Understanding IUPAC Nomenclature in Chemistry

hey all welcome to home school and welcome back to class 11 chemistry series we started with organic chemistry chapter where I have already completed three videos on this video links are provided in the description you can check it out if you have not not yet watched. And coming to today's topic, the most important topic of entire organic chemistry that is nomenclature. So I am going to discuss about the IUPAC nomenclature of organic compounds. First, let me tell you why this nomenclature. Nomenclature in the sense naming, right? Say nomenclature. In other words, we can say this as naming, right? So why do we have names? I mean, why we have to name organic compound? See, why do human beings have name? Each and every one of us have names, right? So what is the purpose of names? With the help of names, we can identify a person. right so for identification we have names otherwise you know among these many people if I have to call you how can I call you if you were not having a name right so with name we can identify a particular person likewise even in our organic compounds as I already told you 5 million compounds exist in our nature. There are 5 million organic compounds, some natural, some man-made. And every year over 30,000 organic compounds are being produced. being discovered. So for example suppose you have an organic compound Y, some organic compound Y discovered by a person X. So this X person discovered this. Normally whenever some theory or some law was discovered in science or when some element is discovered, you know name of the scientist is kept. for that particular element or law or theory whatever it is okay say for example dalton's theory is there so these dalton's theory was discovered by a person dalton so that theory was called called with the name dalton's theory okay so if you apply that concept here say a is the compound discovered by a person x so if i keep name of this person here you know there are you so many compounds discovered every year. So how will you remember each and every scientist name? It leads to a lot of confusion. And there comes another problem. If the same compound was discovered by a person P, then will you keep P again for the same compound? Or you must know that the same compound is already discovered. Right? See, these are some problems that we will face when a name of a scientist is kept for a particular compound that was discovered okay so we can't keep scientist names for the compounds we want some name with the name itself we can identify a compound with the name itself we can study a compound isn't it so definitely there is a necessary thing to name organic compound so we can't keep scientist name because of these problems there are several practical problems behind this and it leads to a lot of confusion and it's very difficult to remember those scientist name because it's not 5 compounds or 10 compounds. There are millions of organic compounds in our nature. So we can't keep some scientist name whoever have discovered or whoever have manufactured. So came a nomenclature called IUPAC nomenclature. So we call naming of organic compound. as IUPAC nomenclature okay fine so what do you mean by this IUPAC nomenclature say IUPAC is an organization of chemistry okay so these people actually solve every problem that comes in chemistry or you know they will refer or you know they are the one which who will actually judge whether the newly discovered theory is correct or not whatever whatever may be the issue regarding chemistry you know these people will solve these people will look over it So the full form of IUPAC, you must have studied in your basic classes, International Union of Pure and Applied Chemistry. So this is the full form of IUPAC. People developed a set of rules. Okay, so they have given so many rules. So many rules are there. So they said that, see these are the rules we have developed. Each and every one in a world, if they want to give names for organic compound, they should follow these rules they said. So everybody. Okay, whoever discovers a new compound, if he or she have to give name for that compound, they must definitely follow these rules. So how does these rules will help in solving problems regarding names of organic compound? For example, the same example, you know, instance I will take, A is the organic compound discovered by a person X and this X person followed these rules and kept the name. right. So, he kept a name something called you know 2-methylbutane, right. Some A compound, he kept a name as 2-methylbutane following these rules 1, 2, 3, 4, 5 set of rules, right. And there was another person, P person discovered some compound, discovered some compound he thought it's completely a new compound but okay he discovered and he had to give a name right so he also should follow the same rules what is the rule says everybody in the world to name a particular compound they should follow these rules so this p person also for his newly discovered compound he followed these rules and kept a name and surprisingly he got the name as 2-methylbutane itself. Then he understood that I didn't discover anything new. The compound is already existed and that was discovered by a person X. That way people will come to know which compound is there in a nature, which compound is not there. And it's like when a compound has a same name all over the world, it's very much helpful. It's very much helpful to identify a particular compound, to study a particular compound and to understand the nature of a particular compound. Okay, so one particular compound must have a same name throughout the world. Only then we can study them in a better way, best possible way. That is why it is very important to study IUPAC nomenclature. So our duty is to learn those rules so that we ourselves can name any organic compound. But this IUPAC nomenclature we are studying in a particular pattern. I am not clumsing all the topics. There are n number of organic compounds. Right. So let us study in a group wise. Right. So I am going to deal this IUPAC nomenclature in four videos. In this video, I am. giving how to name for saturated hydrocarbons. Okay and in the second video I will talk about nomenclature of unsaturated hydrocarbons and in my third video I will talk about organic compounds with functional group. and in my last video i will come up with nomenclature of cyclic compound so this way i have divided the entire class of organic compounds into four categories and category wise we will learn their naming so that it becomes easy for you and you will not get confused right okay so now let me give you some introduction about uh these names organic names And you know every compound has two names normally. Most of the compounds have two names. One is IUPAC name, the other one we say common names. Common names are like pet names right. Usually closed ones or loud ones will call us with a pet name right. But when we go outside, I mean in a school or office or wherever it is, we have our own official name right. So we keep seeing. A person having two names, one is official, one is a real name which was given in records and the other one is a pet name which is called by you know family members. Like that our organic compounds also have two names. IUPAC name is like official name. Everybody will understand this IUPAC name. Everybody will call a compound with IUPAC name. Okay. At the same time, you know, a particular compound have a common name. So how did this common names have come? These common names have come from their source. For example, you know, This particular name is very much known for you. We call something as acetic acid, right? So if you can remember the formula for Acetic acid, it is CH3COOH. So why do we call this particular compound as acetic acid? You know, it's not the IUPAC name here. The actual, after following all the rules, if I have to keep this compound's name, it will come as ethanoic acid. I must call it as ethanoic acid. This compound's official name that is IUPAC name is ethanoic acid. But common name is acetic acid. Acetic acid is like a pit name. So why am I calling this as a acetic acid? It is because this acid is present in vinegar this is present in vinegar okay so vinegar in greek is called as acetam vinegar's greek name or you know the latin name whatever usually you know latin name or greek name be considered so vinegar's latin name is acetam clear so since this acid is present in vinegar it acetic acid you know acetic acids source is vinegar that's the reason you know we call this acid as acetic acid but actually its iupac name is ethanoic acid right so uh it's maybe because of their origin or source you know their nature these common names were kept Most of the compounds have common names. You must be familiar with common names of compounds also. Not all but some famous compounds. The compounds which we frequently use it in our syllabus. You know we keep telling you like for which compounds we have to remember a common name. Right? So don't worry. So now let us come back to IUPAC naming. Right? Fine. For example, you take a human name. Let me take a name Vijay Kumar P. Okay, so let this be Vijay Kumar P. It's a human name, right? A boy's name. I can break this name into three parts, right? We call this Vijay as first name, Kumar as middle name. and P as last name. Even when you fill certain applications, you know, there are three columns, first name, middle name, last name, right? Similarly, every human name can be divided into first name, middle name and last name. Likewise, our organic compounds names can also be divided into three parts. Okay, see we can have a part like prefix, we will have word root and we will have suffix. Okay, prefix is like the first name, word root is like the middle name for an organic compound and suffix is like the last name for an organic compound. Ok, so prefix comes first. We will start writing a name with prefix. First name we will write. Later middle name, this is very very important. And later the last name which is called with the name suffix. Ok, so instead of calling first name, we call it as prefix. Instead of calling as middle name, it's word root. And then instead of calling as last name, it is suffix. right in case of suffix again we have primary suffix primary suffix and secondary suffix whenever we write a primary in chemistry you know we will write it as one degree suffix one degree means what it's primary suffix secondary suffix suffix is again of two types okay so usually when we write an organic name first we will mention what is prefix Later we will mention what is word root. Later we will write primary suffix. And the name will end with secondary suffix. Secondary suffix. So this pattern you have to follow for naming any organic compound. Okay, you will have to mention the first name first, later the middle name which is called as word root, later the last name. Last name again has two parts. Primary suffix you will mention first, later the secondary suffix. So now, for example, you have this organic compound. say this long organic compound you have with you ch2 ch2 uh you know ch2 coo h see if i have to name this organic compound yeah i have to write its name in this pattern i have to follow this pattern first i'll have to write prefix word root then primary suffix and then secondary suffix. Then what should be written as a first name? See if you look at this compound it has branches right? It has branches and there are so many carbon atoms in a chain. I will call this as carbon chain where so many carbon atoms are there and I have a special group called functional group. COOH, OH, CHO all these are special groups. They will decide chemical properties of organic compound isn't it? So here branches name is nothing but prefix and the carbon atoms number of carbon atoms which are present in a chime is mentioned as word root and the special group name is mentioned as suffix. So this is how each and every part of a compound is mentioned in the name. Either as prefix, word root, primary suffix or secondary suffix. Okay. So now I will tell you what groups if there in a compound is mentioned as prefix. Okay. What and all groups will come as prefix side. If those groups are there in organic compound, you have to mention them as prefix. I will give you the list of those groups that has to be written as prefix. And I will give you. you know the number of carbon atoms that you can write it as a word root. If you have one carbon, you will write the word root as meth. If you have two carbons, you will write the word root as eth. Okay, so that list I'll give you. So now these two. 1, 2 and 3 primary suffix. About these three all information I am giving you in today's class because today's class is all about naming saturated hydrocarbons. For naming only saturated hydrocarbons information of this, this and this is enough. About secondary suffix we will discuss later. When we go for naming organic compounds with functional groups, then we will talk about secondary suffix. So, now you take a list of prefix, word root and primary suffix. Clear? See, observe here, if these groups are there in an organic compound, you should write them as a prefix. I mean their names, their names you should mention as a first name. okay and we call these groups these groups as substituent groups prefixes are also called substituent groups so what you have to mention as a prefix name of substituent group substituent group must be written as a prefix okay so all these are prefix writing groups. So, if you have a group F, its name F, F's name you have to indicate in prefix. Okay, you have to indicate as the first name. So, if F is there, what is its name? Fluro, likewise Cl, Chloro, Br, Bromo, I, Ido, No2, Nitro, NH2 if it is there, Amino. CH3. Okay. So how did this CH3 must have come? You all know CH4, right? If one hydrogen is taken outside, you will get CH3. Okay. So CH4 is methane. This methyl group, this is called as methyl group. This is derived from methane, right? That's why it is called methyl. Okay, so usually these groups can stay as branches. Okay, so whenever you have branch as CH3 group, not CH4, CH3, not CH2 also, it is CH3. CH3 if it is there methyl, CH2, CH3. Actually, this is derived from ethane. From ethane, one hydrogen if you remove, you will get ethyl group. And this is propyl group. Whereas CH, CH3, CH3. Okay. So you see this compound. Let me write that group once again here. If this big group is there as a branch, you know, there are so many carbon atoms. Carbon atoms are there in a chain. Some long carbon chain is there. To that, if this branch is there, CH, for that, two methyl groups are again branches. So, this group, this group is called as isopropyl group. Remember? Isopropyl. group. Okay, fine. And now, this is isopropyl. In case, if there is some CH2 to that isopropyl group is there. Then this complete group is called as isobutyl group, right? So, hope you understood what is the difference between isopropyl and isobutyl, right? So, isopropyl is if this group is directly attached to a carbon chain. If it is not directly attached, there is one more CH2. To that carbon chain is attached, then the entire group CH2, CHCH3. So this group is isobutyl group. Then say you have another compound, okay, long carbon chain. And you know, if this group is there, there's a difference, right? So there's a difference between this group, this group and this group. Okay, so if this group is there, you know, this is different and this is different. You can observe that very, very clearly, right? So if this group is there, it is called as tertiary butyl group. Tertiary. T. T-E-R-T in the sense tertiary. Okay. Say tertiary butyl. Why do we call the word tertiary is because you know the main carbon China is getting attached to this carbon. This carbon is called tertiary carbon. It is called as tertiary carbon. Okay. So why do we call this as tertiary carbon? Because this carbon is attached to three other carbons around it. it okay so how many cc bonds you have this is one cc bond this is another cc bond this is third cc bond if a carbon has three other bonds with carbons only then it is tertiary carbon okay so about this tertiary carbon secondary carbon and primary carbon i made one basic video video link will be provided in the description you can go and check it out for an idea about Primary carbon, secondary carbon and tertiary carbon. Clear? Okay. So hope you understood about the groups and their names, right? So you must know this. Okay. So which group is called with which name is very important because if these groups are there, their names are the one which you are mentioning as prefix. Okay. And now coming to... Word root. So what you will mention in word root? Number of carbon atoms In a chyne, in a chyne is mentioned as word root. Okay. So, if you have one carbon in a chyne, it can be called as meth. You will mention word root. Word root in the sense middle name. Middle name you will write it as meth. When? When you have only one carbon in a chyne. Okay, so if you have two carbons, if you have two carbons in a chyne, you will mention the word root yet. Three carbons, prop. Four carbons, but. Five carbons, pent. 6 carbons, HEGS. 7 carbons, HEPT. HEPT it is. Okay. So when you have 8 carbons, it is OCT. 9 carbons, NON. 10 carbons, DEC. 11 carbons undec. 12 carbons dodec. Okay. So till 12 if you can remember it's more than enough. 13 tridec. 14 tetradec. Okay. Like that it goes on. But for your level if you can remember till 12. So what is 12? It is didec. Didec. 13 tridec. Like that. okay so this is how we mention word roots so word root is mainly the number of carbon atoms in a chain okay you see a chain may have four carbons five carbons six carbons if you have four carbons you will use the word root you will write the middle name as butte right so that is about the word root and coming to primary suffix that I told you. Primary suffix. So after writing word root you will mention the name of primary suffix. Say if you have all single bonds in a carbon chain, in a main chain between Verbons, if you have all single bonds, then you will mention primary suffix as ye-yen-yee. If you have a double bond in a main chain between carbon atoms, you will write the primary suffix as E and E. And when you have a triple bond, you know, you will call that particular compound, I mean, primary suffix as Y and E. Right. So, depending on the type of bond between carbon atoms, you are writing your primary suffix. If you have all single bonds between carbon atoms, After writing word root, see to word root only you have to join this primary suffix. If your chain has 4 carbons, butane. Between 4 carbons if you have all single bonds, ane. Butane plus ane, it becomes butane. In case in any of the carbons, between any of the carbons you have a double bond, then ENA. Bute for carbons, bute plus double bond is there, ENA. It becomes butene, right? So, hope you understood about primary suffix. and if functional groups are there COOH CHO ketone group all of their names are mentioned as the secondary suffix. So ending of the name should end with the name of a functional group. So that we will discuss in our next videos when we study nomenclature of organic compounds containing functional groups. So now we will start with nomenclature of saturated hydrocarbons with branches. Clear? See guys, with these three examples, I'm going to explain you the two most important rules here. So the rule number one, what I am actually talking about is naming of saturated hydrocarbons. Naming of saturated. You know the meaning of the word saturated, right? Saturated means having all single bonds. Okay, saturated hydrocarbons. So what do you mean by hydrocarbons? Organic compounds which have only carbon and hydrogen. Okay, you don't have any other functional group here. When you have only carbon and hydrogen, we will call them as hydrocarbons. Is that clear? You see here, three examples are there. You observe these compounds. You have only carbon and hydrogen. Okay. So you do not have any functional group like COOH, CHO all that. Other element is not there. Only carbon and hydrogen is there. Okay. So such compounds are called hydrocarbons. So we are trying to name saturated hydrocarbons in this class. Okay. So coming to rule number one. Rule number 1. Okay, the rule number 1 says select the longest carbon chain first. You have to select the longest carbon chain. So how do you select the longest carbon chain? You have to select a path where maximum carbons are involved. Okay, so this is what we mean by selecting longest carbon chain. So now let's check it out. This is the compound. Which path can cover more number of carbons? Say one way I can think is going in this straight way, right? Straight chain. Say this I consider as a branch. So if I go straight. See you can't count the carbons which are there in a branch. You should select a straight chain where carbons are involved. Say if I select this path, how many carbons are involved? 1, 2, 3, 4, 5, 6. 6 carbons. And there is another path possible. So if you can differentiate, I am using a different colored chalk piece here for the second path. Say second path, this is also possible, right? How many carbons? 1. 2, 3, 4, 5. So in the second path, 5 carbons I am covering. In the first path, uh one two three four five six right so uh six carbons are covering in the first path and another path is possible that is this this path one two three four four carbons are covering in this path so you have to check all possible paths here okay three parts possible one is a straight path second one is this purple color uh chalk piece that i have used and the third one is this okay so in the first path six carbons are covered if i go in a second path five carbons covered if i go in a third path four carbons covered so what is the rule says select a path which can cover more number of carbon atoms okay so that is what we mean by longest chain rule Okay, say if I select this path, I mean observe the orange color chalk piece here. So this is the correct path which involves 6 carbon atoms. Okay, so first thing you need to think about is selecting the longest child. Think that in which way if you go you can cover maximum number of carbon atoms. You can cover more number of carbon atoms. So that is you. your parent chime. You know we call this as now parent chime. So that is your parent chime. Okay fine. And now observe the second example and select the longest chime here. So definitely looking at this say one possible way is selecting this straight chime. Okay how many carbons it involved? One, 2, 3, 4, 5, 6, 7, 8, 9. 9 carbons are involved if you go in this straight path. And one more path is possible that is this. This. Okay. So, this path. This path you observe guys. How many carbons are getting covered? 1, 2, 3, 4, 5, 6, 7, 8. So if you go in this path, 8 carbons are covering. Then any other longest? No, right? So which is longest? That means your straight path. is the longest one where you are covering more number of carbon atoms. Okay. So there are coming 9 carbons if you go straight. Okay. So your parent chain is this. So this is your parent chain. clear so that's how you have to select you should not include these carbons in the parent chain now they are becoming branches okay you you have to write their name as prefix now so these guys are branches here ch3 here ch2 ch3 you know these guys have become branches now once you select your parent chain then remaining stuffs whatever are there they are branches okay fine coming to the third example can you tell me which is a longest path here you observe here if i go straight if i go straight you know how many carbons i can cover 1, 2, 3, 4, 5. 5 carbons I am covering. Then any other way that can cover more carbon atoms. One more way I can think of here. Just observe this. Just observe this path guys. This path. This path. Okay. So how many carbons I can cover here? 1, 2, 3, 4, 5, 6 carbons I am getting covered. I mean right. 6 carbons are coming in this chyme. So any other path that can cover more than 6 carbons? No. So now this is your parent chyme. The way, the path which had covered 6 carbons to the most. that is your parent chain now every other thing this one this group and this group this group everything will become branches now okay so this is where you have to be very very careful so the first thing is you have to select longest chain carefully so you must observe every side you know longest to chinese not always a straight path every time straight path will not be a longest to check you'll see here straight one is not a parent chain right. See this is our longest chain. So parent chain need not be straight always okay. So it can vary. You must be very very careful enough in selecting a parent chain. So that was our rule number one okay. So once you carefully select the longest chain later is numbering. So this is the most important rule one must follow. Rule of numbering. So let's now discuss rule of numbering with the same examples See coming to rule of numbering you have to remember one basic point that Once you select the longest child, parent child in other words You have to give numbers for those carbons Okay the carbons which are coming in a child must be numbered Okay You You should give numbers for them 1, 2, 3, 4, 5, 6 like that. You cannot give numbers for the branches. See once you select this as your parent chain now this CH3 will come as a branch. Right? You have to give numbers for only these carbon atoms which are there in a parent chain. Okay? Fine. How do you number them? Even to number we need to follow certain rules. The first basic point is carbon atom. Carbon atom with a substituent group. With a substituent group. Should get the lowest number. Should get lowest number. This is very very important. What do you mean by this? See, I can start numbering from this end or I can number from this end. From which end you will start? See, if I number from this end, this carbon gets 1, this is 2, this is 3, this is 4, this is 5 and this is 6. Right? Okay. So if I number from this end, this end, this carbon gets 1, this gets 2, 3, 4, 5, 6. Isn't it? And what does the rule says? The carbon that is attached to the functional group, this is the carbon to which, sorry, this is the carbon to which substituent group is attached. Okay, so now this CH3 is a branch, we can also call it as a substituent group and this substituent group is attached to this carbon. This carbon should get a least number, this carbon should get a lowest number, lowest number in the sense not. number one okay numbering you should start from one end definitely but in the process the carbon which has got a branch should get the less number. So which way if you go this carbon is getting less number? When you go from left to right, this carbon is getting 4. When you went from right to left, this carbon is getting 3, right? So which is the correct way of numbering? Correct way of numbering is this, okay? So once you have given number, The only step is writing a name. Okay. So selecting a longest chain and numbering is very very important. If you have done that correctly then remaining thing is writing a name. Okay. So here I am explaining rule number 3 also. Okay. Writing name. Okay. So how do you write name here? First thing is you have to mention prefix. Okay. So how do you write a name here is let me tell you here. First you have to mention the number of carbon to which to which substituent group is attached. Okay. right? S, Sg in the sense, substituent group. After mentioning the number, you have to write the name of substituent group. After that, you have to write the word root. After that, you have to write primary suffix, primary suffix, okay? So, this is, this is the way of writing name for, you know, saturated. hydrocarbons. Okay. First you will mention the number, later name of substituent group that is branch, later word root and finally you will end the name by primary suffix. So we will apply the same thing here to write the name. We selected longest chain. We have given number also. Work is over. First let us finish off writing its name. So what is the name of this compound here? First you have to mention what? Number of carbon. Number of that carbon atom to which substituent group is attached. So, what is the number of this carbon atom? 3, right? After writing 3, you have to put a hyphen, a small hyphen, okay? After that, write the name. This is the substituent group that is branch. What is its name? I told you, this is called as methyl. CH3 is called as methyl. So, it is methyl. Okay, over number we have mentioned, name of substituent group we have mentioned, later word root. Don't give any gap here. Okay, continue the name and word root. What is word root? Number of carbons in a chain you will mention as word root. So, in the Parent chain, how many carbons you have? 6 carbons you have. So what is the word root you will use? Hex you will use. If 6 carbons, word root is hex. And finally, primary suffix. Don't give any gap. You shouldn't give gaps anywhere. Okay, the name. Write from number, the name should continue. There are no gaps. Okay, so trimethylhex, what is the primary suffix? Check, between carbons, all single bonds are there. Okay, so usually for saturated hydrocarbons, the primary suffix is ane, over. So, what is the name of this compound? It is trimethylhexane. Trimethylhexane is its name. clear over so we have completed the first compound coming to second compound okay so actually in every example you are going to learn a new rule right so that's why see i selected examples carefully so that i will cover maximum rules for you right first example very simple just you know selecting a parent chain then there is only one branch so it was very easy the carbon that has got a branch should get a least number that way you have numbered over you have written the name also coming to second example first step is over we selected the longest parent chain here that included a straight chain which has got nine carbons okay so now numbering how do you number you Whether you number from left to right or from right to left is the big question mark, isn't it? And okay, we have to number in such a way that carbon having branches should get the least number, right? And you see here, I'll put a star mark. This carbon has got a branch, even this carbon has got a branch. So now how do you number? How do you number? Comes a question mark and here you have to follow one important rule called rule number 4 I am revealing which we will We will call it as lowest locant rule. Lowest locant rule. Very very important rule guys. So you have to think about it. Okay. So when do you use this lowest locant rule? When you have two or more than two branches. If you have to in that situation if you have to number the parent child. If only one branch is there it's very easy. You will just select a direction in which direction if you go this carbon gets a least number that way you will number. But here both carbons have branches. So whether you number from this end or that end. So how do you decide? You observe. First, I'll number from this end. I'll start numbering from this end. Okay, so this is number 1, this is number 2, this is 3rd carbon, this is 4th, this is 5th and this is 6th, 7th, 8th, 9th carbon. So first I numbered from left to right and now I will start numbering from right to left also. Okay so right to left if I start numbering carbons so this is 1, this is 2, this is 3, this is our 4, this is 5, this is 6, this is 7, this is 8 and this is 9. Isn't it? Okay, so now what you have to do, when you went from left to right, you know this carbon, star mark carbon has got a branch, right? This carbon has got a number 2 and this carbon another carbon which has got a branch has got a number 6 right when you went from left to right when you went from left to right. So you add both the numbers so 2 why did I take because this carbon star mark carbon has got a branch so that carbon had got 2 when I went numbering from left side onwards. So 2 plus 6 if you do you will get the number 8. Okay? And now right side numbering I will concentrate. Right side numbering I have written at the bottom. Okay? Fine. So when you go from right side, your star mark containing carbon has got number 4 and anion carbon containing star mark has got number 8. So 4 plus 8 if you do what is the number you will get? You will get 12. Which is the least number among this? The least number is 8. So you have to follow left to right numbering. This is what we call lowest locant rule. See rule Rules, definitions, meanings and all they will not be asked for the examination. You must know the rules to write the name. Okay, so it's not a matter of by-hatting a rule. It's a matter of understanding a rule. Okay, so when you have two branches or more than two branches, you must definitely follow lowest locant rule. Okay fine say from left to right when we go our lowest locant is least. Locant this addition this sum we will call it as locant. Okay locant is very very least. So left to right numbering we have to follow. Okay so right to left numbering is wrong. So this way of numbering is wrong. Left to right numbering we have to follow. So numbering is over. right and now writing a name so how do you write the name here how do you write the name first numbers you have to mention later name of substituent group word root primary suffix right that's what in the end and now you have two branches so whose name you will mention first this is the branch ch2 ch3 its name is ethyl and this is the branch ch3 its name is methyl isn't it so alphabetically which one will come first e comes first or m comes first e comes first so here One more rule we have studied. Rule number 5. Okay. So when you have 2 or more than 2 branches. When you start writing their name. You have to follow alphabetical order. You should follow alphabetical order. Okay. So here ethyl. Here methyl. E comes first. So mention. So at which carbon ethyl group is attached? It is attached at 6. Don't forget to mention. mention the number. So, it is 6-ethyl, 6-ethyl, put a hyphen, okay? And another prefix is there, methyl. At which carbon this is attached? At the second carbon, right? So, it becomes 2-methyl 2-methyl. Prefix is over. Along with the number, prefixes we have mentioned. 6-ethyl, 2-methyl. Now, word root. Word root in the sense, in the parent carbon, how many carbon, in the parent chain, how many carbon... are there? 9. So, if 9 carbons, what is the word root you will use? Non. And all single bonds, so primary suffix is A and E. So, what is the name of this compound? 6-ethyl-2-methyl-nonane. Right? See, here we have studied lowest locant rule and writing the names of prefixes in alphabetical order. Both rules are very, very, very important. Okay? Fine. Coming to example number 3. Right? So whatever we have studied so far, everything you apply here. You see, parent chain we have already selected that is this format. Okay. And now how do you number this? Numbering is what very very important. From left to right or right to left. First let me number it from left to right. Lowest to low can see more branches are there. Definitely you have to check the lowest to low can't right. See. One. True, this is carbon 2, this is carbon 3, carbon 4, carbon 5, carbon 6. Okay, so from left side onwards, first let us calculate lowest locate. Okay, so at second carbon. At second carbon, you have two branches, right? So you write 2 two times. 2 plus 2. Write it this way. Okay? 2 plus 2. And at fourth carbon also, 2. branches are there. You see two branches are there right. So 4 plus 4 then any other branches that's it. So what is the total you will get? 4 plus 4 is 8. 8 plus 2 10. 10 plus 2 12. Okay fine. And now from right side you start checking. From right side if I number. Right side if I number. Right side if I number. This carbon gets number 3 right. So So two branches are there at this carbon. So 3 plus 3, 4, 5. At fifth carbon, you have two branches. So 5 times 2, I will write 5 plus 5. Any other branches? No. So what is the total? 5 plus 5, it is 10. 10 plus 3, 13. 13 plus 3, it is 16. right. So which is correct left side numbering or right side numbering? Definitely lowest number you got when you went through left side. So left side. So the numbers which I have already put here know that is the correct way of numbering. That is the correct way of numbering. Okay. So once you have numbered later you will have to write the name. Okay, so how will you write the name? How many branches are there? This is one branch, this is another branch, this is third branch and this is fourth branch, right? And observe one thing, all branches are methyl only. All branches are methyl only. Then in that case, in that case, you know, at which carbons these branches are there? Second carbon, right? Two, And two methyl groups are present on the same carbon, right? So, 2 times 2 you mentioned. 2, 2. And the same methyl groups are present at fourth carbon also. And two methyl groups. So, 4, 4 hyphen. First, we have mentioned all numbers. Okay, all numbers why together? Here you see numbers are not together. I did not mention 6, 4. Because the substituent groups are different. Why all numbers together I have mentioned? Because substituent groups are same at these carbons. Why I mentioned double time 2,2? Because two groups are attached to second carbon, same groups. So, 2,2. Okay. So, 2,2, 4,4. How many methyl groups? 4, right? So tetra, we will use the prefixes. Next, next rule. Rule number 6 I am teaching you with this example. You know, use the words like di, tri, tetra, right? When you have same type of substituent groups. So 4 are there. So tetra, tetra, methyl, over. Prefix is over. Now write the word root. So, which is your parent chain? This is your parent chain has got 6 carbons. So, word root HEGS and all single bonds between carbons. So, A and E. Okay, actually this must come here since it may not be visible for you. So, I wrote it down. So, what is the name? 2, 2, 4, 4 tetramethylhexane is its name. Okay, so this is how I think almost all the important and common rules that I taught you for naming saturated hydrocarbons. Okay, so six rules I taught you for naming saturated hydrocarbons. Okay, and I will come up with many more rules for saturated hydrocarbons with heavy branches. Okay. See, these are all small, small branches actually. Methyl, ethyl, they are all very small branches. But if you have one really big branch, how do you name them is also very, very important. So, that one we will learn. Observe these two examples guys. Highly branched saturated hydrocarbons. So, with these two examples, we are learning few more rules actually. Observe this example number 4 here. So first thing is you have to select the longest chain that you know. So how do you select the longest chain? See 1 is directly looking at the straight path. It looks as if you can cover more number of carbons right. So let's count the carbon atoms if you select this as your longest chain how many carbons it will cover? 1, 2, 3, 4, 5, 6, 7, 8, 9. So 9 carbons you can cover when you go in a straight path. And one more path I can see here. Right? So the path is this. This path. This one. This path. Leave the branches. Only the straight chain use in this path. Right? So how many carbons you can cover here? 1, 2, 3, 4, 5, 6, 7, 8, 9. So in this path also 9 carbons you are covering. So which is your longest chain? Straight path covering 9 carbons and this path is also covering 9 carbons. So how do you decide longest chain here? The longest chain is the one with more branches. So a new rule again you studied, rule number 7. Rule number 7 you are going to learn. You know longest chain, longest chain must contain must contain more carbons, more number of carbons more number of carbons right so this is a new point you've learned in this example right so when you have two long chines with the same number of carbons the longest chine is that chine with more branches see if you go in a straight path you have this as a branch and this whole thing as a branch right but if you go in this way see how many branches you will get this is one branch this is the second branch third branch, four branch. So that means when you go in this direction four branches you will get but when you go in a straight path only two branches you are getting. So go in a straight go in a longest path where you can cover maximum number of branches. Okay. So more number of branches that has to be covered. So that way you have to select the longest chain when you have this dilemma. Okay. Fine. So now the longest chain is covered. You have to give numbers. Isn't it? So how do you number from right to down or from down to sorry left to down or down to left? Definitely looking at this, you can understand, you know, from this direction, if you go, you will get the lowest locate. Definitely. Right. So I'll start numbering from here. This is carbon 1. This is carbon 2, carbon 3, carbon 4, carbon 5, carbon 6, carbon 7, carbon 8 and carbon 9. OK, so this is how I'm numbering. So after giving numbers, now it is just a writing the name, right? First, you will write the prefix that is the names of these branches you have to mention. What is the name of this branch? Methyl, right? What is the name of this branch? Methyl. This branch, methyl. This branch, methyl. Three methyl groups are there. And another branch you observe. This is the branch. This is not a simple branch. It's not a methyl. It's not a ethyl. This branch itself is a complex branch. These big branches are called complex branch. Okay. Consider complex branch as a separate molecule and start naming them. Okay. So complex branch itself you consider as a separate molecule. Now I will consider this itself as a separate molecule and first I will name this. Okay. So how do you write the name of complex branch here? Once you have complex branch like this, its name is written as if it is a separate molecule. First you write like that. Okay, see here I will again number this. How do I number? The carbon that is attached to the main chain gets a number 1. Here you must not check a lowest locant and all that. Okay, so go on. The carbon that has attachment with main carbon in a chain, no? That carbon should get a number 1. Okay. Then this is number 2. Then this is number 3. So methyl group is there at second carbon. So it is 2-methyl. 2-methyl. And how many carbons in a chain? This is a chain. Again it's a branch. So 2-methyl. How many carbons? 3 carbons, right? 3 carbons means what is the word root? Prop. Prop you will write. And all single bonds, ANA. But this is a branch, right? This is a branch. So, what we will write? It has profile we will write. So, what is the name of this complex branch? 2-methylpropyl. Understood how we named it? We considered this itself as a separate compound. We started numbering it separately. Okay, we started numbering it. What way you have to number? The carbon that has got attached to main carbon in a main chain, that carbon should get number 1. Then definitely this is number 2, definitely this is number 3. Then at second carbon, methyl group is there, no? So 2-methyl and 3 carbons in a main chain of this branch, right? So propyl, right? So what is the name of this complex branch? 2-methyl propyl. And to which carbon it has attached? Fourth carbon. Right? So now you see methyl, methyl, 2-methyl propyl. Okay. First try to mention the branch name first. You see this whole complex branch is attached at fourth carbon. So it is fourth. I will write it here. Fourth. And complex branch name you write in a bracket. Okay, so what is its name? 4, 2. methyl 2-methylpropyl bracket close. Now as usual mention this methyl groups. Okay so where are the methyl groups present? They are present at carbon number 1 and they are also present at carbon number 2. How many at carbon number 2? 2. So, 2, 2. All together, 3 methyl groups. So, trimethyl. So, this much is your prefix. This much is your prefix. Now, word root. So, main chain has 9 carbons, no? So, non and in the main chain carbons between them, all are single bond. So, A and E. So, what is its name? 4, 2-methyl propyl. 1, 2, 2 trimethyl non-ane. So, you have to be very very careful while naming complex branches. Okay, fine. So, similar to this another example is there. Now you see. So looking at this, yes, we select the longest chain as straight chain. But anyway, try to count the carbons. 1, 2, 3, 4, 5, 6, 7, 8, 9. I'm covering 9 carbons. But if you go this way, this way if you go 1, 2, 3, 4, 5, 6, 7, 8. Less carbon. So straight path only our longest chain. Now this whole thing is a branch, right? This whole thing is a branch and it's not a small branch. It's not methyl, it's not ethyl, it's a complex branch. It is a complex branch. So when complex branches are there, what you have to do? Take them as a separate compound and name them first, write their name first. So what is their name? How do you name them? First numbering right? So the carbon that is attached to the main carbon should get number 1, number 1, number 2, number 3. Now in this these are again branches. So what is the branch name? I am writing branch name. Okay. So branch name is 2 comma 2. At second carbon, 2 methyl groups attached. So 2 comma 2 dimethyl. Dimethyl. Okay. How many carbons? 3 carbons in the main chain. Okay. I mean in a branch. That is propyle. 3 carbons in the sense propyle. Right. So this is branch name. This is a branch name and this branch is present at which carbon? Yes, 1, 2, 3, 4, 5. If you number this way, this carbon is getting 5. 1, 2, 3, 4, 5. If you number from this way also, this carbon is getting 5. So, 5. At fifth carbon, this branch is present. Okay, so what is the name of this branch? Again complex. So, when you name a branch, you have to be careful. Take it as a separate compound and name it. okay feel that it is a separate compound okay so on to a side you work out writing its name and when you work out with its name don't forget numbering you will not do according to the rules the carbon which is attached to a main carbon that carbon should get number one always okay so this is two this is three so for second carbon these two guys are like branches so we have written two comma two dimethyl propyl Over. Branch name is over. Prefix is only 1. Over. Now in a main chain you have 9 carbons. So non. Okay and all single bonds between carbons. So 8. 5 2,2 dimethyl propyl nonane. Over. Right? So this is how you have to be very very careful when you have branched saturated hydrocarbons. Okay? Now we will see few more examples and few I will discuss and remaining is for homework and you are writing their names and posting in a comment box. So let me check it out how many of you could write. See these examples guys. Looking at this, it looks some figures, but no, the compound is mentioned in a bond line representation format. We studied in the previous video how to represent structures in a bond line format, right? So, if you have not yet watched, watch that video. That's very, very important. This is how questions can be asked for competitive exams like NEET or JE or CET, okay? So, don't expect a direct question, right? So, how do you First, you convert this into normal structure. Like every corner carbon is there, right? Here carbon, here carbon, carbon, carbon, carbon, carbon, carbon, carbon. So which carbon? It's CH3. And this one? CH2, right? 1, 2, 3, 4. Four carbons are already there around this, right? So this is CH2. This is CH3. CH2, CH3. CH2, CH3. So, this is our normal structure. So, now you select the longest chain. What is the longest chain? 1, 2, 3, 4, 5. In this direction, if you go 5, 1, 2, 3, 4, 5. In this direction also you are getting 5 carbons. So, let me select this as my longest chain. Okay. And now which, now these two are like branches. These two are like branches. Which is the branch? CH2, CH3. So what is its name? Ethyl. What is its name? Ethyl. At which carbon they have attached? 1, 2, 3. Third carbon. This way if you go, this carbon gets 3 only. Right? So now just a matter of writing its name. right? So how do you write its name? 3,3 because at third carbon, two branches. Both branches are ethyl only. So 3,3 diethyl, diethyl and in a main chain, how many carbons? 1, 2, 3, 4, 5, right? So pent primary suffix a or n. Such an easy compound. Just the way of representation was different. So first you convert to a normal formula then work it out. How about this? So, every, at every point carbon is there. Here carbon, here carbon, here carbon, carbon, carbon, carbon, carbon. Now write how many ever hydrogens necessary. This carbon already has one bond, three more bonds it wants. So, three hydrogens must have been there here, here one and this is CH3, this is CH, CH2, CH2, CH3. That's it. So, this is what your compound and which is the longest chain? Longest chain. Longest chain is definitely this one. Straight chain, right? So, this much. See, this one if you write it normally, how do you write? CH3, CH3, bond CH. For CH, you have one substituent group CH3 and bond CH. For this CH, you have a substituent group CL. CH, CH2, CH2, CH3. So, this is normal way of writing structure. Now, you can guess, right? This is your longest chain. And these two guys are branches. And what is, how do you number this? From left to right, right? 1 because 3, 4, 5, 6, lowest to low will be minimum if you go from left to right. And what is the name of this group? Methyl. The name of this group, chloro. Alphabetically, which comes first? Chloro comes first. So, you have to write chloro first. Chloro attached to which carbon? Third carbon. So, 3-chloro, again hyphen, 2-methyl. Okay, 2-methyl, over. Prefix is over. Write the word root. Main chain included 6 carbons. So, hex. All carbons had single bond, A and B. So, what is the name? 3-chloro-2-methylhexane. Over. So, now this is homework for you. Okay. So, this compound and this compound, try yourself and don't forget to post the answer in a comment section. And you know, I covered each and every rule that makes you easy. To write the names of any saturated hydrocarbon. If you could know these rules, you can name any saturated hydrocarbons. It may have simple branches or complex branches. Okay. So if you have any doubts, you can post it in a comment section. We will try to answer. And don't forget to mention the answers of these two compounds. okay so thank you so much and you can also post your opinion in the comment section about the video if you have liked the video please like it share with all your friends let all of them enjoy the video after all it's a sharing of knowledge isn't it so thank you so much meet you all in the next video for learning nomenclature of unsaturated hydrocarbons. Like in between carbon atoms, if double bonds are there, how to name them? That's what we will discuss in our next video.

Nomenclature in the sense naming, right? Say nomenclature. In other words, we can say this as naming, right? So why do we have names? I mean, why we have to name organic compound?

See, why do human beings have name? Each and every one of us have names, right? So what is the purpose of names?

With the help of names, we can identify a person. right so for identification we have names otherwise you know among these many people if I have to call you how can I call you if you were not having a name right so with name we can identify a particular person likewise even in our organic compounds as I already told you 5 million compounds exist in our nature. There are 5 million organic compounds, some natural, some man-made.

And every year over 30,000 organic compounds are being produced. being discovered. So for example suppose you have an organic compound Y, some organic compound Y discovered by a person X. So this X person discovered this.

Normally whenever some theory or some law was discovered in science or when some element is discovered, you know name of the scientist is kept. for that particular element or law or theory whatever it is okay say for example dalton's theory is there so these dalton's theory was discovered by a person dalton so that theory was called called with the name dalton's theory okay so if you apply that concept here say a is the compound discovered by a person x so if i keep name of this person here you know there are you so many compounds discovered every year. So how will you remember each and every scientist name?

It leads to a lot of confusion. And there comes another problem. If the same compound was discovered by a person P, then will you keep P again for the same compound? Or you must know that the same compound is already discovered. Right?

See, these are some problems that we will face when a name of a scientist is kept for a particular compound that was discovered okay so we can't keep scientist names for the compounds we want some name with the name itself we can identify a compound with the name itself we can study a compound isn't it so definitely there is a necessary thing to name organic compound so we can't keep scientist name because of these problems there are several practical problems behind this and it leads to a lot of confusion and it's very difficult to remember those scientist name because it's not 5 compounds or 10 compounds. There are millions of organic compounds in our nature. So we can't keep some scientist name whoever have discovered or whoever have manufactured. So came a nomenclature called IUPAC nomenclature.

So we call naming of organic compound. as IUPAC nomenclature okay fine so what do you mean by this IUPAC nomenclature say IUPAC is an organization of chemistry okay so these people actually solve every problem that comes in chemistry or you know they will refer or you know they are the one which who will actually judge whether the newly discovered theory is correct or not whatever whatever may be the issue regarding chemistry you know these people will solve these people will look over it So the full form of IUPAC, you must have studied in your basic classes, International Union of Pure and Applied Chemistry. So this is the full form of IUPAC.

People developed a set of rules. Okay, so they have given so many rules. So many rules are there.

So they said that, see these are the rules we have developed. Each and every one in a world, if they want to give names for organic compound, they should follow these rules they said. So everybody.

Okay, whoever discovers a new compound, if he or she have to give name for that compound, they must definitely follow these rules. So how does these rules will help in solving problems regarding names of organic compound? For example, the same example, you know, instance I will take, A is the organic compound discovered by a person X and this X person followed these rules and kept the name.

right. So, he kept a name something called you know 2-methylbutane, right. Some A compound, he kept a name as 2-methylbutane following these rules 1, 2, 3, 4, 5 set of rules, right. And there was another person, P person discovered some compound, discovered some compound he thought it's completely a new compound but okay he discovered and he had to give a name right so he also should follow the same rules what is the rule says everybody in the world to name a particular compound they should follow these rules so this p person also for his newly discovered compound he followed these rules and kept a name and surprisingly he got the name as 2-methylbutane itself. Then he understood that I didn't discover anything new.

The compound is already existed and that was discovered by a person X. That way people will come to know which compound is there in a nature, which compound is not there. And it's like when a compound has a same name all over the world, it's very much helpful. It's very much helpful to identify a particular compound, to study a particular compound and to understand the nature of a particular compound. Okay, so one particular compound must have a same name throughout the world.

Only then we can study them in a better way, best possible way. That is why it is very important to study IUPAC nomenclature. So our duty is to learn those rules so that we ourselves can name any organic compound.

But this IUPAC nomenclature we are studying in a particular pattern. I am not clumsing all the topics. There are n number of organic compounds.

Right. So let us study in a group wise. Right. So I am going to deal this IUPAC nomenclature in four videos.

In this video, I am. giving how to name for saturated hydrocarbons. Okay and in the second video I will talk about nomenclature of unsaturated hydrocarbons and in my third video I will talk about organic compounds with functional group.

and in my last video i will come up with nomenclature of cyclic compound so this way i have divided the entire class of organic compounds into four categories and category wise we will learn their naming so that it becomes easy for you and you will not get confused right okay so now let me give you some introduction about uh these names organic names And you know every compound has two names normally. Most of the compounds have two names. One is IUPAC name, the other one we say common names.

Common names are like pet names right. Usually closed ones or loud ones will call us with a pet name right. But when we go outside, I mean in a school or office or wherever it is, we have our own official name right.

So we keep seeing. A person having two names, one is official, one is a real name which was given in records and the other one is a pet name which is called by you know family members. Like that our organic compounds also have two names. IUPAC name is like official name. Everybody will understand this IUPAC name.

Everybody will call a compound with IUPAC name. Okay. At the same time, you know, a particular compound have a common name. So how did this common names have come? These common names have come from their source.

For example, you know, This particular name is very much known for you. We call something as acetic acid, right? So if you can remember the formula for Acetic acid, it is CH3COOH.

So why do we call this particular compound as acetic acid? You know, it's not the IUPAC name here. The actual, after following all the rules, if I have to keep this compound's name, it will come as ethanoic acid. I must call it as ethanoic acid. This compound's official name that is IUPAC name is ethanoic acid.

But common name is acetic acid. Acetic acid is like a pit name. So why am I calling this as a acetic acid?

It is because this acid is present in vinegar this is present in vinegar okay so vinegar in greek is called as acetam vinegar's greek name or you know the latin name whatever usually you know latin name or greek name be considered so vinegar's latin name is acetam clear so since this acid is present in vinegar it acetic acid you know acetic acids source is vinegar that's the reason you know we call this acid as acetic acid but actually its iupac name is ethanoic acid right so uh it's maybe because of their origin or source you know their nature these common names were kept Most of the compounds have common names. You must be familiar with common names of compounds also. Not all but some famous compounds. The compounds which we frequently use it in our syllabus.

You know we keep telling you like for which compounds we have to remember a common name. Right? So don't worry.

So now let us come back to IUPAC naming. Right? Fine.

For example, you take a human name. Let me take a name Vijay Kumar P. Okay, so let this be Vijay Kumar P. It's a human name, right? A boy's name. I can break this name into three parts, right? We call this Vijay as first name, Kumar as middle name.

and P as last name. Even when you fill certain applications, you know, there are three columns, first name, middle name, last name, right? Similarly, every human name can be divided into first name, middle name and last name. Likewise, our organic compounds names can also be divided into three parts.

Okay, see we can have a part like prefix, we will have word root and we will have suffix. Okay, prefix is like the first name, word root is like the middle name for an organic compound and suffix is like the last name for an organic compound. Ok, so prefix comes first.

We will start writing a name with prefix. First name we will write. Later middle name, this is very very important. And later the last name which is called with the name suffix.

Ok, so instead of calling first name, we call it as prefix. Instead of calling as middle name, it's word root. And then instead of calling as last name, it is suffix.

right in case of suffix again we have primary suffix primary suffix and secondary suffix whenever we write a primary in chemistry you know we will write it as one degree suffix one degree means what it's primary suffix secondary suffix suffix is again of two types okay so usually when we write an organic name first we will mention what is prefix Later we will mention what is word root. Later we will write primary suffix. And the name will end with secondary suffix. Secondary suffix. So this pattern you have to follow for naming any organic compound.

Okay, you will have to mention the first name first, later the middle name which is called as word root, later the last name. Last name again has two parts. Primary suffix you will mention first, later the secondary suffix. So now, for example, you have this organic compound. say this long organic compound you have with you ch2 ch2 uh you know ch2 coo h see if i have to name this organic compound yeah i have to write its name in this pattern i have to follow this pattern first i'll have to write prefix word root then primary suffix and then secondary suffix.

Then what should be written as a first name? See if you look at this compound it has branches right? It has branches and there are so many carbon atoms in a chain.

I will call this as carbon chain where so many carbon atoms are there and I have a special group called functional group. COOH, OH, CHO all these are special groups. They will decide chemical properties of organic compound isn't it?

So here branches name is nothing but prefix and the carbon atoms number of carbon atoms which are present in a chime is mentioned as word root and the special group name is mentioned as suffix. So this is how each and every part of a compound is mentioned in the name. Either as prefix, word root, primary suffix or secondary suffix. Okay.

So now I will tell you what groups if there in a compound is mentioned as prefix. Okay. What and all groups will come as prefix side. If those groups are there in organic compound, you have to mention them as prefix.

I will give you the list of those groups that has to be written as prefix. And I will give you. you know the number of carbon atoms that you can write it as a word root.

If you have one carbon, you will write the word root as meth. If you have two carbons, you will write the word root as eth. Okay, so that list I'll give you. So now these two.

1, 2 and 3 primary suffix. About these three all information I am giving you in today's class because today's class is all about naming saturated hydrocarbons. For naming only saturated hydrocarbons information of this, this and this is enough. About secondary suffix we will discuss later.

When we go for naming organic compounds with functional groups, then we will talk about secondary suffix. So, now you take a list of prefix, word root and primary suffix. Clear? See, observe here, if these groups are there in an organic compound, you should write them as a prefix. I mean their names, their names you should mention as a first name.

okay and we call these groups these groups as substituent groups prefixes are also called substituent groups so what you have to mention as a prefix name of substituent group substituent group must be written as a prefix okay so all these are prefix writing groups. So, if you have a group F, its name F, F's name you have to indicate in prefix. Okay, you have to indicate as the first name. So, if F is there, what is its name? Fluro, likewise Cl, Chloro, Br, Bromo, I, Ido, No2, Nitro, NH2 if it is there, Amino.

CH3. Okay. So how did this CH3 must have come? You all know CH4, right? If one hydrogen is taken outside, you will get CH3.

Okay. So CH4 is methane. This methyl group, this is called as methyl group. This is derived from methane, right? That's why it is called methyl.

Okay, so usually these groups can stay as branches. Okay, so whenever you have branch as CH3 group, not CH4, CH3, not CH2 also, it is CH3. CH3 if it is there methyl, CH2, CH3. Actually, this is derived from ethane.

From ethane, one hydrogen if you remove, you will get ethyl group. And this is propyl group. Whereas CH, CH3, CH3.

Okay. So you see this compound. Let me write that group once again here. If this big group is there as a branch, you know, there are so many carbon atoms.

Carbon atoms are there in a chain. Some long carbon chain is there. To that, if this branch is there, CH, for that, two methyl groups are again branches.

So, this group, this group is called as isopropyl group. Remember? Isopropyl.

group. Okay, fine. And now, this is isopropyl. In case, if there is some CH2 to that isopropyl group is there.

Then this complete group is called as isobutyl group, right? So, hope you understood what is the difference between isopropyl and isobutyl, right? So, isopropyl is if this group is directly attached to a carbon chain. If it is not directly attached, there is one more CH2. To that carbon chain is attached, then the entire group CH2, CHCH3.

So this group is isobutyl group. Then say you have another compound, okay, long carbon chain. And you know, if this group is there, there's a difference, right?

So there's a difference between this group, this group and this group. Okay, so if this group is there, you know, this is different and this is different. You can observe that very, very clearly, right?

So if this group is there, it is called as tertiary butyl group. Tertiary. T. T-E-R-T in the sense tertiary.

Okay. Say tertiary butyl. Why do we call the word tertiary is because you know the main carbon China is getting attached to this carbon.

This carbon is called tertiary carbon. It is called as tertiary carbon. Okay.

So why do we call this as tertiary carbon? Because this carbon is attached to three other carbons around it. it okay so how many cc bonds you have this is one cc bond this is another cc bond this is third cc bond if a carbon has three other bonds with carbons only then it is tertiary carbon okay so about this tertiary carbon secondary carbon and primary carbon i made one basic video video link will be provided in the description you can go and check it out for an idea about Primary carbon, secondary carbon and tertiary carbon.

Clear? Okay. So hope you understood about the groups and their names, right? So you must know this. Okay.

So which group is called with which name is very important because if these groups are there, their names are the one which you are mentioning as prefix. Okay. And now coming to...

Word root. So what you will mention in word root? Number of carbon atoms In a chyne, in a chyne is mentioned as word root. Okay.

So, if you have one carbon in a chyne, it can be called as meth. You will mention word root. Word root in the sense middle name. Middle name you will write it as meth.

When? When you have only one carbon in a chyne. Okay, so if you have two carbons, if you have two carbons in a chyne, you will mention the word root yet.

Three carbons, prop. Four carbons, but. Five carbons, pent.

6 carbons, HEGS. 7 carbons, HEPT. HEPT it is.

Okay. So when you have 8 carbons, it is OCT. 9 carbons, NON. 10 carbons, DEC. 11 carbons undec.

12 carbons dodec. Okay. So till 12 if you can remember it's more than enough. 13 tridec. 14 tetradec.

Okay. Like that it goes on. But for your level if you can remember till 12. So what is 12?

It is didec. Didec. 13 tridec. Like that. okay so this is how we mention word roots so word root is mainly the number of carbon atoms in a chain okay you see a chain may have four carbons five carbons six carbons if you have four carbons you will use the word root you will write the middle name as butte right so that is about the word root and coming to primary suffix that I told you.

Primary suffix. So after writing word root you will mention the name of primary suffix. Say if you have all single bonds in a carbon chain, in a main chain between Verbons, if you have all single bonds, then you will mention primary suffix as ye-yen-yee. If you have a double bond in a main chain between carbon atoms, you will write the primary suffix as E and E.

And when you have a triple bond, you know, you will call that particular compound, I mean, primary suffix as Y and E. Right. So, depending on the type of bond between carbon atoms, you are writing your primary suffix. If you have all single bonds between carbon atoms, After writing word root, see to word root only you have to join this primary suffix.

If your chain has 4 carbons, butane. Between 4 carbons if you have all single bonds, ane. Butane plus ane, it becomes butane.

In case in any of the carbons, between any of the carbons you have a double bond, then ENA. Bute for carbons, bute plus double bond is there, ENA. It becomes butene, right?

So, hope you understood about primary suffix. and if functional groups are there COOH CHO ketone group all of their names are mentioned as the secondary suffix. So ending of the name should end with the name of a functional group.

So that we will discuss in our next videos when we study nomenclature of organic compounds containing functional groups. So now we will start with nomenclature of saturated hydrocarbons with branches. Clear?

See guys, with these three examples, I'm going to explain you the two most important rules here. So the rule number one, what I am actually talking about is naming of saturated hydrocarbons. Naming of saturated. You know the meaning of the word saturated, right?

Saturated means having all single bonds. Okay, saturated hydrocarbons. So what do you mean by hydrocarbons? Organic compounds which have only carbon and hydrogen.

Okay, you don't have any other functional group here. When you have only carbon and hydrogen, we will call them as hydrocarbons. Is that clear? You see here, three examples are there. You observe these compounds.

You have only carbon and hydrogen. Okay. So you do not have any functional group like COOH, CHO all that. Other element is not there.

Only carbon and hydrogen is there. Okay. So such compounds are called hydrocarbons.

So we are trying to name saturated hydrocarbons in this class. Okay. So coming to rule number one.

Rule number 1. Okay, the rule number 1 says select the longest carbon chain first. You have to select the longest carbon chain. So how do you select the longest carbon chain? You have to select a path where maximum carbons are involved. Okay, so this is what we mean by selecting longest carbon chain.

So now let's check it out. This is the compound. Which path can cover more number of carbons?

Say one way I can think is going in this straight way, right? Straight chain. Say this I consider as a branch.

So if I go straight. See you can't count the carbons which are there in a branch. You should select a straight chain where carbons are involved. Say if I select this path, how many carbons are involved?

1, 2, 3, 4, 5, 6. 6 carbons. And there is another path possible. So if you can differentiate, I am using a different colored chalk piece here for the second path. Say second path, this is also possible, right?

How many carbons? 1. 2, 3, 4, 5. So in the second path, 5 carbons I am covering. In the first path, uh one two three four five six right so uh six carbons are covering in the first path and another path is possible that is this this path one two three four four carbons are covering in this path so you have to check all possible paths here okay three parts possible one is a straight path second one is this purple color uh chalk piece that i have used and the third one is this okay so in the first path six carbons are covered if i go in a second path five carbons covered if i go in a third path four carbons covered so what is the rule says select a path which can cover more number of carbon atoms okay so that is what we mean by longest chain rule Okay, say if I select this path, I mean observe the orange color chalk piece here.

So this is the correct path which involves 6 carbon atoms. Okay, so first thing you need to think about is selecting the longest child. Think that in which way if you go you can cover maximum number of carbon atoms. You can cover more number of carbon atoms. So that is you.

your parent chime. You know we call this as now parent chime. So that is your parent chime. Okay fine.

And now observe the second example and select the longest chime here. So definitely looking at this say one possible way is selecting this straight chime. Okay how many carbons it involved? One, 2, 3, 4, 5, 6, 7, 8, 9. 9 carbons are involved if you go in this straight path.

And one more path is possible that is this. This. Okay.

So, this path. This path you observe guys. How many carbons are getting covered? 1, 2, 3, 4, 5, 6, 7, 8. So if you go in this path, 8 carbons are covering. Then any other longest?

No, right? So which is longest? That means your straight path.

is the longest one where you are covering more number of carbon atoms. Okay. So there are coming 9 carbons if you go straight.

Okay. So your parent chain is this. So this is your parent chain.

clear so that's how you have to select you should not include these carbons in the parent chain now they are becoming branches okay you you have to write their name as prefix now so these guys are branches here ch3 here ch2 ch3 you know these guys have become branches now once you select your parent chain then remaining stuffs whatever are there they are branches okay fine coming to the third example can you tell me which is a longest path here you observe here if i go straight if i go straight you know how many carbons i can cover 1, 2, 3, 4, 5. 5 carbons I am covering. Then any other way that can cover more carbon atoms. One more way I can think of here.

Just observe this. Just observe this path guys. This path.

This path. Okay. So how many carbons I can cover here?

1, 2, 3, 4, 5, 6 carbons I am getting covered. I mean right. 6 carbons are coming in this chyme.

So any other path that can cover more than 6 carbons? No. So now this is your parent chyme. The way, the path which had covered 6 carbons to the most.

that is your parent chain now every other thing this one this group and this group this group everything will become branches now okay so this is where you have to be very very careful so the first thing is you have to select longest chain carefully so you must observe every side you know longest to chinese not always a straight path every time straight path will not be a longest to check you'll see here straight one is not a parent chain right. See this is our longest chain. So parent chain need not be straight always okay.

So it can vary. You must be very very careful enough in selecting a parent chain. So that was our rule number one okay.

So once you carefully select the longest chain later is numbering. So this is the most important rule one must follow. Rule of numbering.

So let's now discuss rule of numbering with the same examples See coming to rule of numbering you have to remember one basic point that Once you select the longest child, parent child in other words You have to give numbers for those carbons Okay the carbons which are coming in a child must be numbered Okay You You should give numbers for them 1, 2, 3, 4, 5, 6 like that. You cannot give numbers for the branches. See once you select this as your parent chain now this CH3 will come as a branch. Right? You have to give numbers for only these carbon atoms which are there in a parent chain.

Okay? Fine. How do you number them? Even to number we need to follow certain rules.

The first basic point is carbon atom. Carbon atom with a substituent group. With a substituent group. Should get the lowest number.

Should get lowest number. This is very very important. What do you mean by this? See, I can start numbering from this end or I can number from this end.

From which end you will start? See, if I number from this end, this carbon gets 1, this is 2, this is 3, this is 4, this is 5 and this is 6. Right? Okay. So if I number from this end, this end, this carbon gets 1, this gets 2, 3, 4, 5, 6. Isn't it?

And what does the rule says? The carbon that is attached to the functional group, this is the carbon to which, sorry, this is the carbon to which substituent group is attached. Okay, so now this CH3 is a branch, we can also call it as a substituent group and this substituent group is attached to this carbon.

This carbon should get a least number, this carbon should get a lowest number, lowest number in the sense not. number one okay numbering you should start from one end definitely but in the process the carbon which has got a branch should get the less number. So which way if you go this carbon is getting less number? When you go from left to right, this carbon is getting 4. When you went from right to left, this carbon is getting 3, right? So which is the correct way of numbering?

Correct way of numbering is this, okay? So once you have given number, The only step is writing a name. Okay.

So selecting a longest chain and numbering is very very important. If you have done that correctly then remaining thing is writing a name. Okay.

So here I am explaining rule number 3 also. Okay. Writing name.

Okay. So how do you write name here? First thing is you have to mention prefix.

Okay. So how do you write a name here is let me tell you here. First you have to mention the number of carbon to which to which substituent group is attached. Okay.

right? S, Sg in the sense, substituent group. After mentioning the number, you have to write the name of substituent group. After that, you have to write the word root. After that, you have to write primary suffix, primary suffix, okay?

So, this is, this is the way of writing name for, you know, saturated. hydrocarbons. Okay.

First you will mention the number, later name of substituent group that is branch, later word root and finally you will end the name by primary suffix. So we will apply the same thing here to write the name. We selected longest chain.

We have given number also. Work is over. First let us finish off writing its name.

So what is the name of this compound here? First you have to mention what? Number of carbon.

Number of that carbon atom to which substituent group is attached. So, what is the number of this carbon atom? 3, right? After writing 3, you have to put a hyphen, a small hyphen, okay? After that, write the name.

This is the substituent group that is branch. What is its name? I told you, this is called as methyl.

CH3 is called as methyl. So, it is methyl. Okay, over number we have mentioned, name of substituent group we have mentioned, later word root. Don't give any gap here. Okay, continue the name and word root.

What is word root? Number of carbons in a chain you will mention as word root. So, in the Parent chain, how many carbons you have?

6 carbons you have. So what is the word root you will use? Hex you will use. If 6 carbons, word root is hex.

And finally, primary suffix. Don't give any gap. You shouldn't give gaps anywhere. Okay, the name. Write from number, the name should continue.

There are no gaps. Okay, so trimethylhex, what is the primary suffix? Check, between carbons, all single bonds are there. Okay, so usually for saturated hydrocarbons, the primary suffix is ane, over.

So, what is the name of this compound? It is trimethylhexane. Trimethylhexane is its name.

clear over so we have completed the first compound coming to second compound okay so actually in every example you are going to learn a new rule right so that's why see i selected examples carefully so that i will cover maximum rules for you right first example very simple just you know selecting a parent chain then there is only one branch so it was very easy the carbon that has got a branch should get a least number that way you have numbered over you have written the name also coming to second example first step is over we selected the longest parent chain here that included a straight chain which has got nine carbons okay so now numbering how do you number you Whether you number from left to right or from right to left is the big question mark, isn't it? And okay, we have to number in such a way that carbon having branches should get the least number, right? And you see here, I'll put a star mark.

This carbon has got a branch, even this carbon has got a branch. So now how do you number? How do you number? Comes a question mark and here you have to follow one important rule called rule number 4 I am revealing which we will We will call it as lowest locant rule.

Lowest locant rule. Very very important rule guys. So you have to think about it. Okay. So when do you use this lowest locant rule?

When you have two or more than two branches. If you have to in that situation if you have to number the parent child. If only one branch is there it's very easy.

You will just select a direction in which direction if you go this carbon gets a least number that way you will number. But here both carbons have branches. So whether you number from this end or that end.

So how do you decide? You observe. First, I'll number from this end. I'll start numbering from this end. Okay, so this is number 1, this is number 2, this is 3rd carbon, this is 4th, this is 5th and this is 6th, 7th, 8th, 9th carbon.

So first I numbered from left to right and now I will start numbering from right to left also. Okay so right to left if I start numbering carbons so this is 1, this is 2, this is 3, this is our 4, this is 5, this is 6, this is 7, this is 8 and this is 9. Isn't it? Okay, so now what you have to do, when you went from left to right, you know this carbon, star mark carbon has got a branch, right? This carbon has got a number 2 and this carbon another carbon which has got a branch has got a number 6 right when you went from left to right when you went from left to right.

So you add both the numbers so 2 why did I take because this carbon star mark carbon has got a branch so that carbon had got 2 when I went numbering from left side onwards. So 2 plus 6 if you do you will get the number 8. Okay? And now right side numbering I will concentrate. Right side numbering I have written at the bottom. Okay?

Fine. So when you go from right side, your star mark containing carbon has got number 4 and anion carbon containing star mark has got number 8. So 4 plus 8 if you do what is the number you will get? You will get 12. Which is the least number among this?

The least number is 8. So you have to follow left to right numbering. This is what we call lowest locant rule. See rule Rules, definitions, meanings and all they will not be asked for the examination.

You must know the rules to write the name. Okay, so it's not a matter of by-hatting a rule. It's a matter of understanding a rule.

Okay, so when you have two branches or more than two branches, you must definitely follow lowest locant rule. Okay fine say from left to right when we go our lowest locant is least. Locant this addition this sum we will call it as locant. Okay locant is very very least.

So left to right numbering we have to follow. Okay so right to left numbering is wrong. So this way of numbering is wrong.

Left to right numbering we have to follow. So numbering is over. right and now writing a name so how do you write the name here how do you write the name first numbers you have to mention later name of substituent group word root primary suffix right that's what in the end and now you have two branches so whose name you will mention first this is the branch ch2 ch3 its name is ethyl and this is the branch ch3 its name is methyl isn't it so alphabetically which one will come first e comes first or m comes first e comes first so here One more rule we have studied. Rule number 5. Okay.

So when you have 2 or more than 2 branches. When you start writing their name. You have to follow alphabetical order.

You should follow alphabetical order. Okay. So here ethyl.

Here methyl. E comes first. So mention. So at which carbon ethyl group is attached?

It is attached at 6. Don't forget to mention. mention the number. So, it is 6-ethyl, 6-ethyl, put a hyphen, okay? And another prefix is there, methyl. At which carbon this is attached?

At the second carbon, right? So, it becomes 2-methyl 2-methyl. Prefix is over.

Along with the number, prefixes we have mentioned. 6-ethyl, 2-methyl. Now, word root. Word root in the sense, in the parent carbon, how many carbon, in the parent chain, how many carbon... are there?

9. So, if 9 carbons, what is the word root you will use? Non. And all single bonds, so primary suffix is A and E.

So, what is the name of this compound? 6-ethyl-2-methyl-nonane. Right? See, here we have studied lowest locant rule and writing the names of prefixes in alphabetical order. Both rules are very, very, very important.

Okay? Fine. Coming to example number 3. Right?

So whatever we have studied so far, everything you apply here. You see, parent chain we have already selected that is this format. Okay.

And now how do you number this? Numbering is what very very important. From left to right or right to left. First let me number it from left to right.

Lowest to low can see more branches are there. Definitely you have to check the lowest to low can't right. See.

One. True, this is carbon 2, this is carbon 3, carbon 4, carbon 5, carbon 6. Okay, so from left side onwards, first let us calculate lowest locate. Okay, so at second carbon. At second carbon, you have two branches, right?

So you write 2 two times. 2 plus 2. Write it this way. Okay?

2 plus 2. And at fourth carbon also, 2. branches are there. You see two branches are there right. So 4 plus 4 then any other branches that's it. So what is the total you will get?

4 plus 4 is 8. 8 plus 2 10. 10 plus 2 12. Okay fine. And now from right side you start checking. From right side if I number.

Right side if I number. Right side if I number. This carbon gets number 3 right. So So two branches are there at this carbon.

So 3 plus 3, 4, 5. At fifth carbon, you have two branches. So 5 times 2, I will write 5 plus 5. Any other branches? No. So what is the total? 5 plus 5, it is 10. 10 plus 3, 13. 13 plus 3, it is 16. right.

So which is correct left side numbering or right side numbering? Definitely lowest number you got when you went through left side. So left side.

So the numbers which I have already put here know that is the correct way of numbering. That is the correct way of numbering. Okay.

So once you have numbered later you will have to write the name. Okay, so how will you write the name? How many branches are there? This is one branch, this is another branch, this is third branch and this is fourth branch, right?

And observe one thing, all branches are methyl only. All branches are methyl only. Then in that case, in that case, you know, at which carbons these branches are there?

Second carbon, right? Two, And two methyl groups are present on the same carbon, right? So, 2 times 2 you mentioned. 2, 2. And the same methyl groups are present at fourth carbon also. And two methyl groups.

So, 4, 4 hyphen. First, we have mentioned all numbers. Okay, all numbers why together? Here you see numbers are not together. I did not mention 6, 4. Because the substituent groups are different.

Why all numbers together I have mentioned? Because substituent groups are same at these carbons. Why I mentioned double time 2,2?

Because two groups are attached to second carbon, same groups. So, 2,2. Okay. So, 2,2, 4,4.

How many methyl groups? 4, right? So tetra, we will use the prefixes. Next, next rule. Rule number 6 I am teaching you with this example.

You know, use the words like di, tri, tetra, right? When you have same type of substituent groups. So 4 are there.

So tetra, tetra, methyl, over. Prefix is over. Now write the word root.

So, which is your parent chain? This is your parent chain has got 6 carbons. So, word root HEGS and all single bonds between carbons.

So, A and E. Okay, actually this must come here since it may not be visible for you. So, I wrote it down.

So, what is the name? 2, 2, 4, 4 tetramethylhexane is its name. Okay, so this is how I think almost all the important and common rules that I taught you for naming saturated hydrocarbons. Okay, so six rules I taught you for naming saturated hydrocarbons. Okay, and I will come up with many more rules for saturated hydrocarbons with heavy branches.

Okay. See, these are all small, small branches actually. Methyl, ethyl, they are all very small branches. But if you have one really big branch, how do you name them is also very, very important.

So, that one we will learn. Observe these two examples guys. Highly branched saturated hydrocarbons.

So, with these two examples, we are learning few more rules actually. Observe this example number 4 here. So first thing is you have to select the longest chain that you know. So how do you select the longest chain?

See 1 is directly looking at the straight path. It looks as if you can cover more number of carbons right. So let's count the carbon atoms if you select this as your longest chain how many carbons it will cover?

1, 2, 3, 4, 5, 6, 7, 8, 9. So 9 carbons you can cover when you go in a straight path. And one more path I can see here. Right?

So the path is this. This path. This one.

This path. Leave the branches. Only the straight chain use in this path.

Right? So how many carbons you can cover here? 1, 2, 3, 4, 5, 6, 7, 8, 9. So in this path also 9 carbons you are covering.

So which is your longest chain? Straight path covering 9 carbons and this path is also covering 9 carbons. So how do you decide longest chain here? The longest chain is the one with more branches. So a new rule again you studied, rule number 7. Rule number 7 you are going to learn.

You know longest chain, longest chain must contain must contain more carbons, more number of carbons more number of carbons right so this is a new point you've learned in this example right so when you have two long chines with the same number of carbons the longest chine is that chine with more branches see if you go in a straight path you have this as a branch and this whole thing as a branch right but if you go in this way see how many branches you will get this is one branch this is the second branch third branch, four branch. So that means when you go in this direction four branches you will get but when you go in a straight path only two branches you are getting. So go in a straight go in a longest path where you can cover maximum number of branches. Okay.

So more number of branches that has to be covered. So that way you have to select the longest chain when you have this dilemma. Okay.

Fine. So now the longest chain is covered. You have to give numbers.

Isn't it? So how do you number from right to down or from down to sorry left to down or down to left? Definitely looking at this, you can understand, you know, from this direction, if you go, you will get the lowest locate.

Definitely. Right. So I'll start numbering from here.

This is carbon 1. This is carbon 2, carbon 3, carbon 4, carbon 5, carbon 6, carbon 7, carbon 8 and carbon 9. OK, so this is how I'm numbering. So after giving numbers, now it is just a writing the name, right? First, you will write the prefix that is the names of these branches you have to mention.

What is the name of this branch? Methyl, right? What is the name of this branch?

Methyl. This branch, methyl. This branch, methyl. Three methyl groups are there. And another branch you observe.

This is the branch. This is not a simple branch. It's not a methyl.

It's not a ethyl. This branch itself is a complex branch. These big branches are called complex branch.

Okay. Consider complex branch as a separate molecule and start naming them. Okay. So complex branch itself you consider as a separate molecule. Now I will consider this itself as a separate molecule and first I will name this.

Okay. So how do you write the name of complex branch here? Once you have complex branch like this, its name is written as if it is a separate molecule. First you write like that.

Okay, see here I will again number this. How do I number? The carbon that is attached to the main chain gets a number 1. Here you must not check a lowest locant and all that. Okay, so go on.

The carbon that has attachment with main carbon in a chain, no? That carbon should get a number 1. Okay. Then this is number 2. Then this is number 3. So methyl group is there at second carbon. So it is 2-methyl. 2-methyl.

And how many carbons in a chain? This is a chain. Again it's a branch.

So 2-methyl. How many carbons? 3 carbons, right? 3 carbons means what is the word root?

Prop. Prop you will write. And all single bonds, ANA.

But this is a branch, right? This is a branch. So, what we will write?

It has profile we will write. So, what is the name of this complex branch? 2-methylpropyl.

Understood how we named it? We considered this itself as a separate compound. We started numbering it separately. Okay, we started numbering it. What way you have to number?

The carbon that has got attached to main carbon in a main chain, that carbon should get number 1. Then definitely this is number 2, definitely this is number 3. Then at second carbon, methyl group is there, no? So 2-methyl and 3 carbons in a main chain of this branch, right? So propyl, right? So what is the name of this complex branch? 2-methyl propyl.

And to which carbon it has attached? Fourth carbon. Right?

So now you see methyl, methyl, 2-methyl propyl. Okay. First try to mention the branch name first. You see this whole complex branch is attached at fourth carbon. So it is fourth.

I will write it here. Fourth. And complex branch name you write in a bracket. Okay, so what is its name?

4, 2. methyl 2-methylpropyl bracket close. Now as usual mention this methyl groups. Okay so where are the methyl groups present? They are present at carbon number 1 and they are also present at carbon number 2. How many at carbon number 2? 2. So, 2, 2. All together, 3 methyl groups.

So, trimethyl. So, this much is your prefix. This much is your prefix.

Now, word root. So, main chain has 9 carbons, no? So, non and in the main chain carbons between them, all are single bond.

So, A and E. So, what is its name? 4, 2-methyl propyl. 1, 2, 2 trimethyl non-ane.

So, you have to be very very careful while naming complex branches. Okay, fine. So, similar to this another example is there.

Now you see. So looking at this, yes, we select the longest chain as straight chain. But anyway, try to count the carbons. 1, 2, 3, 4, 5, 6, 7, 8, 9. I'm covering 9 carbons.

But if you go this way, this way if you go 1, 2, 3, 4, 5, 6, 7, 8. Less carbon. So straight path only our longest chain. Now this whole thing is a branch, right?

This whole thing is a branch and it's not a small branch. It's not methyl, it's not ethyl, it's a complex branch. It is a complex branch. So when complex branches are there, what you have to do?

Take them as a separate compound and name them first, write their name first. So what is their name? How do you name them? First numbering right?

So the carbon that is attached to the main carbon should get number 1, number 1, number 2, number 3. Now in this these are again branches. So what is the branch name? I am writing branch name. Okay.

So branch name is 2 comma 2. At second carbon, 2 methyl groups attached. So 2 comma 2 dimethyl. Dimethyl.

Okay. How many carbons? 3 carbons in the main chain.

Okay. I mean in a branch. That is propyle. 3 carbons in the sense propyle.

Right. So this is branch name. This is a branch name and this branch is present at which carbon?

Yes, 1, 2, 3, 4, 5. If you number this way, this carbon is getting 5. 1, 2, 3, 4, 5. If you number from this way also, this carbon is getting 5. So, 5. At fifth carbon, this branch is present. Okay, so what is the name of this branch? Again complex.

So, when you name a branch, you have to be careful. Take it as a separate compound and name it. okay feel that it is a separate compound okay so on to a side you work out writing its name and when you work out with its name don't forget numbering you will not do according to the rules the carbon which is attached to a main carbon that carbon should get number one always okay so this is two this is three so for second carbon these two guys are like branches so we have written two comma two dimethyl propyl Over.

Branch name is over. Prefix is only 1. Over. Now in a main chain you have 9 carbons. So non.

Okay and all single bonds between carbons. So 8. 5 2,2 dimethyl propyl nonane. Over. Right? So this is how you have to be very very careful when you have branched saturated hydrocarbons.

Okay? Now we will see few more examples and few I will discuss and remaining is for homework and you are writing their names and posting in a comment box. So let me check it out how many of you could write.

See these examples guys. Looking at this, it looks some figures, but no, the compound is mentioned in a bond line representation format. We studied in the previous video how to represent structures in a bond line format, right?

So, if you have not yet watched, watch that video. That's very, very important. This is how questions can be asked for competitive exams like NEET or JE or CET, okay?

So, don't expect a direct question, right? So, how do you First, you convert this into normal structure. Like every corner carbon is there, right?

Here carbon, here carbon, carbon, carbon, carbon, carbon, carbon, carbon. So which carbon? It's CH3. And this one?

CH2, right? 1, 2, 3, 4. Four carbons are already there around this, right? So this is CH2. This is CH3.

CH2, CH3. CH2, CH3. So, this is our normal structure. So, now you select the longest chain. What is the longest chain?

1, 2, 3, 4, 5. In this direction, if you go 5, 1, 2, 3, 4, 5. In this direction also you are getting 5 carbons. So, let me select this as my longest chain. Okay.

And now which, now these two are like branches. These two are like branches. Which is the branch? CH2, CH3. So what is its name?

Ethyl. What is its name? Ethyl.

At which carbon they have attached? 1, 2, 3. Third carbon. This way if you go, this carbon gets 3 only.

Right? So now just a matter of writing its name. right?

So how do you write its name? 3,3 because at third carbon, two branches. Both branches are ethyl only.

So 3,3 diethyl, diethyl and in a main chain, how many carbons? 1, 2, 3, 4, 5, right? So pent primary suffix a or n. Such an easy compound.

Just the way of representation was different. So first you convert to a normal formula then work it out. How about this?

So, every, at every point carbon is there. Here carbon, here carbon, here carbon, carbon, carbon, carbon, carbon. Now write how many ever hydrogens necessary.

This carbon already has one bond, three more bonds it wants. So, three hydrogens must have been there here, here one and this is CH3, this is CH, CH2, CH2, CH3. That's it.

So, this is what your compound and which is the longest chain? Longest chain. Longest chain is definitely this one.

Straight chain, right? So, this much. See, this one if you write it normally, how do you write?

CH3, CH3, bond CH. For CH, you have one substituent group CH3 and bond CH. For this CH, you have a substituent group CL.

CH, CH2, CH2, CH3. So, this is normal way of writing structure. Now, you can guess, right? This is your longest chain.

And these two guys are branches. And what is, how do you number this? From left to right, right?

1 because 3, 4, 5, 6, lowest to low will be minimum if you go from left to right. And what is the name of this group? Methyl. The name of this group, chloro. Alphabetically, which comes first?

Chloro comes first. So, you have to write chloro first. Chloro attached to which carbon?

Third carbon. So, 3-chloro, again hyphen, 2-methyl. Okay, 2-methyl, over.

Prefix is over. Write the word root. Main chain included 6 carbons.

So, hex. All carbons had single bond, A and B. So, what is the name? 3-chloro-2-methylhexane. Over.

So, now this is homework for you. Okay. So, this compound and this compound, try yourself and don't forget to post the answer in a comment section.

And you know, I covered each and every rule that makes you easy. To write the names of any saturated hydrocarbon. If you could know these rules, you can name any saturated hydrocarbons.

It may have simple branches or complex branches. Okay. So if you have any doubts, you can post it in a comment section. We will try to answer. And don't forget to mention the answers of these two compounds.

okay so thank you so much and you can also post your opinion in the comment section about the video if you have liked the video please like it share with all your friends let all of them enjoy the video after all it's a sharing of knowledge isn't it so thank you so much meet you all in the next video for learning nomenclature of unsaturated hydrocarbons. Like in between carbon atoms, if double bonds are there, how to name them? That's what we will discuss in our next video.

Transcript for:Understanding IUPAC Nomenclature in Chemistry

Transcript for:
Understanding IUPAC Nomenclature in Chemistry