 Yeah, hi everyone. This is Pratik and today we are going to look at chapter 4th of chemistry, 10th syllabus, which is carbonates compounds. Yeah, hi everyone. So I would like to invite all of you to this revision session on carbonates compounds. Please feel free to post your doubts. You know the, you can always reach out through the WhatsApp chat or you can always put your messages on the chat window here. Let's wait for a few minutes till people join in and we'll just begin in another minute or two. Right, so let's begin. Everyone who is joining in, just please feel free to put in your name in the chat window just below the channel on the video. So I can see Ruchi is here and a few more are just joining in. I again welcome you all and let's look at this chapter today, how to answer the questions that are there. Also, we'll try and see what are the major important points that are necessary to be known before the exams, which are upcoming in the next few days in the coming month or so. So let's get into the topic and understand what this chapter really deals with. I'll also try and give you some tips on writing answers to some typical questions that are asked on carbonates compounds. At the same time, what are the points that you should remember and how should you present that in the exam? So that's our agenda today. Let's begin. Let's understand how we can deal with this chapter going forward. Yeah, so the first thing's first is how is carbon really occurring in nature? What is the occurrence of carbon? How do we find carbon in our surroundings? The most important is the carbon found in atmosphere. It's also found in the earth's crust. It's found in all living organisms. In fact, carbon is present in fuels. So for example, in the atmosphere, it is present as CO2 as carbon monoxide. In the earth's crust, it is present as coal. In all living organisms, there are multiple hydrocarbons as well as organic compounds that are found. It's present in wood either in terms of cellulose, glucose. I can see a few more people joining in. There's Krithika and Aniruddh. Good to see you. Anyone who joins in, please feel free to put in your name in the chat window. So I'm aware that you are there and I can connect and interact with you. Please feel free to ask questions during the session so that we can connect and I can answer any of the queries that you have. Now, carbon, as I was saying, that carbon is present in the fuels as well. It's present in coal. It's present in charcoal or co-petroleum and all the natural gases. So, yeah, Mehul also is here. That's nice. And then we have carbon present in compounds, which are carbonates. For example, calcium carbonate or limestone, as we call it commonly, contains carbon. We also have hydrogen carbonates. For example, baking soda, which is sodium bicarbonate, also has a hydrogen carbonate in it. All the aerated drinks that we drink has carbonic acid, which is nothing but hydrogen carbonates. And of course, carbon is found in free state as it is found in diamond or in graphite or in fuel arenas. You can see I've been able to put up some images for you. So the diamond image is pretty clear, the fuel image, as well as biogas image, where my cursor is. So this is the biogas image. And you can also find petroleum extraction. This is an oil rig on the seashore of the coast of a country. Food, there is coal. These are, again, coal particles, butamin particles. So all of these are basically rich sources of carbon in nature. Now, how is the bonding really that's there in general? And especially in carbon that will look very shortly. So you'll see that we noticed that carbon actually has, so I can see Mehul and Srivastava also joined in. So we can see that carbon actually has six electrons. And all of these six electrons are arranged in an electronic configuration of two, four, which means that the first shell contains two electrons and the second shell contains four electrons. Now, as it has four electrons, it can achieve stability, which is an octet, which means eight electrons, only by either gaining four electrons or losing four electrons. But we'll see that carbon actually chooses to share four electrons with other atoms. Neither gain nor lose. And that's because gaining and losing has a lot of energy that is required. One or two electrons is easy to gain or lose, but four electrons gaining or losing is a huge amount of energy exchange. And therefore, sharing four electrons with other atoms is what carbon mostly prefers. So, yeah, so of course, it cannot, it does not gain four electrons because it is difficult for six protons to hold 10 electrons. At the same time, it cannot lose four electrons, because it needs a lot of energy to lose four electrons. So it ends up sharing four electrons as we said, with other atoms to attain stability. This actually results in formation of covalent bonds. We'll shortly see how in detail can we understand covalent bonds. But this four sharing of electrons is what we call as having being tetravalent. So, tetravalent means having a valency of four. And valency basically means the number of electrons. Please note the difference between valence electrons and valency. Valency means number of electrons that are number of electrons that are lost or gained or shared, that are lost, gained or shared. That is valency, where a shared, yeah, but whereas valence electrons means number of electrons in the outer most shell. In carbon situation, the valence electrons is four, but valency also is four. But if I give you another example, for example, oxygen, the valence electrons is six. Valence electrons is six in number, but the valency is actually only two. So that's typical of compounds. So you'll realize that oxygen, the valence electrons is six in number, but valency is only two. So these are some of the important facets that you have to remember when you write answers. Please do not mix up students, do end up mixing both the concepts pretty much. So that's one of the major reasons why carbon forms covalent bonds. Going further, let's understand what covalent bonds are. So basically covalent bond is formed by sharing of electrons. Anytime the electrons are shared, we say that it is a covalent bond. Now, if one pair of electrons is shared, of course, you'll end up getting a single covalent bond. Whereas if multiple pair of electrons is shared, for example, two pair of electrons, now please note two pair of electrons means each atom lends two electrons each. And therefore, for example, oxygen, when you form O2, it lends two electrons and we'll shortly see how it really happens. So that forms a double covalent bond. And when we say three pairs of electrons are shared, each atom is giving three electrons and that's how three pairs are formed. And that's a triple covalent bond. So formation of single covalent bonds is pretty typical in atoms like hydrogen. In fact, chlorine, bromine, fluorine, all of these atoms would show single covalent bonds. Now, let's understand how this bond typically would form. So a common question that generally is asked is explain covalent bonds with a Louis diagram and give an example of formation of covalent bonds and explain the formation of covalent bonds. Sometimes it's directly asked as explain the formation of hydrogen or fluorine. So in that situation, most important is you have to write the atomic number, you have to write the electronic configuration. This is one of the most important points without writing electronic configuration. If we jump to the stage of just writing the number of bonds, you might lose a half mark or a mark there. So you write the atomic number, you write the electronic configuration or electronic arrangement, and then say that it has one valence electrons and therefore it needs X number of electrons. In this case, it needs only one more to achieve stability. Please note here, a duplicate is achieved and not octet. So that also has to be mentioned that hydrogen needs to achieve a duplicate and therefore it needs one more electron to be bonded with. So two hydrogen atoms share one pair of electrons resulting in the formation of single covalent bond in hydrogen molecule. This is the way to write a Lewy diagram and we'll see some more examples of Lewy diagram as we move forward. Similarly, if the question is how would you form a double covalent bond? For example, an oxygen, again, the process remains the same. You mentioned the atomic number that is, okay, so someone else has joined in. I would be happy to know your name. The one with H2O and CO2. If you can just post in your name, I think I'd be more than happy to understand. Yeah, so the H2O and CO2 are all covalent bonds, by the way. Yes, that's right. H2O has both single covalent bonds, whereas CO2 has two double bonds. So we'll just look at how oxygen molecule is formed. So the atomic number of oxygen is eight and therefore its electronic configuration is two six and hence it has six valence electrons. It needs two more electrons to attain stability. So oxygen atoms share two pairs of electrons. Please note each atom is giving a pair of electrons and therefore two pairs are formed. Now once they are formed, you'll realize that they end up forming a double bond. Now H2O and CO2 are covalent bonds. Just to answer the query, H2O actually forms two single bonds and CO2 actually forms. So I'm drawing a structure for you. Another two bonds with oxygen. So you can realize that if I draw the crosses, the crosses means the electrons by carbon and the dots means the electrons by oxygen. Now you'll realize that carbon and oxygen form two four covalent bonds. In fact, but the number of electron pairs that are formed are also four. CO2 also is a covalent bond. So all of these are covalent bonds. Now oxygen actually share two pairs of electrons with each other to form a double covalent bond and that's why the molecule is termed as O2. Now if you look at triple covalent bonds and please note triple is the highest amount of covalent bonds that you can form. So nitrogen actually the atomic number is seven and the electronic configuration is two five. So it has five valence electrons and it needs only three more electrons to attain stability. We can very well mention here that there is an octet that is that is intended by nitrogen to be formed and therefore two nitrogen atoms get together to share three pairs of electrons. So all these three electrons together will form a triple bond. These are the Lewis structures that can be drawn. So all of these these Lewis structures can end up forming an N2 structure. So and therefore we can write it as N triple bond N or N2. A quick more question is there should be yes definitely there should be eight electrons that are shared not atoms eight electrons shared and they should have to achieve a complete octet. So N2, NO2 in fact not N2O, NO2 or MGO in fact it's always NO2 or MGO. So both of these now MGO is more an ionic compound but NO2 is more of a covalent compound that we can really look at. So these are these are a quick couple of quick looks at how double bonds and triple covalent bonds are formed. Now here's another way to really look at these configurations. So you can see that these are actually the atomic structures of hydrogens which can share electrons and we have two electrons shared by a pair of hydrogen atoms. Similarly fluorine also shares two. These two electrons make one bond. Similarly two electrons here make one bond in fluorine. In oxygen and carbon as CO2 as I was mentioning you'll find that carbon actually shares four electrons. So there are four pairs of electrons or four bonds that are formed. All the four bonds are covalent. In other manner if you really see fluorine and carbon you'll find that the yellow electrons of carbon are shared each with one blue electron of fluorine and therefore there is a tetrafluoride molecule that is formed. So CF4 molecule is formed which actually contains four covalent bonds again. So one quick point that we have to really note here is again a common confusion two electrons means one bond. So that's that's a that's a typical fashion and also covalent bonds are formed by those compounds who have less electronegativity difference. So they don't really make a lot of you know the the electronegativity difference is not very high between the atoms and that's when they form covalent bonds. Now looking at the electron dot structures or the louis structures sometimes so it's written as levists but pronounced as louis. So these are the louis structure that you can draw about. There are questions sometimes asked directly on louis structures so you can put carbon and you can draw four carbon electrons around them. All the crosses mean carbon electrons all the dots mean hydrogen electrons and you can make circles around them forming octets. So you can see the circle around carbon as eight electrons and therefore octet is complete whereas the hydrogen has two plates and therefore hydrogen ends up giving you know sharing one electron and therefore the plates are formed. If you actually look at the carbon hydrogen electrons or louis structures in C2 at six then we'll understand that in all of these there is one electron each shared by hydrogen but four electrons by carbon. One important point is that one electron is shared between two carbon atoms forming a single covalent bond between carbon. So you'll find that this actually tends to form a C2 at six molecule and it's that's called as ethane. So these are some examples of formation of electron dot structures or louis structures. So yes silicon also does exhibit tetravalency. It's just that silicon cannot form as stronger as strong a bond as carbon because of its bigger size or larger size. So therefore silicon does not exhibit cationation property but yes silicon also forms tetravalency. So these are some points on drawing louis structures. Now let's look at the characteristics of covalent compounds. All these covalent compounds all of these molecules generally are molecular in nature. What do you mean by molecular is they would have individual molecules like cl2 or f2 etc. If you look at other ionic compounds like NaCl you'll find that NaCl has an entire crystallite structure so it will be completely present in blocks but if you look at cl2 and f2 all of these generally are in molecular states so they are like individual molecules. So most of these would look like only molecules in nature and they are single molecules to really say. Now all of these covalent compounds mostly are insoluble in water so I'm saying mostly because in general the principle of like attracts like works here and water is a very polar molecule polar in the sense that the charge separation between two atoms for example in H2O is pretty high. The oxygen has a lot of negative charge and the hydrogen has a lot of positive charge and therefore with this charge separation you'll realize that the polarity is induced and therefore covalent compounds because they don't have much of charge separation are rarely soluble in water but they're very readily soluble in benzene kerosene and petrol and the reason is all of these benzene kerosene and petrol are actually non-polar in nature and therefore like dissolves like and therefore they are soluble. Of course because of the unavailability of electrons they are very poor conductors of electricity so you'll realize that electrons would not be present so readily available in chlorine, fluorine, iodine and all of these and therefore generally they would be non-conductors of electricity. So that's some of the characteristics of covalent compounds. Of course the number of electrons contributed by any atom is known as covalency. In other case we just said valency so if valency is for forming a covalent bond then it's called as covalency whereas valency forming an ionic bond is actually called as electrovalency or ionic valency. Okay so now that's a quick look at the characteristics of covalent compounds and then we'll look at electropy in carbon. Now you'll find that the very basic word electropy means of different forms you know so the element remains the same but forms change. Again there is a lot of confusion that students have between electrops and isomers. Now please note isomers are different structures. Electrops are only different forms so they are made of the same element. Electrops is only for the element but isomers would be mostly for molecules. So the property by which elements exist in two or more forms is basically what we call as allotropy and because of this their physical and some of the chemical we have written some of the chemical not all because of course being the same element not all the properties change. Only a few properties would change chemical properties would change so therefore you know but the physical properties change very largely. I've given you two examples here for example in carbon diamond is a very very hard substance whereas if you look at graphite which I have shown here so this graphite is actually used as lubricant so on one side you have a very hard substance on the other side you have a substance so soft that it is actually used as lubricant and this is purely because you will find that there is a different form that they actually connect with each other. Now carbon exists in two allotropic forms one is the crystalline form and the second is the amorphous forms a typical question asked in in allotropy is define the term allotrops and state the different allotropic forms of carbon. So in the first classification of allotropy we mentioned as crystalline and amorphous in the crystalline form we say that there are two more which is diamond and graphite whereas in the amorphous forms it is coal charcoal and lamb black so all of these are basically you know different different allotrops of carbon and then we have fulerines which basically forms another class of carbon allotrops fulerines actually comes under you know crystalline form the first one to be identified was a c60 which we call as the buck ministers fulerine which has carbon atoms arranged in the shape of a football so the NCIT does not speak more on fulerines this could be enough for us to really define fulerines if a question is asked on allotropy. So this is allotropy in carbon particularly there are many other allotrops available for different other compounds sorry different other elements and you know given a question we can also address those. Now a formation of very large compounds is typical in carbon and the reason is cationation as we as we know all know now so just as a point of revision cationation basically happens to be the property in which long chains of carbon atoms are formed so you can see that I've shown one molecule here it just has six carbon atoms but this carbon atoms can extend to a very very long length you know sometimes to a tune of about a hundred molecules or more than that almost two thousand there that are possible in some proteins you know but all of these molecules are polymers so when you form a typical polymer you'll find that the entire carbon chain is connected to each other by covalent bonds and this long chain formation is called as the property of cationation so basically you know we have more than three million carbon atoms or carbon compounds that we have now and every year more and more carbon compounds are registered at this number is I'm sure at least a couple of years old we have much more registered this time now now firstly why is carbon showing the property of cationation we know that the first reason is tetravalency that its valence is four which is the maximum covalency that you can really have secondly carbon being a very very small atom the size the size of carbon atom being very small its bonds are very much stronger so we realize that the carbon is the first atom in fact having four valency and therefore when it forms a tetravalency with other atoms you will realize that the bonds that it forms is much much stronger so these are the two major reasons the third reason is of course it can withstand the bond strain and bond stresses so that's another reason that carbons can be utilized to form cationation it shows the property of cationation or can be utilized to form long compounds now I've shown you three basic ways that carbon forms molecules one is the long chain branch chain and closed ring the point is that whenever they have whenever the property of cationation is asked it is a good idea to actually mention all of these three to show that you know carbons can be linked to each other in multiple ways so these are the examples that you can write in cationation to show the linkages between carbon atoms right now let's look at the different classifications of carbon atoms now the most important class of carbon atoms is called as hydrocarbons please note there are other carbon carbon molecules that are present for example CO2 is an oxide of carbon as CO is an oxide of carbon we also have CCl4 which is actually a halide of carbon so there are multiple other classes of carbon compounds but hydrocarbons is one of the most prominent classes and what we mean by hydrocarbons is compounds which has carbon and hydrogen as the primary atoms you know forming the compound now when hydrocarbons are there there are two major groups of hydrocarbons one is a saturated hydrocarbon is the second is unsaturated saturated hydrocarbons are all of those hydrocarbons who have a single covalent bond please do not say you know they are only alkanes or you know they are they are those atoms which you know either have hydrogens completely etc because please note that in cycloalkanes you have two hydrogens less all the cycloalkanes are also saturated hydrocarbons so a very simple definition of saturated hydrocarbons is to say all of them have single covalent bonds between carbons of course you know alkanes are the most important saturated hydrocarbons and they end up by by suffix which is in so we can write it as methane or ethane I have given two examples so when you write saturated hydrocarbons always write the definition and write both of these examples or maybe one example should be okay so that's the saturated hydrocarbons what are unsaturated hydrocarbons is when you have more than one bond between carbon atoms so yeah so when you have carbon hydrocarbons with double and triple covalent bonds between carbon atoms we call them as unsaturated carbon atoms triple bond is the maximum that carbons can form between themselves for that matter any two bond two atoms can form between themselves an example is an alkene where a double covalent bond is present between two carbon atoms and it ends with an ene so you'll find that ethene or propene is a classic example of an unsaturated hydrocarbon at the same time an ethane where there is a triple bond that is that is put between two carbons ethane or propene will be will be present so you'll find that two carbon atoms having triple bond will end up with an ion so these are the two examples of unsaturated carbon atoms now let's look at isomerism we just spoke about allotropism now we'll look at isomerism so whenever carbon compounds have the same molecular formula I hope you are able to read this if you don't find it legible you can always let me know but I'll read it for you so carbon compounds having the same molecular formula but different structural formula are called as isomers and this property is called as isomerism okay so I've shown you an example this is a butane with four carbon atoms they're all arranged in a straight chain here as you can see and here is a butane where you have three carbon atoms in a straight chain and the fourth carbon atom you know branched so the molecular formula if you see both of them is actually C4H10 you'll find that there are 10 carbon atoms four at the top four at the bottom and two on the side if you look at this you'll also find that the carbon the hydrogen atoms are also 10 here so both of them actually have the same molecular formula with a C4H10 but their structures are completely different so so this is actually what we what we call as isomers you know having different structural formula but same molecular formula when if if another example is asked or they ask you to write the different isomers for pentane you'll find that for pentane there are three isomers possible so one is called as n-pentane which is a straight chain compound the second one is called as isopentane where only one branch is possible so this is an iso compound isopentane and then we have a neo-pentane where there are two branching on the same central carbon so this carbon has four carbons attached to it so iso and neo isopentane neo-pentane these are the three isomers of pentane that are possible now now let's look at isomerism once we have seen isomerism let's look at functional groups the functional groups are of you know multiple types so some of the functional groups are generally pretty simple in nature for example chlorine bromine iodine so what's a functional group really to understand so an atom or a group of atoms which decides the properties of a carbon compound is called as a functional group so by its very words we know that it defines the function you know ideally but in our sense in the in the language of chemistry to that function we'll call it as either chemical property or physical property so an atom or a group of atoms which decide the the the properties of the compound carbon compound is called as functional groups the most easiest or the common functional group is our halide so you'll realize that the halides are the ones that actually would be forming you know the helo groups will be forming the easiest of the functional groups now whenever functional groups are mentioned they generally are written either as chloro or bromo ethane first firstly this functional group halides is generally written as halo ethane or halo alkane in general so you'll realize that if I have to write it as chlorine with methyl group I will call that as chloromethane okay so that's the way that you can actually you know work out on the functional groups you can name the functional groups now if you look at the alcohols in alcohols we will use a suffix all and we'll shortly look at all the suffixes of functional groups in nomenclature but so kritika is asking how do you define homologous series yeah I'm just coming there kritika in a minute so alcohols are ones which has the OH group as the functional group aldehydes are the ones which has the CHO group please note how the bonding is so high carbon is directly bonded to hydrogen and then doubly bonded to an oxygen this is an aldehyde and when there is no hydrogen attached please note to the carbon you don't need a hydrogen you can only attach it to carbon this is called as a ketonic group so remember the difference one has the hydrogen the second has the ketone group in carboxylic acid the carbon is attached to two oxygen atoms only oxygen further is attached to hydrogen so that is the carboxylic group please remember the carboxylic group the ketone group aldehyde group and carboxylic group are one of the most important important functional groups that we that we need to know now going back to other functional groups I'm going to just make a fleeting mention of two more functional groups for you we have CO and C this functional group is called as ether it's called as ether and C double bond O O where carbon is attached to one oxygen and this carbon is attached to another carbon this is called as an ester so ether and ester please do not forget this remember that ethers have only one oxygen so you can remember two and you can remember so with the double O so with the double O so esters means with double oxygen and ethers mean with one oxygen okay so that's an easy way to remember ethers so so e to her or that's also we sometimes say that e to her which means that it has only one oxygen and iso her so you know so that's so the very word so the way we pronounce it that's one way to remember that esters have two oxygens with them so so that's a that's a quick note on functional groups now let's understand you know what is a homologous series so to answer even kritika's question what is a homologous series so homologous series is a group of carbon compounds having similar structure similar chemical properties and whose successive members differ by ch2 one of the very very major mistakes that people do is same chemical properties they write these are same chemical properties absolutely wrong absolutely wrong or or you know same physical properties also wrong okay same physical properties also wrong the properties are similar now because of the exceptions please understand that as it goes from smaller carbon to larger carbons as the weight as the molecular weight increases the physical properties definitely change and substantially change while most of the similar most of the chemical properties remain the same same means exactly identical as they become very high for example when you end up getting to for example c10 h22 you'll realize that the chemical properties also slightly vary slightly vary so therefore we say that you know as you go larger and larger in the molecule you'll find that similar word is used which is a very important word you know similar structures and similar chemical properties is what we use in fact you can also very easily mention whose physical properties are either incrementing or decreasing by a regular interval that is also a very good way to say that the properties how the properties change in a homologous series so so that's a quick way to look at homologous series and understand what they are so i've given you one homologous series here which is the alkene so you'll realize that methane ethane propane butane all are the homologous series for alkene the general formula for this is cn h2n plus two and one quick note is sometimes you might have to derive the general formula for homologous series and all you have to do is look at the sequence and try to put in values at n and try to derive this so whether it is cn h2n plus two or simply cn h2n or cn h2n minus two all of that would be possible if you just simply put in values and check what formula is true right so that's that's one of the ways of really writing homologous series and mentioning a general formula this is called as a general formula or the molecular formula for a homologous series again another spelling mistake that generally people i see is they write it as g us no it is g o us so this is another mistake that i've found recently that people keep on making so beware of these whenever a question of homologous series is asked please write your definition please write general formula of one homologous series please give an example write at least four members not three but four because four establishes the fact of homologous series pretty strongly so please write four i've given you five if you get time it's more than happy to write five also mention if it is a four mark or three marker question in generally a three marker question and it's just a quick point that if you write you can write two more points now where you can say that the chemical properties are similar and physical properties differ by regular intervals right so they actually increase or decrease by regular intervals to give you an example the boiling point and the melting points they increase by a regular interval but if you look at for example molecular weight also increases let me see so all so these properties increase at regular intervals so you can you can mention that how physical properties increase or decrease at regular intervals so that's that's homologous series and for us and we can always mention them in the texts now a deeper look at alkenes we have definitely seen as alkenes but if you have to look at the homologous series of alkenes of course there is no methane possible but there is ethene which is the lowest member of the homologous series is possible the general formula as i mentioned is c and h2n and their names always end with an ene so you'll find that ethene propene butene and pentene are the first four members as i said you have to write minimum four members when you write a homologous series if you get time it's always good to really draw the structures as well please note in in cbc in your board exams try to write in as much as possible keeping in mind the the time that you have okay so of course you know sometimes this goes overboard and people write so much that they don't get time to write the entire paper so it's always a good idea to mention things in point wise but also give more points you know so sometimes if one point is wrong or the teacher or the examiner is not happy with your answer for one typical point you can always give an additional mark or a half a mark with some additional point that you have written so that's a that's a that's a good idea of course if you don't know any answer for any question i strongly recommend that you at least write what you know sometimes it is quite often in the board exams that just for the way that you have analyzed the answer for example the way that you have written the given or you have written the units for the question you might end up getting a mark or two so so please always attempt all the questions as far as possible to the best of your knowledge but do not leave anything blank do not also read the question carefully if there are three or four bits it is it is mandatory to write all the three or four bits today we are at the last chapter of chemistry we have already done chapter one chapter two chapter three and chapter five i strongly recommend that you remember remember all of these points that i'm telling you at this chapter it will help you in scoring the max possible okay now so this is what we have done done with alkanes now let's go to the next alkanes again i've given you three here you know so in alkanes you'll realize that the general formula c and h2n minus 2 and you'll realize that the lowest member is an acetylene or ethane propane and butane you can also draw the structure for ethane propane and butane all of them can have three triple bonds please note to draw all the hydrogens for all the other carbons if you're drawing structures very very important point to have very important point to have actually the maximum you know bonds that you can see okay so so these are these are a few things that you can actually work out with so these are homologous series of alkene alkene and alkanes now let's go to nomenclature one of the most important topics that of carganites compounds most people need practice on this so today i'm going to talk about all the different rules of nomenclature as we go forward the nomenclature system is the system given by iupsc which is the international union of pure and applied chemistry this is the one who established the system and gave certain rules so that we can have a common language across the geographies to have communication between chemistry names names of compounds now we will refer to the names derived from the system as systematic nomenclature or the iupsc nomenclature generally shown in blue but sometimes there are also additional names which are very common that are used and i've tried to show and show all of those names in red for example isopentane or neopentane are common names they are not iupsc names but they are very much used in in in our texts in fact iupsc also accepts them it's not given by iupsc but it accepts if you use those nomenclature by naming so that i've tried to show you in red in the following examples and a compound may have more than one name but it will always have only one in one compound specified so a name must specify only one compounder one name cannot specify two compounds so so if you if you want to look at the analogy what i'm trying to say is names you know you can have for one compound you can have two names but the you know the reverse is not true so the reverse one compound you know so if you if you say that the name whatever name you take the name should only give you one compound but a compound can have two names but names cannot you know have two compounds so this is the way that you can actually represent it through a relationship or a set method now let's look at how do you really name hydrocarbons using the iupsc system so this is actually a series of prefixes that are used for a root you know so there is something called as a root that we use and the prefixes and suffixes are added to this root so that we get a final name now what are the roots methyl ethyl propyl but myth et prop but penthex sept oct non-deck these are the roots of naming carbon compounds these roots are for the number of carbons that are used for example if there are eight carbons used you will say it as oct if there are four carbons used you will call it as butte if there are six carbons it is hex so depending on the number of carbons you have to choose the root remember these roots pretty well i still have seen students who are confused with these roots these roots are still not perfect for them i strongly recommend that you remember these roots and have a strong hold on on knowing these roots so so these are the roots i'm gonna keep this slide with you any point you feel that these roots have to be you know memorized just scroll back to this point of the recording you know anyways this recording is there on the youtube come back to this recording and you'll realize that uh you you'd be able to memorize this now uh how do we really name some alkyl groups right so if you if there is a cs3 just there are cs3 in the molecule then that is what we'll call as the methyl group and when there is two cs3 please note methyl is something that is one hydrogen less than methane which is an alkane ethyl is something that is one hydrogen less than an ethane so anytime when you take out one hydrogen you write ethyl and methyl please do not forget that these are not methane so the l and any do not mix those methyls are substituent groups but methane and ethane are compounds they are complete compound these substituent groups are partial compound there is something they are attached to the primary compound so methyl ethyl propyl isopropyl butyl isobutyl sec butyl now i'm going to tell you the definitions of iso and sec whenever there are two methyl groups attached to carbon please note whenever there are two methyl groups we call that as an iso molecule or iso substituent rather now whenever there is a methyl and an ethyl group please note methyl and an ethyl group it is called as a sec or secondary butyl or sec only sec okay i can give you one more example you can have this molecule also present here there is a methyl and a ethyl group this is an isopentyl because there are five carbon atoms so this is an isopent sorry this is a sec pentyl i am sorry please note it is a sec pentyl because there is an ethyl and an methyl group attached to carbon it's called a sec pentyl and when there are three methyl groups attached to one carbon it is stirred this is a normal pentyl and you'll realize that isopentyl again has two methyl groups attached to carbon so two methyl groups a quick formula i'm going to give you two methyl groups means iso and a methyl plus one methyl plus one ethyl okay one methyl plus one ethyl is nothing but a but a sec okay sec compound and there are three methyl's attached it is called as a third compound and the neo means there has to be a four degree carbon okay so neo is this group where one carbon has attached to four methyl groups so or four carbon atoms so four carbon atom attachment is called as a neo you can write this down as a formula for yourself and this will be you know this is something that you have to remember you have to really really be with you so these are some nomenclature some common alkyl groups that you can always refer to okay you can always come back to this video and see if any points that you feel are you might have missed out or you need to remember you can come back here and and connect to it now typically an alkyl group is always represented by r so all of these compounds that you see on the page can sometimes always be written by a simple r just to show that okay there is an alkyl group present in it so this is the this is the way to you know represent substituents on the root now let's look at how we go by the rules now alkyl substituent group names are always combined with the alkene name for the longest straight chain so we have to always firstly identify the longest straight chain compound so for example you'll realize that here there are about seven carbon atoms and so that is an heptane please note here there are always these substituents and therefore although there are seven carbon atoms the longest chain is only sorry there are in one two three four five six and seven so there are seven carbon atoms so although this is an iso heptane in common name if you write the iupsc name you will find that we write it in in in terms of hexane so hexane is what we choose because the longest chain is only of six carbon atoms the total number of carbons is seven but that is only applicable to common name not applicable to iupsc now let's take another example here the longest chain is of six carbon atoms and there is one methyl on it here the methyl was on the second carbon atom so this is this was a two methyl hexane now this numbering we did because we need the lowest number we are quickly going to come to that point as well how to write do the numbering but the point that i'm making here is only of one point which is check the longest carbon chain now if this has to be this i had to write it in the common number literature since there is an methyl and an ethyl group this is called as sec heptane it can also be called as sec heptane okay so but this is a common name or a common name that you can have it's not an iupsc name so therefore you'll find that you know the iupsc name will be still three methyl heptane a three methyl hexane sorry so note these compounds all have the formula c7 at 16 and therefore they're all isomers so all of them have the same formula but they are different isomers their common names do not change their common names still remain heptane iso heptane and sec heptane as i showed you but their iupsc names definitely change this is simply an heptane in iupsc this is a two methyl hexane and this is a three methyl hexane so remember the longest chain rule that i've just mentioned so far so did you mind the longest chain of parent compound we just saw how to do that second is cite the name of the substitute and before the name of the parent hydrocarbon along with the number two carbon to which it is attached this is the second rule that we have to follow for example here you will find that in this compound the longest chain is of an octane please note this is the longest chain so if i have to really draw it for you i would choose this as the longest chain and in this chain i'm going to increase the decrease the transparency a bit yeah so you'll realize that in this longest chain there are two substituents on it and therefore when you write octane before octane is what you you really write you know either methyl or isopropyl so this is an isopropyl one so in isopropyl you realize that it is written in the form because there are two methyl groups so this compound can also be written as isopropyl as i mentioned isopropyl is commonly accepted in you know iupsc now the numbering which is the second rule that we'll come to is it has to have the smallest numbers possible so you'll realize that methyl is can get a two year and this can get a five but if you look from the other end you'll find that you will end up getting one two three four and this will be actually at five six seven so instead of taking a four comma seven we would be very happy to take a two comma five so this is the second rule that i'm mentioning and the second rule says that the numbering should be lowest to the substituents so the substituent should always get the lowest number as much as possible so this is you know the numbering rule and the way that we write it now the next is as i mentioned a number in in the direction that gives a lower number for the lowest number substituent and substituents are listed also in alphabetical order neglecting the prefixes diatri tetra etc i've said this time and again so if there are multiple suffixes multiple methyl ethyl you do not have to take dt you have to simply take methyl etc so so if you if you really see that here we have three ethyl groups you know one is this one second is this and third is this so you'll realize that in all of these three you simply go by the alphabetical rules so you'll find in fact the first one is that you'll always choose the lowest number so lowest number beats the alphabetical rule so if you get lowest number from one side you go by that but if the numbering is the same from both the sides then you will go by the alphabetical rule so you'll find that here there is a third carbon each there is an ethyl group at the sixth carbon there is an ethyl group and at the seventh carbon there is a methyl group so you'll write this as three three three six try methyl please note the word try so you have to mention for every substituent that is there on the carbon atom you have to have at least one number for it had it been tetra methyl you would have to write your four numbers four numbers are important and of course with methyl you'll realize that there is only one so therefore you have to write one seven okay seven methyl so that's a decaying because there are 10 carbon atoms in the longest chain so we all know these rules we are just revising it so that you know you you are very thorough with it now when both the directions yield the same lower number for the lowest substituent select the direction that yields lower number for the next lower substituent for example in this scenario you will find that from both the directions you you have the same number you know which is two two for methane so you will realize or the methyl group you'll realize that I will still we will still go from this side because the second substituent is getting lowest number if I go from this side so once methyl methyl are taken care of I have to think about the second substituent and therefore I would choose this carbon as two and this carbon is one and I write it as two six dimethyl three ethyl and while writing I'm writing in the alphabetical order please note that e comes first and m comes later although d is less than e or d is alphabetically senior or or earlier than e but d is not to be considered d is not to be considered you only have to consider ethyl and methyl please do not write it as five ethyl two six dimethyl no because three is lesser than five so this is this is a quick method to sorry this is a quick method to really do the nomenclature yeah so we just saw this now some more rules if the same substituents are obtained in either direction number in direction giving lowest number to the first named substituent so let's like you know we'll look at one of the examples and if you compound as two or more chains of the same length parent hydrocarbon is chained with greatest number of substituents okay so please check here you know I've just mentioned an example for you so in this scenario this also has six and this also has six but if you go by this chain you'll find that there are two substituents on it which means two branching on the main chain if I go by this way there is only one branching on the main chain so then I will not choose this I will choose this with the two substituents okay so three ethyl two methyl exen why three please note it is on the third carbon also please note I have started numbering from here so it will always be two methyl and therefore it really works pretty well on on this now that's that's a quick you know a glimpse of all the what what should I say the rules of nomenclature only these rules are important for you to go forward and you'll realize that these rules will be suffice will be sufficient for you to really answer all the questions in the board so these are the rules for nomenclature of all the stretching I mean all the alkene alkene without the functional groups a quick look at the functional group nomenclatures if there is a functional group and groups have unique suffixes then you know this is how you should name it for aldehydes you will write it as all so for example ethanol methanol propanol for aldehydes you will write it with an al ethanol methanol propanol for ketones you'll write it as own or one which is you know so so the lowest ketone that you'll have is actually propanone so propanone butanone pentanone and that's how you'll name ketones acids are with an oik acid okay with an oik acid so you write this as ethanoic acid butanoic acid propanoic acid esters is not really important but i'm just giving all these three so don't worry about esters amides and amines but you simply for example write this as ethanamide propanamide amines can also be written as ethanamide propanamide butanamide so and so forth and ethers can be written as etoxy with the prefix yeah bother less about amides amines and ethers esters but these four are very important for you and that's where you know you can really uh get get a question or two you'll also realize that fluro, cluro, bromo and iodo are also written before as a prefix this is the only one which is different please note all of these where suffix says only this one is a prefix only if this one is a prefix in iopsc so uh you know at any point of time whenever there is a functional group always give importance to functional group first over substituents over double bonds or triple bonds or anything else except for the halogens halogens are not even any preference at all they actually come after double and triple bonds also but for all the other functional groups except halogens always give a preference just remember these these three rules you know you can go over these rules once again as i always said you can just rewind this video at any point of time and go through these rules and you realize you know how to name them so this is this this actually completes the nomenclature you know this this should be suffice for your nomenclature rules i i don't think so that there would be a direct question as to state the rules for nomenclature but they definitely would give you a molecule and ask you to name it which is where you need to remember the rules and you can always attempt that now uh now this brings us to the you know the the last major component and there are some smaller components as well but the major component of today's chapter which is the chemical properties of carbon compounds there are specific chemical properties that are very important for you in this chapter and i have tried to keep them in one single array i have tried to align them the reactions that are important to you is combustion oxidation addition and substitution reactions so only four of them are very important the first one is combustion combustion simply means heating or simply burning in oxygen anything that you burn in oxygen you'll realize that you'll end up getting a co2 which is the oxide of carbon you also end up getting co but that is when incomplete combustion so whenever there is a complete combustion always co2 will be formed so the carbon compounds burn in oxygen to form water and carbon dioxide when it is only carbon you'll end up getting co2 plus heat plus light but when there is a you know a methane or an alkyl alkyne here you'll find that alkyne plus oxygen will end up giving you you know h2o plus co2 so carbon compounds mostly hydrocarbons is what i would suggest is is what actually end up giving water and co2 but if you have other carbon compounds like alcohols you'll find that the oxygen ratios changes slightly but it still ends up giving you water plus co2 please note to balance all the reactions at each point of time and it's a good idea to mention an arrow upward saying that release of co2 as the molecules actually you know get combusted or simply burn so so this is this is the combustion reaction complete combustion give this incomplete combustion gives you carbon monoxide so you can write that as ch4 plus oxygen giving co plus h2o now in this scenario you'll realize that let me see so you you need two of hydrogen so you basically have two plus one three three by two so you'll get here two you'll get here three here you will get another two and here you will get four that is how you can balance this this reaction so it is two three two and four that will end up giving you an incomplete combustion with co molecule on the formed in incomplete combustion now also remember one more property that is very typical that is asked is in complete combustion you will always have a blue colored flame whereas in incomplete combustion you'll either have a yellow or reddish yellow or orange colored flames so blue and yellow or orange yellow is something that you have to remember so that's your you know combustion reaction now let's look at the oxidation reaction the oxidation basically means addition of you know oxygen in the molecule so for example if you oxidize alcohols you'll end up getting ethanoic acid these go through two two intermediates where it does not stop but in between two intermediates are formed and those are so alcohols basically end up going to aldehydes and ketones so aldehydes and ketones are mentioned and above from aldehydes and ketones it further goes to acids okay so acids is the highest oxidation state so it cannot get oxidized any further but aldehydes and ketones can definitely get oxidized further and that can also happen so you'll realize that alcohol alcohols to acid aldehyde ketones to acids is how the you know the the action proceeds what are the reagents that are used alkaline kmino4 or acidic k2cr2o7 both of these are used and a small amount of heat is given to end up giving ethanoic acid which is also called as acidic acid so the reagents alkaline kmino4 and k2cr2o4 are called as oxidizing reagents or oxidizing agents and they are nothing but potassium per magnet and chromium chromic oxide okay chromium oxide so potassium chromium oxide so a chromate potassium chromate that's also how we call it okay so potassium chromate and potassium dichromate also chromate is with one chromium atom and dichromate is with two chromium atom so potassium dichromate or potassium per magnet is what really gives these oxygens for oxidation reaction please remember the oxidation reaction directly all that has been there in the ppt can be directly written as answers i've tried to model this ppt in the way that you can write your model answers directly so this is a this is one one quick mechanism of you know one quick method of writing their chemical reactions and then we have addition reactions where you will find that unsaturated hydrocarbons undergo addition with hydrogen majorly in presence of nickel or platinum palladium as catalyst to form saturated hydrocarbons so you'll realize that you know for example c2h4 which is nothing but your ethene it has a molecular structure like this it undergoes an addition with hydrogen in the presence of nickel or platinum or palladium to end up giving you c2h6 which is your alkene so ethene undergoes addition reaction with hydrogens to form ethene in presence of nickel or palladium as catalyst so that's a that's a quick way to do that the second is addition of hydrogens to unsaturated hydrocarbons to form saturated hydrocarbons is called as hydrogenation so this this reaction is also called as hydrogenation hydrogenation simply means that you are adding hydrogen to the molecule so that's hydrogenation hydrogenation is also used to convert unsaturated oils and fats to saturated oils and fats okay so that's also one of the ways where you know saturation can be brought in and then there is a substitution reaction substitution reaction by its very name means that you are going to substitute one from the other so here we are substituting the hydrogens from with chlorine okay so you will realize that in the first reaction you'll find that only one chlorine is substituted this is called as chloromethane and then further another hydrogen is substituted you'll realize that we call this a dichloromethane and then one more hydrogen gives you a chloroform which is also called as trichloromethane and then you end up getting carbon tetrachloride so from a hydrocarbon now you have got a carbon tetrahalide or carbon tetrachloride in the situation so this is a substitution reaction so addition substitution combustion and oxidation are the four reactions that are pretty important in your syllabus which I have all mentioned here all these four reactions should be should be you know memorized or should be known you know and which should be practiced pretty well now some important compounds that are also important in the in the syllabus is basically firstly ethanol and a common question is asked is how do you differentiate between ethanol and carboxylic acid now carboxylic acid being acid you can simply put in either a metal and you'll find that hydrogen gas is released whereas in ethanol hydrogen gas will be will be released only with sodium okay so both of these are you know shows in fact you know you can also say that you can put a base for example you know acids especially you know acetic acid reacts very easily with COOH with NaOH or even with CaOH twice which is a weak base so then there is another thing that you can do is you can use soda lime so that it gives CO2 you know CO2 is given out by acetic acid when you use soda lime so that's another way to really know difference between ethanol and and acetic acid or ethanoic acid but just to look at the properties ethanol is a colorless liquid and it has a very pleasant smell and a burning taste it's also soluble in water now ethanol reacts with sodium to form sodium hydroxide and hydrogen so you'll end up getting C is to C2H5O Na and H2 ethanol also reacts with hot concentrated H2SO4 to form ethene and water so this is a dehydration reaction please note that this is also called as dehydration reaction so what does a dehydration means that you are basically taking out an H2O so minus H2O whenever you remove H2O from the solution you will realize that it's called as a dehydration reaction so that's dehydration for us and then some of the uses of ethanol is basically it's used for making alcoholic drinks it's used as a solvent it's also used for making medicines like tincture iodine, cup syrups or tonics so ethanol is a very very crucial component to make you know a lot of drugs which are basically for human benefit medical drugs clinical drugs so all of those really help in you know formation of compounds which are necessary for life sustenance so that's ethanol so remember whenever compound ethanol is given you have to write its structure you have to write its IOPSC name which is ethanol then you have to write its properties if it is asked you know both physical and chemical i've given you both physical properties as well as two chemical properties and then you have to really write the reactions for this please do not find forget to write the reactions with a complete balance form the last is that you write its uses so all of these together would fetch you three marks okay all of them put together will fetch you three marks mind this most of these are generally for a half a mark so a three marker will need all of these five points to be mentioned if it is a five marker you'll need to give the reactions and elaborate them with one more sentence each so that's that's the way to write you know some special compound especially ethanol now let's look at the second special compound which is acetic acid which is in our syllabus so ethanoic acid or acetic acid is again a colorless liquid with a pungent smell and sour taste it is soluble in water very very much like ethanol and the solution is five to eight percent ethanoic acid also called as vinegar commonly found in households now the another important reaction that you know is mentioned in our syllabus is actually the esterification reaction now esterification reaction means where esters are formed you know where esters are formed so in esters you'll find that your acetic acid actually reacts with your alcohol to end up giving CS3CO C2H5 so you know concentrated esters for ends up giving you you know esters basically dehydrating so OH is taken from your please note that I've always said said this to you it is the acetic acid which ends up giving you OH okay and the alcohols ends up giving you hydrogen so please note this so the hydrogen NO and C2H5 the dehydration happens with OH being given from the acetic acid this was a common mistake that you you know most students had done in the previous exam also that I checked that OH is given from the acid and H is given from the alcohol people generally take H from acid and OH but that's not true in esterification reaction so please note how do how do you write the reaction if you're doubtful don't like write this okay please don't write this circling on all but if you're confident you can write this HOH and you you would write then the molecule as CS3COOC2H5 which is an ester now this is named as ethyl acetate okay so you generally take whatever is after oxygen as the alkyl group and something that is before as the OH so this is ethyl acetate and and that's ester so carboxylicosate and alcohol form ester this reaction is called as esterification and then you have saponification reaction you know so this is another very important reaction mentioned under these special you know molecules so the saponification reaction is the one when an ester basically reacts with sodium hydroxide and it gives you a sodium salt of carboxylic acid and the parent alcohols are formed back okay so this reaction is called as a saponification reaction you'll end up getting parent acid but this is a salt of the acid so acids cannot remain by themselves because there is a base present around the solution so they end up forming a salt so you'll find that you will end up getting sodium acetate and you'll end up getting C2H5 so this is an alcohol and and and the salt of the parent acid now the next one is you will end up getting ethanoic you know the reaction is pretty simple and acid based reaction you will find that H2O is formed so with you know with acids you end up getting salt and water but with with an alcohol you'll end up getting hydrogen gas so please note this difference between ethanol and you know ethanoic acid as I mentioned to you now ethanoic acid reacts with carbonates and hydrocarbonates to give CO2 this is also another test that you can mention for distinguishing ethanol and ethanoic acid ethanoic acid with carbonates and bicarbonates end up giving CO2 but alcohols do not end up giving any CO2 so these are the quick you know points on which you can actually look at to to understand the different reactions of ethanoic acid so so now that brings us to probably the last topic of today's chapter and after this I would you know I really encourage if you have any questions now is the time that you can post this question so I can address them else we are just at the end of today's session in understanding what are the different aspects of or how do we really write the answers for different questions today so soaps and detergents are basically one the basically a topic of importance in carbonates compounds soaps are long-chain sodium and potassium salts of carboxylic acids whereas detergents are long-chain calcium and magnesium salts of carboxylic acid so please note this sodium and potassium world so soaps you know sorry so if you sorry so if you if you really see that sodium and potassium salts are the ones that are present in soaps and for example sodium steroid you know is one of the soaps you you see that it has the carbon will be generally from 16 carbons to about 20 carbons and so this is one typical steroid molecule that we have where you will find that the salt of a long chain which is C17 in fact it is 18 carbons the acid long chain acid is present and this is salt with sodium hydroxide is present now the structure of a soap is basically formed by you know two parts one is the hydrophilic and hydrophobic so this is water attracting which means this is the hydrophilic part hydrophilic means water loving and then you have what the the long chain rippling which is an hydrophobic part so you'll realize that both of them actually are separate or the behave separately rather this is a very long chain and then there is a small you know molecular interaction at the end of it like the head of the and this is the tail of the molecule so now how the cleansing action happens this is a cleansing action of soap which is a typical question asked in cbsc for quite many years so so they asked you explain the cleansing action of soap so basically when soap is dissolved in water we are going to look at this diagram in the next slide in in much more detail but for the time being when a slope is dissolved in water it forms spherical structures called as micelles now each michelle basically ends up forming soap molecules why because they arrange themselves radially now radially is again another good word to be used because you know you'll find that there are spears that are formed so they are arranged radially says that the hydrocarbon part is towards the center because it is the one that dissolves the dirt okay so the dirt whatever is present here whether it is grease or oil they are hydrocarbon in nature and therefore they are attracted by the hydrocarbons themselves from the tails of the molecule or the micelles and the ionic part is attracted towards the outside because it is polar and therefore it will try to go towards where water is going and this seapart dissolves the dirt or oil so basically you form an enclosure for the dirt oil or grease and it forms an emulsion at the center of the michelles right so an emulsion is when you know liquids are dissolving inside liquids and these emulsions can then be washed away by water okay so you'll find that these these emulsions further once they are washed out the with with their washing the dirt particle is also taken out so these are these are the cleansing action of soap you'll find that in both the water of the dirt here there is no dirt but here there is a dirt and the soap molecule is formed and michelle has entrapped the dirt particle and here there is only a michelle that has been shown so that's how the cleansing action of soap happens now let's look at the the figure of that that is necessary that you should draw that you'll find that here there is a soap molecule very clearly shown a soap michelle and here you will find that there is a dirt molecule that is seen and with this dirt molecule you'll find that the soap michelles are dissolving the dirt molecule with them and then there are hydrophilic parts which are outside which are basically flowing with water and you'll realize that as water is gushed in then it basically pulls out the dirt particle from the fabric or from from from the wherever wherever it is stuck to so that the cleansing action happens so these two figures can be pretty well drawn you know standard figures right from ncrt and you can actually show the cleansing action so the figures also carry a lot of weightage i'm going to share some important points of answer writing at the end of this session today and we can then that's the point when we can discuss more about it so so this is this is the soap action or the cleansing action of soap let's look at detergents the last slide for today you'll find that detergents are long chains of salts of sulfonic acids sometimes there are also calcium and magnesium salts is what we really mentioned but they are generally of sulfonic acids so you can very well write sulfonic acids in the in the solution soaps do not wash well with hard water okay so hard water is a is kind of a problem for soaps because it forms insoluble precipitates of calcium and magnesium right so because you know calcium and magnesium present in hard water they basically replace the sodium and potassium you know because sodium and potassium are very reactive so they will end up getting you know forming any any ions that are possible but calcium and magnesium cannot remain in the solution so they will get attached to the salt form and they will they will precipitate out because sodium and magnesium being more soluble they will kick out the calcium and magnesium out of the solution so the salt that came in with sodium is now attached to calcium and precipitated out so in hard water these soaps form insoluble precipitates of calcium and magnesium and therefore they are very less effective in hard water but if you look at detergents detergents are very supportive of hard water because they do not form insoluble precipitates because they themselves contain magnesium and calcium salts also they contain sulfonic acid you know ions as well so calcium and magnesium remain in the in the ionic form which can be washed out so detergents are effective even in the hard water a question that has been asked time and again and you know I've given you four points of difference also the soaps are sodium salts of sodium or you can also write as potassium salts of fatty acids whereas detergents are sodium salts of sulfonic acid you can also write calcium salts of sulfonic acids both are okay but sulfonic please do not miss out therefore I've explicitly mentioned it here then soaps clean in soft water but do not clean detergents clean well both in soft and hard water soaps do not clean as as well as detergents because of their limitations of solubility detergents clean better than soaps so you'll realize that you know detergents also have you know ability to clean in hard and soft water so when we say clean better it means that the ability to take out dirt from the solution is much higher for detergents and the ability to take out dirt is limited when we speak about soaps so so that's the difference between soaps and detergents now you'll realize that soaps are also biodegradable and they do not cause any pollution when you say biodegradable it simply means that they can be decomposed into smaller atoms smaller molecules and you know the normal organic action can be carried out but detergents because it is an inorganic compound because there is a sulfonic compound involved in it you'll find that you know there cannot be degradation further so as it as it can does not really go and break down further you'll find that detergents are non biodegradable or basically they cause pollution so these are the four points of difference that you can always mention and it can actually help you in writing the differentiation between soaps and detergents now that's the difference between soaps and detergents as i mentioned to you another quick topic so what we'll do is this actually brings to the end of the slide i'm going to quickly revise the entire you know chapter for you in the next minute or so minute or two minutes i would like you guys to now post any of your doubts post this revision i will tell you the important points that you should remember while writing answers i've already mentioned that in the presentation a few of them but anything that's remaining i'll try and address those so today we saw this entire chapter in the in the following sub parts so starting from the beginning you'll realize that we saw the occurrence of carbon atoms which whether it's in the you know earth or it's in the atmosphere so and then we have seen what are the different types of bondings that are there majorly covalent bond is what we have really looked in deeper we have seen why carbon forms covalent bonds its lettering configuration has to be written valency difference between valency and valence electrons is what we have seen we've also seen you know how covalent bonds are formed how to write louis structures we have seen single covalent bond double covalent bond and triple covalent bonds there are maximum covalent bonds that you can form is triple between two atoms which are neighboring to each other so only three bonds can be found maximum which is like for nitrogen even carbon form three bonds so we have seen how double triple and single bonds are formed we have seen the louis structures now we have seen how to really share the electrons how to really you know write louis structures these are the louis structure that you can write please note that here because i could use coloration i have been able to share them in different colors but for you you'll have to use different symbols so symbols are going to be critical if you have to write louis structures when you write electron dot structures it is a good idea to actually mention circles sometimes people just leave by writing the electrons which is also okay but drawing circles gives a more effectiveness to it please note how the circles are drawn each one of them is being seen to either complete a duplicate or an octet they are not left behind so that's the way to understand electron dot structures and then there are different compounds with you know who are molecular in nature basically who are who generally those who form single molecules they exist you know for example chlorine chlorine bromine iodine i have given you all of those examples including nitrogen and oxygen atoms hydrogen gas they're all single molecule compounds this is not similar to ionic compounds ionic compounds come as crystals or a huge for example diamond the entire diamond is like one molecule they are connected across to each other uh in in in a in a definite format right so so they are completely like one molecule but here you will have single single small small molecules in in in place and most of the coiling compounds will be water insoluble but they'll be soluble in benzene kerosene or petrol because benzene kerosene petrol are all uh what you should say uh non-polar and therefore uh non-polar substances are soluble in non-polar substances alight then we had seen covalency covalent compounds covalency we have seen allotropy in allotropy we have seen that you have to distinguish it as crystalline and amorphous uh fulorines another class that we saw we saw the formation of very large number of carbon atoms and cationation property a definition of cationation and its reasoning is what we had seen in this slide then we saw hydrocarbons classification as saturated and unsaturated uh majorly and then the definitions of saturated their examples unsaturated their examples with alkene alkene alkynes then we have also seen isomerism so isomerism is where it has the same molecular formula but different structures please do not mix up isomerism with allotrops i have said this again and again then we are also seen how to write iso neosec uh you know all of those we have seen functional groups uh what are the functional groups and how do we name them we have seen homologous series especially the homologous series with uh you know uh methane ethene and alkene all of these three put together uh we have also seen uh how to really write answers for homologous series their definitions as well as the examples uh we are also seen the nomenclature rules the ipse rules the common names so the ones in red in this ppt are the common names where the ones in blue are actually your ipse names so you know then we have seen what are the roots so we have seen the root for all the uh you know 10 carbon atoms uh we are also seen what are ethyl iso neotert uh you know all of those prefixes with this prefixes you can actually understand how alkene group gets attached we have also seen uh the uh you know the rules of nomenclature uh for example we take the longest chain and then sometimes if the longest chain is not uh uh you know straight through the substituent to form the longest chain again you look at the red ones the red ones are common names the blue ones are actually ipse names the red ones consider all carbons together the blue ones do not the blue ones actually break down the carbons to the only number of carbons in longest chain and not others so that's one then you will find that ipse nomenclature these are the rules firstly to take the longest uh uh chain the second one is to actually name the parent atom depending on the longest chain and uh then name the substituents on it then we had seen uh died to suffix that with diet right etra giving them some numbers the final thing that we saw that how the numbering has to be done and writing the name in alphabetical order while you write in alphabetical order diet right etra does not matter even while numbering ethyl methyl propyl dimethyl does not matter only matters is the is the root uh that you're using ethyl or methyl uh if there are same substituents on either side you'll use the one that gives you least number so you'll find that you know here we saw we will write it as hexane because there are more substituents on the root and there are less substituents here so you use the one that with more substituents the naming function groups is what we have seen uh all with all the functional groups we have seen this we have seen five four different reactions in combustion we have seen two now which is basically complete combustion and incomplete we have seen uh important compounds of carbon which is ethanol and ethanoic acid and the last one we saw was soap and detergents cleansing action of soap and their differences so so that's the entire chapter for you now a few points to note right uh some common instructions because this is the last session for you guys in terms of the crash course of course we will be solving papers and we'll be meeting quite often going forward but some points that I would like to mention here on this on this session right now is the first one is that always always uh yeah so one second uh uh yeah now uh let me write here yeah there's a few points first always check how many marks is the question for okay how many marks is the question for now once you know the marks uh then always try and see if there are multiple parts to it let's say part a part b part c and let's say the question is for five marks okay then definitely one will be for one mark and the other two will be for two two marks it is rare that one is for 1.5 and 1.5 that is rare it's always one two two whenever it is a one more question you are always expected only one point and an example if there is an example if there is a two more question you are expected to write two to three points always write three points and then an example or something again here also two to three points and then an example if there is a problem to be solved explicitly mention the formula the formula is something that will always fetch you marks even if you get your answer wrong please note that sometimes in the hurry you make calculation mistakes and all of that you end up getting a wrong answer please write the formula in the answer which is important to have okay so these are the these are the first few questions now second one whenever you write an answer it is a good idea to actually write the answer with the answer remember writing the answer number you know whether it is answer number answer 1 2 3 12 13 14 whatever it is always write it there if you buy some method you were not able to complete the answer if you're scratching it up either scratch completely and if you're attempting it at the end go there and write 11 and then attempt I have seen people attempt half the answer here and then half the answer at the end of the paper not allowed not allowed it is it is very rare that you will be getting marks in such such situations it will no marks will be given you lose marks in either of those or you'll simply end up getting marks only in one so please do not do this mistake if you're attempting an answer attempt it at the same position once the answer is finished and you feel or you're not getting the answer for some other some reason and you feel that you know you really need to answer it answer it at the back simply scratch okay so so that's that's another that that's another you know reason reason for this okay I'm not sure if this is clearly visible to you I'm going to use a different color or maybe it's not visible so I'm going to use a different color so that you can remember that you can you can realize that okay the next is always try to solve you know questions so there are two making ways that people generally solve the questions either they go by numbers one two you know three as the questions are there in the paper or they have a different method that they'll solve all physics earlier all chemistry later and all bio later I propose both of them okay there is there is there is no difference in either of them right if you feel that you can do physics chemistry bio separately please do that if you feel that helps you writing answers better and memorizing answers and giving a better performance absolutely okay so whether you go chronological or physics chemistry bio ideally it is nice to give get physics chemistry bio separately because you know when your papers go for correction generally they go for correction to maybe multiple people so if you're and if there is a bifurcation for correction generally it would be through either physics chemistry bio bio kind of a correction sometimes they also go over number wise the first five to one teacher next five to other and then the next five in either ways the getting through the number is a very easy question easy part to do so but getting through the you know physics on chemistry part is a difficult one so I would recommend that if you're using that go forward with it you can write all physics earlier all chemistry and all bio having said it is please don't spend time in doing this bifurcation and it's useless there's no point of doing that so waiting you know really searching you're not finding a physics question sometimes a physics question was forgotten earlier sometimes it so happens that you mess up the entire order you don't know whether you've solved the entire paper or not so it's a good idea to tick a question number once you have solved it if you're not really solved it put a question mark and go forward okay so tick or put a question mark second is that do not attempt to write both the ors no useless you know I have seen people attempting both our questions feeling that you know at least in one they will get some marks no whatever you're most confident just write that and move on it's just going to consume time for you and and and you will end up forming getting only the same amount of marks so only write one answer which you feel confident do not attempt the second order question at all no matter you how confident and you feel that you are going to impress the teacher with that doesn't work doesn't work okay so these are the few points the next few points are what I'll recommend is that have a good handwriting very very critical very critical have a good handwriting okay without a good handwriting forget getting a symptom in science okay not possible have a good handwriting have a good presentation it's always very nice to write in paragraphs to write in paragraphs or to write point wise okay write in paragraphs or write point wise both of them are very very okay okay I would recommend to write either of that whatever you're comfortable on most important is draw diagrams also when you draw diagrams do not sketch them like you're sketching you know out of your hand okay like no don't don't do this is a beaker and with a you know for example a conical flask you simply draw like this no very bad you can use this only if you're completely short of time you feel that you know you don't have enough time and you know the bell is gonna ring then you can use your hand drawings but as far as possible use scales use use proper you know geometry material to draw good diagrams always use both pencil and pen both pencil and pen only pencil or only pen is something that I don't recommend only pen also I definitely don't recommend but only pencil also I don't recommend generally you should draw the diagram with pencil use a dark colored pencil don't use light pencils okay use good pencils use erasers very well do not overwrite or over draw do not keep on doing this or do not write c c c c on top of it no bad habits okay bad habits do not do that if you feel that okay you have written something just put a small two line cross and write next just a two or three line maximum two or three line do not dirty your page okay do not dirty your page presentability is very important now generally in the diagrams label with pen label with pen and draw the diagrams with pencil I'll tell you why because the pen marker will remain for a very long time and therefore most of the marks are generally for labeling you know they give it for labeling so if your if your labels are good you'll you'll end up getting a lot of marks even if there is a problem with you know your pencil where someone was not able to read it or something of that sort okay so so do that the next is that when you solve mathematical questions it is good to do step by step and box it and box it okay one one something you're written for example x is equal to three okay just box it in chemistry you can very simply put an underline very good habit to underline okay please underline simply two lines you know and underline doesn't mean that you have to take a scale and keep on underlying no you have written okay ethane you have written less something like ethane just go and underline it softly with with your own pen okay won't pen or even if you want to do it with pencil that's okay the one last important point always check your paper at the end of the exam it's very very important to check your people if you feel that you know you're done with entire subject you know you will you it's a good idea that you can you can just go through the paper and make sure that you know everything is written everything is in place okay do the checking of the paper at least 10 minutes prior you know as the exam time is coming closer do the checking of the paper at least 10 minutes prior now whatever I've said why I'm saying this so early is because in all the upcoming exams try to use the strategy because that will become a habit for you to attempt in the board exams once you use the strategy over and over again you'll realize that at some point of time it will just come naturally to you okay so that's that's a very important point I'm just gonna pause here for a minute or two you know I if there are any questions that you have please feel free to drop it on the chat and I'll be happy to answer them yeah so just feel free to answer you know ask up any questions and I would answer them here so if there's anything that you feel to ask now we just we just come to the end of the today's presentation you know I'll be happy to take up your queries good to see you all all you guys I think it's nice to really connect yes if you have questions please feel free to ask else we'll be pausing in a few minutes okay so it seems that you don't have any more questions then I'll wish you the best and I will I will suggest that you do you do your okay so that's nice then I'll wish you all the best thank you so much for being here you know I hope you are studying well and you know if you have any questions you can always reach out to me on WhatsApp or any other means you can always call me and I wish you the best please feel free to yeah so study well and attempt your exams pretty pretty well thank you so much bye Sharers thanks thanks guys Krithika Anirudh and all the others thank you okay so may only sing why sodium kept immersed in kerosene oil so may only it is because sodium is very very reactive so if you if you keep sodium in air or with moisture you'll find that it it just explosively will react to form sodium hydroxide so therefore it is kept immersed in kerosene oil because kerosene oil is very under reactive kerosene oil is flammable but not reactive there is a difference flammable means if you bring fire then it will burn but if you just keep it then it is it does not react by itself yeah so that's the reason that it is under under kerosene okay any other questions I'm here if there for another minute or so if you have questions else thank you so much take care bye thank you thank you mayhole thanks so much everyone