ugal hang out please tell me if i should respond or act on it because i will not be able to get in But i am just beginning the session now Everyone who seems to want to join are there on the call now i am gonna share my screen on both the platforms i am sharing my screen on skype to begin with let me see...let me know all of you are able to see my screen तो वो जोग़ूँाँउँउँउउउउउउउउउउउउउउउउउउउउउउउउउउउउउउउउउउउउउउउउउउउउउउउउउउउउउउउउउउउउउउउउ Celebrate your self I think it's Shraddha's background noise that I'm hearing okay okay guys so let's begin okay okay anyone who's not getting any info or not able to hear me just feel free to stop me at any point of time. उता, can someone just tell Shradha to really mute herself because it is only Shradda whose mic is on now. Best everyone seems to be ok. Okay, now in the last class we had seen how basically atom and their structures react with each other. today you know what i wanted to touch base upon is on carbon is compounds which is also the core fundamental of organic chemistry and you know just last class if we have seen does she is muted but i don't see her to be muted 15 lakh compounds were just registered last year right now where do all these compounds come from you know nature some compounds are found in nature some compounds are synthesized the idea is that whether it is found in nature or synthesized it if it is useful for us then we go through the process of registration okay now if 15 lakh compound themselves were registered it means much more were actually okay yes now if 15 lakh compounds were just registered you know about 1.5 million that means much more were actually found out or assimilated or synthesized okay now look at the key factors of this entire chemistry this is a very new chapter for us and you know so I would like either अनिडुद अरी तु वन अख्यु because I think you guys have a good reception to respond to the questions so that I understand that you know it's going in the good flow. अनिडुद अरी अबल तु येर मी अरी तु अरी अबल तु येर मी okay so have you have you seen at any questions from previous year in terms of you know the. नवदिता अनन आदिन दिसूज अज़्द आगे hello now you just go to the youtube channel and join there you know because only you are not able to join rest all have been this has been sky problem. वह जुढ़ मट्यों have proper ुष भी आन ठान्रतां ॑ बार दियान तेरा meerदे जिया।रॄunt आद सदी ख़ाई सदी गसर क्या � Tamam traders उब एक know & बार दिया तेता हँवाउ गी तच की तेpe राईं product Aj man दी रेद माखल pleasant शन 선배ि españolिстा ने मुल दे करपं слेप the And I add another group which could be C double bond O OH. So these are very foreign to the normal hydrocarbon chain where there is not just hydrogen and carbon but there are oxygens in it and these oxygens are in different forms. So these are called as functional groups. In the last class we saw that what is a functional group. A functional group is something which is foreign to hydrocarbon. So it is a group of atoms or atoms which is foreign to hydrocarbon. C H 3 or other carbon atoms okay so it could be so i'm just going to draw a stick here so that you recall you know that this is not an hydrogen so there is just a carbon and oxygen but no hydrogen in it so you have any other uh you know nomenclature on both the ends or any other compound in both the ends which is only a hydrocarbon so only carbon and hydrogen will be here only carbon and hydrogen will be here this group is called as a ketone okay and its ending is with an own okay so any compound you get like this will be for example this can be a methane known sorry methane one cannot be there because uh since methane is the first compound it meets at least three carbons so one carbon should be on this end and the second carbon can be on the other end so the first possible is propanone propanone okay so this is the ketonic group the next that comes in the series is carboxylic group this is c o o h so this is the name the family of this is called as the carboxylic groups carboxylic acid or carboxylic group and it ends with an oik acid oik acid okay so for example you will write this as propanoic acid propanoic acid getting it so for example uh yeah propanic acid there is also methane oik acid so you can also write this as methane oik acids so these are all different foreign compounds and these are the families of those compounds and this is how if we have to identify this compound in the mechanism this is how we name it okay for the time being this is this is what we need to understand i'm going to revisit this in in a few minutes from now but i'm i'm going to talk a few points on nomenclature now now you see if we really look at the series of alkene alkene alkene the first one so let's say these are the number of carbon atoms okay number of carbon atoms the first with only one carbon atom is p h 4 this is an alkene let's talk about alkene alkene okay and alkene okay so if you have only one carbon atom this is an alkene now alkene cannot be there with one carbon atom it needs minimum two carbon atoms so this will be c h 3 c h 3 so here there would be okay because there would be two bonds between the carbon atoms and alkyne will be c h and only two hydrogens on both the sides this first carbon atom is called as myth it's always written written with meth and since it's an alkene it is a methane the second one here it is meth but since it's an alkene it is methane sorry not so this this first cannot be there here there are two carbon atoms so i will have to directly go to ethene okay since here also there are two carbon atoms i will have to go to ethane okay so first one carbon atom is methane two carbon atoms is eth three carbon atom is prop four is butte you have you have known all of this right five is pent six is hex seventh is hept eight is oct nine is non and ten is deck okay so this becomes ethane methane propane butane pentane hexane heptane octane non in decan similarly if i go to alkene except for methane because methane cannot be possible you need minimum two carbon atoms to have a double bond so it becomes ethene propane butene pentene hexane heptane octane non in decan and alkene also you need minimum two carbon atoms so you cannot have a methane you only end up from getting to ethane so it becomes ethane propane butane pentane hexane heptane octane nonine and decane okay so this is the nomenclature of all the carbon atoms this is the sequence with which the names happen right now between alkene alkene and alkene it is very easy that you simply change a into e into nine okay this changing of nomenclature is also possible with functional groups so with functional groups what happens you change instead of methane now you are saying methane all so propane all methane you know then then you can also end up saying a decan all okay so all that so this ending changes from all l own and oil gas okay now once we have understood this let's try a few examples to see this in a much more depth okay so let's say i have a a straight stick stick chain compound and i have a oh year okay now this becomes one two three four five six okay so there are six carbon atoms so this definitely becomes hex and since it is an alcohol so i have to have a perfect prefix all it becomes hexane null if i would have written hexane then i cannot write this OH if i've written hexene then i will have to put a double bond hexane i will have to put a triple bond right so this is an hexane null okay so that is that is one nomenclature now let's look at one more let's say carboxylic acid so this is the compound that i have but here i have a oh and oh you remember that we don't generally write carbon so i'm just writing double o and oh here so how many carbon atoms are there here one two three four five so this becomes pent and since this is a carboxylic group we'll use the suffice as pentanoic acid pentanoic acid right because we know that if it is a carboxylic acid the suffixes that we use is oik acid okay oik acid now so so this is this is one one way of nomenclature now there is something we are so this is so what we have understood so far before i go to the next topic just to be doubly sure is that we know what are the what are a few functional groups we have seen four there are to see three more in some time but the functional groups that we have seen are alcohol aldehyde ketone and carboxylic acid the difference between aldehyde and ketone is that the hydrogen that is there on the carbon on one side is replaced by a hydrocarbon okay so there is no more just hydrogen it is in hydrocarbon so one example of ketone is this propanone is nothing but ch3 c double bond ch3 but if i had i had to draw a propane with an aldehyde it would have been something like this so this is a propanone okay but let's say i had to try propanone so it would have been ch2c double bond oh so this would have been propanone okay now please understand why this is why this double bond has come here because on the carbon atom i need to have hydrogen only on one side i cannot have double bond oh and another alkyl group if i have another alkyl group this is called as an alkyl group alkyl group means anything that is derived from alkanes so if there is an alkane group on both the c double bond oh then it is a ketone but if it if there is a hydrogen hydrogen is a must here if there is a hydrogen on at least one end of c double bond oh that is called as a aldehyde and propanone therefore you realize that here you have only one end that is free so this will always be what we call as a terminal carbon atom what do you mean by terminal it means at the end of a chain now a chain can have very a lot many threads but at any one end of the thread you can have an aldehyde group this is also always a terminal carbon atom carboxylic group because see it has only one free end but for ketone it has two free ends i can draw at i can attach any carbon atoms on both the ends you know i can attach for for example here i have attached one two three four five six seven eight nine carbon atoms here here i have attached one two three four five six seven carbon atoms right so this is a seven hydrocarbon this is a seven nine-membered hydrocarbon and they are on the opposite sides of the ketone so ketone cannot be a terminal carbon atom alcohol also not necessary to be a terminal carbon atom because alcohol can be at any central carbon and on all the three sides there can be a there can be another hydrocarbons that are present okay so this is this is the uh uh what you can say nomenclature as well as understanding of a few aldehyde groups let's do some examples okay especially examples that are there in your text to begin with yeah now let's say uh we have to define a few compounds or define rather than name a few compounds so what would be the nomenclatures i am going to give you a few compounds and see if the if you are able to predict the names okay so okay just one second yeah so let's say i am drawing a compound for you you have a compound which is like this okay so let's say you have carbon carbon carbon carbon and you have a double bond o h okay so this will be c h 3 c h 2 c h 2 c h 2 and c o c o h what do you think would be the answer for this what compound could this be anyone yes okay let me check if you are able to respond anywhere okay yes are there any answers on youtube or okay any answers what could this compound be c h 3 c h 2 c h 2 c h 2 c o h where is everyone are you guys around mm-hmm yes i think i can hear ritu's voice a bit yeah but with pent what would this be so this is an aldehyde group so what would be the suffix so for aldehyde groups what is the suffix all right al right so like we are methanol this would be pentanol okay so this is just pentanol getting it easy yeah uh okay now i am i'm still not convinced whether if everyone is there on the call and if i'm able to connect because this is i'm having a it's like a blind game that i'm having i'm not sure if people are able to really watch and see and therefore i'm concerned a bit there are seven viewers that i can see on youtube now okay pentanol yes i could see that someone could answer i could answer that that's pentanol that's good so i think a few are at least able to connect perfect let's go go ahead druthi aniruddh are you guys there can you just make your presence felt because i don't know whether you are there or not you know wherever either yeah anjitha is okay excellent uh anjitha are you there on the skype anjitha that's good i can i can see you i can hear you now yeah better perfect good aniruddh so keep interacting because that that makes me understand that we are i'm you know you guys are able to understand me okay right so this is pentanol i'm going to give you one more example which is ch3 let's say ch2 ch2 ch2 and see uh let me put this as double bond o and ch3 yeah what could this be any guesses from anyone yes g2 aniruddh anjitha anyone on youtube yeah what could this be mm-hmm guys mm-hmm you're right in recognizing that it is a hex derivative but this is not an all okay so this is hexanone why because it is a ketone isn't it it's a c double bond o so a hexane is right this suffix would be on so it is a ketone hexanone okay now we'll we'll do some more practice maybe in the physical class on all of these but just remember these what i want you to remember is the sequence of all these methethpropute penthexept octnondec and and uh okay yeah this this this one of that and what next you need to really understand is these alcohols all alone and oilic acid okay all of these these work okay now uh let's go and understand a few more about nomenclature starting in alkene alkene so the next level of complexity okay now we all know that so far we have only seen straight chain compounds which means that if you have c c c and c this is a straight chain compound what happens if you have a compound that is on the top okay ch3 how do i name this right because this this compound is is is very different from having five carbon atoms like this okay c c c okay so here here we have ch3 ch2 ch2 ch2 ch3 so these are five carbon atoms these are also five the only difference is this carbon atom the end one is now at the top if you really see the formula for this is c5 h uh h12 yes 3 plus 3 6 plus 3 9 9 plus 3 that's 12 this is 3 plus 3 6 6 plus 6 is 12 here also the chemical formula is c5 h12 but the difference between them is their structure okay if someone tells me tomorrow you know let's say druthi comes up and says sir you know i'm studying about c5 h12 uh you know i will not be really understanding whether she's studying about this compound or this compound or i will tell you there is one more compound that can be formed which is like this okay ch3 ch3 ch3 ch3 the formula for this compound is also c5 h12 now out of these three compounds which one is she really studying i have no idea so hence all of these three compounds have the same chemical formula but different structural formula so the structural formula is different okay different but it has the same chemical formula okay now when you have this kind of a situation all of these together same chemical formula or molecular formula right molecular or chemical formula when you have this kind of a structure all of these three together are called as isomers isomers so what are isomers isomers have the same molecular formula but it they have the different structural formulas so all are c5 h12 but their arrangement is very different so they are called as isomers now isomers can be here because of different ways this is just one way of writing an isomer in fact you know if I have to tell you this is also an isomer for example check this okay now i'm writing a compound ch3 ch2 ch2 oh okay the formula for this is c3 h if you see three plus three six plus two eight this is h8 o this is a molecular formula for them so general molecular formula i'm talking about but if you really see if i write like this ch2 you know ch ch3 oh this is also c3 h8 but these two are completely different compounds for example this compound very easily does not it does not react very easily but this compound reacts very easily with basis their properties are very different their densities are different all of that is different so if that is the scenario how do i identify these these are again isomers now i'm going to draw one more compound just for your understanding i am i am drawing ch3 ch2 c double bond oh now the formula for this compound is c3 h6 o okay now i want to draw a compound which is like this c3 c double bond oh ch3 this is c3 h6 o again now this actually is an aldehyde if you see this compound is ch o group so here if you see this functional group itself is ch o okay whereas this functional group is actually c o okay this is a c o functional group now if this is the difference between both of them then the formula remaining the same the functional group itself has changed so these are something called as functional isomers okay functional isomers these are called as position isomers so isomers that are happening through excuse me sorry this is isomers happening through position this is isomers happening through change in the functional group itself and in the previous scenario i'm sorry in the previous scenario we are having functional groups which are you know there is no change in anything except the chain has changed this is a straight chain this is a branch this is highly branched okay so these are different chain isomerisms so isomerism happens through different ways okay but whatever the reason is having a different structure being a different molecule but having the same chemical formula is what an isomer is okay now let's look at a few more isomers in in such terms okay now if i have a carbon compound like this okay ch ch3 okay and then i i have a carbon compound which is c ch3 ch3 ch3 so i've taken a very unique molecule just to show you a point this carbon is attached to only one carbon okay since it is attached only one carbon it is called as a one degree carbon compound this carbon atom is attached to two carbons so it is one on this side and one on this side so any carbon atom which is attached to two carbons is called as a two degree carbon atom this carbon atom is attached to three it has one year one year and one year but rest are all hydrogen this is a three degree carbon atom and this is attached to four one two three four so this is a four degree carbon atom okay so what are the different degrees of carbon atom any one any carbon atom who is attached to one carbon atom is called as a one degree carbon atom or a primary carbon atom any carbon atom that is attached to two carbon atoms is called as a two degree or secondary carbon atom anyone who is attached to three is three degree or tertiary okay can you tell me what is this carbon atom is it primary secondary or tertiary yes anyone what carbon atom is this any answers guys you there yeah that's primary correct okay yes so this is a primary carbon atom why is although this is tertiary this carbon atom is only attached to one so it is primary this carbon atom is to attach to four carbon atoms in all of its vicinity this is this quaternary for four carbon atom carbon atom is also called as quaternary carbon atom okay but you see all the others these are primary carbon atom sorry one degree primary carbon atoms okay all are one degree carbon atoms now okay so now now that you know this what are primary secondary and tertiary there are some different names also for this so generally a carbon atom which has a single carbon atom coming out is called as an iso carbon atom and this is called as a neocarbon atom okay so for example if you have a th3 th2 th3 this is an n propane this is n propane n propane means normal normal propane okay when you have a carbon atom which is coming out at the top okay so for example you can have ch3 chch3 and a ch3 this is an isobutane isobutane okay why butane because now there are four carbon atoms okay so this is an isobutane now if you have five carbon atoms coming out okay this is a ch3 ch3 ch3 now there are five carbon atoms this is a neopentane neopentane but having said this these are very unique names guys so these are only used in common nomenclature in iupsc nomenclature this is not even a pentane this is a propane in iupsc this is also a propane but in common nomenclature this is a butane because in common nomenclature you take the total number of carbon atoms in common nomenclature also you are taking total number of carbon atoms which is spent five in common nomenclature you are taking total number of carbon atoms which is four okay here there is three okay so all that really matters okay now so so these are these are structures isomers so what are the total concepts that we have seen today i'm you know i just don't want to rush because of you know it this online classes gives a lot of flexibility to move through the topics but i want you to be with me so what are the things that we have seen today today we started with functional groups in functional groups we said okay these functional groups can be different foreign atoms or molecules that can be joined to the main carbon atom and they dictate the chemical properties of the carbon atom that's very important then we said okay what are these functional groups like so then we found that this is a COH or only OH okay here there is a CHO okay so there is a CHO group then we found that ketones there are only CO but on all the both the sides there are alkyl groups so in ketone so alcohol is also called as OH group aldehyde is also called as CHO group ketone is called as CO group okay and also represented something like this sometimes like this and this is called as a COH groups are represented sometimes like this okay so remember how they are represented also aldehyde is represented as CHO or C if bonded form it is represented written like this in short form condensed form it is written like this ketone is written only like CO like carbon monoxide is written because there is only one double bond between carbon and oxygen right and carboxylic acid is written as COOH okay in nomenclature you have ol-al-on and oic acid okay ol-al so this is the nomenclature you end it writing as propanol-propanol-propanol-propanoic acid okay non-al-al this is what we saw next thing we saw this series of the entire structure one by one i'm going to send you these notes so don't don't bother you know but i would also like you to take your own notes maybe writing of those i'm going to send this pdf to you any which way is on that group but having said that it's good to keep on taking your own notes as well okay now if you already see that we have seen a few examples so for example this is an hexanol this is a pentanoic acid and all of these examples please note that we have attached the functional group only to the end that does not mean that it should be attached only to the end you can attach it anywhere so for example here also we have attached it to the end attach it to the end but this is just for the simplicity right and we have taken straight chain compounds here we have started taking branch chain compounds so here we saw the concept of what are isomers okay isomers are different compounds with the same chemical formula but different molecular structure and then in the end we also saw that okay now i'm changing the functional group to the center also i'm changing the position sometimes i'm changing the functional group the formula remains same and yet the compound molecule completely changes okay and then we saw what are primary secondary tertiary and quaternary functional groups now what we are going to see is what are homologous series homologous series homologous series are all those group of compounds carbon compounds which have same general formula okay remember isomers had same molecular formula or chemical formula here we are talking about the general formula what is the difference between general formula and molecular formula general formula is like an equation like a code okay for example tn h2n plus 2 this is like a code i can put any value of n i can put n equal to 1 2 3 and any of that i can put n equal to 100 also does not matter now if i put n equal to 2 for example i get c2 h6 okay if i put n equal to 3 i get c3 h3 to the 6 plus 2 8 okay now if i expand this this molecule looks like this ch3 ch3 this molecule looks like ch3 ch2 ch3 let's put take one more c4 h10 this molecule looks like ch3 ch2 ch2 ch3 if you find incidentally i am getting all similar kind of compounds only okay so all of these are alkanes now someone might come up and say sir i can write c4 h10 like this also ch3 ch3 ch3 and this formula is also c4 h10 but this i cannot include okay so i will not include this compound because it has changed the way that i'm writing here i was writing all straight now i started branching so this cannot be used okay but for all of these circumstances the the pattern remains the same so what are homologous series they are the same general formula but incremental incremental molecular formulas molecular formulas okay molecular formula okay now okay so if someone asks me what is the importance of this you see all of these turn out to be normal alkanes n alkanes okay n alkanes why am i saying normal because i'm they are all straight chains so now you understand what is normal and what are branched or iso and new carbon atoms so what are normal alkanes normal alkanes are all straight and i can write even c100 for example c100 would look like c100 plus h202 okay by this formula so that is also a n alkane and therefore all of them are homologous series so this this is an homologous series all are the members so each of these are is a member of homologous series and this is a series why do we call why do we not call it as homologous group where we are calling it as homologous series it's because it is actually like one after the other like one two three four so there i will always find a member which is uniquely placed equidistant from the previous member okay uniquely placed equidistant from the previous member which means for c3 h8 i will find c3 h8 only i cannot get c3 h7 or c3 h9 i will get c2 h6 only i cannot have c2.5 and h something that's that's a that's a nonsense way of saying things right so equal distribution another way to look at it is if you really look at their difference what is the difference between these two it is ch2 what is the difference between these two it is ch2 what is the difference between let's say c4 h10 and c5 h12 it will again be ch2 okay so the each member of homologous series is is always you know differentiated by a ch2 group okay now why are you studying this what is the importance of studying homologous series if anyone has to ask anything you can please go ahead and ask because i think someone yeah if if someone has to ask just feel free to ask up yeah you are saying something you okay yeah you got unmuted okay okay no problem yeah so all of them are with the difference of ch2 now you see why are we studying homologous series now in a homologous series the properties the chemical properties of all the substances are the same okay slightly different but majorly they are all the same okay so for example how c2 h6 will react with for example a base everyone will react with the base similarly okay with slight variation and one more important point is so similar i would say similar chemical properties similar chemical properties see i have not said same chemical property similar means very close to each other and the next most important thing is incremental physical properties incremental physical property what does this mean that if there is a density that i'm looking at if the density of for example c2 h6 is 0.1 gram per liter okay because it's very very small in volume very very light in volume then if this i'm just taking some random numbers okay we'll say this is 0.2 then this will be 0.3 this will be 0.4 maximum this will be 0.48 you know my instead of 0.5 so the increment is quite it's quite patterned you know it's it's quite predictable that's very important thing so but but they will incrementally rise okay so their weight of course if you see the molecular weight the molecular weight this is 24 plus 6 this is 30 the molecular weight here is 12 plus 2 14 so this is 44 so this is the incremental weight here is 58 okay now the difference is all 14 14 14 because c2 group is changing so molecular weight are incrementally increasing by 14 so in homologous series all the properties of chemical properties are more or less the same and physical properties slightly keep on increasing one after the other so what are the physical properties that could be its weight it could be the boiling point it could be its melting point it could be its density it could be the state that they are in earlier would be gases then there would be liquids then there would be solids and then there would be denser solids so and so forth right so physical properties incrementally chemical properties remain the same because they all being alkanes no functional group or their functional group being just the the same alkane that they are their chemical properties remain the same so that's homologous series now what are different types of homologous series so this is an alkane homologous series but i can also have an alkene homologous series alkene homologous series will start with ch2 ch2 you know with with ethene i cannot start an alkene homologous series with methane okay now what could be the other one this is there ch2 double bond ch2 what will be the next ch3 ch2 ch2 double bond ch2 sorry this will be ch this will be ch okay because yeah and and so on so forth i'm just going to draw one more ch3 ch2 ch2 ch2 double bond ch2 okay now so what is the formula here it is c2 h4 the formula here is c3 h6 the formula here is c4 h8 check 2 plus 2 plus 2 this is ch here it will be ch this will be ch and ch okay so this is 2 plus 1 3 3 plus 5 8 here it is 3 plus 2 5 5 plus 2 7 7 plus 3 10 so this is c5 h10 so for alkene we had a formula which is very important you know you should also remember this formula very well so i'm going to box it so the formula was c n h2 n plus 2 okay now with alkenes suddenly because i'm always missing two hydrogens my formula becomes c m h2 n okay so if you really put n equal to 1 sorry n equal to 2 you will get c2 h4 if you put n equal to 3 you will get c3 h6 if you put n equal to 4 you are getting c4 h8 so this is the general formula for alkene's homologous series okay homologous series now similarly you can also have for alkines and i'm just going to write directly here it will become c n h2 n minus 2 now please note whenever i'm saying this is the homologous series i am talking about only one double bond everywhere there is only one double bond if i start putting two double bonds the general formula would change similarly for alkines also there is only one triple bond there are not more than one triple bond okay so quickly once again quickly the quick revision after we saw that what are one degree two degree three degree four degree carbons and what could be the common nomenclatures for a few things this is a neopentane okay but remember in iups this is not pentane this is propane you have to remember that i'm saying this again and again this is an isobutane in common nomenclature but in iups nomenclature which we will study in a or maybe in the next class this is actually propane why because longest chain is considered there now homologous series is the series which has general formula same and increasing physical properties but similar chemical properties general formula for alkene is c n h2 n plus 2 for alkene it is c n h2 n and c n h2 n minus 2 if you really observe if i write all of them in the same okay 2 n plus 2 one one below the other if you see you will realize that the difference between them is two hydrogens okay so this is the difference is two hydrogens and difference here is also two hydrogens fine where does those two hydrogens go those two hydrogens go when this bonding happens so cs3 cs3 was there two hydrogens i take out that single bond has you know that that single bond has now become double so i remove two hydrogens i end up getting alkene i remove another two hydrogens i will end up getting alkene so for example the first alkene would be simply c h triple bond c h please note c h triple bond c h and this are no different compounds they are the same compounds okay i'm just writing hydrogen at the back and the fourth and and then the fun whereas this is a much better way to write it okay so what has happened is i've just made single bond into a triple bond and i've taken out two more hydrogen atoms okay so that's uh that's alkines so good so what we have seen today are uh you know different types of uh compounds nomenclature there's one more very important point that i am i'm just going to share is what are alkyl alkenyl and alkyl nyl groups okay so let's say i have c h 4 okay now instead of this c h 4 i want to attach this group to a larger compound let's say this compound okay so this was another compound but i want this c h 4 to attach it so how will i attach i'll have to remove one hydrogen and then attach well i will attach it like this okay now since this was created from a methane and it was joined here this is called as a methyl group okay so methane becomes methyl okay similarly see if i would have joined here as c h 2 c h 3 now this actually would come from c h 3 c h 3 so this is ethane and it will turn out to be an ethyl group okay so from ethane it's gonna turn to ethyl okay now let's let's let's join one more okay let's let's see if i can join c h 2 double bond c h 2 okay so i'm using the same compound so that you realize the difference now here i'm going to again take out a hydrogen and this will be joined here so this will be c h double bond c h 2 now since this was ethene and ethene came to join here this group is called as ethene nyl group so check this was ethane this is ethene nyl ethene nyl very simple ethene becomes ethene nyl here ethene becomes ethene becomes ethene and let's say here if i join c triple bond c h this will be ethene nyl as simple as that so ethene becomes ethene nyl ethene nyl becomes so this comes from ethene which is c h triple bond c h this is an ethene so ethene becomes ethene nyl ethene becomes ethene and ethene nyl becomes sorry ethene becomes ethene nyl okay so this is one more very important point that we need to understand we also know now the general formula of all the hydrocarbons whether it is great chain branch or alkyl or alkyl or alkyl or alkyl kinds okay so now okay i just want to pause here for a minute can can can you guys quickly come back saying are you getting this is everyone with me okay good so i'm seeing there was some comment your primary primary sir screen not clear okay hexane and cheetah perfectly two says yes aniruddh is also okay brilliant i think everyone is there now okay okay so now the guys who are on youtube you are going to have slight lag and therefore whatever i paused for by the time you respond you know i would already be doing something else so but that's okay you can always put a comment and i i can always see that to get back to you so that's that's not an issue okay so let's go back to our understanding of the chapter further now so how do we name alkins okay so this is another very important point how do we really name name them now in naming you have to remember these these three things okay what are the three things that you have to remember the first is you have to find how long the chain is okay what do you mean by how long so let's say i have this molecule ch3 ch2 ch2 ch3 okay so this is a three-step long chain so this is called as a a propane okay propane okay now if it is three if i put a double bond okay if i put a double bond it becomes propane i'm going to take a slightly longer chain for you to realize the difference so let's say i take ch2 ch2 ch2 ch3 so how many carbon atoms are there here now it starts from here it becomes 1 2 3 4 5 6 till there are six carbon atoms this becomes an hexane okay now what i'm going to do is i'm going to erase one of them one two hydrogens and i'm going to create a create a hexane here okay so this becomes ch double bond ch2 so this becomes hexane but tell me how is this compound different from ch3 ch2 ch2 ch2 ch sorry double bond ch single bond ch3 or how is it really different from ch3 ch2 ch double bond ch ch2 ch3 all of them have the same formula which is c6 h12 okay so check everywhere you will find 12 h one two three four five six yeah there's six so this is three hydrogens three and six are nine nine and three are 12 you're also you'll find 12 so everyone has c6 h12 in fact everyone has a double bond but the double bonds are placed very differently now how do we handle this situation to differentiate these compounds is we number these compounds with different uh uh you know uh what should you say a uh numberings okay so for example in the first scenario the carbon atom is central so wherever we go you know we start numbering them okay so let's number them so this is one this is two this is three this is four this is five this is six okay now why did i start from here i could have also started from here from the other end but you should start numbering from there where the smallest number can be given to the alkene okay so if you if i start from here here the smallest number given to the alkene is one therefore i will write this as one hexene here i write one two three four five six the smallest number can be given to two so this becomes two hexene okay here i start from here one two three four five six the smallest number can be given in the third carbon so this is three hexene okay now i'm going to show you a variation and and uh this is this is something that is very interesting is that cch3 ph2 here i put double bond okay this time so i'm going to put the double bond here and make this as ch and i make this as ch2 ch2 ch3 now if you guys come up and say look sir you started numbering from here let's number from here only okay let's number this as one two three four five six this will be wrong okay why because we decided that the lowest number should be given to the uh the uh you know double bond from that end wherever it is possible so here this numbering will not work this numbering will work one two three four five six and therefore this molecule also is two hexene it is simply a mirror image of this so if you take this molecule like a strip of this molecule and you simply reverse it like you know you you turn it like this okay you'll end up getting this this compound okay so if you end up getting that compound you basically find that the both the hexenes remain the same okay give me one second guys i think uh yeah just one second yes so uh uh so so right so now oh i hope there is any there's no questions yet okay perfect yeah so what how did we really uh distinguish this is that uh so for a hexene there are only three straight chain isomers we will say because see the molecular structure is very different sorry the molecular structure is very different these three are three different compounds mind it guys for looking at it everyone would say sir what this is alkene only you know there is a double bond here there are also double bonds here so so what you know it looks very much the same but no that are not the same the way that this compound reacts with care compounds like i have given you some examples so for example if i put uh you know ki in this compound and i put ki in the other two compounds i'm going to get different products i'll not get the same product okay so therefore these three compounds they look similar but they are very different because the difference is the change in the molecular positions so you know all those people who have given ntsc's or who have studied mat or something in that you know we used to find out find the odd man out or which figure fits best or can you find the mirror image so these you know organic compounds are very similar to that all of them would have different mirror images different ways of you know really uh changing structures maybe water image so if you really see these two are actually mirror images of each other if i put a mirror in front of this okay if i put a mirror here like this you'll find that this compound is exactly the mirror image of this nothing else okay so they are not very different compounds unless you are able to figure out a completely new compound which cannot be uh overlapped or in any way matched with the earlier compound you have to give it a different name and uh because it's a different compound right so you have to have a different name maybe they are they are like twins or triplets or you know quarterly plates something of that sort if you have that kind of a scenario you will you'll have to have a nomenclature system which can recognize that so here we are able to recognize that with different numbers okay so numbering is what this is a new term that we have just seen numbering is very important okay so that's how that's how double bonds are numbered and that's similarly triple bonds also so it becomes one exine two exine three exine so and so forth okay now okay now that we have understood this we are also going to see how we are going to number you know different compounds and let's take our butane right we have been talking about it and i said i'll i'll show you that in a few minutes so let's say you have ch3 ch2 ch3 and ch3 we saw a few minutes ago that this is called as isobutane okay but in iupsc nomenclature so this numbering and chain all of this formula is this is called as iupac nomenclature or iupsc nomenclature why was a nomenclature established so they established a rule that if we name the compounds in this fashion so you see in computer science you know how we name the folders and files we name it in a certain fashion so that we remember you know what where the file was kept and what file it is if we do not remember number it with the same file number then we will be confused array which file was where and how how to really communicate to other people that okay this the file is kept here or something or that so path is there number is there similarly iupsc was established to give this numbering in a very different in a in a very typical fashion nothing else right so we can uniquely have a compound now in this scenario isobutane is what the molecule really looks like but if you really see there are three carbon atoms so what is the first rule the first rule is find the longest chain longest chain and what was the second rule the second rule is that number the chain says that you get number the chain says that you get smallest number to the number the chain says that you get smallest number smallest number either to the double bond first to double bond or if there is no double bond then to the substituent okay what does the substituent mean substituent means on this longer chain what is the branch that you have the substituent means branch okay so what is the substituent here here the substituent is this ch3 so what do you mean by so what substituent is this i told you that this substituent is derived from methane so this substituent is called as methyl okay and which is the longest chain this is the longest chain okay does that mean that this is not a longest chain yes it is also a longest chain you can take that also no problem no problem if there is a conflict in the longest chain take that longest chain so see if there are two long chains why am i saying this is also a longest chain because this is also three-membered carbon ring the longest chain does not mean that the molecule has to be straight see this is just the writing the representation the molecule does not look like this the molecule in fact looks very differently i have shown you so let me also show you here today you know how this cs3 molecule will really look like if i have mol view take how the molecule really looks like the molecule looks like this okay let me clear this first okay now i'm going to take a carbon so what is this this is a ch3 ch2 ch3 cs2 so isobutane let me just figure it out i'll have isobutane yeah okay so see the molecule actually looks like this okay so you see this is one cs3 if the way that i've written on the notebook if i have to write write it that way let me just align it that way okay yeah now see this is how i've written it cs3 ch2 cs3 cs3 but in 3d space this is cs3 ch2 are you able oh why am i written cs2 this is ch sorry yeah ch ch then you will find cs3 so look there are three hydrogens here there are three hydrogens here there is a carbon there is a carbon there is carbon in one hydrogen and there is carbon in another three hydrogen here so this is the same molecule but that does not mean that the molecule actually is straight chain so if i ask you which is the longest chain this is also a longest chain this is also a longest chain this is also a longest chain all three of them are longer chains and none of these chain and root gives it a propane now at the second position you are having a methyl group and therefore it is two methyl propane okay because the substituent is methyl right so that's how we number the chains okay and we have nomenclature done now let's look at neopentene the second chain we let's look at the this molecule yeah okay so now here also the longest chain are any of these so i'm going to draw all a few lines for you this is although three-membered ring this is also a three-membered ring this is a three-membered this is a three-membered this is a three-membered three-membered all of these chains are three-membered so we take any of those so let you know last time we took straight this time we will take something different okay so let i'm drawing the same molecule i'm going to take this as a chain because all of them are same there is no difference i'm going to take this as the longer chain okay since it is a three-membered the first thing that i write it as propane now on this propane i have to do the numbering numbering is my second rule so i can start numbering from here one two three now since there are at the second position at the second caravan there are two groups two substituent groups in these and this these are the branches on this chain okay so what do i write them as now since both of them are there i have to write positions for both so i write this as two two because at both the positions there are two two and what groups are these both are methyl so i write this as dimethyl please note i cannot just write one two okay for every group i have to write a number so i write this as two two dimethyl propane okay so i am not going to go to much more complex numbers here but i'm just going to revise nomenclature one more time what are the rules the rules are you take the longest chain the longest chain you do not calculate total number of carbon atoms in the molecule you calculate total number of carbon atoms in the chain so if you take the longest chain there are three carbon atoms so you say this as propane and then in this three carbon atoms you number the number of atoms on the carbon atoms so one two three so and so forth at whatever number you are getting a substitute you write that number and this number should be lowest so the your choice of numbering should be such that you get the lowest number on the substituent and whatever is the group that you write after that number and you say two methyl propane okay so that's that's nomenclature iupc nomenclature for us in alkene that numbering will be for double bond or triple bond and alkyne it will be for triple bond right yeah similarly here so i'm just going to pause here for a minute and ask you guys a question and then then we will we will move to probably we'll you know the uh have have the last session for today so can you guys member name this yeah try and um try and name this compound try and name this compound it's an easy one see if how many of you are able to do that yeah let's see how many of you are able to really do this yeah numbering part or did hexane become two axene anjita did you get a numbering part if not you can please comment on the youtube channel once again yeah anjita if you've not got that you can comment on the youtube channel one more time okay you have got it seems good uh see numbering is simply the same yeah so what you do is you start from any end of the carbon atoms for example your whichever chain that you have chosen once the chain is chosen you start numbering from one end okay once you've started numbering from that end you do the numbering in such a fashion that the substitute end should get the lowest number that's it so for example how did a hexane become two axene is because i started numbering from this side and in this side at the second carbon there is a double bond so it becomes two axene okay see i could have also started from here from if i would have started from here it would have become one two three four so it would have become four axene but four axene cannot exist in nature there is no compound called as four axene because the naming itself is wrong according to the rules the naming should be in such a fashion that if there is a lower number possible there is a lower number that i have to get so four axene cannot exist in nature there cannot be four axene you can only do two axene because four axene is nothing but what you are trying to say basically it was two axene i should have number at the other end okay so that's how numbering has to be done what is the rule of numbering the rule of numbering is start from any end of the carbon chain but number in such a fashion that the numbering should be smallest to the functional group or to the substitute to end that you have simple as that okay anyone else who has yeah so what is the answer to this compound who can give me the nomenclature to the compound that i just mentioned is it two three dimethyl butane that's right that's right now guys let's look at this how this is okay now just for your surprise and trick i'm not going to choose so there can be multiple chains that are longest see this chain is also longest which is a four carbon atom but i'm going to choose the blue one just so that to show to show you that you know it does not make a difference if the chains are the same i'm going to choose blue it also has four carbon atoms check one two three four so if i name through the blue one it will be at the blue one this is a substitute to end okay and this is a substitute to end substitute means branch on the main chain now if i start numbering i can number from here which is one two three four or i can number from this side it also becomes one two three four so in either cases here two and three is what where i'm getting my substituent so this becomes two at the substituent is at the second carbon this is the substituent again at the third carbon and both of them are methyl substituents so i will write this as two three dimethyl and how many total number of carbon atoms are there in the root four so therefore it will be butane okay now let me name it through the pink one let's see what turns out for the pink one this is my substituent and this is my substituent okay so i can start from here one two three four or i can start from here one two three four in any which ways i am getting two and three as my substituents the red ones check the red ones now so through the pink also if i number it becomes two three dimethyl butane only and therefore it is okay to number in any fashion okay it gives me the same product okay is everybody connected to this can you guys just quickly confirm all all that you that you are there whether you are on skype or on youtube either you say or instead of saying i think you can just comment in the skype if possible or on the youtube if possible but i know that you guys are getting this yeah anchita uh shraddha yeah can you please comment and just confirm because we are just coming to the end of the class i just want you to know that i mean i okay perfect yeah okay ritu says got it that's good uh okay perfect yeah that's nice perfect good so what i'm going to do guys is what i what i want you to do is because we're just at the end of time and i have a next class to really get into is that uh uh what we will do is i'm going to send you the perfect what if the substituents are not the same then you just use the different names of the substituent for example you will say this as two three methyl ethyl okay methyl ethyl and not just the substituents there are a lot many conflicts that we are going to see but i don't want to complicate at this very state i want you to really contemplate on this there are multiple variations that we will see in the next class whenever we meet next we will also going to have a question paper discussion in the next class so i'll be giving you your answer sheets and we'll have a discussion on that because that's been pending but yes if the substituents are different then we simply use those substituents with the number okay so we'll say this as at two there is a methyl at three there is an ethyl so and so forth okay so we are going to see those variations also slightly in the next class okay good so fine guys this is what i want you to really do uh you know and since this is also in the recording you guys would find that uh uh you know please go through your text you know your textbook also has some some questions what i'm also going to do is i'm going to send you a nomenclature sheet right now right away i'm i'm sending this on on the group okay so please go through those nomenclature rules also once before coming to the class because you know there is nomenclature is slightly tricky subject in the in terms that you know there are too many rules to really remember in the first go but it only needs slight practice so it's like chess you know all the rules that if you remember then you are able to play well similarly in nomenclature if all the rules are clear with you then you'll be able to do it in a much better fashion so let's do that and uh uh next class whenever we meet we are going to discuss nomenclature in much more detail i'm going to send you two sheets one is that i'm going to send you the pdf of this itself okay the pdf of whatever we have done today and the second is i'm going to send you the nomenclature rules pdf on the group please go through this pdf and uh uh you know try some examples that is there in the nomenclature also okay okay good uh thanks for joining in uh i hope we were able to connect although we got a bit late in joining in there's a technical uh you know problems you have to sort out before we join the class you know so from next time you know let's let's do it slightly earlier than where we begin okay take care guys bye bye uh uh yeah i'll see you in the class next time good take care bye