 In this video we'll look at the naming of carboxylic acids and amines. Carboxylic acids and amines are structurally related. In a carboxylic acid you have a carbonyl group with an alcohol group attached to the same carbon. The combination of a carbonyl group plus an extra oxygen that we have here is known as a carboxyl group. The hydrogen on this extra oxygen in the carboxylic acid turns out to be acidic hence the name carboxylic acid. When you name a carboxylic acid you add oic acid onto the name. For instance if you put a carboxylic acid group onto ethane that would become ethanoic acid. In an amide the alcohol of the carboxylic acid is replaced by an amine group and to name this you add amide to the name. So in this case ethane with an amide group on would be called ethanamide. Let's try some examples. This molecule at the top is clearly an amide so we count the longest chain and don't forget to include the carbon that is part of the amide group it is part of the main chain. So there are nine carbons so it's based on non-ain and to indicate the presence of the amide group we change the suffix to give non-anamide. The next molecule is a carboxylic acid. This one looks a bit tricky but we can break it down by remembering our naming rules. We have to find the longest chain that has the functional group in it. Here the functional group is the carboxylic acid and the chain that includes it is this straight chain section which has four carbons butane. So with the carboxylic acid group that's going to become butanoic acid. And because a carboxylic acid has to be on an end carbon can you see why? We don't need to specify that it is on carbon number one that's just assumed. Now what about the ring? Well we just treat it as a substituent because it's attached to the end carbon of the main chain. Note that this ring with five carbons is actually longer than the four carbon straight chain that we've called the main chain. But it is the straight chain that's designated the main chain because it includes the functional group. So our five carbon ring is cyclopentane but since it's a substituent we'll call it cyclopental and it's attached to carbon number four, numbering from the end with the functional group. So the complete name is four cyclopental butanoic acid. Alright so here's a crazy looking one to finish with. Let's break it down. First the longest chain with the functional group. So the functional group is the carboxylic acid here and we will number from that end. So we could go one, two, three, four, five, six. Or we could go one, two, three, four, five, six. Or we could go one, two, three, four, five, six. Which to choose? Well we want to make it as easy as possible for ourselves. So we're going to choose a chain that doesn't give us a branched substituent. You can see if we choose this to be the main chain then we have to name a substituent that has a fork in it. Now that's not impossible but it's not the easiest solution. Better is to choose one of the other two options like this. Then we see that the main chain is hexanoic acid and that it has two bromo substituents on carbon number two, a propyl on carbon number three and an ethyl on carbon number four. So assembling that alphabetically we get two, two, dibromo, four ethyl, three propyl hexanoic acid.