 And I write, and I write is this function C double bond O O O O O O O O O O O O O O O O O O O O O O O O O Sir, only carboxylic acid. Right, do carboxylic acid. When you heat this, then the hydration takes place. Water molecule goes out. One acid gives H plus and another molecule gives OH minus bombs H2O. This carbon and this oxygen combines and this forms C H3 C double bond O O C double bond O C H3, this is the molecule. It is an anhydride. So anhydride forms by the combination of two acids. We can have same molecule or different molecule also. So first of all we will see in this one only the carboxylic acid, the nomenclature of carboxylic acid is which is nothing but C double bond O O H functional bromide acid. And in this also we will start numbering from this carbon atom, the carbon atom of the functional bromide. So we will start numbering from the carbon atom of the functional bromide. So if the molecule is this, H C double bond O O H, for this you write down the suffix. For carboxylic acid suffix is Oic acid. So we have only one carbon present here. We will start numbering from this carbon atom. Only one carbon atom. So the name of this compound is mythanoic acid. If you have C H3 C double bond O O H, one, two carbon atoms, the name of this compound is ethanoic acid. It is a suffix, it will have a suffix for people. So we will discuss that, after this we will discuss that polyfunction what happens. Sometimes we will take alkoxy, we will discuss that. So this we call alkanh to this. First we will do this and then we will come back. So it is a butynoic acid. Butynoic acid, one, two, three, four. The name of this compound is butynoic acid. The double bond is present at second carbon, butynoic acid. What is the name of this compound? It is a four chloropentamide. So carboxylic acid like nitriles, acid halide, aldehyde, other compounds will do that we have done. Similar to that we have to start numbering from the carbon atom of the functional group and the suffix is oic acid. Now the number to name this anhydride, since this anhydride is formed by two ethanoic acid, right, ethanoic acid and ethanoic acid. So name of this compound is ethanoic anhydride, right. It is formed by ethanoic acid, name of this compound is ethanoic anhydride. Is there a space between oic and acid? No. Two ethanoic acid, so it is ethanoic anhydride, okay. We will just count the number of carbon atom. Anhydride means this group, right, the name of this compound is ethanoic acid. Suppose we have two different group present, then we will take one example and we will tell you, okay. Sometimes they also ask this question, what is the original molecule with which this anhydride has been formed, okay. So what you have to do, this bond you have to break. What you do here, just write down H O and H like this, okay. This bond you have to break, write down H 2 O and you break this bond and you break this bond also. You can break this bond also, any one of the carbon-oxygen bond you break. Carbon and all the bond you are breaking, you see these two atoms, which one is more electronegative oxygen. The more electronegative atom goes with the less electronegative atom, okay. So you have to consider the bond that you are breaking. This carbon-oxygen bond you are breaking, oxygen is more electronegative and these two bond you are breaking, oxygen, hydrogen, oxygen is more electronegative. So the more electronegative atom here goes with less and the less electronegative atom goes with more. So the compound here it is what, CS3 C double bond O, OH, CS3 C double bond O, okay. We will take some more examples in the next slide. So suppose the molecule is this, CS3 C double bond O, OH C double bond O, H. What is the name of this compound? Sir, how do you name it if the two are different? Ah, that's one. So first of all let me, what are the two acids we have with which this molecule has been formed? O can be the two. What we'll do, H and OH, right. So this bond will break, suppose. This O will take this H, this carbon will take this O. So the two compounds are what? CS3 C double bond O, OH and H C double bond O, OH. This is ethanoic acid, this is methanoic acid. The name of this compound will be ethanoic, methanoic and hydride. Ethanoic, methanoic, alphabetically we'll write. Ethanoic, methanoic and hydride, alphabetically we'll write. Just we count the number of carbon atom this side and number of carbon atom this side and alphabetically we'll write. Only one carbon atom, methanoic, two carbon atom, ethanoic. Got it? So you don't have to write down these molecules always. Number of carbon atom this side and this side and accordingly you can write down the name. CH2 C double bond, H C double bond O, what is the name of this one? CS3 C double bond, H C double bond O, OH. So do we have to write it too? Because then it can't be at first. In this case it's not required. But suppose other molecule we have then you have to write them. OH and I'll write the product. Esther, Esther is C double bond O, OH. Sir, is there a space between OH and anhydride? OH and anhydride, is there a space? We don't write this. We just continue to write. Sir, isn't this all just one? Yes. So even with acid it's just one? Yes, you'll write continuous. There's no capital letter in between. And I'd write. So fix this. Alkyl alkynoid. Which is alkyl? This is alkyl. This R is alkyl. And alkynoid will write from this part. Alkyl alkynoid. Write down the name of this compound. CS3 C double bond O, OET. OET? Ethyl. Ethyl. Methanoid. Ethyl. Ethanoid. Even the C is under that. Do we count the C which is under that? Yes, we count this also. It's the same thing. Okay. Sir, the compound double bond is not there. Sir, is there any rule that states that we have to start counting from the source of the compound? See, in this part, we always start counting from this constant. One and two. Okay. And we always write down this part first. If it comes alphabetically, fine. If it won't come, then also we'll write down the alkyne part first. And then we'll write alkynoid. So how the numbering will be separate? Right. Yeah, here this will be separate. This will be separate. But this part will write first. Like you see, for this one, it is ethyl. Right. Ethyl. Ethanoid. This one is methyl. Propanoid. This one is... It is one, two. One, two, three and four. Right. Or if you do this one first, one, two. One, two, three and four. So you see here, it is one chloroethyl. Right. Chloroethyl also you can write. See, one chloroethyl is three promo. So we won't write this three promo first and then once again. First we'll write this part. So the name of this compound is... One chloroethyl. Then three promo... Three promo eutenoid. Three promo eutenoid. This one, again this part will write first. So one promo... Ethyl. Then three chloro... Eutenoid. Eut... Two eenoid. Two eenoid. So while naming this, you always have to put the alkyne first. Yes. First we always write alkyne. While naming the alkyne, you have to take the one. Yes. You have to start from this part. What is the name of this part? Two. Two. Three. One. Two. Three. One. Two. One. Three. One. Two. Three. One. Two. So why is it two in? Double bond is five. No, so why is it numbered? Double bond is five. Double bond is five. So I hope we continue the numbering. No, it's a ring. It's the substituent of this carbon atom. It's one number. Why do you think it's one? This is the substituent of this carbon atom. If it is not there, then it is methyl and this part you'll write. But it is two-cyclo-propenyl methyl. But won't that become the main thing? No, no, no. This is the carbon which it has in this carbon atom. C-C-O-O-R. This is the R group. Substituents on this R group. No. It's one. The first carbon atom is this. And in this, the double bond presents the second carbon. One and two. Okay. This is the carbon which is in this cycle. Won't it become cancel to be part of the main chain? No, then it will be one extra carbon. Because it is on the main chain. And cyclo-propenyl when you write that carbon also. Then you can't say cyclo-propenyl. Understood.