 So what we have out here are different sets of cations and we need to figure out their relative stabilities So let's start by looking at this set of cations Well out here. I have a carbon cation that has these methyl groups that are attached to it, right? Now we have seen that in such cases hyper conjugation is possible for hyper conjugation to take place We need an sp3 carbon atom that has at least one hydrogen We need an sp3 containing one hydrogen atom at least one hydrogen atom That's directly connected or we can say that's at the alpha position of a carbocation, right? So whenever we have a carbocation or more specifically whenever we have a carbon with an MTP orbital and if there is an sp3 carbon atom at the alpha position of this carbocation at the first position of this carbocation containing at least one hydrogen atom We call this the alpha hydrogen the alpha hydrogen then The sigma bond between this carbon and hydrogen can actually overlap with this MTP orbital, right? This is what we call a hyper conjugation hyper conjugation and a greater number of this alpha hydrogen's presence of a greater number of alpha hydrogen's Implies greater chances of this kind of sigma pi overlap and because this kind of overlaps Ultimately shifts some of the electron density of this sigma bond to this electron deficient cation So therefore a greater number of alpha hydrogen ultimately means a more stable cation, right? Let us now take a look at these cations Well, as you can see in this cation, this is a third degree cation There are three sp3 carbon atoms that are at the alpha position of this cation and all of this has 33 hydrogen's attached to it So that's going to be a grand total of a Nile alpha hydrogen's out here that can undergo hyper conjugation and If you compare it with this cation Then this has only two sp3 carbon atoms directly attached to it. So there are only six alpha hydrogens out here while this one has only three alpha hydrogens and This doesn't have any sp3 carbon atom attached to it. So this does not have any alpha hydrogen, right? So there's only there's no alpha hydrogen out here Now because a greater number of alpha hydrogen means a greater stability So therefore this third degree cation is going to be more stable than this one compared to this and this, right? Let us now move to our second set of cations In fact, why don't you just pause the video and take a shot at this particular question? Pause the video and try to arrange these cations in order of their increasing stability Well out here the cation is placed Exactly here at this terminal position and we only have this carbon atom this sp3 carbon atom That's directly attached to it, right? Now this carbon has one to three bonds So this means that this has one hydrogen attached out here as a neutral carbon always has four bonds, right? So this cation has one alpha hydrogen attached to it, right? Now if you look at this cation, this has three sp3 carbon atoms that are directly attached to it at the alpha position And this one is going to have three hydrogen atoms attached to it This is going to have another three hydrogen atoms attached to it and this carbon is going to have one more hydrogen attached to it, right? So there's going to be a grand total of one two three four five six seven alpha hydrogens out here So there'll be more number of hyper conjugating structures out here. There'll be greater hyper conjugation here So this is going to be definitely more stable than this cation, right? Now finally if you look at this cation, then this has these carbon atoms that are directly attached to it and If we count the total number of alpha hydrogens, then this carbon has two bonds So there's going to be two hydrogen atoms attached out here This one too is going to have two hydrogens and this is going to have only one hydrogen out here, right? So the total number of alpha hydrogens is going to be one two three four five So this is going to have five alpha hydrogens attached to it, right? So clearly number Two this one. Let's let's name this. Let's call this B Because B has more number of alpha hydrogens So therefore B is going to be more stable compared to C Which is going to be more stable compared to A, right? Let us now take a look at these cations Okay Can take place Whenever we have a carbon with an empty pure battle, right? So instead of having a carbon cation per se, we can also have an Alken so we can have a carbon double bond carbon out here So let's say we have something like CH3 CH double bond CH2 This is exactly what I've drawn out here. So there's a Pi bond between these carbon atoms and There's an sp3 carbon atom. That's directly attached to this pi bond, right? Now the electrons in this pi bond. They are not static. They are moving around So it might so happen that both of these electrons they move over here right So if you move both of these electrons out here Then we are going to get a cation out here and I'm going to have a CH2 minus out here, right? So this is going to become negatively charged and this is going to be positively charged Now if this happens This carbon hydrogen sigma bond can once again overlap with this empty orbital that's being created, right? So this is also a possibility. So hyper conjugation can also take place whenever we have an sp3 carbon atom containing at least one hydrogen Attached to an alkene, right? So if you look at this particular cation We have this sp3 hybridized carbon atom that's directly connected to a double bond, right? Now this carbon also has this hydrogen atom attached to it. So we can have hyper conjugation out here This carbon hydrogen sigma bond can overlap out here and this pi electrons can move over to this carbon atom, right? So this will lead to a new hyper conjugating structure. That's going to look like this Now this lone pair of electrons that are formed over this carbon atom can then Resonate it can move out here and this pi electrons can move over to this carbon atom, right? So this will lead to a new resonating structure. That's going to look like this and the moment this happens The moment we have a lone pair of electron connected directly to a cation So there's an empty p orbital over this cation and we have this lone pair of electrons So both of this can overlap and this will lead to the formation of a pi bond out here, right? So therefore Because of hyper conjugation because of hyper conjugation out here This carbocation is getting ultimately stabilized, right? Now coming back if I look at this particular cation, especially if I look at this particular system You can see that there are three alpha hydrogens that are connected to this alkene, right? So this has three alpha hydrogens While this one only has two While this only has one alpha hydrogen that can undergo hyper conjugation with this alkene So it only has one alpha hydrogen while this doesn't even have a single hydrogen atom that can undergo hyper conjugation, right? So this does not have any alpha hydrogen Now because of this particular reason This cation cannot be stabilized by hyper conjugation by this particular group that we have attached out here While the greatest hyper conjugating stability will be imparted by this particular group as it has the greatest number of alpha hydrogens That can undergo hyper conjugation, right? So therefore this particular cation is going to be more stable compared to this compared to this Let's do another question. This time we need to compare the stability of alkenes rather than the stability of cations So how do you do that? Now in alkenes because hyper conjugation leads to delocalization of these pi electrons Because hyper conjugation leads to the delocalization of of these pi electrons So therefore a greater number of alpha hydrogen atoms means greater number of hyper conjugating structures And therefore a greater delocalization of these pi electrons And because delocalization of these electrons ultimately leads to an increased stability So therefore greater the number of alpha hydrogen more stable will be my alkene, right? So if we apply this to our given problem So if we apply this out here You can see that there are only two alpha hydrogens that can undergo hyper hyper conjugation in butte 1 in While in butte 2 in there are six alpha hydrogens that can undergo hyper conjugation So therefore butte 2 in is going to be more stable than butte 1 in, right? Similarly coming to this particular problem There are these three carbon atoms that are attached at the alpha position of this alkene And because every carbon every neutral carbon has four bonds So there are these hydrogens attached out here, right? So this one is going to have three hydrogens out here And this is going to have another two hydrogens out here So there's going to be three four five six alpha hydrogens out here While if we look at this particular alkene it only has one two three alpha hydrogens While this one only has one two Three four alpha hydrogens, right? So this has four alpha hydrogens attached out here So stability wise Let's call this a b and c So stability wise a is going to be more stable compared to c which is going to be more stable compared to b, right?