Hi and welcome back to my channel. Today we're going to be looking at reactions of carboxylic acids. There are four reactions that we're going to be looking at. The reactions of carboxylic acids with bases to form salts, with alcohols to form esters, with amines to form amides and with reducing agents to form primary alcohols. The first reaction that we're looking at.
is the reaction between carboxylic acids and bases. Carboxylic acids react like any other acid in a neutralisation reaction. This means that they will produce a salt and water and carbon dioxide if reacted with a carbonate. Let's look at some examples of carboxylic acids reacting with metal oxides, metal hydroxides and metal carbonates. First we have a metal oxide, sodium oxide, reacting with propanoic acid.
This will form the salt sodium propanoate. All of the salts of carboxylic acids will end in the O8 ending. Water is also produced in this reaction.
Looking now at the reaction of a metal hydroxide or alkali with a carboxylic acid. Here we have lithium hydroxide reacting with hexanoic acid. In this reaction we will get a salt and water produced. The salt will be lithium hexanoate.
again with the O8 ending, and water also being produced. Finally, in the reaction between a carboxylic acid and a metal carbonate, we will get a salt, water and carbon dioxide produced, just as you would between a metal carbonate and a mineral acid, such as hydrochloric acid. In this case, we have calcium carbonate reacting with ethanoic acid. This will produce the salt calcium ethanoate. We will also get water and carbon dioxide.
In our next reaction we're looking at carboxylic acids reacting with alcohols. When carboxylic acids react with alcohols in the presence of a concentrated sulfuric acid catalyst we will get a condensation reaction. In this reaction, water is produced whilst the carboxylic acid and the alcohol join to form an ester. Let's look at an example. In this example, we have ethanoic acid reacting with methanol.
The OH from the ethanoic acid will be removed and the H from the hydroxyl group on the methanol will also be removed. These will join to form water. The C double bond O will then join to the oxygen of the methanol to form the ester link. The ester is named by taking the alcohol's name, methanol, and removing the ending and replacing it with YL to form methyl. Ethanoic acid then forms the end of the name by changing to ethanoate, giving us an ester, methyl, ethanoate.
Water is also produced in the condensation reaction. As we can see from the double-headed arrow, this is a reversible reaction. Hydrolysis of the ester, methyl, ethanoate. would produce methanol and ethanoic acid.
The next reaction we're looking at is that between carboxylic acids and amines. Amines contain the NH functional group, amino. They can react in a condensation reaction with carboxylic acids in a similar way to alcohols. This produces an amide.
Let's look at a reaction. Here we have propanoic acid reacting with methyl amine. In the same way as making an ester, The OH group from the carboxylic acid will be removed, leaving the C double bond O.
One of the H's from the amine will also be removed to produce water. The resulting N atom will then join on to the C double bond O. This produces the amide link, which is the C double bond O NH.
Our final reaction is the reaction between carboxylic acids and reducing agents. This is the opposite of oxidation. Reduction of carboxylic acids will produce a primary alcohol.
The most common reducing agent is lithium aluminium hydride. Let's have a look at an example. Here we have ethanoic acid. This will be reduced all the way back to ethanol. Pause the video now and either name or draw the products produced in each of these reactions.
In this first reaction, we have a carboxylic acid reacting with an amine. This means we'll have a condensation reaction where an amide is produced. In this next reaction, we have a carboxylic acid reacting with a base. This means we'll produce a salt and water. In this case, the salt is sodium butanoate.
In this third example, we have a carboxylic acid reacting with an alcohol. This will produce an ester. Remember the first part of the ester's name comes from the alcohol. In this case it was pentanol so it would be pentile.
The second part of the name comes from the carboxylic acid, in this case propanoic acid, therefore we have pentile propanoate. In this last example we are reducing a carboxylic acid. To do this we are finding the carboxyl group and we are taking this back to be a primary alcohol. You need to remember to put back in the hydrogens onto the carbon to make sure that it has a valency of 4. Thank you for watching my video, I hope that you found it helpful. Please remember to subscribe and ring the bell to be notified of new videos.
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