charges, okay? So we need to make sure that we do illustrate the ionic charge when it comes to the product. You must write the charges. So when we treated them, this made a Na plus salt, which is going to change the solubility of this compound immensely. The second you add that ionic characteristic, ion dipole forces are possible, which is the strongest intermolecular force that you can have. So, this is stuff that makes like fats and oils soluble if you think of in the sink, right? If you mix it with, let's say, if you are washing a pan after cooking and it has oil on it and you wash it with only water, does the oil come off? And the answer is no, obviously not. What do you do? You add soap. Well, soap is what's going to make it have an ionic charge and make it very similar to this, causing it to be soluble and immiscible in water and cause it to go down the drain, right? So it's a very similar idea here. So we'll also make an alcohol component as well. So alcohol in that carboxylic salt is the two different pieces. Let's go through trying to practice the idea of trading positives to make our products. And if this is something that you want to try it on your own, fully I recommend pausing it. We're going to go through two examples of how to look at these reactions. All right, let's do an example of base hydrolysis with an actual chemical compound. Now with this one, you can see that we have an ester compound on the left hand side, and it's being added to sodium hydroxide, and this is under heat. Now the question you might think of is, oh, I thought this was hydrolysis. Where's the water? Well, remember, sodium hydroxide, or an acid or a base, is made in water, so it's always assumed that this is aqueous, and that there is water present in the reaction. So same idea here is we are going to be treating our positive components. So, trading positives, well, let's label our charges to help remember, right? Sodium is a plus, hydroxide is a minus charge. Same idea here is we're going to label our oxygen and then we'll label our carbonyl portion with a positive. Now, when we are doing that, right, we are cutting our two charges apart, and we can even draw scissors even on the sodium hydroxide to help show that, right, we're cutting both these pieces, and we are trading them as in the, as a result, right, so trade, let's even draw some arrows. So it never hurts to draw a bunch of arrows, we're making a trade. Now, when that happens, We are going to redraw our carbon chain, right? So we have a CO double bond O. We have our oxygen, right? And remember this has a minus charge next to it, and we are trading it with the sodium, which also has a positive. Now keep in mind, this is a carboxylic salt. So we need to make sure we realize that is a salt. Now to make that even more specific, right? So the carboxylic salt You can go through and try to name it, too, if you ever needed to. So, for example, this would have been acetic acid if it was an H instead of an Na. In this case, it's sodium acetate is our specific chemical. So, sodium acetate. So, sodium for the metal and carbons. Now you can also name it sodium, um, I guess you do ethanate. Yeah, that sounds a little weird I don't think I've ever heard it not acetate. So maybe just sodium acetate would be fine for the salt. Now Is that the only thing? Well, we missed a part of our molecule, right? We had to trade the other portion as well So we have our two carbons attached to an alcohol would be your other part. So we also would have ethanol made in our reaction, right? So ethanol and then a carboxylic salt. Specifically, sodium acetate. This is how you can do this reaction. Let's do one more. Okay, let's predict the product of the following reaction. So let's do a question. So if I have the following ester, how do we go through base hydrolysis? Well, like I said before, we're going to do a little bit of a swappy swappy and trade our two different charges. So let's go through and label them for ourselves. So the first thing we're going to do is we're going to label the sodium, label the hydroxide, right? So our plus and minus. Then we're going to do the same thing on our ester as well, right? So the, the oxygen is a minus. The part portion of the ether outside is going to be our positive. We're going to trade the two positive components, okay? So we're going to go through that trade. So after we do the trade, we're going to be making two completely different components. So we're going to bring it back over the, um, the benzene ring here, right? So just like this. Then we will put in our O, our C double bond O, as well as, and I'm going to just kind of emphasize that O minus with an Na plus, right? So that's what makes our salt compound. Now the other portion is going to be an alcohol. So we'll have our h o attached to being that this is a one member chain, so it'd be the H three oh or also known as methanol. So we have our two individual components of our reaction. So we'll make methanol and a carboxyl salt. I hope that this video helped. So this is the whole idea of how to do base hydrolysis and acid hydrolysis. Kind of looking at both of them, right? So base hydrolysis makes the salt compound. When it comes to acid hydrolysis, it goes back to the original components of the reaction, which is a carboxylic acid and an alcohol. The one good thing about remembering is that they both make alcohols. It's just whether or not they make a salt or not. Usually the way I always remember it personally is that if I have, let's say, sodium here, We can see that a metal is involved or something that is on those alkali metals, right? So when you see that, that hopefully will raise that flag, like, Oh, I need to make sure I include that in the product versus when you had HCl, for example, as an acid, there's nowhere for that, for that chlorine to go. So the sodium attached to the positive portion is always attaching. So I hope that this video helped. Please feel free to like, and subscribe and to come by for future videos. There will be much more coming out for organic chemistry as well as introductory organic chemistry. And this has been Dr. Dan. Please let me know what you thought and if there's anything else you'd like to see in future videos. Bye now!