 So, so far we have discussed about resonance, hyper conjugation, eye effect and their applications. So, what are the applications of all these electronic effects we have seen, but the question that you get in the exam it is not necessary or true or always necessary that you will get questions only of hyper conjugation or resonance or eye effect. So, most of the time you will get questions where all the effects are taking place and then we have to you know identify that which one is more stable less stable or more acidic less acidic. So, now onwards from this session we are going to discuss about the stability of few intermediates various intermediates and then acidity and basicity of the compounds according to all the electronic effects. So, where we have the molecules given in which in which we have more than one electronic effects is taking place and according to that we have to compare the stability and acidity basicity order. So, to discuss this first we are starting with carbocation like if you remember carbocation stability we have already discussed in you know eye effect resonance hyper conjugation. But now again we are going to discuss the stability of carbocation according to all effects taking place. So, stability of carbocation here you see I will give you the order first and in this order only you have to check. So, first of all you have to check dancing resonance is just a common name we use it is just a resonance and cyclopropane I will discuss this done resonance only. But resonance of cyclopropane we generally call it as dancing resonance. So, first of all dancing resonance will check then we will check if aromatic city is there or not right if aromatic city is there or not then we will see plus M effect then plus H will see plus I will see hybridization difference also we will check then we will check minus I minus H minus M and then anti aromatic city. So, this is the order you have to follow what is this means means if you have dancing resonance suppose if you have these three electronic effects are present in four given compounds then the molecule in which dancing resonance is there it is most stable then aromatic city then plus M and then plus H. So, we will you know we will check in this order only right the compound in which the carbocation or positive charge involve in anti aromatic city that is least stable and we also know that the you know the preferred order is what aromatic city will first of all will check aromatic city then we have if you have equal resonance then we have resonance then hyper conjugation and then I effect this is the order we have means what if you have aromatic city fine means I am talking about the electronic effects. So, in electronic effects the order is this only this you have to consider resonance is the most dominating then hyper conjugation and then I effect in resonance only we have this equal resonance and aromatic city both comes in this only right. So, in the electronic effects the order will follow is resonance hyper conjugation and I effect. So, in electronic effects will consider resonance first hyper conjugation and aromatic inductive effect and now we also know that carbocation is positively charged and all this positively charged is stabilized by electron releasing group which is nothing but the positive effect which can be plus M plus H or plus I right. So, all these three effects stabilizes the carbocation right and in this the order will be what mesomeric effect comes under resonance. So, plus M plus H and plus I that is what we have here plus M plus H and plus I then will check hybridization and since this will mesomeric effect will establish the carbocation most plus M effect and in the same way this carbocation is destabilized by electron withdrawing group which is nothing but minus M then minus H and then minus I and order of these three will be what again mesomeric maximum then hyper conjugation and then I effect here also the order will be what mesomeric maximum then hyper conjugation and then I effect. So, mesomeric effect is always dominating if it is plus 1 then it will establish most if it is minus M then it will destabilize most the carbocation and with this only you see here plus M plus H plus I minus M will destabilize more in which it means what if you have two molecule in which minus M and minus H is present then the minus 1 minus H 1 gives you the more stable carbocation. Because minus M will again destabilize more then minus H and that is why the order is this minus I minus H minus M and then when it is anti aromatic it is most unstable. So, this is it this is the order you have to follow first we will check dancing resonance aromaticity plus M plus H plus I hyper conjugation minus I minus H minus M anti aromaticity. Now, few examples we will see here dancing resonance like I said. So, suppose if I take this example now in this what happens you see if I take this one also I will come to this again this one will discuss C S 2 positive charge and it is 1 cyclo propyl group attachment this one I am taking here. So, what happens here in cyclo propyl group in cyclo propyl angle strain is very high angle strain is very high here right angle strain is very high and that is why it is highly unstable right to gain stability what happens this cyclo propyl group or this ring breaks and what happens this sigma electron this sigma electrons comes over here and we get what you see we get this positive charge double bond C H 2 right or this sigma electron will come here like this it will be both way you will get the same molecule here only right. So, in this happens what you see here it is very important because you see here is resonance is there correct, but the sigma electron is taking part in resonance sigma electron is taking part in resonance. So, this is a special type of resonance we call it as dancing resonance. So, it is a special type of resonance in which sigma electrons are taking part right. So, this is what you have to keep in mind this is overcome all other factors of stabilizing carbocation. So, number of cyclo propyl group if it is more mode will be the stability simple thing right. So, if it is a if this is a this is b and this is c this kind of resonance is thighs here in comparison to this and twice here in comparison to this more resonance mode will be the stability the order here it is what a is most stable then b and then c this kind of resonance we call it as dancing resonance ok you can copy it down this e r stands for equal resonance. If you compare the stability of these carbocation this carbocation ok this compound is having 2 pi electron aromatic this has 6 pi electron aromatic and this has 4 pi electron anti aromatic. So, the stability here if it is a b and c. So, obviously b being anti aromatic is least stable right. If you compare stability of these 2 here we have more resonating structure possible. However, both are aromatic, but since more conjugation is there. So, c is the most stable and a will have in between this is the order see aromaticity is more stable than anti aromatic we know this already ok. Some more examples I will write down you can try it on your own and then we will discuss this ok. You see this is minus m c n o c s 3 has plus m nature n r 2 n r 2 has plus m c l what it shows minus i e ok. So, we have plus m minus m and minus i group. So, you see the dominating factor plus m dominates minus m and minus i you see the minus m has the minimum out of the 3 right. So, which shows minus m this if it is a b c and d then the order will be what a will have the minimum stability right plus m will have the maximum stability. First a and then d now b and c if you compare which one has more plus m effect right n r 2 the plus m effect of n r 2 is more because the nitrogen being less electronegative than oxygen. Then we have b and c is the most stable carbocation ok. Another example you see these molecules what effect we have here plus h here we have minus m a b c and d one is what minus m or minus i it shows minus i because at meta position minus m is not possible again it is at meta position this shows plus i right you can write plus h also, but again at meta position plus h not possible ok. Now, stability is maximum because of all these if you compare stability is maximum because these two are destabilizing factor minus m and minus i minus m and minus i all these you see these last are destabilizing factor and these are from here to here hybridization these are destabilizing factor all these negative things are an anti aromaticity all these the last four I have written over here these are destabilizing factor ok. So, minus m minus i are the destabilizing factor and in these two also minus m is more destabilizing factor right. So, b will have the minimum stability then we have c and plus i and plus h plus h is dominating then we have d and then we have a most stable is a because of plus h effect here. Another one you see all this this carbocation is found by sp hybridized carbon and this carbocation is found by sp 2 hybridized carbon and this is found by sp 3 hybridized carbon see I am not writing it down the hybridizing state of this carbon I am writing down the carbocation which is found over here it is found from sp hybridized carbon this is found from sp 2 and this is found from sp 3 ok. So, we know the electro negativity of sp hybridized carbon is maximum then we have sp 2 and then we have sp 3 because of percentage as corrective right electro negativity order is this and we know negative charge on more electro negative atom is stable and if you have positive charge on less electro negative atom is a stable atom is stable. So, we have positive charge here. So, we will see the least electro negative atom positive charge on that will be stable ok. So, if it is this is sp 3 least electro negative right. So, this is most stable first rank this is the second most second rank third most first second and third. So, like this we can again compare the stability of these carbocation ok. Some more examples will see these 3 molecules here what we have resonance here also we have resonance here we have plus i also and plus h also, but plus h is dominating here right and we know resonance the dominating factor on hyper conjugation resonance is nothing, but this plus m you can write down resonance also right is dominating on hyper conjugation right and here we have more number of r s possible more r s large conjugation we have here. Hence the stability of a is maximum here then we have b and then we have c. One last example we will see c s 2 plus in these 3 you see a and c. Here we have resonance the first one this is aromatic and this is anti aromatic. So, this is stability order aromatic is most stable then we have resonance and then we have anti aromatic this is the order of stability of these carbocation ok. So, friends like this we can compare the stability of carbocation on the basis of on the basis of various electronic effects ok. So, you have to keep this in mind and then you can compare in the given molecule whether all where which of these electronic effects are taking place and according to the nature of that effects you can consider the stability of you can find out the stability of carbocation ok. So, next class we will see the stability of free radical also depending on this ok stability of free radical. In the case of free radical what happens the aromaticity will not discuss over there ok. So, like this only we will write down the order of various electronic effects for the stability of free radical and then we will see free examples ok. So, like till not we have almost finished the you know 80 percent portion of GOC ok. 80 percent portion we have we have almost finished the 80 percent portion of GOC ok. We are left with again free radical carbon ion we will discuss we will discuss acidic basic nature depending on all electronic effects and then in the last we have to discuss the tautomers ok tautomerism ok. So, we will see in the next class. Thank you.