Basics of Organic Chemistry for Class 11

Hey all welcome to homeschool and welcome back to class 11 chemistry series and today I am with the most important and the most requested chapter from students that is organic chemistry basic principles and techniques involved in organic chemistry the moment I say organic chemistry for many It is a completely a difficult topic. But know this is the most easiest and the most interesting topic ever that you study in chemistry. To understand this organic chemistry, you need to have some idea on the basics. Once you are strong with your basics, then working with organic chemistry or studying organic chemistry is just, you know, making a piece of cake. So try to understand every concept in a detailed way and get strong with your basics. And to understand this organic chemistry, you should have a knowledge of first four chapters. That means some basic concepts of chemistry, atomic structure chapter, periodic classification of elements and most importantly chemical bonding. So here structure of atom chapter and chemical bonding is the essential chapters that you need to understand to understand this organic chemistry. Okay so I have covered the first three chapters in a detailed way. The fourth chapter that is chemical bonding is going on. So along with chemical bonding you know I will be releasing the videos on this organic chemistry also. So, get strong with your basics first then come to this organic chemistry. I can say this organic chemistry is the scoring topic in chemistry for all types of competitive examinations. But many feel working with organic chemistry questions is a difficult task. Why because questions will not be asked from a single topic from a single chapter. You will have combined concept from all the chapters. See if you have to attempt or solve a question of organic chemistry, you should have complete knowledge on all organic chemistry chapters. Two chapters you will study in class 11 and four core organic chapters you will study in class 12. So all together six core organic chapters. You should have a thorough knowledge on all the six chapters only then you can confidently attempt the questions relating to organic chemistry right. So they will not be asking you from a single topic from a single chapter. Question is a combined question. to attempt a question you should have knowledge on all the six chapters right so and coming to this particular chapter very very fundamental and very very basic chapters of organic chemistry very much essential to understand each and every topic of this chapter in a detailed way Only then you can confidently understand or confidently study rest of the organic chapters both in class 11 and class 12. So I am here to make your study of organic chemistry much easier. I can assure you that after watching my videos your confidence levels will increase in studying organic chemistry. So do watch the videos till the end and get maximum benefit. Okay, let's come to a chapter organic chemistry so today i will give introduction of organic chemistry some history of organic chemistry and why this carbon is so special organic chemistry is nothing but study of carbon compounds so carbon is a very very special element we'll discuss why this element is special why this separate branch for studying carbon compounds you know all that And also let's discuss about hybridization of carbon atoms. I mean shapes of organic compounds. Okay. Fine. Coming to the word organic chemistry, try to understand the meaning of the word organic. Organic means life, right? So initially, long back, people thought that Organic compounds can be obtained only from plants and animals. Okay, so they thought that these are certain chemical compounds which are naturally present in plants and animals see take human beings our body is completely made up of chemicals so we have lots of chemicals inside us right and you you take a plant body and plant body also has lots of chemicals inside it so these natural chemicals were called as organic compounds initially And they thought that these organic compounds cannot be artificially prepared in chemical labs. If you want organic compound, you should take it from plant or animal they thought. And there was a vital force theory which was introduced by Berzelius. So, Berzelius was... the scientist who introduced a theory called vital force theory and according to this vital force theory you know you can't prepare organic compounds artificially if you want them you should get you should get only only from plants and animals okay so to make this organic compounds which are present in plants and animals some vital force some natural force is required. Okay, so some natural force is responsible to prepare you know to make these organic compounds which are present in plants and animals. So you can't prepare them artificially to make them some vital forces necessary, some natural forces necessary. So you can only get them from plants and animals, he said. So that is what we call as vital force theory. But there came another scientist called Ohler. Okay, very famous scientist. So this Oller has done some experiments in a chemical laboratory and he took ammonium cyanide NH4CNO. This is the formula of ammonium cyanide. Okay, so from this ammonium cyanide in a chemical lab he could prepare you know nh2 co nh2 which is nothing but urea and urea is organic compound okay see artificially in a chemical laboratory from inorganic substance and you know this substance is called as inorganic substance you know previously All chemical substances which are present in plants and animals were called as organic. Every other chemical substances which are not present in plants and animals were called as inorganic. Okay. So what did this Euler do? He took some inorganic substance and from this he could prepare an organic compound called urea. Okay. So this... came up as a revolution in the field of organic chemistry. From then different scientists have tried preparing different organic compounds from inorganic sources. Okay so this was one of the example and there came another scientist called Cole. He is a very famous scientist and you have many reactions on his name a person Cole. Okay. And he prepared acetic acid. Similarly, in a chemical laboratory, he prepared acetic acid. Acetic acid is nothing but vinegar. Okay. Vinegar. So, you know the formula, right? CH3COOH. Little of organic chemistry we studied in class 10, carbon and its compounds, right? So, there we know the formula of acetic acid that is CH3COOH, which is nothing but a vinegar. Okay, so this, you know, this compound was artificially prepared by a person, Cope. Okay, and there came another person called Berthelot. Berthelot. Okay. And he prepared methane. So we all know what is methane, right? CH4. So methane was also artificially prepared, you know, from the elements that is carbon and hydrogen, right? So like this, many scientists came up and they could prepare organic compounds artificially in the chemical laboratories, you know, from inorganic substances. They are not preparing from plants and animals. They have not extracted from plants and animals. In turn, they have prepared from some inorganic substances. By conducting some chemical reactions, they could prepare artificially in the chemical laboratory. From then, you know, hundreds of organic compounds were artificially made in a chemical laboratory. And these organic compounds are extensively used in all kinds of fields. okay see naturally speaking all the chemicals which are present all the substances which are present in plants and animals is organic compound right so that we know and apart from that you know the drugs or the medicine that we take up during various diseases belong to organic compound you know the cloth we wear is organic right and the food we eat has organic compound and various things various things that we use you know the fertilizers insecticides uh so dye industry colors various colors various pigments various flavors you know all these are organic compounds right so you know what uh already about 5 million organic compounds are there in our nature so how many 5 million organic compounds are already existed and every year 30,000 new organic compounds are being discovered. Right. So this way, you know, by conducting various reactions, people are making hundreds of organic compounds which have so many uses. Right. So now we understood how this organic compounds are prepared and their history. Right. Now, let us try to understand what actually we mean by organic compound. okay so organic compound is nothing but compounds of compounds of carbon okay so in a simple language if i have to talk about organic compound i can say They are nothing but compounds of carbon. Okay. See, if you have to call something as organic compound, then that compound must compulsorily have carbon and hydrogen. Okay. So only then you can call it as organic compound. Is that clear? Say we have carbon monoxide, we have carbon dioxide. We will not call them as organic compound, right? But we call CH4 as organic compound, CH3, CO, OH as organic compound. Why? Because carbon is there with hydrogen. So what is the compulsory criteria to call something as organic compound? The compound or a substance must have carbon and hydrogen. Along with carbon and hydrogen, you will also find oxygen sometimes. Many times oxygen you will find or sometimes sulfur can be present. Sometimes halogens like Cl, F, I, Br, these guys can be present or phosphorus can be present. Okay, nitrogen can be present, right? But the necessary condition is compound must have carbon and hydrogen. Not just the carbon. Carbon must be there with hydrogen. Along with these two elements, these elements also can be present. Only then you will call it as organic compound. Okay, so organic chemistry is all about studying the nature of organic compound, properties of organic compound, reactions of organic compound and everything about organic compound. Okay, fine. See. Carbon, the main element present in organic compound is carbon. So without carbon, you cannot call it as organic itself, right? So what is so special about that carbon, right? So why this carbon can make crores and crores of compounds, you know, that can exist in our nature. So what is so special about this guy called carbon? That's what we will try to discuss now. See guys there are mainly three reasons why carbon is very very special right. So normally we say the versatile nature of carbon. Versatile in the sense what? You know, we say the person is very much versatile. That means if he is multi-talented person, we call him as versatile, right? So like that our carbon is also multi-talented element. Okay, it will show many many different properties. That is the reason it is so special and it is forming many molecules or compounds in our nature. So the first special character of carbon is having tetravalency. So tetravalency nature. So what do you mean by tetravalency? Tetravalency in the sense valency of carbon is 4. Say carbon. Atomic number 6. If I have to write its electronic configuration 1s2, 2s2, 2p2, right? So, in the outermost shell, outermost shell is our second shell and you have 4 valence electrons, okay? So, our carbon has 4 valence electrons, right? So since 4 valence electrons are there, it can form 4 bonds around it. How many bonds it can form maximum around it? Only 4 bonds. So here the 4 electrons can be shared with other atoms. The other atom can be carbon itself or the other atom can belong to any other element. Okay, so it has an ability to share, to share, it has an ability to share four valence electrons. Okay, so that way it can satisfy octet rule, right? All these octet rule, why the atom shares electron, all that we have discussed in chemical bonding chapter, isn't it? So, since four valence electrons are there, it can share four. electrons with carbon itself or with some other atoms and form four bonds. Okay. So, it can form all four single bonds around it or it can form, you know, two single bond and one double bond around it or it can form one triple bond and one single bond around it. Okay. So, all together you will observe only four bonds. You see here 1, 2, 3, 4. You see here 1, 2, 3, 4. You see 1, 2, 3, 4. Right. So, all four bonds can be single or it can have a double bond or it can have a triple bond. Okay. So, This nature we will call it as tetravalency nature. Okay. Fine. And coming to a second special property of carbon that is catenation. So this is very very important property. We have studied in our basic classes also. Catenation is nothing but self-linking capacity of carbon. Self-linking capacity of carbon. right so carbon can link with carbon atoms itself to form a long chain to form a cyclic chains or it it can form various shaped chains isn't it say for example uh you know carbon links with other carbons and forms a long chain we call it as long straight chine okay or you know you can observe bonding something like this right so a long chain with a branch So this we will call it as branched chine. So this is a straight chine. Right. And carbon can link with its own carbon atoms and form a cyclic chines also. Like this carbon can link in a cyclic manner. Right. So, you know. it can form a straight long chain, it can form a branched chain or it can form a cyclic structures. Right. So this nature we will call it as tattination. Second important special property of carbon. And coming to the third property that is isomerism. Carbon shows isomerism. So what do you mean by isomerism? Carbon compounds exist as isomers. Isomers in the sense compounds which have same chemical formula okay but different structures or you know different chemical properties. For example don't worry understand this particular example see I have a compound CH3 CH2 CH2 CH3 okay so I have another compound CH3 this is what don't worry about their names, their properties etc. All that why we have written this kind of structures, everything I will teach you. So just observe here how many carbons are there? 4 carbons are there. How many hydrogens are there? 10 hydrogens are there. So 3 plus 2, 5. 3 plus 2, 5. 5 plus 5, 10. So here count how many carbons? Here also 4 carbons are there. And how many hydrogens? Here also 10 hydrogen atoms. See. This is one organic compound. This is another organic compound. This was having a straight chain. This is a branched one. Right? Okay. Molecular formula is same. But both compounds are very much different. Okay. So this compound behaves in a different way. And this behaves in a much different way. There is no comparison between the properties of this compound and this compound. What is similar? Molecular formula is similar. What is different? Their physical and chemical properties are entirely different. Okay. So carbon compounds have this kind of isomerism. They will show this kind of isomerism. This is one of the different property of carbon. Okay. So mainly three reasons why carbon is special and why carbon is forming many people. compounds in our nature i told you know we have around 5 million carbon compounds so far and every year 30 000 compounds are being synthesized newly right so why these crores of compounds are being manufactured every single year is because of mainly these three properties okay so this is the versatile nature of carbon Now let us understand the type of bonding that you will observe in organic compound. Okay so here I will teach you the concept of hybridization also. Okay so more detailed aspects of hybridization you will study in chemical bonding but now I will teach you how much ever is essential to understand the structure of organic compound that much I am going to teach you. See you guys. The type of bonds that you observe in every single organic compound is covalent bonds. So remember this point very very important and the type of bonds you will observe is covalent bonds. So how are covalent bonds are formed? It is by sharing of electrons right. Sharing of electrons between the atoms leads to the formation of covalent bonds. Okay, so in the lower classes we have studied, you know, the dot structure for methane, right? So how did methane molecule formed? Say you will mention carbon. Carbon has four valence electrons, right? So always which electrons can be shared? valence electrons that is the electrons present in the last shell. So it has four valence electrons and hydrogen has one valence electron. This is one hydrogen, this is second hydrogen, this is third hydrogen and this is fourth hydrogen. So these two electrons are shared. between carbon and hydrogen so that this hydrogen gets stability right. So it will have two electrons around it so that it becomes stable. It just shows the electronic configuration of helium so it is stable. And you know these two electrons are shared between carbon and hydrogen. So it's like these two electrons belong to carbon also and they belong to hydrogen also. So this is how all hydrogens are becoming stable. and carbon 1 2 3 4 5 6 7 8 right so this is how you will show the electrons present around carbon so this way carbon has eight electrons around it so that it is getting stability right so this one how do you show between this carbon and this hydrogen two electrons are show Two electrons are shared. So you will write that as bond. So between this carbon and this hydrogen, two electrons only shared. So one bond. So here also one bond, here also one bond. So this is how you will write the structure of methane, right? So here when one pair of electrons are shared you will write one bond. This is one covalent bond. This is another covalent bond. Third covalent bond. Fourth covalent bond. So this is how you will show how electrons are shared between carbon and four other hydrogens. Okay. So this is a basic way of learning covalent bond. But actually speaking in the chemical bonding chapter we will learn that covalent bonds are formed when atomic orbitals overlap. So when do the electrons are getting shared between this carbon and this hydrogen? When carbon's orbital overlaps with hydrogen's orbital. When do sharing of these two electrons takes place? When carbon's orbital overlaps with hydrogen's orbital. Okay. So covalent bonds are formed when atomic orbitals overlap with each other. Okay. So I am giving much a standard definition for covalent bond actually. You know. Covalent bonds means sharing of electrons takes place when atomic orbitals overlap. Atomic orbitals overlap. Okay. You see here. I am showing you how these atomic orbitals can overlap with each other to form these covalent bonds. Okay. So observe carefully guys. This is very very important. Okay. Fine. So I am explaining you the form. formation of formation of CH4. Okay we know how this is formed basically we studied like this in our class 10 but now we are going to study in a detailed way. Okay so actually these bonds are formed when atomic orbital of carbon overlaps with atomic orbital of hydrogens. So how that overlapping business takes place that's what we are going to learn. Okay first we are going to do a little bit of a test. What I will write here is carbon's electronic configuration. Okay. So it is 1s2 2s2 2p2. Okay. So I'll see 1s. S orbital is only one right. So one box. This way of writing electronic configuration also I taught you in atomic structure. So I told you you should have complete knowledge on atomic structure and chemical bonding. Video playlist links are provided in the description. Go and check it out. S orbital is only one in that two electrons are there. P orbitals are how many? There are three P orbitals Px, Py and Pz right. So two electrons one electron in Px the other electron in Py okay. So this is how the electrons are present in the valence orbitals. So I am not worried about this orbital. Inner shell electrons will not participate in any kind of bonding. So valence shell is second shell. So this is S orbital, 2 electrons. P orbitals are 3, 2 electrons are there like this. Okay. So now what happens is, you know, as hydrogens approach, carbon is here. Okay, hydrogens are coming to make a bond. So as hydrogens approach to make a bonding with this carbon, this carbon will excite. This will get excited. Okay, so I am writing you excited, excited carbons electronic configuration. Carbon when it gets excited, one of the electron from S orbital will get shifted to pz orbital. So now the electronic configuration, last electronic configuration is like this. Okay, so this is our 2s orbital, this is px, one electron, py1, pz1. Okay, so when does this electron will go to this empty orbital? When carbon gets excited. Okay, when does carbon gets excited? When four hydrogens are coming near to it to make a bonding. Okay fine. So now this is excited state electronic configuration of carbon. Right? Okay. So these are what our atomic orbitals ready to overlap with hydrogen's atomic orbital. Okay. So how many orbitals are there? Four orbitals are there. Okay. But Actually all of them must have same energy otherwise they are not ready to make a bonding okay. So here 2s orbital has different energy these 2p orbitals have different energy okay. So to make their energies equal, they will combine with each other. They get mixed up. It's like they distribute their energy. Say P orbital has much higher energy. S orbital has lower energy. So what do these P orbitals do? They give little of their energy to S orbital. Okay. So, you know, the mixing of orbitals takes place. During this mixing of orbitals, energy gets distributed equally. Okay. Four orbitals are getting mixed up to make their energies equal. So, we are getting four rejuvenated orbitals. I am not telling new. Four rejuvenated. Four rejuvenated orbitals I am getting. okay. So, see all orbitals energy is equal now, right. So, which orbitals have combined here? 1 s orbital, right. Let me do it. 1 s orbital and 3 p orbitals have combined to make their energies get equalized, right. So, that is why this mixing of orbitals only we will call hybridization. Okay so four orbitals if they get mixed up four new rejuvenated orbitals are formed. Okay so now how many sp3 hybrid orbitals are formed? There are four sp3 hybrid orbitals are formed. Each orbital has one one electron. This is one sp3 hybridized orbital. This is second sp3 hybridized orbital. Third sp3 hybridized orbital. Fourth sp3 hybridized orbital. Okay, so now this is what we call. Say if somebody asked you what is the hybridization of carbon in methane, then your answer must be sp3 hybridization. Okay, so carbon underwent sp3 hybridization. okay why we call sp3 because 1s and 3p orbitals have mixed up with each other just to distribute their energies equally okay now they have become active orbitals completely rejuvenated orbitals. Now we call their name as sp3 hybridized orbitals. Okay. There are four sp3 hybridized orbitals. Okay. Fine. So now this is our carbon. So how do these orbitals are arranged around carbon? Something like this. Okay. Orbitals are directed in certain position. They are arranged. They are like balloon like structures. Okay. So if you hold four balloons, how do you hold them? Say for example, see I have four chalk pieces. If I have to hold them as far as possible, you know they should not be present very much near to each other. When they are very much near to each other, they are with electrons, right? If they are near, you will observe the repulsion. Electron, electron, negative, negative charge. So repulsion. So these orbitals are arranged as far as possible, right? Say four chalk pieces if I have, how do I direct them? How do I show them? in different directions in space, like I should show them that there is as much distance as possible between them, okay? Say one chalk piece like this, the other one like this, other one like this, right? So, four orbitals, center carbon is there, four orbitals, the new orbitals, rejuvenated orbitals have formed, you know, they are arranged in space something like this. okay they are like balloon like structures okay so each orbital has how many electrons one electron this is one sp3 hybridized orbital this is another sp3 hybridized orbital with one electron third sp3 hybridized orbital with one electron fourth sp3 hybridized orbital with one electron okay so orbitals are balloon like structures so they are directed in certain positions in space. Okay. So that is what giving a shape for organic molecule. Okay. See this is actually what is this shape? This is a shape of tetrahedron guys. This is a shape of tetrahedron. You know these four hybrid orbitals are arranged in this. shape of tetrahedron. That is why we say methane molecule has tetrahedral structure. So the arrangement of hybrid orbitals in the space is a reason for a shape of a molecule. Okay, so what hybridization carbon in a methane underwent? SP3 hybridization. Okay, so now orbitals are ready for overlapping. So now as hydrogen's orbital, okay, hydrogen, hydrogen, what is hydrogen's electronic configuration? It is 1s2 right? So hydrogen has s orbital. S orbital is always spherical. So this is one hydrogen orbital carrying one electron. Here comes another hydrogen. carrying one electron. This is the third hydrogen. Okay let me change the color for differentiation purpose. So this is the third hydrogen, second hydrogen, first hydrogen. So fourth hydrogen atom carrying one electron. Okay so when hydrogen's orbital carrying one electron overlaps with this sp3 hybrid orbital then we say a bond is formed. This is one CH bond, another CH bond, third CH bond, fourth CH bond. bond. Okay. So, this is how methane molecule is formed. Definitely sharing of electron took place. When do sharing took place? When atomic orbitals overlap. Okay, so hydrogen's atomic orbital overlap but carbon's atomic orbitals, four orbitals to overlap they should get ready. They must have equal energy. Just to make their energies equal they will undergo a process of mixing orbitals called hybridization. Okay, so hope you are clear with the concept of hybridization, right? So here the carbon atom is undergoing sp3 hybridization. Okay, so this is how methane molecule is formed. Now let us understand another type of hybridization called sp2. Carbon can undergo sp3, it can undergo sp2, it can also undergo sp3. When it undergoes sp3 hybridization you know it will form 4 single bonds around it. When it undergoes sp2 hybridization it forms 1 double bond around it. And when it undergoes sp hybridization it will form triple bond around it. Okay, so this is a very very important concept. Now we will study how carbon can undergo sp2 hybridization. Take an example of ethene guys. So you must have studied about ethene structure in your lower classes. How do we write ethene? CH2, double bond CH2, right? Again if I have to elaborate carbon, single bonds with hydrogen, double bond with another carbon right so this is the elaborate structure of ethene so now i will tell you how this molecule is formed how these two single bonds and how this double bond is formed okay so this is carbon number one okay and this is carbon number two so both of them have to undergo hybridization here but they will not undergo sp3 hybridization here okay they will undergo sp2 hybridization you See we all know carbons electronic configuration 1s2 2s2 2p2 right. So orbital diagram s orbital is only one in that two electrons are there p orbitals are three you have two electrons each okay. So now as these two hydrogens and this carbon approaches towards carbon, approaches towards carbon, carbon gets excited. Carbon number 1 gets excited and one of the electron will move to empty PZ orbital. So now excited state electronic configuration of carbon 1 is... you know like this right say 1 1 1 right and second carbon second carbon also gets excited and its excited state electronic configuration is this okay so each right so both carbons gets excited as hydrogens approaches so this is their excited state electronic configuration okay and but here You know, when these hydrogens approaches, carbon will undergo only sp2 hybridization, only this orbital, this orbital and this orbital overlap. So, how many s orbitals? 1. How many p orbitals? 2. So, here the carbon is undergoing. going sp2 hybridization sp2 hybridization okay so how many new hybrid orbitals you will get you will get only three so how how they are arranged say if this is c1 carbon so this is one sp2 hybrid orbital this is another sp2 hybrid orbital this is the third sp2 hybrid orbital okay so when there are three things how they will get arranged as far as possible in a triangular way okay Fine. So our carb number 2 also will undergo sp2 hybridization only. It will also undergo sp2 hybridization and 3 new sp2 hybrid orbitals it will get. Okay. So here also these orbitals are arranged in a triangular way itself. So each orbital has 1, 1 electron. This is how. Okay. And now. Remember the unhybridized orbital is as it is right. So this is unhybridized orbital I will mention like this. This also has electron. Even in this carbon there is one orbital which did not undergo hybridization that is there as it is with one electron okay fine. So now what will happen you know two hydrogens will come to two hydrogens will come to these carbons. So they will overlap. okay so here another hydrogen overlap two hydrogens will come to this carbon they will overlap and this orbital you know this orbital gets overlapped with this orbital okay is that clear so now let me write the bond there is one bond with hydrogen another bond with hydrogen this carbon also So one bond with hydrogen another bond and there is a bond one of the hybrid orbital of this carbon and one of the hybrid orbital of this carbon also overlap. So there is a bond. Now you know unhybridized. orbitals are there no they will also get overlapped but this overlapping is very very weak this unhybridized orbital of this carbon this unhybridized orbital of this carbon also overlap because they also contain electrons they can share right so that's how you will get a double bond actually this bond we will call it as pi and this bond we will call it as sigma okay when hybrid you orbitals overlap, it leads to a stronger bonding called sigma bond. When unhybridized orbitals overlap, it leads to a weak bond, weak covalent bond called pi bond. So, that is why we say, you know, this is also sigma bond because hybrid orbitals only are overlapping, right? This is also sigma bond, this is also sigma bond, this is also sigma bond. So, one pi bond is a one sigma bond is there. So, here what is the hybridization of every carbon? This underwent sp2. This also underwent sp2 hybridization. So, this is how sp2 hybridization is formed with carbon atoms. So, similarly if I take an example of ethane. Okay ethane how do you write the structure? CH triple bond CH. So here actually the carbon must have undergone sp hybridization. Okay say sp hybridization every carbon underwent. So here this bond is sigma this CH bond is sigma among the triple bond. you know one bond is sigma two bonds are pi that means these two bonds are formed by overlapping of two unhybridized orbitals of this carbon and two unhybridized orbitals of this carbon okay so like this if you have a double bond with a carbon it is you know noted that that carbon must have underwent sp2 hybridization if you have triple bond with carbon it should be noted that those carbons must have undergone sp hybridization okay if a carbon has all single bonds only around it then that carbon must have undergone sp hybridize sp3 hybridization so this concept is really very very important guys you If a carbon has all single bonds around it, then that carbon has what hybridization? sp3 hybridization. Okay. If a carbon has a double bond associated with it, then that particular carbon must have undergone sp2 hybridization. Okay. If a carbon has a triple bond with it, then that carbon must have undergone sp hybridization. Okay. So identification of carbon atoms hybridization is very, very important guys. Why? Because you know what? sp hybridized carbon is more reactive than sp2 hybridized carbon this is more reactive than sp hybridized car sp3 hybridized carbon clear so you know what as s character increases as s character increases reactivity you reactivity of carbon increases okay clear say for example among the three carbons which is more reactive this particular carbon is more reactive if a carbon has triple bond then that is a more reactive okay so a triple bonded carbon will show more reactions varieties of reactions compared to double bonded carbon you Okay single bonded carbon if a carbon has all single bonds around it actually that is the least reactive. Okay so it is a very very passive inactive type inert type of carbon atom. Okay, so hybridization has this much importance in organic compounds. So it is very much essential to understand that which carbon has what hybridization. Okay, so now let us deal with some questions relating to this hybridization of carbon atoms topic. See guys, observe the question here, CH3CH2CH double bond CHCH3. Okay. of every carbon in a molecule, okay? So, CH3 means what? You know, three hydrogens are arranged around it something like this with single bonds only, right? So, with hydrogens, always single bonds you will find between carbon and hydrogen, okay? So, all single bonds around this carbon, right? So, this carbon has sp3 hybridization. This carbon has sp3 hybridization. So, this Two hydrogens means two single bonds and this is one bond, this is another bond. So, even this carbon has sp3 hybridization. What about this carbon? Double bond is there. What did I tell you? Always remember a trick here guys, very very important. If a carbon has all the bonds, it's a double bond. single bonds around it then that carbon is sp3 hybridized carbon. So if a carbon has at least one pi bond if a carbon has one pi bond with it then that carbon has sp2 hybridization. If a carbon has two pi bonds then that carbon has sp2 hybridization. around it then that carbon is sp hybridization. See here is a double bond. Among a double bond among a double bond one bond is pi one bond is sigma. Among a triple bond you know one bond is sigma two bonds are pi okay so this is a double bond so here one pi bond is there so this carbon has one pi bond around it or whenever a carbon has a double bond then definitely that carbon is sp2 this double bond also belongs to this carbon so it's like this carbon also have double bond so even its hybridization is sp2 whereas this carbon's hybridization is sp3 because all single bonds only around this this. 3 hydrogens means 3 single bond and this is the fourth bond. So, sp3 right. So, one more example try to observe. CH3, C double bond worm, CH3. So, what is the hybridization of every compound? This carbon, all single bonds, 3 hydrogens means 3 single bonds plus this is 1 bond, 4th bond. So this carbon hybridization sp3. What about this carbon? 2 single bonds and 1 double bond for this carbon. So its hybridization is sp2. This carbon, 3 single bonds and this is the 4th single bond. All single bonds only around this. So this carbon also has got sp3 hybridization like this. So questions can be asked like this. Every carbon atom's hybridization they will ask you to find. Okay. So only hybridization means it is related to only carbon atom. It is not related to hydrogen or oxygen or any other element present. Okay. So one more example. For example, you see CH3, C double bond O, CH2. Okay or CH2, C triple bond N. So imagine this is organic compound. Every carbon's hybridization you have to find. So what is the hybridization of this carbon? SP3, all single bonds. Hybridize of this carbon double bond is associated with it. So sp2. This carbon all single bonds sp3. This carbon you see triple bond is there with this carbon. Triple bond means what did I tell you? If you have a two pi bonds then that carbon must have undergone sp hybridization. Okay. So this is how you will have to decide the answers. Very very important concept. Okay, so now take a question. So this question's answer I will be discussing in my next video. Please do watch. It's a quite challenging question. Think and answer. So before I give this question, again I'm telling you if a carbon has all sigma bonds, all single bonds sp3, if a carbon has one pi bond around it, sp2 if a carbon has two pi bonds around it sp okay so observe example So this is the organic compound. This is carbon number 1, carbon number 2 and carbon number 3. So tell me the hybridization of carbon number 1, carbon number 2 and carbon number 3. Okay and post your answer in a comment section. Let me check it out who will give a correct answer. Very very important question guys. It's answered. I will discuss in my next video that is in part. two of organic chemistry okay so with this i am completing this session meet you all in the next video enjoy organic chemistry videos definitely this will give you lots of confidence for you to solve any question on organic chemistry thank you so much

Once you are strong with your basics, then working with organic chemistry or studying organic chemistry is just, you know, making a piece of cake. So try to understand every concept in a detailed way and get strong with your basics. And to understand this organic chemistry, you should have a knowledge of first four chapters. That means some basic concepts of chemistry, atomic structure chapter, periodic classification of elements and most importantly chemical bonding.

So here structure of atom chapter and chemical bonding is the essential chapters that you need to understand to understand this organic chemistry. Okay so I have covered the first three chapters in a detailed way. The fourth chapter that is chemical bonding is going on.

So along with chemical bonding you know I will be releasing the videos on this organic chemistry also. So, get strong with your basics first then come to this organic chemistry. I can say this organic chemistry is the scoring topic in chemistry for all types of competitive examinations. But many feel working with organic chemistry questions is a difficult task. Why because questions will not be asked from a single topic from a single chapter.

You will have combined concept from all the chapters. See if you have to attempt or solve a question of organic chemistry, you should have complete knowledge on all organic chemistry chapters. Two chapters you will study in class 11 and four core organic chapters you will study in class 12. So all together six core organic chapters. You should have a thorough knowledge on all the six chapters only then you can confidently attempt the questions relating to organic chemistry right. So they will not be asking you from a single topic from a single chapter.

Question is a combined question. to attempt a question you should have knowledge on all the six chapters right so and coming to this particular chapter very very fundamental and very very basic chapters of organic chemistry very much essential to understand each and every topic of this chapter in a detailed way Only then you can confidently understand or confidently study rest of the organic chapters both in class 11 and class 12. So I am here to make your study of organic chemistry much easier. I can assure you that after watching my videos your confidence levels will increase in studying organic chemistry. So do watch the videos till the end and get maximum benefit.

Okay, let's come to a chapter organic chemistry so today i will give introduction of organic chemistry some history of organic chemistry and why this carbon is so special organic chemistry is nothing but study of carbon compounds so carbon is a very very special element we'll discuss why this element is special why this separate branch for studying carbon compounds you know all that And also let's discuss about hybridization of carbon atoms. I mean shapes of organic compounds. Okay.

Fine. Coming to the word organic chemistry, try to understand the meaning of the word organic. Organic means life, right?

So initially, long back, people thought that Organic compounds can be obtained only from plants and animals. Okay, so they thought that these are certain chemical compounds which are naturally present in plants and animals see take human beings our body is completely made up of chemicals so we have lots of chemicals inside us right and you you take a plant body and plant body also has lots of chemicals inside it so these natural chemicals were called as organic compounds initially And they thought that these organic compounds cannot be artificially prepared in chemical labs. If you want organic compound, you should take it from plant or animal they thought. And there was a vital force theory which was introduced by Berzelius. So, Berzelius was...

the scientist who introduced a theory called vital force theory and according to this vital force theory you know you can't prepare organic compounds artificially if you want them you should get you should get only only from plants and animals okay so to make this organic compounds which are present in plants and animals some vital force some natural force is required. Okay, so some natural force is responsible to prepare you know to make these organic compounds which are present in plants and animals. So you can't prepare them artificially to make them some vital forces necessary, some natural forces necessary. So you can only get them from plants and animals, he said.

So that is what we call as vital force theory. But there came another scientist called Ohler. Okay, very famous scientist.

So this Oller has done some experiments in a chemical laboratory and he took ammonium cyanide NH4CNO. This is the formula of ammonium cyanide. Okay, so from this ammonium cyanide in a chemical lab he could prepare you know nh2 co nh2 which is nothing but urea and urea is organic compound okay see artificially in a chemical laboratory from inorganic substance and you know this substance is called as inorganic substance you know previously All chemical substances which are present in plants and animals were called as organic. Every other chemical substances which are not present in plants and animals were called as inorganic.

Okay. So what did this Euler do? He took some inorganic substance and from this he could prepare an organic compound called urea. Okay.

So this... came up as a revolution in the field of organic chemistry. From then different scientists have tried preparing different organic compounds from inorganic sources. Okay so this was one of the example and there came another scientist called Cole. He is a very famous scientist and you have many reactions on his name a person Cole.

Okay. And he prepared acetic acid. Similarly, in a chemical laboratory, he prepared acetic acid.

Acetic acid is nothing but vinegar. Okay. Vinegar.

So, you know the formula, right? CH3COOH. Little of organic chemistry we studied in class 10, carbon and its compounds, right? So, there we know the formula of acetic acid that is CH3COOH, which is nothing but a vinegar.

Okay, so this, you know, this compound was artificially prepared by a person, Cope. Okay, and there came another person called Berthelot. Berthelot. Okay.

And he prepared methane. So we all know what is methane, right? CH4. So methane was also artificially prepared, you know, from the elements that is carbon and hydrogen, right?

So like this, many scientists came up and they could prepare organic compounds artificially in the chemical laboratories, you know, from inorganic substances. They are not preparing from plants and animals. They have not extracted from plants and animals.

In turn, they have prepared from some inorganic substances. By conducting some chemical reactions, they could prepare artificially in the chemical laboratory. From then, you know, hundreds of organic compounds were artificially made in a chemical laboratory. And these organic compounds are extensively used in all kinds of fields.

okay see naturally speaking all the chemicals which are present all the substances which are present in plants and animals is organic compound right so that we know and apart from that you know the drugs or the medicine that we take up during various diseases belong to organic compound you know the cloth we wear is organic right and the food we eat has organic compound and various things various things that we use you know the fertilizers insecticides uh so dye industry colors various colors various pigments various flavors you know all these are organic compounds right so you know what uh already about 5 million organic compounds are there in our nature so how many 5 million organic compounds are already existed and every year 30,000 new organic compounds are being discovered. Right. So this way, you know, by conducting various reactions, people are making hundreds of organic compounds which have so many uses. Right. So now we understood how this organic compounds are prepared and their history.

Right. Now, let us try to understand what actually we mean by organic compound. okay so organic compound is nothing but compounds of compounds of carbon okay so in a simple language if i have to talk about organic compound i can say They are nothing but compounds of carbon.

Okay. See, if you have to call something as organic compound, then that compound must compulsorily have carbon and hydrogen. Okay.

So only then you can call it as organic compound. Is that clear? Say we have carbon monoxide, we have carbon dioxide. We will not call them as organic compound, right?

But we call CH4 as organic compound, CH3, CO, OH as organic compound. Why? Because carbon is there with hydrogen.

So what is the compulsory criteria to call something as organic compound? The compound or a substance must have carbon and hydrogen. Along with carbon and hydrogen, you will also find oxygen sometimes.

Many times oxygen you will find or sometimes sulfur can be present. Sometimes halogens like Cl, F, I, Br, these guys can be present or phosphorus can be present. Okay, nitrogen can be present, right? But the necessary condition is compound must have carbon and hydrogen.

Not just the carbon. Carbon must be there with hydrogen. Along with these two elements, these elements also can be present.

Only then you will call it as organic compound. Okay, so organic chemistry is all about studying the nature of organic compound, properties of organic compound, reactions of organic compound and everything about organic compound. Okay, fine.

See. Carbon, the main element present in organic compound is carbon. So without carbon, you cannot call it as organic itself, right?

So what is so special about that carbon, right? So why this carbon can make crores and crores of compounds, you know, that can exist in our nature. So what is so special about this guy called carbon? That's what we will try to discuss now. See guys there are mainly three reasons why carbon is very very special right.

So normally we say the versatile nature of carbon. Versatile in the sense what? You know, we say the person is very much versatile.

That means if he is multi-talented person, we call him as versatile, right? So like that our carbon is also multi-talented element. Okay, it will show many many different properties. That is the reason it is so special and it is forming many molecules or compounds in our nature.

So the first special character of carbon is having tetravalency. So tetravalency nature. So what do you mean by tetravalency? Tetravalency in the sense valency of carbon is 4. Say carbon. Atomic number 6. If I have to write its electronic configuration 1s2, 2s2, 2p2, right?

So, in the outermost shell, outermost shell is our second shell and you have 4 valence electrons, okay? So, our carbon has 4 valence electrons, right? So since 4 valence electrons are there, it can form 4 bonds around it.

How many bonds it can form maximum around it? Only 4 bonds. So here the 4 electrons can be shared with other atoms. The other atom can be carbon itself or the other atom can belong to any other element.

Okay, so it has an ability to share, to share, it has an ability to share four valence electrons. Okay, so that way it can satisfy octet rule, right? All these octet rule, why the atom shares electron, all that we have discussed in chemical bonding chapter, isn't it? So, since four valence electrons are there, it can share four. electrons with carbon itself or with some other atoms and form four bonds.

Okay. So, it can form all four single bonds around it or it can form, you know, two single bond and one double bond around it or it can form one triple bond and one single bond around it. Okay.

So, all together you will observe only four bonds. You see here 1, 2, 3, 4. You see here 1, 2, 3, 4. You see 1, 2, 3, 4. Right. So, all four bonds can be single or it can have a double bond or it can have a triple bond. Okay.

So, This nature we will call it as tetravalency nature. Okay. Fine.

And coming to a second special property of carbon that is catenation. So this is very very important property. We have studied in our basic classes also. Catenation is nothing but self-linking capacity of carbon.

Self-linking capacity of carbon. right so carbon can link with carbon atoms itself to form a long chain to form a cyclic chains or it it can form various shaped chains isn't it say for example uh you know carbon links with other carbons and forms a long chain we call it as long straight chine okay or you know you can observe bonding something like this right so a long chain with a branch So this we will call it as branched chine. So this is a straight chine. Right.

And carbon can link with its own carbon atoms and form a cyclic chines also. Like this carbon can link in a cyclic manner. Right. So, you know.

it can form a straight long chain, it can form a branched chain or it can form a cyclic structures. Right. So this nature we will call it as tattination.

Second important special property of carbon. And coming to the third property that is isomerism. Carbon shows isomerism.

So what do you mean by isomerism? Carbon compounds exist as isomers. Isomers in the sense compounds which have same chemical formula okay but different structures or you know different chemical properties. For example don't worry understand this particular example see I have a compound CH3 CH2 CH2 CH3 okay so I have another compound CH3 this is what don't worry about their names, their properties etc.

All that why we have written this kind of structures, everything I will teach you. So just observe here how many carbons are there? 4 carbons are there. How many hydrogens are there? 10 hydrogens are there.

So 3 plus 2, 5. 3 plus 2, 5. 5 plus 5, 10. So here count how many carbons? Here also 4 carbons are there. And how many hydrogens?

Here also 10 hydrogen atoms. See. This is one organic compound.

This is another organic compound. This was having a straight chain. This is a branched one. Right?

Okay. Molecular formula is same. But both compounds are very much different.

Okay. So this compound behaves in a different way. And this behaves in a much different way. There is no comparison between the properties of this compound and this compound.

What is similar? Molecular formula is similar. What is different?

Their physical and chemical properties are entirely different. Okay. So carbon compounds have this kind of isomerism.

They will show this kind of isomerism. This is one of the different property of carbon. Okay.

So mainly three reasons why carbon is special and why carbon is forming many people. compounds in our nature i told you know we have around 5 million carbon compounds so far and every year 30 000 compounds are being synthesized newly right so why these crores of compounds are being manufactured every single year is because of mainly these three properties okay so this is the versatile nature of carbon Now let us understand the type of bonding that you will observe in organic compound. Okay so here I will teach you the concept of hybridization also. Okay so more detailed aspects of hybridization you will study in chemical bonding but now I will teach you how much ever is essential to understand the structure of organic compound that much I am going to teach you.

See you guys. The type of bonds that you observe in every single organic compound is covalent bonds. So remember this point very very important and the type of bonds you will observe is covalent bonds.

So how are covalent bonds are formed? It is by sharing of electrons right. Sharing of electrons between the atoms leads to the formation of covalent bonds. Okay, so in the lower classes we have studied, you know, the dot structure for methane, right? So how did methane molecule formed?

Say you will mention carbon. Carbon has four valence electrons, right? So always which electrons can be shared? valence electrons that is the electrons present in the last shell. So it has four valence electrons and hydrogen has one valence electron.

This is one hydrogen, this is second hydrogen, this is third hydrogen and this is fourth hydrogen. So these two electrons are shared. between carbon and hydrogen so that this hydrogen gets stability right.

So it will have two electrons around it so that it becomes stable. It just shows the electronic configuration of helium so it is stable. And you know these two electrons are shared between carbon and hydrogen. So it's like these two electrons belong to carbon also and they belong to hydrogen also. So this is how all hydrogens are becoming stable.

and carbon 1 2 3 4 5 6 7 8 right so this is how you will show the electrons present around carbon so this way carbon has eight electrons around it so that it is getting stability right so this one how do you show between this carbon and this hydrogen two electrons are show Two electrons are shared. So you will write that as bond. So between this carbon and this hydrogen, two electrons only shared.

So one bond. So here also one bond, here also one bond. So this is how you will write the structure of methane, right? So here when one pair of electrons are shared you will write one bond. This is one covalent bond.

This is another covalent bond. Third covalent bond. Fourth covalent bond. So this is how you will show how electrons are shared between carbon and four other hydrogens.

Okay. So this is a basic way of learning covalent bond. But actually speaking in the chemical bonding chapter we will learn that covalent bonds are formed when atomic orbitals overlap.

So when do the electrons are getting shared between this carbon and this hydrogen? When carbon's orbital overlaps with hydrogen's orbital. When do sharing of these two electrons takes place? When carbon's orbital overlaps with hydrogen's orbital.

Okay. So covalent bonds are formed when atomic orbitals overlap with each other. Okay.

So I am giving much a standard definition for covalent bond actually. You know. Covalent bonds means sharing of electrons takes place when atomic orbitals overlap. Atomic orbitals overlap. Okay.

You see here. I am showing you how these atomic orbitals can overlap with each other to form these covalent bonds. Okay.

So observe carefully guys. This is very very important. Okay. Fine.

So I am explaining you the form. formation of formation of CH4. Okay we know how this is formed basically we studied like this in our class 10 but now we are going to study in a detailed way.

Okay so actually these bonds are formed when atomic orbital of carbon overlaps with atomic orbital of hydrogens. So how that overlapping business takes place that's what we are going to learn. Okay first we are going to do a little bit of a test. What I will write here is carbon's electronic configuration. Okay.

So it is 1s2 2s2 2p2. Okay. So I'll see 1s.

S orbital is only one right. So one box. This way of writing electronic configuration also I taught you in atomic structure.

So I told you you should have complete knowledge on atomic structure and chemical bonding. Video playlist links are provided in the description. Go and check it out. S orbital is only one in that two electrons are there. P orbitals are how many?

There are three P orbitals Px, Py and Pz right. So two electrons one electron in Px the other electron in Py okay. So this is how the electrons are present in the valence orbitals.

So I am not worried about this orbital. Inner shell electrons will not participate in any kind of bonding. So valence shell is second shell.

So this is S orbital, 2 electrons. P orbitals are 3, 2 electrons are there like this. Okay. So now what happens is, you know, as hydrogens approach, carbon is here. Okay, hydrogens are coming to make a bond.

So as hydrogens approach to make a bonding with this carbon, this carbon will excite. This will get excited. Okay, so I am writing you excited, excited carbons electronic configuration. Carbon when it gets excited, one of the electron from S orbital will get shifted to pz orbital. So now the electronic configuration, last electronic configuration is like this.

Okay, so this is our 2s orbital, this is px, one electron, py1, pz1. Okay, so when does this electron will go to this empty orbital? When carbon gets excited. Okay, when does carbon gets excited? When four hydrogens are coming near to it to make a bonding.

Okay fine. So now this is excited state electronic configuration of carbon. Right?

Okay. So these are what our atomic orbitals ready to overlap with hydrogen's atomic orbital. Okay. So how many orbitals are there?

Four orbitals are there. Okay. But Actually all of them must have same energy otherwise they are not ready to make a bonding okay.

So here 2s orbital has different energy these 2p orbitals have different energy okay. So to make their energies equal, they will combine with each other. They get mixed up.

It's like they distribute their energy. Say P orbital has much higher energy. S orbital has lower energy.

So what do these P orbitals do? They give little of their energy to S orbital. Okay.

So, you know, the mixing of orbitals takes place. During this mixing of orbitals, energy gets distributed equally. Okay.

Four orbitals are getting mixed up to make their energies equal. So, we are getting four rejuvenated orbitals. I am not telling new.

Four rejuvenated. Four rejuvenated orbitals I am getting. okay. So, see all orbitals energy is equal now, right.

So, which orbitals have combined here? 1 s orbital, right. Let me do it. 1 s orbital and 3 p orbitals have combined to make their energies get equalized, right. So, that is why this mixing of orbitals only we will call hybridization.

Okay so four orbitals if they get mixed up four new rejuvenated orbitals are formed. Okay so now how many sp3 hybrid orbitals are formed? There are four sp3 hybrid orbitals are formed.

Each orbital has one one electron. This is one sp3 hybridized orbital. This is second sp3 hybridized orbital. Third sp3 hybridized orbital. Fourth sp3 hybridized orbital.

Okay, so now this is what we call. Say if somebody asked you what is the hybridization of carbon in methane, then your answer must be sp3 hybridization. Okay, so carbon underwent sp3 hybridization.

okay why we call sp3 because 1s and 3p orbitals have mixed up with each other just to distribute their energies equally okay now they have become active orbitals completely rejuvenated orbitals. Now we call their name as sp3 hybridized orbitals. Okay.

There are four sp3 hybridized orbitals. Okay. Fine.

So now this is our carbon. So how do these orbitals are arranged around carbon? Something like this.

Okay. Orbitals are directed in certain position. They are arranged.

They are like balloon like structures. Okay. So if you hold four balloons, how do you hold them? Say for example, see I have four chalk pieces.

If I have to hold them as far as possible, you know they should not be present very much near to each other. When they are very much near to each other, they are with electrons, right? If they are near, you will observe the repulsion.

Electron, electron, negative, negative charge. So repulsion. So these orbitals are arranged as far as possible, right? Say four chalk pieces if I have, how do I direct them? How do I show them?

in different directions in space, like I should show them that there is as much distance as possible between them, okay? Say one chalk piece like this, the other one like this, other one like this, right? So, four orbitals, center carbon is there, four orbitals, the new orbitals, rejuvenated orbitals have formed, you know, they are arranged in space something like this. okay they are like balloon like structures okay so each orbital has how many electrons one electron this is one sp3 hybridized orbital this is another sp3 hybridized orbital with one electron third sp3 hybridized orbital with one electron fourth sp3 hybridized orbital with one electron okay so orbitals are balloon like structures so they are directed in certain positions in space.

Okay. So that is what giving a shape for organic molecule. Okay. See this is actually what is this shape? This is a shape of tetrahedron guys.

This is a shape of tetrahedron. You know these four hybrid orbitals are arranged in this. shape of tetrahedron.

That is why we say methane molecule has tetrahedral structure. So the arrangement of hybrid orbitals in the space is a reason for a shape of a molecule. Okay, so what hybridization carbon in a methane underwent?

SP3 hybridization. Okay, so now orbitals are ready for overlapping. So now as hydrogen's orbital, okay, hydrogen, hydrogen, what is hydrogen's electronic configuration?

It is 1s2 right? So hydrogen has s orbital. S orbital is always spherical.

So this is one hydrogen orbital carrying one electron. Here comes another hydrogen. carrying one electron.

This is the third hydrogen. Okay let me change the color for differentiation purpose. So this is the third hydrogen, second hydrogen, first hydrogen. So fourth hydrogen atom carrying one electron.

Okay so when hydrogen's orbital carrying one electron overlaps with this sp3 hybrid orbital then we say a bond is formed. This is one CH bond, another CH bond, third CH bond, fourth CH bond. bond. Okay.

So, this is how methane molecule is formed. Definitely sharing of electron took place. When do sharing took place?

When atomic orbitals overlap. Okay, so hydrogen's atomic orbital overlap but carbon's atomic orbitals, four orbitals to overlap they should get ready. They must have equal energy. Just to make their energies equal they will undergo a process of mixing orbitals called hybridization. Okay, so hope you are clear with the concept of hybridization, right?

So here the carbon atom is undergoing sp3 hybridization. Okay, so this is how methane molecule is formed. Now let us understand another type of hybridization called sp2.

Carbon can undergo sp3, it can undergo sp2, it can also undergo sp3. When it undergoes sp3 hybridization you know it will form 4 single bonds around it. When it undergoes sp2 hybridization it forms 1 double bond around it. And when it undergoes sp hybridization it will form triple bond around it.

Okay, so this is a very very important concept. Now we will study how carbon can undergo sp2 hybridization. Take an example of ethene guys.

So you must have studied about ethene structure in your lower classes. How do we write ethene? CH2, double bond CH2, right? Again if I have to elaborate carbon, single bonds with hydrogen, double bond with another carbon right so this is the elaborate structure of ethene so now i will tell you how this molecule is formed how these two single bonds and how this double bond is formed okay so this is carbon number one okay and this is carbon number two so both of them have to undergo hybridization here but they will not undergo sp3 hybridization here okay they will undergo sp2 hybridization you See we all know carbons electronic configuration 1s2 2s2 2p2 right. So orbital diagram s orbital is only one in that two electrons are there p orbitals are three you have two electrons each okay.

So now as these two hydrogens and this carbon approaches towards carbon, approaches towards carbon, carbon gets excited. Carbon number 1 gets excited and one of the electron will move to empty PZ orbital. So now excited state electronic configuration of carbon 1 is... you know like this right say 1 1 1 right and second carbon second carbon also gets excited and its excited state electronic configuration is this okay so each right so both carbons gets excited as hydrogens approaches so this is their excited state electronic configuration okay and but here You know, when these hydrogens approaches, carbon will undergo only sp2 hybridization, only this orbital, this orbital and this orbital overlap.

So, how many s orbitals? 1. How many p orbitals? 2. So, here the carbon is undergoing. going sp2 hybridization sp2 hybridization okay so how many new hybrid orbitals you will get you will get only three so how how they are arranged say if this is c1 carbon so this is one sp2 hybrid orbital this is another sp2 hybrid orbital this is the third sp2 hybrid orbital okay so when there are three things how they will get arranged as far as possible in a triangular way okay Fine.

So our carb number 2 also will undergo sp2 hybridization only. It will also undergo sp2 hybridization and 3 new sp2 hybrid orbitals it will get. Okay. So here also these orbitals are arranged in a triangular way itself.

So each orbital has 1, 1 electron. This is how. Okay.

And now. Remember the unhybridized orbital is as it is right. So this is unhybridized orbital I will mention like this. This also has electron.

Even in this carbon there is one orbital which did not undergo hybridization that is there as it is with one electron okay fine. So now what will happen you know two hydrogens will come to two hydrogens will come to these carbons. So they will overlap.

okay so here another hydrogen overlap two hydrogens will come to this carbon they will overlap and this orbital you know this orbital gets overlapped with this orbital okay is that clear so now let me write the bond there is one bond with hydrogen another bond with hydrogen this carbon also So one bond with hydrogen another bond and there is a bond one of the hybrid orbital of this carbon and one of the hybrid orbital of this carbon also overlap. So there is a bond. Now you know unhybridized. orbitals are there no they will also get overlapped but this overlapping is very very weak this unhybridized orbital of this carbon this unhybridized orbital of this carbon also overlap because they also contain electrons they can share right so that's how you will get a double bond actually this bond we will call it as pi and this bond we will call it as sigma okay when hybrid you orbitals overlap, it leads to a stronger bonding called sigma bond.

When unhybridized orbitals overlap, it leads to a weak bond, weak covalent bond called pi bond. So, that is why we say, you know, this is also sigma bond because hybrid orbitals only are overlapping, right? This is also sigma bond, this is also sigma bond, this is also sigma bond. So, one pi bond is a one sigma bond is there. So, here what is the hybridization of every carbon?

This underwent sp2. This also underwent sp2 hybridization. So, this is how sp2 hybridization is formed with carbon atoms.

So, similarly if I take an example of ethane. Okay ethane how do you write the structure? CH triple bond CH. So here actually the carbon must have undergone sp hybridization. Okay say sp hybridization every carbon underwent.

So here this bond is sigma this CH bond is sigma among the triple bond. you know one bond is sigma two bonds are pi that means these two bonds are formed by overlapping of two unhybridized orbitals of this carbon and two unhybridized orbitals of this carbon okay so like this if you have a double bond with a carbon it is you know noted that that carbon must have underwent sp2 hybridization if you have triple bond with carbon it should be noted that those carbons must have undergone sp hybridization okay if a carbon has all single bonds only around it then that carbon must have undergone sp hybridize sp3 hybridization so this concept is really very very important guys you If a carbon has all single bonds around it, then that carbon has what hybridization? sp3 hybridization.

Okay. If a carbon has a double bond associated with it, then that particular carbon must have undergone sp2 hybridization. Okay.

If a carbon has a triple bond with it, then that carbon must have undergone sp hybridization. Okay. So identification of carbon atoms hybridization is very, very important guys.

Why? Because you know what? sp hybridized carbon is more reactive than sp2 hybridized carbon this is more reactive than sp hybridized car sp3 hybridized carbon clear so you know what as s character increases as s character increases reactivity you reactivity of carbon increases okay clear say for example among the three carbons which is more reactive this particular carbon is more reactive if a carbon has triple bond then that is a more reactive okay so a triple bonded carbon will show more reactions varieties of reactions compared to double bonded carbon you Okay single bonded carbon if a carbon has all single bonds around it actually that is the least reactive.

Okay so it is a very very passive inactive type inert type of carbon atom. Okay, so hybridization has this much importance in organic compounds. So it is very much essential to understand that which carbon has what hybridization. Okay, so now let us deal with some questions relating to this hybridization of carbon atoms topic. See guys, observe the question here, CH3CH2CH double bond CHCH3.

Okay. of every carbon in a molecule, okay? So, CH3 means what?

You know, three hydrogens are arranged around it something like this with single bonds only, right? So, with hydrogens, always single bonds you will find between carbon and hydrogen, okay? So, all single bonds around this carbon, right?

So, this carbon has sp3 hybridization. This carbon has sp3 hybridization. So, this Two hydrogens means two single bonds and this is one bond, this is another bond.

So, even this carbon has sp3 hybridization. What about this carbon? Double bond is there.

What did I tell you? Always remember a trick here guys, very very important. If a carbon has all the bonds, it's a double bond. single bonds around it then that carbon is sp3 hybridized carbon.

So if a carbon has at least one pi bond if a carbon has one pi bond with it then that carbon has sp2 hybridization. If a carbon has two pi bonds then that carbon has sp2 hybridization. around it then that carbon is sp hybridization. See here is a double bond.

Among a double bond among a double bond one bond is pi one bond is sigma. Among a triple bond you know one bond is sigma two bonds are pi okay so this is a double bond so here one pi bond is there so this carbon has one pi bond around it or whenever a carbon has a double bond then definitely that carbon is sp2 this double bond also belongs to this carbon so it's like this carbon also have double bond so even its hybridization is sp2 whereas this carbon's hybridization is sp3 because all single bonds only around this this. 3 hydrogens means 3 single bond and this is the fourth bond.

So, sp3 right. So, one more example try to observe. CH3, C double bond worm, CH3. So, what is the hybridization of every compound?

This carbon, all single bonds, 3 hydrogens means 3 single bonds plus this is 1 bond, 4th bond. So this carbon hybridization sp3. What about this carbon?

2 single bonds and 1 double bond for this carbon. So its hybridization is sp2. This carbon, 3 single bonds and this is the 4th single bond.

All single bonds only around this. So this carbon also has got sp3 hybridization like this. So questions can be asked like this. Every carbon atom's hybridization they will ask you to find. Okay.

So only hybridization means it is related to only carbon atom. It is not related to hydrogen or oxygen or any other element present. Okay. So one more example. For example, you see CH3, C double bond O, CH2.

Okay or CH2, C triple bond N. So imagine this is organic compound. Every carbon's hybridization you have to find. So what is the hybridization of this carbon? SP3, all single bonds.

Hybridize of this carbon double bond is associated with it. So sp2. This carbon all single bonds sp3.

This carbon you see triple bond is there with this carbon. Triple bond means what did I tell you? If you have a two pi bonds then that carbon must have undergone sp hybridization.

Okay. So this is how you will have to decide the answers. Very very important concept.

Okay, so now take a question. So this question's answer I will be discussing in my next video. Please do watch.

It's a quite challenging question. Think and answer. So before I give this question, again I'm telling you if a carbon has all sigma bonds, all single bonds sp3, if a carbon has one pi bond around it, sp2 if a carbon has two pi bonds around it sp okay so observe example So this is the organic compound. This is carbon number 1, carbon number 2 and carbon number 3. So tell me the hybridization of carbon number 1, carbon number 2 and carbon number 3. Okay and post your answer in a comment section.

Let me check it out who will give a correct answer. Very very important question guys. It's answered.

I will discuss in my next video that is in part. two of organic chemistry okay so with this i am completing this session meet you all in the next video enjoy organic chemistry videos definitely this will give you lots of confidence for you to solve any question on organic chemistry thank you so much

Transcript for:Basics of Organic Chemistry for Class 11

Transcript for:
Basics of Organic Chemistry for Class 11