 So, next we are going to discuss the feasibility and spontaneity of acid based reaction. What all acid based reactions are feasible means possible and spontaneous. That is what we are going to understand. So for our reference I have listed down some order of acids. These all are very strong acids. These are very strong acids actually and you do not get any comparison of all these, okay. But with respect to this we have other comparison also, right. So all these acids are very strong. Then we have sulfonic acid, carboxylic acid, 2, 4 dinitrophenol, 4 nitrophenol, H2CO3, ortho-nitrophenol, then para-nitrophenol, H2O, then alcohol, alkyne, alkene and then alkene. This is the order of acidity. One more thing that sp3, sp hybridized carbon atom is more acidic than sp3 hybridized nitrogen atom. This is also the acidic order, right. So these you know comparison you have to keep in mind, right. Now when we have acid base reaction, for example, suppose I have taken CS3COOH and this reacts with NaOH. What it forms? CS3C double bond O, ONA plus minus plus H2O, salt plus water, right. So if I write down the ionic form, CH3C double bond O, O minus plus OH minus gives you CS3C double bond O, O minus and plus will get H2O, right. So this is what we have. This is base OH minus and this is acid CS3COOH behavior, okay. Now when this acid loses H plus ion, it forms conjugate base CB, conjugate base and this forms conjugate acid. So this is what? Conjugate acid base pair. This is also, this is also conjugate acid base pair, okay. But we are not concerned with conjugate acid and conjugate base. We are concerned with acid both side or base both side. So both side we have acid, both side we have base, okay. So the point here that we have to consider is if this acid, if this reaction is going towards like going from strong acid to weak acid or strong base to weak base, those reactions are feasible, okay. What is the point I am trying to make? Is that how we can understand that the acid base reaction is feasible or spontaneous. So all those reactions in which the reaction is going from strong acid to weak acid or strong base to weak base, right. All those reactions are spontaneous and feasible. So what we have to compare here, the reaction must go from strong to weak side, right. And this is strong can be acid also or it can be base also, right. Here also weak acid or weak base. So basically we will just compare both side acid and base. So both side acid will compare or both side base will compare. So here you see the base we have these two are bases, right. These two are bases and these two are acids if you compare, the red one, okay. This is acid and this is acid, right. And these two are bases, these two are bases. So either we compare these two or we compare these two, right. So you see CS3COOH is a stronger acid than H2O. You see here CS3COOH, Calboxylic acid is a stronger than water, right. Since the reaction is going towards weak acid, anyone you can compare acid or base. I am comparing acid here. Going towards weak acid here, hence the reaction is spontaneous and feasible, right. That is what you have to compare. So for this comparison you should know this order, okay that is the first thing. Now the question that they ask here, like type 1 here, the first type of question, they will give you few number of acids here, right. They will give you like 6, 7, 8 acids here, right. And the question is which of these acids produces NH3 molecule on reaction with NaNH2. Right, produces an A on reaction with NH2, right. So what happens here you see, this NaNH2 will give what NH2, one electron here, right. And when it accepts H plus from acid, from acid it forms what NH3? It forms what NH3? So all those molecules, okay, so now the question is which of these molecule produces NH3 on reaction with the base NaNH2, right. So Na molecule, NaNH2 molecule gives, this is the ion we have like in case of NaOH, we are getting OH minus, okay. So all those molecules, all molecules which are stronger than NH2 produces NH3. So for example you see, if I take alcohol, right, OH or phenol or if you take alkyne, carboxylic acid alkyne, right. Now the question is which of these molecule produces NH3 from NaNH2, right. So NaNH2 you see, the nitrogen atom here it is sp3 hybridized, okay. And we know sp hybridized carbon is more acidic than sp3 hybridized, okay. So sp hybridized carbon here, so this will produce NaNH3, sorry NH3 here. We know alcohol is more acidic than amines, okay, we know already alcohol is more acidic than amines, carboxylic acid also more acidic than amines, okay. But this is alkyne which is not more acidic, you see sp2 hybridized carbon even sp3 hybridized carbon is even more, you know less acidic than sp3 nitrogen, so this is also not possible. So in this example these four molecules produces NH3 on reaction with NaNH2, okay. If I take an example of alkyne also, suppose CH3, CH double bond CH2, okay. So you know the carbon atom is sp2 hybridized and sp2 hybridized carbon is also less acidic than nitrogen, so this molecule also won't produce NH3 from this base, okay. Similarly you see type 2 NaOH, what all molecules acids reacts with NaOH, so NaOH when reacts we have already seen it forms H2O, right. So all those acids which are stronger than H2O can react with NaOH, okay. So here you see H2O will have here, right. So all these acids reacts with NaOH and forms H2O. Then only the reaction will go into forward direction otherwise forward direction reaction is not possible it is not spontaneous or feasible. Similarly you see type 3 example is NaHCO3. So the conjugate acid of this will be H2CO3, so all those acids which are stronger than H2CO3 we have here produces H2CO3 on reaction with NaHCO3, okay. So again in this case all these acids can produce H2CO3 when reacts with NaHCO3 and the reaction will proceed into forward direction, okay. So this is what the three different bases on the basis of this they have asked question in J exam, okay. That's why I have explained this what you need to know, you need to know the order of these, okay. All these are a strong acid you already know then we have sulfonic, carboxylic, 2, 4 dinitrophenol, right, 4-nitrophenol, H2CO3, orthonitro, metanitro, H2O then alcohol, alkyne, alkene, alkene, okay. And you have to memorize that sp hybridized carbon is more acidic than sp3 hybridized nitrogen and sp2 hybridized carbon is less acidic than sp3 hybridized nitrogen, okay. This is what the comparison I have written here you have to keep in mind, okay. One more type of reaction we will see that is reaction with Na metal. Now the last thing we are discussing here is the reaction with sodium metal, Na metal. Now this reaction you see this reaction is not an acid base reaction, right. I have written here acid base that we have already done, okay. This reaction is not acid base reaction but this is a redox reaction, right, redox reaction, okay. So the compounds in which active hydrogen is present reacts with sodium metal and forms its salt, forms its salts, okay. Now what I have written here the reaction in which active metal is there, right, active hydrogen. So now what is active hydrogen that is the point, right. The hydrogen in which the hydrogen is attached with, hydrogen is attached with any electronegative element, right, or when the removal of hydrogen produces stability towards aromaticity, for example you see when hydrogen is attached with oxygen, when hydrogen is attached with sulphur, when we have hydrogen halide, right, in this case or if you have with nitrogen NH3 because of the electronegativity difference, nitrogen also, these hydrogens are also active hydrogen, right. For example with alkyne CS3 C triple bond CH this is also active hydrogen, SP hybridized carbon atom or the cases like this, here you see two hydrogen we have, so all these hydrogens are active hydrogen because when this hydrogen comes out as H plus the ring becomes stable through aromaticity, 6 pi electron becomes aromaticity stable. So in all these cases hydrogens are active hydrogen, all these hydrogens are active hydrogen, right, all these hydrogens, right. So when any metal reacts with these kind of molecule it forms salt of it, few examples I will write down here, this gives RCH2 C triple bond C minus NA plus half of H2 gas evolves, okay. How it is a redox reaction? Because hydrogen you see here it is plus one, right, here it is zero, nitrogen is zero and plus one, right. So for example in case of alcohol plus NA, R O minus NA plus, plus half of H2 gas, right, see it is plus one, zero, plus one and zero. In case of phenol also the same kind of reaction possible, if you have molecules like this H C triple bond CH plus it reacts with excess of NA then it forms NA plus C minus triple bond C minus NA plus plus H2 gas evolves. So this kind of salt formation takes place when the reaction of active hydrogen takes place with sodium metal, okay. What all active hydrogen I have written here, this reaction is a redox reaction it is not acid type reaction, why redox reaction it is seen that the change in oxidation number here, okay. So this is it friends for this almost finished.