What's up VCNs! How are you? Confirm in the chat whether you can hear me or not so that we can very quickly get started with today's session. In today's session, we will once again do 4 numbers in a fist. And believe me, I will not teach you a lot of theory today. I am going to teach you the best way to do this chapter. We will read everything to the point and whatever I will teach you, after learning that much, you will get a strong level of confidence. You will feel very good because you will be able to make it your own questions. So 2022, 2023, 2021, whatever past year questions you want to do, all the questions will be made by you. Not even a single question that my child said that ma'am it seems difficult. It is not a question of looking difficult. The easiest chapter chemical kinetics which we are going to discuss today. Yes you can hear me, is everything good, audible, visible? Yes. Good evening. Okay, ma'am, in this chapter, please tell us the shortcuts. Brothers, today you must have studied chemical kinetics in thousands of places. You must have studied in your coaching, you must have studied in school, you must have studied in tuition, online, offline, wherever you study, you must have studied. But the way we will study chemical kinetics today, Means you will like that method so much See I have divided your entire chapter into 5 parts I have divided the whole chapter in just 5 topics If you do those 5 topics All the questions of your main will be made You just have to give me one thing That is, the next 1.5 hours You have to sit completely focused You have to learn as much as you can Something means the 1.5 hours you have If you study hard, don't think that you will get selected or not. Will my girlfriend agree or not? Which IIT will I get? When I get selected in IIT, I will go to Bombay. I will take CS. Or I don't know anything. My life is a waste. You should not think like this for the next 2 hours. So, 2 hours and your entire chapter will be fixed. If you gain 4 marks in 2 hours, this is called real study. That the child is coming with the maximum output by putting the least effort. So without any delay, let's quickly get started with our JEE brief. We are revising your entire JEE syllabus within 40 days. Classes are going on on a regular basis every day. And if you see every day, I know a small thing. When the exam of the child is only 30 days away, then the seriousness of the child is so good that if that seriousness had been shown in the last one year, then the paper of that child would have been cleared. The last 30 days of seriousness is of no use because you don't use that seriousness positively, you spend it in tension. The time you have is so perfect that if a child completes their syllabus, if a child asks questions from the previous year, if a child makes short notes, that child will feel very relaxed in the last 30 days. He does not have that phobia from the exam. But until we are not serious now, we will sit and wait. We will see later. That will not come later, children. ok so let's start yes by the way I will make another small announcement for you the JEE booster batch which is going on its week 4 will be completed tomorrow so all the students who want to enroll this booster batch you can definitely make sure that when our week 5 starts from Monday you can start fresh whatever your previous batch is left you can wind up it slowly because already one month This booster batch has been started. Many topics have been completed. My entire physical chemistry has been completed. All the chapters of 11th and 12th physical chemistry, whether they are in your revised NCERT or not, every chapter has been completed by the children in the last month. So make sure when our Monday starts, we are going to start organic chemistry in JEE booster. So whoever has an organic week, who thinks that ma'am, I can't do organic and this time organic is going to be the highest weightage portion of all chemistry So make sure that who wants to do organic seriously you can be a part of the booster batch you will get a lot of confidence Puri theory aapko karai jaari hai. Sare ke sare previous year questions 2023 ke 1980 sawal hai. Sare sawal ho ki discussion kar rahe hai. And iske saath saath jo booster sessions hotay hai. Jo live booster sessions hotay hai. That is the specialty of this batch because in those sessions when the child asks time based questions like timer means there must be 10 times bell in our class that just give this much time, this much should be done So that practice brings a good impression in the child So those who are interested you can definitely be the part of booster batch And those children who are following brief, they should follow brief because by following brief all your topics are getting revised well you will have to practice it yourself. So, kids, as I told you, our whole session is divided into 5 topics. So, first of all, we will discuss the topic number 1 of our session. That is, what is the rate of reaction? We have to study chemical kinetics. I want to study the speed of my reaction. Right? I can hear my voice. Just give me one second. My voice is coming right right right right yes yes yes So my voice is coming in a very good way So kids in chemical kinetics we have to first discuss that we want to find the speed of any chemical reaction That it will end in 10 minutes, in 50 minutes, in half an hour, when will it end So for that let's assume I have a balanced chemical equation AA plus BB to form CC plus DD Today this AABBCCDD reaction will be with us till the end Small ABCD is stoichiometric coefficient and big ABCD is our reactants and products If I want to discuss the rate of any reaction Rate means speed So I can discuss speed with two things I should know how much product is being made with per unit time or my reactants are breaking with the speed of the reaction so if I tell you the free talk that how to calculate the rate of any reaction then listen carefully to calculate the rate of any balanced chemical equation whatever is your stoichiometric coefficient you will take minus of 1 by A if it is reactant then minus I am not telling the whole story now there is no time for this chemical kinetics chapter I have to spend 12 hours for this chapter its worth is not there and time is also not there You should know to the point, any chemical reaction of mine, if you want to write the rate in the terms of reactant, then minus 1 by A, dA by dt, which will be equal to minus 1 by B, dB by dt, for product you will add plus, plus 1 by C, dC by dt, will be equal to 1 by D, dD by dt. I know you are getting questions in your mind, why did you do this? I did this because, first of all, I am going to write A, B, C, D here. Either I can write them in moles terms or I can write them in molarity terms. or I can write them in terms of pressure other than this, I will never write my rate in terms of mass remember, it is very important, PYQ is also asked on the basis of this or it should be in terms of moles, the term of molarity or pressure should not be in terms of mass I want to find out what is the change in concentration of D how much is the change in concentration of D per unit time with the time, how much is the change in concentration of D Suppose if I had not divided the reaction by stoichiometric coefficient Then I would have had multiple rates of the same reaction For example, I have a reaction 2a to form b If you are writing that ma'am any reaction's rate is minus dA by dt is equal to dB by dt This is wrong He is saying that rate is dB by dt which will be different value and rate will be different in one atom. So, my rate of one reaction should be same. That is why I will divide by the stoichiometric coefficient. Minus for reactant because the concentration of reactant will be less. So, dA by dt will be negative. So, my rate, my speed can't be negative. This is not a physics that I am talking about velocity. I am talking about rate, speed. Speed can't be negative. That's why I said that whatever reaction it is, first of all, you will write minus. We will write minus for reactant. 1 by stoichiometric coefficient dA by dt for reactant will be equal to 1 by stoichiometric coefficient dB by dt for the product. I think this thing shines to everyone. It has been clearly clear. Now we have two types of rate, one is average and other is instantaneous rate of reaction. For example, I will make a graph. Suppose I have said that this is a graph of concentration time. and this concentration of A was there before and it gradually decreased, something like this So someone told me that tell me, T is equal to when the time was 10 seconds to T is equal to 20 seconds. How much has your concentration changed? If you find a change for a finite time interval. You said that ma'am initial concentration is A1 and final concentration is A2. So how much change has come in concentration A2 minus A1. Because it is a reactant, I have put a negative sign. How much time did it change? 20 minus 10. So when I want to find the rate for an interval, then the rate is known as average rate of reaction. But suppose a surfer comes and says, no, no, no, we don't want to see in 10 seconds. Tell me what was the speed of reaction when the 15th second was running? That person comes and says, no, no, we want 15 seconds. Means t is equal to 15 seconds per rate. Now, if you have studied physics, maths, and chemistry of class 11, then I think you know that if I have to find the rate of one point here, if I have to find its slope, then what will I do? I will find the slope of this particular graph. I will do nothing but minus DA by DT, which is the slope of this particular graph at T is equal to 15 seconds. So, if you want to calculate the rate of any reaction in a very small interval, what will it be called? Instantaneous rate of reaction. So, the average rate is represented by delta concentration of A by delta T. Delta means a very fine change. And if you want to take a very small change, then we will represent it by D. So, we will do D by D. So, the story shines to everyone. Now I will teach you one, two, three more things. One is that I have a rate of appearance. One is that I have a rate of disappearance. When I wrote rate of disappearance, who will disappear in your reaction? Reactant. Whenever I talk about rate of disappearance, I always talk about reactant. Whenever I talk about appearance, who will appear? Always, always, product will appear. So whenever I have to find the rate of disappearance of any reactant in the world, you will do nothing. You will do minus of DA by DT. You will do nothing but you will simply do change in concentration. change in concentration of reactant divided by time taken divided by time taken whatever time taken, I have to take out for reactant only every reactant will disappear at different speed the overall rate of the whole reaction was 1 but some reactant is saying that I will finish 10 moles in 1 second second one is saying that I will finish 20 moles third one is saying that I will finish only 5 moles so for every particular reactant we have to find the rate of disappearance separately and if I talk about rate of appearance means change in concentration of product divided by the time taken for that change. Means, whenever you will take out rate of appearance or rate of disappearance, you will never divide it by stoichiometric. Ma'am, you tell me a free thing. Right? If tomorrow, I have to correlate rate of reaction, if you have rate of reaction, you have to correlate rate of appearance or rate of disappearance, with the rate of appearance. so what to do? whatever is the rate of reaction will be equal to rate of appearance by stoichiometric coefficient of product rate of disappearance by stoichiometric coefficient of that particular reacted means rate of reaction, rate of appearance, rate of disappearance can be correlated just by using stoichiometric coefficient for example now you will take a big good hiya You are going to see a very good thing here. We will add a new slide. Some extra points which we will write. Look in front. Suppose I have a reaction. AA plus BB to form CC plus DD. This will work in the whole class today. See, if you write the rate of reaction of someone, then how will you write? Minus 1 by A, DA by DT. Minus 1 by B, DB by DT. 1 by CE, DC by DT, 1 by DE, DD by DT. Chamka. If someone says no, no, no, ma'am just write rate of disappearance and show me. So do you know what I will write for A? Minus DA by DT. Do you know what I will write for B? Minus DB by DT. Do you know what I will write for C? DC by DT. And do you know what I will write for D? Do you know what I will write for D? DD by DT. Sorted. This was the topic number 1 of our today's lecture. That's all you have to do. You don't have to go into the depth of this. You don't have to go from top to top. I am teaching you more than enough. Now you will try some questions of JEE mains. The question is in front of you. There are two questions. One question is of 2022 and the other is of 2023. Try it and tell me whether you will be able to answer this level of questions or not. Please take your time and tell me the answer for this question. All students will take time and answer this particular question. Yes, you have to take minus sign for rate of reaction and minus sign for rate of disappearance. Quickly answer this particular question. Let's see who is getting the correct answer for this particular question. It is a very easy question, don't be scared. For a chemical reaction, I have a chemical reaction A to B. It was found that concentration of B is increased by 0.2 mol per liter in 30 minutes. The concentration of B increased by 0.2 mol per liter. In how much time? In 30 minutes. Very good. The average rate of reaction is dash into 10 raised to the power minus 1 mol per liter per hour. It will be funny to ask such questions. It is not a very old question. It is a question from 2022. How do we calculate the average rate? How much concentration did it change? 0.2 mol per liter divided by time taken. Here the time is 30 minutes. 30 minutes means half an hour divided by 1 by 2 hours. Will our children answer this question? Is the answer here? Is it here? 0.4 So, 0.4 is here. How much is this? 0.4 mol per liter per hour. But brother asked for the answer. So, the answer is 4 into 10 raised to the power minus 1 mol per liter per hour. So, the answer is 4. I didn't make this question. NTA has given this. Now the next question. You say, no ma'am you are making it easy for 22. You can ask the question of 2023. This is the question from J.E.Main 2023. On your computer screen. Please take your time and tell me the answer. I don't know who told the kids that JEE is very tough. The kid was scared from inside that I can't do this. Imagine the situation when you were young. All kids have this situation in their life. When you were young, on your first birthday, I gave my son a cycle on his second or third birthday. So what happened when I gave him a cycle? So, we never told him that cycling is very tough. We told him that he should ride like other toys. So, he started riding the cycle happily. Suppose, you tell a small kid that don't go on the cycle, you will fall. If you hold the cycle properly, you will fall. Do you remember when you used to ride the cycle in your childhood, you used to put the wheels on the side of the four wheels, right? And it was said that if the wheels are removed, you will fall. If we stop telling the child to put the wheels on the side of the four wheels, and you fall. The child will confidently ride the cycle and never fall. People will say that you will sit on the cycle and fall. The poor child gets scared. The same situation will happen to you. The paper is not tough, nor will the paper questions be dirty. Whatever the paper is, it is very tough, it is so syllabus. They will say this and that and the poor child will be so worried that even if a simple question comes, the child will feel that it will not be made by us. So, throw away this fear, all the questions will be made. It will be organic and inorganic. Maths will be made, Physics will be made, just a time to scare. What is it? KCLO3 plus 6 FeSO4 plus 3 H2SO4 to form KCL plus 3 Fe2SO4 whole thrice plus 3 water. This time, the JEE person gave a very good reaction balance. He is so chunty, I tell you, he does not balance here, never balances here, sometimes he balances half. So you have to balance on your responsibility. The above reaction was studied at 300 Kelvin. Very good. By monitoring the concentration of FeSO4. We monitored the concentration of FeSO4. In which initial concentration was found to be 10 molar. And after half an hour it became 8.8 molar. He says the rate of production of Fe2SO4 thrives. Instead of rate of formation, he wrote rate of appearance, not rate of production. So, haven't you studied English so much that appearance and production are the same thing? So, can I write this by looking at the reaction? Ram chahe Leela chahe Leela chahe Ram In dono ke love mein duniya ka kya kaam Just recognize Ram Leela, focus on these two only. What you are seeing? Minus 1 by 6, D of FeSO4 divided by DT will be equal to 1 by 3, D of Fe2SO4 whole thrice divided by DT. Is this right? Is this right? Now tell me one thing, if we do 2 from here, what will come? minus 1 by 2 D of FeSO4 divided by DT will be equal to D of Fe2SO4 whole thrice divided by DT Brother, this is what I have asked you, rate of production. So you have minus 1 by 2. How much time did it take? Half an hour. Brother wants it in seconds. I said okay. 0.5 hour. You have the responsibility to convert hour into minutes and minutes into seconds. And how much concentration did it change? First it was 10, now it is 8.8. You will do 8.8 minus 10. Now this is the answer. What happened in the question? That we get scared, we don't ask questions about J-Mains. It was simple, right? Just a small thing that I taught you, it was of great use. Do as much as I teach in every concept. Practice questions. Now there is no time to watch lectures for 20 hours. So make sure that the details that I am teaching you in the class, each detail should be your short notes. The better these short notes are, the more confidence you will get in the last 10-15 days. If there are no short notes, then the child keeps looking at it, what to do if I revise? Then there is no time to revise, what to do? This was our topic number 1 which I hope is sorted. 333 is the correct answer. 333 is the correct answer. Now we will do our topic number 2. How many topics did we have to do? 5. 1 out of 5 is done. How many topics are left? 4. Out of 4 topics, we have another topic where we will discuss rate law expression. Listen. Assume I have a reaction AA plus BB. to form CC plus DD. I have to write rate law for any reaction. So, I said, ma'am, first shoot the products. Our focus is not on the product. Our focus is AA plus BB to form product. I said, ma'am, if you have to write rate for this particular reaction, then I will tell you that rate will be directly proportional to A's concentration. It will be directly proportional to B concentration raised to some power. Now you have to keep something of A power, that is X. You have to keep something of B power, which is Y. There is no guarantee that the value of X will be A and the value of Y will be B or not. We don't know. Until you go to the lab, you will not set the apparatus, you will not do the experiment of 15-20 minutes. You don't know that the value of X is A, the value of Y is B or C or D or something else. This is called rate law expression. The rate of any reaction depends on the concentration of reactants in your reaction to some power. And this X and Y can be determined only experimentally. There is no saint in the world who can determine the value of X as A. You will have to experiment to know the value of X. Now if I want to remove this proportionality sign, then I will write rate is equal to k into a to the power x into b to the power y. And to remove this proportionality sign, we have put a symbol. This symbol is called rate constant. What will be called as rate constant? And you know if we have to explain any proportionality symbol, then what to do? Here all things are 1. Means if the concentration of my reactants is unity, then what will be called as rate constant of the reaction? Kids, this x will be called order. with respect to A that in respect to A, what is the order of reaction? X what will be called by Y? this will be called order with respect to B and this stochastic means this power which you have applied if you will sum these powers then this X plus Y will be called overall order of reaction What will be called as overall order of reaction? Is this clear or not? Now listen carefully Someone asked me, what is the unit of rate? Someone asked me what is the unit of rate? I said rate means the concentration in which it is changing per unit time So what can be the units of rate? It can be mol per liter per second This will be it right? or you can take mol per litre per minute or mol per litre per hour which means concentration per unit time If someone says, okay ma'am, so the rate constant you wrote k, find out its unit and tell me. I said, do one thing. You know this, right? That rate is equal to k into concentration of the reactants raised to some power. I said, I don't know the power, so you say nth power to the power n. So if power n is there, then what do I say to it? This is nth order reaction. Should I call it nth order reaction? So now watch carefully. So what are the units of rate? The units of rate are mol per liter. I have to subtract the units of k. What will we write? Mole per liter. Okay? Mole per liter. Do per second here. What will this be? Mole per liter raised to the power n. So, do you feel that Ma'am, mole per liter divided by Mole per liter raised to the power n Second inverse is the unit of k. Let's simplify it a little. k is mole per liter raised to the power 1 minus n Second inverse. What is this Chamki? You don't have to remember all of them. There are 3 orders in your main syllabus which you have to write down. Yes, did you hear it correctly? Either it is 0 order, 1st order or 2nd order. We have 3 in our syllabus. 0 order reaction, 1st order and 2nd order. Remember for 0 order reaction, put value as 0 and n as 0. So what will be the unit? Mol per liter per second. First order will have unit second inverse Second order will have per mole liter second inverse You believe me now believe me more In the paper of 2023, a question was given that For any reaction K's value was Whatever was the value 3.6 x 10 raised to the power minus 2 Mole per liter per second You were asked what was the order of reaction I didn't give this question This question is given by JEE If you know the units of K, you can predict the reaction of 0, 1st, 2nd, nth order No one asks you 2nd, 3rd order, you are asked to remember the order of 0, 1st, 2nd order Mol per liter per second, second inverse per mol, liter, second inverse Did everyone understand? So, this was the story of rate constant which I hope is clear to everyone. I have also told you the order of reaction that whatever the sum of the power above in any reaction is known as order of reaction. Now listen to me carefully. I have two terms, one is elementary reaction and other is complex reaction. Listen. Elementary reactions are those which happens in one step means for example you said ma'am A and B meet each other and the product is formed then you said ma'am you know this reaction happened in one step A and B meet and the product is formed the reaction is elementary reaction so those reactions which are taking place in one step absolutely basic reactions they are called elementary reactions However, the complicated reactions we write, for example, first we have A and B, a complex is formed, now that complex is reacting further with B and it is converted to C. So, the reaction in one step 1 and in one step 2, then we will cut it, I will get A plus 2B to form C. That means the reaction which is in more than one step, in which category will we keep that reaction? Complex reaction. This was there in childhood, SN1 reaction. Remember? It was happening in more than one step. The things we learn in organic, those were all complex reactions. Is there any reaction which is happening in one step? A plus B I got it. A plus B plus C I got it. So these reactions will be called elementary. Ma'am, how will we know if any reaction is complex or not? If it is mentioned in the question that it is elementary, then only you will consider the reaction as elementary. Otherwise, every reaction is complex for you. The mechanism of complex reaction will never be asked from you. Paper wala yeh nahi expect kar raha ki koi bhi duniya bhar ki reaction utha ke dedi aur tumko kera mechanism likho wo bhi itna nirdai nahi hai. They will not ask you mechanism. But aapko kuch chote chote facts mai batati hu. Dhihan sa dekhna. Agar mujhe koi kahe ki yeh ek complex reaction hai. and someone writes me or asks me to write its rate law expression so I will write rate is equal to k A concentration into B concentration I know here is 1 but still I will write x and y Whenever the reaction is complex, the soul should shiver from the distance. It is not that you stick it on 1 or 2, it will be wrong if you don't stick it. But suppose the paper writer writes that your reaction is elementary. If the paper writer writes that you should apply full on. If the paper writer says that the reaction is elementary. So the A and B will come. It will be 1 and 1. That means for elementary reactions, write it in big letters like in Hindi and English. For elementary reactions, the power that is equal to stoichiometric coefficient. Not for all. For complex reactions, this rule is never valid. Never ever it is valid for complex reactions. It is possible that you did it even if it was a complex reaction. It is possible that the value of x is 1 and y is 2. It is possible that no one has denied it. You can't know, until you experiment, you won't know. You always know for elementary. Moreover, remember one more thing. The rate of any reaction, whenever I want to represent the rate of that reaction, suppose I have a complex reaction, A plus B, first C is made, then C is combined with D and E is made, then we say C is cut, then I have A plus B, plus B plus D to form E. I know this is a complex reaction. Whenever I have to write the rate of this complex reaction, I will pay attention to two things while writing the rate. The first thing is that the rate will always determine the slow step. I had learned this in organic. I will give you an example. I will tell you. We make samosas at home. She makes very good samosas. I know how to make Punjabi samosas and Gujarati samosas. There is a difference between the two. Whenever we make samosas, I don't make it alone. Who works so hard alone? You also help your mother when she is making samosas in the kitchen. I don't make it alone. I distribute the work to everyone. If I sit and say that making samosa is not an easy task. First you have to roll the flour dough, then you have to make the roti, then you have to cut it, then you have to make corn, then you have to fill the masala, then you have to put water on the sides. Now will you learn the whole recipe from me? I will make good samosas and serve them to my family. So, we divide the work. If there is someone who is not at home, I tell my mother, my mother-in-law, that you do this, you fill the masala in the samosa. I have told sir to cut some onions, or whatever work you have to do, I have told him that. Then we tell Naksh to do one thing, he should do a round of the whole house, to see if everything is good or not. We put everyone to work. Then we make one person stand to fry. So, I made the samosas. Our entire family does the work. What happens in that is, let's say a guest comes to our house. He says, what did Sakshi make today? I said, I am making samosas. Poor samosas, we are not even going to serve them. We gave the serving task to Naqsh, he was going at a speed. The frying task was mine, I was frying at a speed. Then we found out who was doing it late. Then we found out that Nishant sir was asked to fill the material in the samosas. He was not doing it, he was solving the math question. So who slowed down the reaction rate? Naqsh did not do it, he came quickly. I did not do it, I am frying the samosas in a good way, my mother is also doing a good job. For sending the samosas. We told sir that this is wrong, you are filling samosas slowly. So the slowest step of the whole reaction, this was a hypothetical situation, don't take it seriously. The slowest step of the whole reaction is the one which determines your rate. This is called rate determining step. If I write it in short, RDS. So the rate determining step of any reaction is the slowest step. Now when you write rate law expression then your rate law expression should contain the same reactants It should not be like that that even if it was C then C is also contained in our rate law expression No, if C is cut then C should not be contained in your rate law expression So I have taught you all these important stories Now I will teach you a small term This is called the molecularity of any reaction We study the molecularity of any reaction in microscopic details. I know that you are making NO2 by combining N2 plus O2 together. I said no, we will not agree. We will bring it and see how many molecules are making NO2 by combining 1 N2 with 1 O2. Or whatever reaction we did, 1 N2 with 1 O2 is making 2 NO. So actually in any reaction, how many molecules are colliding with each other? Actually how many molecules are colliding? In an elementary reaction is known as molecularity. Now tell me, can a reaction's molecularity be zero? Zero molecules can collide, right? Can the molecularity of a reaction be 3 by 2? Can a molecule collide with a molecule? No. Can the molecularity of a reaction be minus 1? Minus 1 molecule collides. So, the molecularity of a reaction can neither be a fraction, nor negative, nor zero. The molecularity can be either 1, 2, 3, 4 and so on. But, it has been seen that the maximum number of reactions we study, the molecularity is only 1, 2 or 3. If more than 3 molecules collide with each other, it becomes an ineffective collision. So, you will get to see 1, 2 or 3 molecularity at every stage. But remember, if we define molecularity, then for what? Only for elementary reactions. For every elementary reaction you can define molecularity So this was our topic number 2 You will say what is this? I have taught only theory I have not done any question on topic So this topic will not be known Ok, questions related to topic also come But now this is a little less information Let's add some more things Then we will add questions together Means after topic 3 I will ask you many questions But simple simple questions related to topic 2 also come But I thought first I will ask you some questions I will teach you more. We will do fit questions. How many topics are there? Tell me quickly in the chats. Confidence is coming. First tell me this. If you find out that ma'am is telling stories and you are not getting confidence, then it won't be fun. Confidence is coming. Confidence is coming. First tell me this. Is it good? Is Okay ma'am. I am scared that I have studied JEE main but still nothing. You have studied from the beginning. There is one thing which is trust. No magician in the world can give you that. No saint or Mahatma in the world can give you that trust. That trust comes from within, from within you. It is hidden within you. I will repeat one thing. If today in this whole session, in this two hour session, even one child learns this thing that I have to get rid of the fear within me. You will be half-win, this will be your half-win. Who taught you that JEE is tough? Who said it? Who? You pick up the previous year question and don't do it too much. Remember one fact. There is a stone line on a big paper. Take it from me. See how well it is written here. Write a big thing on it. Take a big thing and write on it. That JEE is not tough. Say yourself 50 times a day that it is not tough. But yes, this is wrong. You are saying yourself that it is not tough, it is not tough. When teacher is saying that today I am doing 15 PYQ, you do 15. You are sitting on the trust of ma'am, ma'am has done 15, so that is it. Why should we do? Brother, it is tough, so write on the paper that this is tough for you. It is simple, the more hard you work, the more confidence you will get. I am telling the truth, children. We feel from inside that why won't I get it? I agree that not all children are intelligent and not all children should have it. So the child should be scared from inside that how will I get it? Another fear is that we have not studied anything for the whole year, so what guarantee that I will get it? How much time is left for the paper? 85-86 days are still left. Either accept defeat and go to the corner of the room and sit and say that it is very difficult, I will not be able to do it. Either this option. Second option, stop thinking that it is tough. Stop thinking that my 11th is a waste, my 12th is a waste. Do it. You wake up at 8 in the morning, no, wake up at 6. Wake up at 5, study as much as possible. Apart from studies, nothing will make you select anything. No motivational video, no motivational song, no meditation. Nothing will make you select anything. selection nai hoga agar selection hoga paper mein it is just because of your hard work tum 8 ghante padhto 9 ghante padho Push your limits, come out of your comfort zone, you will get selected. You will not come out of your comfort zone, start cribbing, you will not be able to do anything. Even today, even after 3 years, nothing will happen, even if you do a job, nothing will happen. You will do the same job, life will be the same. That you were born, your parents raised you, then you got a strange job, then you got married, you got children, you got old, you got dead. This will be life. If you want to do something good, then work hard, if you work hard, everything will be good. If you don't work hard, then it will never be good in your whole life. God will say, wow! You are so special that God should do extra for you. Wow! He is a special child. No special. Work hard and everything will be done. I mean today's session you have made motivational session I will do topic and you will say something in between I mean I will start motivating you Anyway, today's class topic number 3 This is the third topic of today's class How many you have to do? 5 How many you have done? 2 See the third topic in front Now I will tell you a small term which is called Degree of Completion I had taught you equilibrium I remember I taught you one thing Which we called Degree of Dissociation Do you remember the degree of dissociation which we used to write alpha in our childhood? What was the degree of dissociation? Ma'am, how much amount of dissociation has been done? Divided by total amount, how much did you take? Remember we used to write A to B. Ma'am T is equal to zero. Assume this was A. Ma'am T is equal to T. Assume this X is broken. So A minus X is left. Don't say that I didn't learn this in equilibrium. I had taught you. So how much amount did X break? How much did A take? So what was the value of X? A alpha. Then that degree of dissociation, degree of ionization, degree of hydrolysis, we did all those things in terms of alpha, right? Now, because I am talking about a chemical reaction which I have to complete, I want to see whether my reaction is 10% complete or 20% complete. It is written that a reaction gets completed 30% in 30 minutes. So, many times, in chemical kinetics, it is written that, 10% reaction will be finished in this time, tell me how much time 70% will be finished? So for that we made our story easy, we said we will discuss degree of completion. Paper guy wants to discuss completion, I said let's discuss completion. So what is the meaning of degree of completion? Alpha. Alpha is the same thing that how much amount of reactant has been consumed. Amount of reactant which has been consumed. amount of reactant which has been consumed, which has been consumed divided by total amount taken. total amount taken alpha is amount of reaction completed amount of reaction completed divided by total amount taken how much amount you took in the beginning initial amount of reactant and how much amount of reaction completed You understood that if 10% reaction has been completed, then it is nothing but percentage alpha. So, I will divide 10 by 100. If yesterday it was written that 85% reaction has been completed, then I know that alpha is 85 by 100. I am not going into more detail than this. When I had taught this chapter in booster, I tried to give more details to those students. I did all the derivation. But it is not possible to do the full derivation in such a short time. So, I will... I am teaching you the to the point crux of every derivation. We are learning the one which will be directly asked in the paper. If someone wants to do everything in detail, then you can definitely follow the booster. But you are getting the SAR of booster in brief. Brief is all about brief. SAR of all the chapters, right? So see, for me, it is important that you take a formula today. You heard me right. I said take this formula. The formula is, the amount of reactant left over at t time is equal to the initial amount of reactant multiplied by 1 minus alpha. Where did it come from? It doesn't matter. What does it mean? Ma'am, if I want to see the amount of reactant left at T time, then what will be the value of AT? A0. A0 is initial concentration into 1 minus alpha. Alpha is the degree of completion, that is, how much reaction is completed. It shines, look at the front. Now, we don't have to do any derivation. I am very clear, we are not doing any derivation. But, I will tell you how to do every question. We have two reactions which I have to study. One is our zero order reaction. One is our first order reaction. Second order reaction does not come in mains. Zero order reaction means, suppose, whenever I write any reaction, then rate will be equal to k into a raised to the power zero. Rate will be equal to k into a raised to the power 0. a raised to the power 0 means 1. So the rate is, if the rate of any reaction is constant with time, means k was constant right, rate is constant if the rate of any reaction is also constant then you should be able to see that ma'am you are talking about zero order reaction means suppose I have plotted the rate here with respect to concentration of A if I take any concentration of A then my rate is not changing you should be able to see the graph and see that ma'am this is zero order reaction why did I say zero order because power was zero Now we will do derivation about this. Derivation goes like, we write rate as minus dA by dt, rate we write as k into A, A raised to the power 0, then we do derivation of 5-6 steps. I will tell you a free thing, what you have to remember. You have to remember that for any zero order reaction, A naught minus A t is equal to kt. I don't say this for any physical chapter, that you should write the formula. But, there is a chapter in Chemical Kinetics, if you know the formula, you don't have to do the derivation. If the formula is known, children don't know how to use the formula. So, the formula should also be known. To the point should be known, and how to use it is the most important. For the order of zero, remember one thing, A naught minus A t is equal to K t. Say it four times, you will remember it. A naught minus A t is equal to K t. A naught minus A t is equal to K t. a t is equal to k t a naught minus a t is equal to k t. Ho gaya? Look at the front. Children, for the order 0, I have just taught you. A0 minus AT is equal to KT. Ma'am, tell me the meaning of this. The meaning of this is, suppose you had a reaction from A to B. T is equal to 0. Suppose your initial concentration was A0. This was something. T is equal to T time. This something broke. Suppose what is left? A0 minus X. This became X. So, A0 means initial concentration. And the concentration of T time will be called AT. Chamka, you should remember two reactions when you write 0 order. A0 minus AT is equal to KT. And what is the second? Second is the same. That AT is equal to A0 into 1 minus KT. That's it. I want all my students to know these two things. Now there is a time which we call T half. T half means here T alpha. That the value of this alpha is 1 by 2. T half means if you multiply half by 100, it means 50%. So if tomorrow you write T 50%, it means that this is the time when 50% reaction is over. Okay? Time in which 50% reaction has been completed. I have to find the value of t half. I said ma'am, we have to find t half. So, we know alpha is 1 by 2. So, find 80. 80 will be a naught into 1 minus 1 by 2. How much will it be? a naught by 2. Here put a naught minus a naught by 2. How much will it be? k into t half. And a naught by 2. How much will it be? k into t half. Now, see I have already given you this derivation. Okay. I have done the calculation. But will you listen to me? You might feel bad that ma'am is saying to cut it. But I am saying the truth because there is a lot of time left in the paper. We should not even do derivation. A good kid who knows the nature of the paper, from where the question will be asked, he should remember three things as soon as he writes the zero order. What? a0-at is equal to kt. kya AT is equal to A0 into 1 minus alpha kya T half ki value hai A0 divided by 2k ab thik hai tumhe bura lagay, achcha lagay magar end of the day agar tumhe ye cheez pata hai toh tumh baki bachos se aage nikhloge If you want to derive, you can do it. I will not refuse. But if you know this thing, then the questions will be quick. Do you see that for 0 order, T1 half is directly proportional to initial concentration? If initial concentration is more, then T1 half is more. If initial concentration is less, then T1 half is less. This was the whole story of our Zero Order Reaction. Don't do more than this. I will solve the questions for you and you will feel that ma'am you were right. That our reactions and questions are becoming our own. Now, let's talk about the first order reaction. First order reaction means the rate of which I will write as k into a raised to the power 1. And the rate of which I will write as minus dA by dt. I will equate these two, I will do derivation of 5-6-10 steps, I don't want to do it. I should directly know this, for first order, ln of a0 by at is equal to kt. That's it. From where? From derivation. What do you know? For 0, what did you do? a0 minus at is kt. Here also it is simple. ln of a0 by at is equal to kt. a0 is the initial concentration. at is the concentration of t time. Now, once again, you should know this. What should you know? That at is equal to a0 into 1 minus alpha. Now, I will tell you to take out t half and show me. You do one thing. Keep alpha as 1 by 2. Then substitute at here. Solve it completely. Your free talk is t half value. 0.693 by K. That means the half-life of first order reaction does not depend on initial concentration. The half-life of first order reaction does not depend upon initial concentration. I would like to tell you, all our radioactive decays They all follow first order kinetics. That's why you must have seen that the use of nuclear weapons is banned. They can't do it without any reason. Do you remember the case of Hiroshima and Nagasaki? Even today it is said that if a child is born there, then somewhere or the other that radioactivity is found. Why? Because first order reactions are never complete. They never go to completion. It is not complete. See how. Suppose I have T is equal to zero time. Suppose I had 100 moles. Suppose I had 100 moles of something. Suppose the half life of that radioactive particle was one year. One year. So, do you know how much will be left after one year? Half. 50. Then again after 50, do you know how much will be left after one year? 25. Then after 1 year of 25, how much will he be left? 12.5 After 12.5, again after 1 year, how much will he be left? 6.25 Then 3 point something something, did you understand? So, brother, it can definitely be 0.0000 But even after crores of years, something or the other will remain Understand? That's why it is said that the radioactive days follow the first order kinetics They never go to completion This is known as half life. Now you know, I will tell you a nice thing. Sometimes he gives us a reaction like how much time will it take to get a 75% reaction? I say that 50% reaction was completed here and 75% reaction was completed here. 100% was there and 25% was left. So, 75% was completed. So, it took 2 half-lives. How much half life did it take? 2 half life took for 75% of reaction to be completed. So for first order kinetics, you don't need to apply formula. On the basis of these, your answer is given. Now one question is asked to you depending upon order of reaction. How do we get the order of any reaction? One is what is taught in NCRT. I think everyone must have learnt this. What happens is, in NCRT, they write like this, suppose I have A, B, C, D. There are 4 experiments. Here we have taken concentration of A as 0.1, 0.1, 0.2, 0.4. B concentration is that we have taken point 1, here we have taken point 2, here we have taken point 2, here we have taken point 3. Here we get some rate written. Here the rate is 1 into 10 raised to the power minus 1. Here 10 raised to the power minus 1, I will remove it for simplicity. Here the rate is 1, here 2, here 4, here 8. Look carefully. He said write rate law expression and show me. So how do we do it? In this we have to do like this. First I will choose those two experiments where A is same. I said ma'am in both these experiments A is same. By doubling B, rate doubled. I doubled B, so the rate doubled. How is that possible? It is possible only when B is 1. In the rate law expression, if B is 1, then if I double B, the rate will double. So, the corresponding order of B is 1. Let's do one thing like this. We said ma'am, now you do one thing. Select something where B is same. So I said, see B is same here and here. Select these two. So I said ma'am, by doubling A, the rate has doubled again. So what does it mean to say ma'am, A has one power too. So what is the overall order of reaction? 2. You must have solved such questions in NCERT, right? I am 100% sure you must have done such questions in school too. You are not doing it for the first time, this is already known. The thing that was not taught in your school, the thing that was not taught in tuition or coaching, I will teach you now. This is important. What happens, the T half of any nth order reaction, Let's write it on the next page. Any nth order reaction's T half is directly proportional to initial concentration raised to the power 1 minus n. I will also ask questions about this. But first remember this. No proof required. Any reaction's T half is It is directly proportional to A0 raised to the power 1 minus n. If there is a zero order reaction, then T half is directly proportional to A0. If there is a first order reaction, then T half is directly proportional to A0 power 0. You know that T half does not depend upon initial concentration. If there is a second order, then T half will be directly proportional to 1 by A0. So, if you put any value of n here, you will get the answer. These were our three topics. Now, what kind of questions are asked in J-Mains related to these three topics? You will start getting questions on your computer screen one by one. So, without any delay, you will keep asking me these questions. So, this is the first question on your computer screen. Let's see whose correct answer is coming. I answer. If nothing is the same, then you won't be asked a question where nothing is the same. He also wants the kid to ask questions. Why will he ask questions that can't be solved? Look. The graph which represents the following reaction. Now, those who don't know about organic, they will never ask about chemical kinetics. Organic was not necessary. This is C6H5 whole tri CCl, we will put OH-in the presence of pyridine. I saw that ma'am, Cl must have come out, OH must have come. It is a nucleophilic substitution reaction. Ma'am here one carbocation is made which is very stable carbocation. See the tertiary carbocation which is resonance stable. Means reaction proceeds by SN1. If reaction goes from SN1 means nucleophilic substitution unimolecular. Then it is first order kinetics. First order kinetics means rate of the reaction will be directly proportional to concentration of alkyl halide. So rate will be equal to K into Rx. So as the concentration of Rx increases, the rate increases. Y is equal to Mx. So he says that the rate and concentration are same. He says that it does not depend on OH-and on pyridine. So C is the correct answer. I know that it is possible that I do not ask you this question today. How can you not be surprised to ask this question? So that you know that it is not easy to get rid of organic. Means easy? It is not possible. So if you feel that we should leave organic then you are also leaving physical. Ok, if you are leaving organic then you will leave physical. Because nowadays there are such questions where organic and physical are asked together. So don't even dare leaving organic chemistry. Even if you don't do much Hi-Fi but you have to do this much that if tomorrow there will be a question of physical then we don't have to leave it because we don't know organic. There are many children's things SN1, SN2. Those who have not done organic, the lectures of JEE brief, the initial lectures, GOC, hydrocarbons, haloalkanes, haloarenes, I have taught everything, I have taught in this only, I have taught this only there, so make sure all the children will definitely watch it. And if you want to do it in detail, then in booster, in week 5, I am starting organic, you can do it from there. JEE main 2022 question, see, Can I add 30 degree C, the half life for decomposition of AB2? He said, if AB2 decompose, its half-life is 200 seconds. I said, very good. And is independent of initial concentration of AB2. I said, ma'am, if T half is independent of initial concentration, then it is possible only if it follows first order kinetics. For first order, you said that Rutlow T half is 0.693. Brother! If you know this 200, then don't you know K? 0.693 divided by 200. This is known. Now you do derivation. Sit to do derivation. Won't you get He says the time required for 80% of AB22 decomposes. He says how much time is required to decompose 80%. I said it is first order. You had taught us one thing. ln of A0 by 80 is equal to KT. Did you teach this? I had told you to remember directly. So assume initial concentration is A0. If he is saying that 80% is decomposed, then how much is left? 20% So how much is left? 20 by 100 times. A naught is left. K value from here is 0.693 divided by 200. Kids, what kind of problem did you face in solving this? Can't you write Ln of 100 by 20? You will do it, these are simple things. If you don't understand Ln, then log 2.303. This is a question of 2022. I am not asking old questions. That the child used to come easy earlier, now it is difficult. These are the questions of today. 23 was also easier than 22. Do you understand? I said, throw away the fear. Once you throw away the fear, then the paper will be done. This is a question of 2023. So, how much is left? 12.5% Just like this 100, 50, 75, 87.5, you can see this 100, 50, 25, 25, 12.5 Minus 12.5 out of 100, you get 87.5. I was just telling you this. It says that T87.5% is the time required for reaction to undergo 87.5% completion and dash 2 is the time required for the reaction to undergo 50% completion. Okay, this T is 50. Either T is half or T is 50, it is a little misprinting. T is 50% is the time required for reaction to undergo 50% completion. He said, tell me the relation T is 87.5 and T is 50 for a first order reaction. I said, Ma'am, what are you saying? You had taught me the first order reaction. If it has to come from 100 to 50, 50 to 25, 25 to 12.5, so can you see that 87.5% reaction completed? Assume this is my t half, so this is also t half, this is also t half. Do you know ma'am t 87.5 is nothing but 3 times t 50%. Tell me what I have thought that it will be very difficult. Tell me, tell me, tell me. Look and tell me the answer. Is it so that ma'am this is a very difficult question, I mean we are not capable of asking such questions. Will you do it or not? Ma'am is this enough? Yes, this is enough provided that you are doing everything carefully. If you are doing every topic carefully, I am doing many PYQs myself, but if you are doing the same PYQs yourself, then yes this is enough. Focus on the major things and if it becomes a major thing then the minor things will happen later We always focus on the minor things and our major remains like this So change the way of thinking and thinking Jaye Men, another question from 2023, he said that topic 3 will be done and then we will do many more questions He said that A and B are two substances undergoing radioactive decay in a container I said do anything first order kinetics half life of A is 15 minutes means A will be A by 2 in 15 minutes and that of B is 5 minutes B will be B by 2 in how many minutes? 5 minutes if the initial concentration of B is 400 times than that of A First I said A is 100, so I said B is 400. The initial concentration of B is 400 times that of A. And they both start decaying at the same time. How much time it will take for their concentration of them to become same? This is not the first time the question has come. This is a repeat question. Let's change the data. I said, Ma'am, let's play on B first. B will convert from 400 to 200 in 5 minutes. Then it will convert from 200 to 100 in 5 minutes. And it will convert from 100 to 50 in 5 minutes. Even a very small child will say that. Ma'am, this is simple. And I said, how much time does A need? A needs 15 minutes. In 15 minutes, where will it reach? At 50. So when both the concentrations are same, how much time will it take? 15 minutes. Now, many great kids solve this. ln of A0 by 80 is equal to kT. ln of A0 by 80 has to be same for both. And I don't know what all we will apply. Because in first order kinetics, we have to use our brain, not values. It's not that we know that all the values are being put in the equation. That a0-at is equal to kt. All these stories are being told. Don't do this, you will get stuck, it is so easy. So, whenever you see this term, Teeha, First order, Radioactive, 87.5, now, I did 87.5, tomorrow it will be 75, tomorrow it will be 87.5, from 12.5, do 6.25, then do 6.25 minus 100, you should be able to recognize these terms from a distance, it is first order. Next question, of 2023, all of them are of 2023, I have put some 22, so that you know what level of questions come. A student has studied the decomposition of gas AB3. He obtained the following data. When the pressure of gas or concentration is the same and this is T half. Order of reaction. Did I teach you a little while ago that t1 half is directly proportional to initial concentration raised to the power 1 minus n? Did you learn this or not? Did you not do any derivation? I am proud that we are not doing derivation. There is no point of doing derivation. t1 half. I said if my t1 half is 4 minutes, then what was my a0? 50. Raised to the power 1 minus n. If my t1 half is 2 minutes. So my initial concentration was 100 raised to the power 1 minus n. Kids, do you know how to take the ratio? 4 by 2 will be equal to 50 by 100 raised to the power 1 minus n. Kids, 2 will be equal to, what is this? 1 by 2 raised to the power 1 minus n. Do you feel that if you do the value of n as 2, then 2 will be equal to 1 by 2 raised to the power minus 1. So 2 raised to the power minus 1 is 2. So what is the order of reaction? Did it shine or not? Is this the same question that is for JEE? Yes. I have not conducted any mock test by Sakshi ma'am in which ma'am has put such cheap questions that the children feel that wow it is very easy. I have not said anything like that. The question is in front of you. So now you are getting confidence that we have only JEE. That it is difficult, difficult, difficult. One thing means you... If you say one thing repeatedly, it is a fan. I say no, it is not a fan, it is a remote. If I say it 100 times, it is a remote. I will see this remote only 101 times. Have you become deluded that it is difficult? No, it is not. So this was our topic number 3. How many topics did ma'am have to do? 5. What time is it now? 7.19. It hasn't been 1.5 hours yet. How many topics did you have to do? 5. How many did you do? 3. Have you seen how many questions you have done? Now let's talk about topic number 4. Topic number, once again, I will teach topic 4 and 5 first, then I will ask questions because only topic 4 and 5 are not asked. Both should come, then the questions will be asked. This is Transition State Theory It is based on Organic Theory We say that we have a molecule A2 and B2 If I want these molecules to collide with each other and these get converted in the molecule AB so this is possible only when the bond between A and A breaks the bond between B and B breaks and the bond between A and B should be formed so the transition state theory says that if you want to convert products from reactants So first your molecules should come close to each other, they should collide with each other. When they collide with each other, the bond will be formed and the bond will break. At the same time there will be simultaneous breaking and formation of bond. So you know I will write this, bond is breaking, bond is forming, bond is breaking, bond is forming. This boyfriend is getting angry. This is a story of a couple who are in a bond break. The bond will be formed and the bond will break at the same time. Now he says that these reactants were very stable. He says that you tried to make such a product, the reactants were very stable. He says that the product was also fine. But when you go from the reactant to the product, the thing that is made is called activated complex. It is so dangerous that its energy is so much that it has more energy than the reactant. It has more energy than the product. So, let's assume you have to make a potential energy diagram here. Here I am plotting energy. Here, see, many times it is written that the reaction coordinate is given. Many times it is written that the progress of reaction is given. So, there is only one thing to be afraid of. Let's say I make two panels, I want to teach both the graphs at the same time. So now you know that here is energy and here is the progress of reaction. You get curves in two ways. Let's say the product of reactant is here and it is of more energy. or you can assume that my reactant is here and my product is of low energy you will get these two graphs now there is such a wisdom in all of us that our reactant's energy was low earlier now the product's energy has increased so ma'am we must have given energy this graph is called endothermic endothermic reaction graph ma'am earlier the reactant's energy was high product's energy has decreased When energy is released, this graph is called exothermic graph. In 2023, the question was on the basis of graph. See, this energy from zero to reactant is called energy of reactant. This energy from zero to product is called energy of product. And once again, we use the same color here. This energy is called energy of reactant. This energy is called energy of product. Thank you. Do you remember we had read Enthalpy in Thermodynamics? The difference in energy of reactants and products is called Enthalpy of Reaction. The question is, you must have been given energy of reactants and products and it is simple. Now, we are afraid of the question of JEE. This is a question for children. This is 50, this is 100. Tell me how much is the enthalpy of reaction? This is a question for children. If you are afraid, then you will not see any difficult question. Now, look carefully. So, my transition state is called transition state or activated complex. What is transition state or activated complex? If I want to cross this transition state, then I should have a minimum energy to cross this barrier. So, when I want to cross this barrier, it is called threshold energy. This is known as Threshold Energy. Let us say I am in Delhi and I want to go to Rajkot. To go to Rajkot from Delhi, I will need at least Rs. 2500. Whether I go by plane, car, petrol or scooter. Or I will go by bicycle or I will go by foot. I need some minimum money. So the minimum energy you need to cross this barrier is called Threshold Energy How much energy do you have in present? This much The difference between what you have and what you need Which color is left? Which one is left? This one is purple, I don't know if you have seen it or not The difference between this is called Activation Energy You have 100 and you need 1000 So the difference of 900 is called Activation Energy Now if you get a feeling of heart attack after seeing this complicated diagram then it is wrong This is not complicated. This is not complicated. When I made it with simple yellow-yellow color and then blue-blue color, then everything was shining. So, after making it complete, you should not be afraid of it. Why? This is what I teach. Don't think that it is very tough by looking at any question. Divide that question into pieces. In small parts, make a hold on each part. This is the energy of reactant, product, enthalpy, threshold, activation. Someone, show me the activation energy of backward. The same thing is done by JEE. Let's ask things in style. Say, take out the activation energy of backward. I said, brother, you are our reactant in backward. You are still in transition state. We have this much, we need this much. So, did the activation energy come out of backward? Now if I say 60 and he says 20, then you will not come to do this 60-20 question. 20 out of 60, 40, 20 out of 60, 80, you will do this. The logic should be clear, you are here. Some backward activation, I said you are here, you have to go here. How much energy is required? We will call this EA. Where for? For backward. It was brilliant. This was the complete transition state theory. Topic number 4 was said. It was completed. Today's class's last topic. The name of this last topic is Arrhenius. equation, Arrhenius theory, Arrhenius equation, what is this? You will understand this thing very carefully. I had told you that, any reaction of which we used to write, rate is equal to k into a raised to the power something. So that k was k, rate constant. So how does this rate of constant vary with the temperature? The variation of K with temperature is known as Arrhenius equation. We don't have to do derivation. It is an empirical relation. Derivation is not required. You should know the direct formula. K is equal to A. E raised to the power minus EA by RT. K is A. E raised to the power minus EA by RT. This K is called rate constant. E raised to the power, this E is the activation energy which I just taught you. This T is the temperature but remember that no degree will put in C. Now the first term of E is called pre-exponential factor. This is known as pre-exponential factor because before exponent this is known as pre-exponential factor. So, this is the pre-exponential factor. You should know the rata. You will say that you will derive in the paper but we don't remember negative plus. That is your mistake. k is equal to a e raised to the power minus ea by RT. Sometimes direct question will be asked. He will say tell me the value of ea. I will ask that question now. Sometimes what he says is that take log on both sides. What was it? k is equal to a e raised to the power minus ea by RT. Take ln on both sides. What will come? lnk is ln A minus E A by RT. Convert log. So, I got log k is log A minus E A by 2.303 RT. Kya aapko ye chamak raha hai? Ki ma'am, ye y is equal to, ye 1 by t kar dana, m into x plus c. Kya aapko ye y is equal to mx plus c dikhayi dera hai? Kya main ek graph plot karu, jahan par mujhe log of k ko plot karna hai, versus 1 by t. Mera ea negative ho nahi sakta, r negative ho nahi sakta, to meri negative slope aayegi with some intercept. Kya? My graph is like this. Do I know that this is log of A? Do I know the value of slope? Minus Ea by 2.303 You don't know this. You know this. There is nothing wrong with this. Everything is simple. What was the This will work, everyone got a good idea. Now, one thing happened. Now, one last formula which I want to teach you. See, either the question comes from the graph, or directly related to this question comes. Or asks how much is the slope, what will be the intercept? Or, many times he asks that if T1 temperature has rate constant K1, and T2 temperature has rate constant K2, then tell me Ea. How much is the value of the teacher? Now once again, many students say that they will do derivation. Madam, you do derivation or not. We like the teacher who does derivation of everything. Then brother, then teacher will have to take along in the paper. Because derivation is not made in the paper by itself. And even if it is made, then the clock will keep on ticking. The clock will not say that I will stop, you do derivation and I will start again. It is not KBC. Amitabh ji says that stop. Then it stops until the audience does not answer or the phone off friend does not happen. That your clock will stop during JEE. Then the clock stopped, we are doing derivation. There is no time in the paper. Even if it is a board paper, I will not say that do derivation. It does not take so much time. What did you do for two years? If you want to do derivation in paper, then what did you do for 2 years? Then we would have taught you directly. What was the need to do derivation for the child? So listen carefully. If I want to know that one rate is constant at T1 temperature and one rate is constant at T2 temperature. So I will write log of K2 by K1 is equal to Ea by 2.303R 1 by T1 minus 1 by T2. Direct value substitution is the question. Log K2 by K1 is Ea by 2.303R. 1 by T1 minus 1 by T2. This was our fifth topic. Now it is time to see what kind of questions are asked. The question of J-Main 2023 has come on your computer screen. You will tell me the answer to this question. Please take your time and tell me the answer for this question. Is question ka answer batayenge. Theek hai? Hi Ma'am, Ma'am you are great, you helped me to cover whole chapter syllabus from Bounce Back. Thank you so much Ma'am. Oh man, we should thank you all. You kids do it. This is very important for us. Teacher does hard work but teacher's hard work is successful only when kids use it. So this is very good. If you are doing it, from anywhere. Okay, we took that too. We took 8-8 hours classes. So you are doing it from anywhere, from brief. If you are following IIT express for advance and you are using booster then the bounce back which was there at that time means now you can say that advance version is booster because a lot of things have been added on it like you have to give test, proper your All the speed based questions, how much time to do the question, all the PYQs, all that is added on and it is booster now. Yes. It says the rate constant of above reaction, there was one reaction. At 200 Kelvin, there was one reaction which got missed here. It says 200 Kelvin. And the rate constant at 300 Kelvin was 0.03 minute inverse and 0.05 minute inverse respectively. He says, get the activation energy. The question is for 2023. Now, someone must have done it in the derivation paper. It must have taken 7-8 minutes. In this, the rest of the students, Inor, Gani, took 3 questions and moved ahead. Then, the difference will come. In rank, there will be a difference of 12-15,000. So, what we had to do? Log of K2, 0.05 divided by K1, 0.03 is equal to EA by 2.303R into 1 by T1, 200 minus 1 by T2. So, see who I have taken as K2, K1. So, that is K1, this is K2. Log of K2 by K1 is Ea by 2.303R 1 by T1 minus 1 by T2. Did you do it? It was a question of 2023. Next question, look at the paper, the paper ones are good, log 2, log 3, log 5, I tell the children that you at least write down the values of log 2, log 3, log 5, log 7, log 11, so that no one trusts the paper. Next question is from Jai Men 2023. It says, the equation, there is an equation given, k is equal to 6.5 into 10 raised to the power 12, this is the second inverse. e raised to the power minus 26123 k divided by T care is followed for decomposition of a compound a the activation energy for the reaction in kilojoule per mole other chemical kinetic may but chaffa stahit oh bhopal stahit units may jinko s a look like a units con dekhta unko my batado unit dekha garo naito galat ojega so what cap co-chamak raki k is equal to a e raised to the power minus e a by RT jaisa lag raha hai What do you think? K is A e raised to the power minus Ea by RT It seems so. So, A becomes A. So, should I tell you that minus Ea by R is minus 26000 divided by just minus 26000 negative to negative R you know the answer will come in joule per mole which will be divided by 1000 and the answer will come kilo joule per mole. Sorted? Let's see further. I think that was all the questions. Yes. So these were all the questions. I had promised you that I will make you do only 5 topics And I will make you do those 5 topics in such a way that your formula is ready, approach is clear and you don't have to make any mistake I have tried my best to make you understand all the most important topics of this chapter in as much detail as possible I have taught you everything Now apart from this, see what you have to do Your previous year questions of 2023 and 2022 You will have to practice some PYQs yourself. Like I said earlier, if I solve 200 PYQs in front of you, until you do not do even 10 PYQs, you will not have confidence because I will not go with you in the paper. Maybe for me as a teacher who has been teaching for so many years and who has studied so much before, maybe for me as a teacher, all these things are very easy. But these things will be easy for you when you will put your time on these things. So make sure you have to work a little extra hard. Now you think that we can work hard on our own well and good. You think that we don't do it. What happens if you don't say it? I don't have time. I don't know where to start. I don't know the theory. So you can definitely follow the booster. Look, as much as possible, in this chapter, I did explain each and every minute detail. But then also you need to understand that I I am telling you clearly that I have not done derivation because in 2 hours I cannot do derivation with you which are not even required But yes if you want clarity of concept you are like no ma'am I can't take risk and I want to do such studies which will be useful for my mains and advance You can definitely follow booster without any second thought because there is time we have that time right Child has time he has to do only 3 chapters in a week so child is doing and then so many previous year questions practice as much as you do PYQ The more you do, the more performance you will get. The result will be better. You compromise on PYQ. Go to the booster and apply this book, apply this book, apply this book. Nothing will happen with any book. What has to happen is done by PYQ practice. So make sure all PYQs have to be done. Take a target that I have to do PYQ for 2023. These booster students are also doing it. They have also given a timetable to them. They tick tick and come to me every Saturday and Sunday. I am done, I am done. Whoever does not have, he writes such a big note below and sends. Ma'am, I was sick, I could not be. Thank you. I will promise you next time, when a child is keeping track of everything, you have to keep track too. So make sure you keep studying from that track because you should not miss the track. In this journey, only two things will support you. One is your hard work, one is your consistency. You study for 20 hours a day, do nothing for the next two days, that accounts to zero. You are consistent but not doing hard work That accounts to negative then So make sure you keep hard work and consistency constant If you face any problem anywhere, we are always there You can mail me, I try to reply to all your questions You can come to YouTube and do it You can do it like that, through message Whatever we can do, we definitely try to help you out So make sure you stay connected with us And who haven't subscribed this channel yet Do it quickly because now you are going to see a lot of things. Today Nishant sir uploaded a video and I think after uploading that video so many messages came that this was our doubt and you really discussed all those things which were going on inside us but we were not able to discuss it with anyone. So you also first watch that video and if there is any other problem do let us know. because we are always there to help you out. So, thank you so much for the session. I will be meeting you in the next class. Take care. Bye-bye.