so in this video we're going to talk about the first video of unit 2 the topics here is hydrocarbons and types of carbons so let's get started when we talk about the hydrocarbons we're talking about the organic compound that composed of carbon and hydrogens means the organic compounds that is basically composed of carbon and hydrogen elements hydrocarbons could be of two types could be aliphatic hydrocarbons or could be aromatic hydrocarbons so here are the example of some organic compounds as you see basically these are the compounds are made of carbon and hydrogen's elements and we're going to talk about the alipatic and aromatic a little bit in a minute in a second um so those hydrocarbons mostly they're insoluble in water and we have talked about the carbon-carbon bonds and carbon hydrogens bonds are non-polar bonds and non-polar bonds means the overall hydrocarbons usually are non-polar molecules and because of that non-polarity they cannot be solubilized in water because water is a polar solvent so if you know the likeness of like uh rule means polar solvent can be dissolved can dissolve polar compounds and nonpolar solvents can dissolve only non-polar compounds so this is why um the nonpolar hydrocarbons are not uh are not readily soluble in uh water so hydrocarbons uh aliphatic hydrocarbons usually they are they could be saturated elevated hydrocarbons or could be ancestored uh elephant hydrocarbons if it is saturated elephanted hydrocarbons we usually call them by name alkanes and if it is unsaturated hydrocarbons we call them by alkenes or alkynes here are some examples of alkanes as you see here this is abs aliphatic hydrocarbons these elevated hydrocarbons and unsaturated uh means they are alkene or alkynes so if you have carbon carbon double bonds that we call alkene carbon carbon triple bonds equal alkyne we will go over this one in details in our coming slides so those are all basically aliphatic um hydrocarbons uh alkane alkene kind it could be it could be appearing in in a chain run chain forms or in ring form just like here this is a six member ring uh that is also an alkane structure uh it could be like a long chain like the straight chain or it could be a branch molecules whereas the aromatic hydrocarbons they usually have an aromatic ring for example in this case here you see this six-member ring with alternative carbon-carbon double bond or discard double bond and single bond double bond single bond terms alternative carbon carbon double bonds the six member ring we call aromatic ring so any organic compound that contain these aromatic rings we usually call hermetic hydrocarbons so what we pretty much learn now the hydrocarbons are the organic compounds which is composed of hydrogens carbon and hydrogen's elements hydrocarbon could be two types aliphatic hydrocarbons or aromatic hydrocarbons aliphatic hydrocarbons could be a compound or equal saturated saturated hydrocarbons which you would call it as alkane it could be unsaturated hydrocarbon that could have a carbon-carbon double bonds carbon-carbon triple bonds if they have a carbon-carbon double bonds we call alkene if they have carbon-carbon triple bonds we call alkyne and then whole new different types of hydrocarbons we have learned that's aromatic hydrocarbons usually they contain aromatic ring that's a six member ring with alternative carbon-carbon double bond and single bonds so let's talk about all of these in more details uh all this saturated hydrocarbons unsaturated hydrocarbons aromatic hydrocarbons so this type of story that you must need to learn more details so first we will begin with the saturated hydrocarbons so what what type of substrate we can call saturated hydrocarbons any organic compounds which is composed of carbon hydrogens and if that has a carbon if that has all carbon-carbon single bonds we usually call that organic hydrocarbons as the saturated hydrocarbons so when you say saturated hydrocarbons the compound is saturated with hydrogens you cannot add any more hydrogens to that particular substrate for example here the saturated hydrocarbon could be like chain like structure could be a cyclic ring these are all uh the example of calm saturated hydrocarbon you can see here you will find all carbon carbon single bonds all carbon carbon single bonds so there is no uh multiple bonds uh um the carbon carbon double bonds or carbon carbon triple bonds present here so saturated elephant hydrocarbons um we call them by the name called alkanes uh so these are stretch and alkene this is cyclic alkanes if they are chain formed then their general formula usually cn h2 and plus two that means they n is here could be any integers number so it if it is like n equals one that this will turn into ch4 that's the uh smallest inlet of hydro saturated hydrocarbon alkane then if you have n equals to two that's a c two h six so that's the ethane uh again that's the general formula for chain alkanes but if you have a ring alkane they have also carbon-carbon single bonds as you see here but they have fewer number of hydrogen than a chain with the same number of carbon atoms so usually in that case they are general formula c and h2n for cyclic alkane so in this case if you count the number of carbon and hydrogens you will find it is cn c6h12 is just exactly the double of double double of double hydrogens compared to the number of carbons so for this case if you count one two three four five six seven you have seven carbon so c n so c seven so h uh hydrogen should be sixteenths and if you count the number of hydrogen this should be uh you should have 16 hydrogens in that structure so to summarize all this thing here again saturated hydrocarbons have all carbon carbon single bonds they are usually saturated with the hydrogens saturated uh elephant hydrocarbon has a name we call alkane if it is in if it is in chain form the general formula would be cnh2n plus two if it is in ring alkene form then the general formula is going to be cn cnh2n now we're going to talk about the unsaturated hydrocarbons any hydrocarbon that has one or more carbon-carbon double bonds or carbon-carbon triple bonds we usually call them as unsaturated hydrocarbons if the unsaturated hydrocarbon has carbon-carbon double bonds we call them as alkenes so the general formula for monosaturated chain alkene is cnh2n you basically remove two hydrogens more two more hydrogens for each additional double bonds so again just unsaturated hydrocarbons acute they could have one or more carbon-carbon double bonds or carbon-carbon triple bonds and if the unsaturated hydrocarbon has carbon-carbon double bonds we call them as alkene the general formula of a monosaccharide monounsaturated chain alkene c and h2n if the unsaturated hydrocarbons contain carbon-carbon triple bonds we call them as alkyne and the general formula for the alkyne with one triple bond is cnh2n minus two you remove four more hydrogens for each additional triple bond then you will end up with this general formula c and h2 and minus two so here is the structure for alkane so this is not alkene this is a spelling error so this is a l k a n u s and this should be the alkene because it has a carbon carbon double bonds and here we have carbon carbon triple bonds we call alkynes and as you if you apply this rule c n h two roll so that should be two carbon and four hydrogen so this is c2h4 if we apply the alkene general formula rule here so this is cn h2 so cnh2n minus two so this is c2h2 that's the alkaline formula and then the then another category of hydrocarbon we just talked about this aromatic hydrocarbons aromatic hydrocarbons they contain a ring structure that seems to have a carbon-carbon double bond usually they don't behave that way so the most prevalent example for the aromatic hydrocarbon is the benzene and the structure of benzene is like this you have six membrane with alternative carbon carbon double bond this carbon has one hydrogen attached to it it can be written in this structural form also sometimes in the textbook you will see the benzene ring is written in this in this structure form now where you have six membrane and there is a circle inside so that is also benzene we'll talk about that more when we when we will learn the normal cluster of benzene so this is a type of hydrocarbon again as we can see it has a carbon and hydrogen so this is a hydrocarbon but because of this aromatic ring six member ring bins in ring we call this call them aromatic hydrocarbons there are other type of aromatic hydrocarbons you can find where hydrogen is replaced with some other substituents it could be replaced with the chlorine you could have a chlorine here then that would be chlorobenzene if you have a methyl group here that would be a toluene so those are aromatic hydrocarbons again they have a carbon-carbon double bonds although uh so don't treat it out and don't treat this aromatic hydrocarbon as an alkene so they are completely a different type of uh hydrocarbons they do they do not have any similarities uh just that similar they don't have any similarities like alkene now take us for the next lecture problem here assuming only chain with the maximum of one's unsaturation decide if each of the following molecular formulas represent an alkene alkane or alkyne so if you want you can pause this video and then you can try to answer these questions on your own so we have here several molecular formula of hydrocarbon we want to predict which one could be an alkane which one could be an alkene which one could be an alkyne so what we learned in our previous slide if if you have an alkane then the general formula for alkane is c and h2n plus two if you have alkene that should be cnh2n and if you have alkyne that should be cnh2n minus two if you use that general formula here then you should be able to figure that out the ch4 that molecular formula is for alkane this should be ch3c3h8 that's a cnh2 and plus two there's also an alkene c2h4 that's a cnh2n that's an alkene and this is c4h6 that's an alkyne and this is also a cn h20 cluster this is for alkane and this is alkene again you must need to memorize these general um formula cnh2n plus 2 and cnn h2n cn h2 minus 2 that we should be able to identify what whether the molecule of given molecular formula is an alkane alkene or alkyne again to summarize these things here alkenes usually have all those carbon-carbon single bonds you wouldn't find anywhere carbon-carbon double bonds or carbon-carbon triple bonds for alkene you will you can have one or more carbon-carbon double bonds in the substrate for alkyne you will have one or more carbon-carbon triple bonds so those are we call alkyne which of the following compound is a saturated hydrocarbons and unsaturated hydrocarbons again the saturated hydrocarbons the mean the hydrocarbon has all carbon carbon single bond unsaturated hydrocarbons means hydrocarbon they have at least one or more carbon carbon double bonds or carbon carbon triple bonds so if you have propane you know the protein we use for grilling purpose so this is the structure of the proteins and you can see all the carbon carbon single bond here there's no carbon carbon double bond so this should be a saturated hydrocarbons how about this one that's right it has a carbon-carbon double bond so that should be an alkene that's unsaturated hydrocarbons how about this one that's right this substrate has carbon carbon triple bonds so this should be on such a hydrocarbon how about this one this is toluene often used as a thin paint thinner material so this is an aromatic ring you can see here is the benzene ring here benzene ring is substituted with ch3 group so this is an aromatic hydrocarbon and we and you have since alternative carbon carbon double bond single bonds this is an unsaturated hydrocarbon as well now next uh we have one learning check problem so if you want you can pause this video and try to answer these questions and figure out whether this molecular formula represents an an alkene alkene or alkyne c14h28 what do you think that's right that's that is an alkene h52 that's an alkane and c2 alpha h22 that's an alkyne right now we're going to talk about the types of carbons in organic chemistry this is very important you need to know what type of carbon you are dealing with so there are three types of carbon primary carbon secondary carbon and tertiary carbon so primary carbons are type of carbon that are connected to one carbon atoms and the hydrogen attached to the primary carbons we call primary hydrogens the secondary carbon definition is the carbon connected to two carbon atoms and the hydrogen is connected to secondary carbons we call secondary hydrogens and then tertiary carbons connected to three carbon atoms and the hydrogen attached to tertiary carbons we call tertiary hydrogens so now we are going to solve one problems together and to figure out how many primary carbon secondary carbon tertiary carbon we have and how many primary carbon primary hydrogen secondary hydrogen tertiary hydrogens you have in the two different structure given here so we have butane c4h10 that's the structure here we have another structure isobutane the c4h10 same molecular formula we'd like to count how many primary hydrogens we have primary carbon carbons we have and primary hydrogens we have for the first structure according to the definition of primary carbons it says carbon connected to one carbon if you look at this structure we can see this carbon connected with this carbon this is one carbon so this is a primary carbon on the other hand this carbon is connected with only one carbon here so this is also primary carbon so we have two we have two here two primary carbon and if you count the number of hydrogens they test on the primary carbon so three on this primary carbon and three on this primary carbon so total is six so we have six primary hydrogens now count the secondary carbons so secondary carbon definition is carbon connected to two carbon atoms so we have here this carbon connected with this carbon first carbon and this is the second carbon so this is the secondary carbon similarly this carbon here is connected with this carbon and this carbon so we have here two secondary carbons and how many secondary hydrogen we have so we have one and two on these carbons one and two on this secondary carbon so turtle is four so we have two secondary carbons and four secondary hydrogens how about the tertiary tertiary definition the carbon connected to three carbon atoms we don't have any carbons here in this structure that that is connected with three carbon atoms so the tertiary carbons here is zero now we are going to focus on the second structure isobutane we want to find out how many primary carbons we have so this is the first carbon is connected with this only one carbon here so this is one and this is also connected with one carbon so this is the second primary carbon this is connected with this carbon this is the third primary carbon so total we have three primary carbons and each of the primary carbon has three hydrogen so three times three nine so we have three primary carbons and nine hydrogens do we have any secondary carbons if you look at this carbon here this is connected with this carbon disconnected with this carbon so it's connected with two carbon so that is uh this must be the secondary carbons and it is connected with only one hydrogen so this should be you