Electrochemistry Key Concepts

So, dear students, we are going to start Electrochemistry And Electrochemistry is a very big chapter in itself But we will cover all those important points Which a student should know for a board exam If we talk about Electrochemistry, then it deals with In Electrochemistry, we read Conversion of Chemical Energy That is, the Chemical Energy Chemical Energy Converted into Electrical Energy That is, to generate electricity with the help of Chemicals That is, to light the bulb with the help of Chemicals That's it Second, in Electrochemistry, we read Conversion of Electrical Energy to convert it into electrical energy or chemical changes What does it mean? That you will use electricity and bring about chemical changes For example, I have NaCl on my palm If I want to separate chlorine gas from my palm NaCl means salt I have salt in my palm and I want to separate sodium from NaCl and chlorine from NaCl, then it won't happen But if I put electricity in it, then sodium can be separated and chlorine can be separated That means we will use electricity and bring chemical changes In the chapter named electrochemistry, we read that we are electricity from chemical And second, chemical changes from electricity Understood? That is electrochemistry Now whenever we do any work, we have to use a device So remember, the device that will give us electricity from chemical The device will be called electrochemical cell, or voltaic cell, or daniel cell, or galvanic cell Anything can happen Means You will get electricity from chemicals, but you will have to study these devices Secondly, if you want to get electricity from chemicals, then reverse it If you want to get it done in reverse, then the device is called an electrolytic cell So friends, we will study the device one by one First of all, we will study the electrochemical cell So what is the construction of the electrochemical cell? And what happens here? Here you have to pay attention to the chemical I will show you electrochemical cell So we are studying electrochemical cell What happens in electrochemical cell? You generate electricity from chemicals You generate means you convert electricity You convert chemical energy into electricity energy How? You take a box You put some chemical in it You put copper sulphate in it Here you put zinc rod Here you put copper rod And you connect from here And here is bulb or voltmeter, whatever it is, it will burn. What will happen? It will burn. You put chemicals, you get electricity. Now friends, to complete this circuit and to keep it neutral, what did I say? To complete the circuit and to keep it neutral, we put in the middle, it is called salt bridge. What does salt bridge do? It completes the circuit and keeps it neutral. What does it keep? Neutral. Why is its name salt bridge written in it? Because it contains salt, KCL. This is called saturated solution. The solution we make, we make it in gelatin or in agar agar jelly. What did I say? KCL is a salt. What is KCL? Salt. Who makes this salt? In gelatin or in a jelly called Agar-agar. Thick paste. We make it thick. Why thick? So that the salt doesn't fall. And here we also apply cotton. You will say, sir, we don't understand. Let me read you a little about salt bridge. If we read about salt bridge, what will you see? It is inverted YouTube. This is an inverted YouTube. Joining two half cells, which joins half of them. Containing saturated solution. of electrolytes such as KCL, KNO3 It has electrolyte solution or KCL or KNO3 and it is written that the saturated solution is generally taken in agar agar and in gelatine I have told you that it is made in gelatine or agar agar Understood? So YouTube, this salt bridge is inverted YouTube and what is added in this YouTube? Salt, what is added? Salt and who makes the solution of salt? Agar agar or in gelatine friends Now friends we understood this salt bridge I have also understood the function of salt bridge I have told you the function of salt bridge, pay attention The function of salt bridge is, now it will be written I am disappointed, it didn't come Here it is, where is the function of salt bridge? It is missing, here it is, function of salt bridge It came, complete the electrical circuit It completes both the circuits and maintains the neutrality I told you, to keep it neutral and to complete it We use salt bridge Now friends, what happened, we did nothing We used chemicals and we got electricity So this is called electrochemical cell Now friends, you will have to pay attention to some things. Here, the zinc is the rod of zinc. The zinc rod melts. What did I say? The zinc rod melts. How does it melt? The zinc removes two electrons from inside and oxidizes itself. What does it do? Oxidation. That means, the zinc oxidizes and the zinc rod melts. The copper below goes up. Why do they go up? Because when Zinc melts, it will produce two electrons Those two electrons, the two electrons that have come out, they go from here to here Electron is a negative particle, so to get this negative particle, the copper plus 2 inside goes up and gets accumulated So this copper plus 2 goes up, takes two electrons, becomes copper zero and will do its own reduction It is called reduction, okay? So on one side there is oxidation, on the other side there is reduction So from here the electrons will go this way, and we know, we have studied in physics, if our electron is going this way then our current will come this way that means the flow of electron is from zinc to copper and the flow of current is from copper to zinc ok friends, there are some more things which you need to understand everything is clear, is the recording happening or not? everything is clear, pay attention pay attention, so this one is called anode and this one is called cathode here anode is negative and cathode is positive the way to remember is, left hand side will be oxidation, this is my left hand This right and left side will be oxidation, we will call it anode and it will be negative So oxidation is happening in the left, it is called anode and it is negative See this is known as lone, what is known as lone This is called electrochemical cell, so you can see that the current is applied for the emitter The current flow is shown here, the electron flow is shown here If you see in the salt bridge, then you will not see KCL and KNO3, this is very small written This is very small written, I will show you again KCL and KNO3 are shown in the salt bridge So this is a proper setup, I have told you the trick, I have told you everything, that is electrochemical cell So we just finished electrochemical cell and I hope that if you are paying attention to my words then I have not left out any point I have also covered salt bridge Even it was not necessary to tell that it is made of gelatin I have told you that function of salt bridge also I have told you Now friends the next topic is your electrode potential Now understand what is electrode potential When we were taking utensils like this We were taking utensils like this remember So we were saying that here is the rod of zinc And we were saying that here will be zinc plus 2, you know Zinc will be plus 2 right So what happens is, let's talk about something, let's say there is a solution here And suppose there is a rod here, or anything, we call it an electrode So if there is a charge separation between them, anywhere, let me teach you from a physics point of view You must have read in physics, wherever there is a plus or minus, there is an electric field from plus to minus And suppose there is a distance here, suppose D, you must have read V potential, potential is equal to electric field into distance If there is an electric field at a distance, there will be potential as well That means, there will be a separation of charge at any place There will be a separation of charge, plus or minus, so there will be potential as well So friends, we are going to study here, I will cover all the points here We are going to study electrode potential here Now, what is electrode potential? Read it Due to separation of charge between electrode metal and solution That means, the solution and the metal that we have added, we did not understand The solution and the metal, there will be a separation of charge And due to the separation of charge, there there is development of potential, which is called electrode potential what is he trying to say? he is trying to say, let me explain to you that here and here, this is the solution and this is metal electrode this is metal, zinc metal there will be a separation of charge between them and due to the separation of charge, potential will be created here we call that electrode potential anyone has any problem? so I have taught you electrode potential, it is very easy we were talking about electrode potential so due to separation, you can read it yourself, you will understand it by yourself now see, we will read in our syllabus for now That is standard electrode potential What is the definition of standard electrode potential? Here we take concentration of 1m 1m means that Molarity will be 1 Concentration is this much Concentration means molarity It will be 1 If I write concentration of zinc sulfide If I write concentration of 1m It means that this is standard case For standard case, electrode potential is called E0 Standard electrode potential is called E0 Did you understand? Now let's talk about work If we talk about Oh man Now we will talk about our cell. If you remember, there are two parts of our cell. If you remember two parts of our cell, one is this and the other is this. Here are two parts, one on the left and one on the right. So this will also have electrode potential. And this will also have electrode potential. So if I want to find out the whole cell, then for the whole cell, we use from the right one, we have to minus the left one. Or on the right, we have reduction. From the reduction one, we have to minus the oxidation one. Many children will have a question, why do we have to minus? Because at one place, oxidation happens. What happens at the other end? Reduction. Both are different things, so we have to minus them. If both have reduction, what would we do? Plus. Or if both have oxidation, what would we do? Plus. But one has oxidation and one has reduction, so we have to minus them. That means, if we minus the left one from the right one, that means, if we minus the value from here to here, then we will get the electrode potential of the whole cell. For example, if I take a question in a fun way, I will tell you that there is a box here and there, and this is our setup, there is a rod here and there, and this bulb is burning. And he said that the value here is 2.314V And the value here, the e0 here is 1.073 Minus He gave us values like this And he said tell me how much will be the whole cell So you will say that the e0 cell is very easy e0 of right minus e0 of left You will minus the left one from the right one What does this mean friends? You will minus 2.314 Here is one more minus, extra minus, from minus 1.073 If you minus it, then whatever answer you get, will come out of the whole cell So what is the electrode potential? Due to separation of charge, potential is created It will be created in the left and right as well If you minus both, then you will get the potential of the whole cell That is a very simple and very interesting topic Now friends, we are going to talk about a small thing, we are going to talk about SHI The full name of SHI is Standard Hydrogen Electrode What is this? Understand It is the device that measures the half Cell Electrode Potential What does this mean? It means that Assume Pay attention Some new You made a new Electrochemical cell You made a new Electrochemical cell And you have to Find out the Electrode potential Of this one So its value Is found out by She Who knows? She So what is she? What is she? She is a device That measures The half Cell Electrode Potential of Cell Now this is a small thing She doesn't know much But still See how the diagram is She is a device You don't have to study it How does she become? I am giving you an idea out The idea is, let's take a glass and make a hole here So that we can put hydrogen gas inside Here we have a platinum wire and a platinum foil And here in this beaker, we take the solution of SCL This is platinum and this is also platinum This foil is platinum Now this is the solution of SCL We have taken SCL as 1M 1M means standard And from here we will leave wiring for connection We will connect from here That is she Just remember some conditions I will tell you the condition, see she is like this We leave a gap here so that we can put hydrogen gas inside This will be the wire of platinum, here platinum foil coated with finely divided platinum Platinum is coated on the foil of platinum Hydrogen gas is being put inside the pressure for one time What am I saying? Hydrogen gas is being put inside the pressure for one time Did you understand? It is written here, it is a reference electrode, for reference Reference means, with the help of this, we will extract the other ones And the special thing about this is, it can be anode and cathode It is a reference electrode, it can be anode and cathode It can be anode and cathode, that is the most important thing And the second thing is, look that here platinum wire, platinum foil, hydrogen gas has to be put on 1 bar pressure only can you understand me? say 1 bar or we will call it 1 ATM also now friends, what is special here? that here you have to maintain 1M SCL solution whatever SCL solution will be, it will be 1M means if someone asks you, tell me 2 conditions for she so the first condition is that you have to keep hydrogen gas on 1 bar pressure so hydrogen gas is being put on 1 bar pressure so pressure must be 1 bar and what is the second condition? 1M SCL solution and son, the most important thing I will tell you It has zero volts. What happens? Because it is a reference electrode. Reference means exactly reference line. It has zero volts. What is its value? Zero. Understood? So, the work of she is to give the value of any half cell. And this is the arrangement of she. You don't have to do anything more than this. For she, the matter is over. There is no tension. Now, I will tell you some small things here, friends. It is written, disadvantage of she. See, 1M SCL is difficult to maintain. He is saying that 1M SCL is required and 1M SCL is difficult to maintain. Who knows, it may become 1.1. What happens? It may become 1.1. One bar pressure, it is difficult to maintain. He says, brother, one bar pressure should be there. when it becomes 1.1 bar then it is difficult thirdly, easily get poisoned in the presence of small impurity. If something small comes from somewhere, then it gets spoiled. It doesn't work properly. So, easily get poisoned. It becomes useless. It becomes poisonous. Do you understand? If something small comes from somewhere, then it has to be run in a very special condition. In a very special condition. Do you understand? So, we have finished this by reading about Sheet. Now, my friends, the next topic is Nurse Equation. Now, you will have a question in your mind that when do we use Nurse Equation? Look, we were reading back now that concentration should be 1. But if 1 concentration is not there, then what will happen? If concentration is not equal to 1. If it is not 1, then it is not a standard case. Then we use Nernst equation. Nernst equation is, if we are reading what we have used in our NCERT repeatedly. If your concentration is not 1, suppose the value is written 0.01. This is not 1. Suppose 0.02 is written. This is not 1. If it is not 1, then you cannot apply the previous concepts. Now you have to apply a new formula. So we keep the temperature 298 Kelvin or 25 degrees. So when the temperature is 298 Kelvin or 25 degrees Celsius and there is no 1 value, then we use this formula. E cell. E cell. What is E cell? Nernst equation. E cell is equal to E naught cell, the old one. Minus 0.0591 and log QC. Now what is QC? Let me teach you how to get it. For example, if A plus B gives C plus D. So what do you have to do to get QC? Do you see C? Let me teach you how to get QC with a reaction. Suppose this is zinc. This is zinc plus 2. Suppose this is copper plus 2 and this is copper 0. If a question asks you to get QC, then to get QC, remember the equilibrium of class 11. You have to remember that in this case, you have to always take ions. So the concentration of ions, the value given in the question, you have to write it up. and divide product ions up and reactant ions down we have to take ions only, ions means the ones with plus the ones with plus or minus, we have to take them only the simple ones, the ones with zero, we don't take them in QC suppose the question is, copper value is 0.01 m and zinc value is 0.04 m so what I do is, I write 0.04 I write 0.04 here, and what do I write in place of copper? 0.01, I write 0.01 so it is very simple to get QC so QC you understood, log is log value, that is it now you have learnt to get E0, E right minus E left Now the question is N, what is N? If you know, I am explaining you about N Look carefully about N If you remember, basically Zinc goes to 2 and leaves 2 electrons Copper goes to 0 with 2 electrons So, how many electrons are there in between these two? The condition is that the reaction should be balanced. Here is one zinc, here is another zinc, here is one copper, what is here? So, how many electron moles are involved in the balanced reaction? Here is 2, how many are there here? 2. So, n equals to 2. So, the reaction should be balanced first. Then you have to see how many electron moles are there next to the electron. And how many numbers are there next to the electron. So, the answer to this question is 2. So, I have taught you how many electrons are involved in the balanced equation. How many electron numbers are involved? The moles that we call it So you understood this? So this is called the Nernst equation Now my dear students, keep a small note You are moving forward Very simple and easy thing Where are the slides? I can't find them Here they are Equilibrium constant from Nernst equation Now friends, if you don't remember the equilibrium chapter a little, don't be afraid I have taught you how to write QC See, there are some special things about equilibrium Whenever we talk about equilibrium, we have to write KC to our QC That is, we will write KC to the QC Have you written it? When we talk about equilibrium, you have to write KC to the QC And let's zero this cell That means this thing will be zero So this is zero. That's it. Now from here, if you want, if you bring this part here, then what will be minus? Plus. So our enote cell plus 0.0591 by n log Kc. Kc will come in place of Qc and this will become the formula. Do you know what we read? Do you know the name of this topic? Kc means equilibrium constant. We read this topic, friends, equilibrium constant. Equilibrium constant from the Nernst equation. How did we reach equilibrium constant from the Nernst equation? That is a very important topic. Question comes on it in exams. Sometimes it comes, but it's tough because you have to put anti-log in it. I hope all clear. Those who are watching online, please write all clear in the comments. My heart will be happy Those who are watching online, please Look, pay attention here The topic is Representation of electrochemical cell I had told you left hand side Oxidation Anode Negative So, follow the same method Like he said This is our electrochemical cell Of zinc and copper How will you represent it So, you will not do anything like this Zinc Say Zinc plus 2 You have to show this by pulling the line That the zinc is in Zinc plus 2 And there are two lines in between These two lines are salt bridge Do you remember salt bridge Which was in the middle Zinc plus 2 from this side Then in between a salt bridge And copper plus 2 Copper zero and in between two lines are drawn, this topic is called representation of electrochemical cell and this question is often asked in one number in exam, so you will take care of this now my dear children, next topic is gives free energy now you will think what is gives free energy, see carefully this was in your 11th, but I will revise it here, see two things, one will be delta G, this will be delta G so delta G formula is minus N, we know what is N E, we know what is E and F I will tell you here this E is this one, E cell, to find this E you have to use the Nernst equation Delta G is the Gibbs free energy where you know the meaning of N Now which is this E? This is the Nernst equation This E is derived from the Nernst equation and F means 96500 Coulomb This is called Faraday constant 96500 Coulomb, this is the value If someone tells you to find Delta G you have to find N first and then you have to find E How will you find E? Through Nernst equation which was E cell is equal to E naught cell minus 0.0 Now there is Delta G naught Delta G naught is the standard Gibbs free energy 90% of the questions are the same, because it is very tough. First you know the n, then you get the NURSE equation, then you get E, then you add F. This is a little tough. This is easy. Why? Because here, delta G naught is standard. So you have to use minus n, then E naught here. E naught. And you know how to get E naught of cell. How do you get E naught of cell? Do you remember? Here, the E naught will come out from this. E right minus, or E reduction minus E. So this one is easier. And F means, you know, there are two types of questions. There will be two types of questions in Gibbs free energy. One is only delta G. So to get only delta G, you have to get E, in the NURSE equation. Guys, what will happen? Delta G naught, which is standard. So the standard one is easy. Why is it easy? Because the E note that has to be taken out here, will come out from E right minus E left. Or E reduction minus E oxidation. So this one is easy and this one is a little tough. Is it clear to everyone? Very good. Now my friends, the next topic in this chapter is about electrolytes. What are electrolytes, friends? As you can see here, Na plus Cl minus, NH4 plus OH minus, H plus Cl minus, all these are electrolytes. So what are electrolytes, friends? Those who have plus and minus in them, we call them electrolytes. What do we call them? Electrolytes. Now friends, here you have to understand the types of electrolytes. We have two types of electrolytes. See, one is strong electrolyte and weak, so first types of electrolyte, we are studying strong electrolyte strong electrolyte is salt, your salt is strong electrolyte, why? because when we put it in water, it will dissolve completely so completely dissociate, what does dissociate mean? breaking, the one which breaks completely in water, we call it strong electrolyte the one which breaks completely in water, what will be its name? strong electrolyte, keep this in mind then like NACL, KCL, now we have weak electrolyte it is gone, wait, I am only saying this See, this is the one that is down there. I am saying where did it go? One is our weak electrolyte. Weak is the one that doesn't break completely. Don't go by name, that it is strong, how can it break? The strong one will break completely. And the weak electrolyte do not completely dissociate. Like this one. It doesn't break completely. If you put it in water, then 10% breaks, 20% breaks. It will not break completely. 100% will never break. Salt breaks 100%. That's why it is a strong electrolyte. Weak one that doesn't break completely. Now friends, we are going to talk here. We are talking some basic things that you have studied in physics. I don't think you should study all this yourself. See, you must have studied the formula of resistance in your childhood. 2 minutes left, what is resistance formula? R is equal to Rho L by A where Rho means resistivity, R means resistance, L means length, A means area Now listen to me when we are reading It is written that Reciprocal of resistance is conductance Resistance means resistance, conductance means conducting So conductance and resistance will be opposite So Reciprocal means the opposite of resistance will be conductance So conductance is 1 by resistance So for conductance we use G as 1 by R So remember G is equal to 1 by R Similarly what will be conductivity? Reciprocal of resistivity Resistivity means resistance, what does it mean? Conductivity means conducting So what will be conductivity? Reciprocal of resistivity This is resistivity, stop, this is conductivity, both are opposite. resistivity, stop, conductivity, conduct, both are opposite. So what have we learnt till now? We learnt that G is conductance which is 1 by R. This is kappa, kappa is conductivity which is 1 by resistivity. We were just going to learn two things and nothing else. Now friends, here you will understand a very simple topic. See, the name of the topic is relation between conductance and conductivity. See, here is a vessel. What is a vessel? What is special about this vessel? We will give it a name later. But the special thing about this utensil is that here are two rods The distance between them is L and the area is A. What is the area? A So L by A is called cell constant. What is it called? Because its length and area will never change So its name is L by A is equal to cell constant. L by A is called cell constant And this is G star. Its name is G star. So G star means L by A. Now look carefully Resistance rho L by A. I am doing this protocol. 1 by R, 1 by rho, A by L Did I do it the other way round? I did it the other way round. So I will say 1 by R is G. What will I say? G. Kappa. and what is this? a by l, what is this? next time I will send l here and a down so what will become of kappa? k will become g l by a, didn't understand? l up and a down so kappa will become g l by a now tell me honestly instead of g, what did we say? g star so kappa means conductivity, kappa means what is conductivity? conductance into my cell constant conductivity is equal to conductance into my cell constant so keep a small relation in mind relation between conductance and conductivity conductance and conductivity it was a very simple topic friends, then we will move ahead quickly No need to be scared, chapter will be completed, no tension, just these slides are here Now friends, let me remind you of some definitions See what is the definition? A word is written here, conductivity So what does conductivity mean? Kappa How will you define kappa? So now I have told you that the formula of kappa is G, means conductance L by A So let me tell you, suppose the vessel you have taken is a cube, what is a vessel? Cube And the side of this cube is 1, how much is the side? 1 So what will be its volume? Volume will be 1 cube, how much will be the volume? YOKIDAKA! If its side is 1, then its area will also be 1. Do you know? And its volume will also be 1. Do you know? If the side of the cube is 1, then the area will also be 1. And if you find the area of any face, then it will be 1. And how much will the volume be? If I find the area of any face, then it will be 1. So, we said, if our cube has a length of 1, then what is the length? 1. And what is the area? 1. Do you know what L by A was? G star. We were saying L by A to G star. Oh man, I won't go so far back. I won't go so far back. This L by A was called G star So this was our GxG star So if length becomes 1 and area becomes 1 then your conductivity will be equal to conductance So it is written there What is conductivity? It is the conductance of 1 unit cube, 1 unit of electrolytic solution If there is 1 unit cube, means length is 1 and area is also 1 and volume is also 1 then K will be equal to G So conductivity is conductance Now it is written on dilution When we will do dilution then conductivity decreases Kappa's value decreases, dilution means adding water If we add water, if we dilute then K's value will decrease What will be K's value? Decrease. Why? Because number of ions per unit, volume decrease Number of ions decrease, what did I say? Number of ions decrease So because number of ions decrease, what will happen? Conductivity also decreases By adding water, number of ions decrease and by adding number of ions, conductivity decreases Now friends, next topic is molar conductivity The name of the topic is molar conductivity friends and molar conductivity is nothing You have studied conductivity you divide it by molarity, how? by molarity, so this is called molar conductivity and the symbol is lambda m what is the symbol of this? make it lambda or make it pi, what should I make? I am explaining, see you make pi and write m below and say there was conductivity, I divided it by molarity so conductivity per unit molarity is molar conductivity some people write it like this, lambda m conductivity by molarity, understood? so when we divide conductivity by molarity, then it will be called molar conductivity, if we open molarity then what will happen? what is our formula friends? Our formula is kappa upon the molarity. Molarity means, mol upon the volume. So, this volume will go up. Mol upon the volume will go up. Now, friends, pay attention here. Keep in mind that mol conductivity depends on volume. How does it depend? If I do dilution, dilution means adding water. You imagine, my friends, my dear children, if I add water, what will happen? If I add water and dilution, what will happen? Please pay attention. If you add water, what will happen by adding water? K value will decrease. K value. But volume will increase. What will increase? And in order to increase volume, volume increases a lot. In order to increase volume, me the molar conductivity will increase. Molar conductivity. So molar conductivity always increases. What did I say? By dilution, molar conductivity increases a lot. Reason? Volume. Volume is directly proportional If you increase the volume, then molar conductivity will also increase That means dilution reduces conductivity Molar conductivity Did you understand? Molar conductivity increases, you will notice this, please I request you Now my dear students, there is an important topic here Which is likely to come in the exam, there is no tension What is written here is variation with dilution Now I told you that dilution means adding water Friends, I just told you that dilution means adding water Adding water Now let's talk logically If we talk about conductivity, it will decrease, we know But molar conductivity will increase Now remember one word, concentration and dilution Remember this word, both are inversely proportional If we are increasing the dilution somewhere, then we are reducing the concentration If we are diluting, then the concentration will be decreasing, these are opposite to each other So don't take tension, understood? So here we are studying variation in molar conductivity with dilution It says that how will the change in molar conductivity, lambda m, with dilution happen? That is, when we add water What to add? When we add water So pay attention, what we are doing here, look at this side We are increasing the dilution on this side What is written? Increase dilution By increasing dilution, we are adding water And I told you that when dilution increases, concentration decreases Dilution increases, concentration decreases So here is molar conductivity and here is dilution What is this going for? This is written as root concentration Here is written as root concentration But what we have to keep is that we are adding water So I know that by adding water, molar conductivity increases So it increased But here it increased by a shock This graph is of strong electrolyte This graph is for KCL And this graph is for weak electrolyte weak electrolyte means C-S-C-D-C-O-H so we thought that we should increase it for strong increase it for weak too, but why increase it for weak? so we will say, why anomalous behaviour in weak electrolyte? anomalous means weird, what does it mean? why increase it in weird way? here it is increasing a little, and here it is suddenly what is happening here? attack so we thought that by dilution, molar conductivity increases but why increase it for weak? so the reason behind this, I am explaining to you, study it yourself what is the reason? I am explaining to you, study it yourself, I will show you the slide leave it, I am explaining the reason, see Our strong electrolytes, strong means KCL or salt, NACL, KCL These are already 100% broken, 100% All the people here are already working But what happens here in the weak side? In the weak side, 10% are broken, that is 10% people are working But when we add water, what will we add? Water When we add water, do you know what happens? Now there are 10% people who were working When we add water, it will start to break more If it breaks more, then the remaining 90% that were not broken Now they will also start to break, because of which new ions will be produced What will be produced? And as new ions are produced, the conductivity will increase suddenly So in strong electrolyte, people are already working And in weak electrolyte, 10% are working And 90% are sitting somewhere, like in the pot In the pot, there are 10% people who broke down And 90% were sitting somewhere in the corner And as soon as the rain started, people started breaking down New number of ions were created and suddenly the conductivity increased I am teaching you the written version, wait a second The slides are missing because it hangs I will buy a new one, I am waiting for some money Wait, I am not joking, I will buy a new one It hangs a lot, but it is still expensive 3-3 lakhs in 2 years, now it has been 2 years and 2.5 years Its screen time is over, don't you understand screen time? I'll show you. Where is it? See the reason. See the reason. In case of weak electrolyte on dilution, degree of dissociation increase. Degree of dissociation means breaking. What does it mean? Breaking. In weak electrolyte, people were not broken before. Now, it will start breaking. In weak electrolyte, hence, number of ions increase. Number of ions. Which leads to increase in molar conductivity. Due to which, molar conductivity increases. In case of strong electrolyte on dilution, there is no increase in number of ions. Here, the number of ions doesn't increase but by adding water, the motion increases. That's why the conductivity increases. See, it's increasing in both. Increasing in the weak. Reason? New number of ions. New number of? It's increasing in the strong but less. Why? By adding water, the motion increases. See, it's written, due to dilution, the force of attraction between the ions decrease and movement of ions increase. So, it's increasing in the strong. Reason? Because of movement. Increasing in the weak. Reason? Because of the arrival of new number of ions. It's increasing in both. Tell me, why is it increasing in the strong? because of movement, did you understand? so this was a very important topic, then we will move forward now a small topic is Kohar Laws Law, what is this? Kohar Laws Law, you pay attention when we apply Kohar Laws Law, pay attention like we were reading in the back we were reading that here is molar conductivity and here is concentration so this point is called zero concentration and the opposite name of this is infinite dilution so friends, on infinite dilution or zero concentration zero concentration or infinite dilution We use the Kohler's law. Where is it? We use the Kohler's law. When does the Kohler's law work? When it works on infinite dilution or zero concentration. You don't need to read all this. I am explaining what it says. It says, what does it say? It is written in rough. Fair one on the next page. It is not important to read this. You don't understand what I am explaining. It says, if it is lambda m and we have reached zero. Where have we reached? Zero concentration. Then you will have to write lambda m naught. Read this zero. If you are on zero concentration. And someone says to you that you have to find out the value of this Weak electrolyte value And you are given something separately CS3 COO-NA+. and its value is 40, and someone has given this as well, the value of SCL is 10, and someone has given this, lambda M0, we have to find this, keep listening, we have given NACL, value 12, so it is saying, if you have given some values like this, if you have given some values like this, and you want to get this, then how can you get it? So we will pick up CS3O- from here, we will pick IN, so first we will need 40, then we will pick H, because we want this and H, so we will need 10, But When we take 40 and 10, then we get 1 Na and 1 Cl extra. What is NaCl? So we have to minus NaCl here. So we have to do minus 12. So 38 out of 50. That means, how much is the value of COH in CS3? 38. That means we can subtract ions by doing plus minus and get our answer. This is called Corrallois law of independent migration. I will explain its definition to you. See, I have already explained this to you. We call it zero concentration or infinite dilution. You don't have to understand this. I have asked the same question above. Now I will explain its definition. It states that at zero concentration or infinite dilution zero or infinite the molar conductivity of electrolyte is equal to the sum of the conductance of the cation and anion you can find the answer of cation and anion by adding plus minus did you understand? if you want to find the answer you still didn't understand what else can I explain the definition is sum of the conductance of the cation and anion if you want to find the answer of zero concentration then that's it this is a small thing now we are moving forward here is alpha alpha is alpha is in 11th class it is called degree of dissociation means breaking weak electrolyte breakage is known by alpha like I said, my alpha is 1 1 means 100% here, what does it mean? 100% if I said my alpha is 1 by 2, then it means 50% I said my degree of dissociation is 1 means all the particles have broken I said my degree of dissociation which is alpha alpha means degree of I said my alpha is 1 by 2 means 50% particles have broken we have read about alpha in the solution chapter now see the method of removing alpha normal molar conductivity has to be kept up and keep the infinite one below, didn't you understand? I said, my normal molar conductivity is 40 and my infinite one is 80 and my infinite one is 80 so how much alpha will I get? 40 by 80 which means 1 by 2, which means my particle is broken by 50%, so you can get alpha by this way no problem for anyone, no problem now my friends, we are going to study electrolysis what are we going to study? electrolysis and I am explaining what is electrolysis, see we take a device, the name of the device is electrolytic cells what is the name of the device? electrolytic cell this device, which is called electrolytic cell, how does it make? Take a button. We will call one anode and the other cathode Here anode is positive and cathode is negative Anode will have oxidation and cathode will have reduction I am saying it again, here anode is positive, don't put a loan here Loan is not right everywhere Here anode is positive, cathode is negative Here oxidation and here reduction What happens is We put batteries with anode and cathode, like we did here, plus and minus What chemicals do we put in it? Suppose we have NaCl here, Na plus and Cl minus So see this is plus, so a person with minus will go to plus And who will go to minus? Will go to plus That means a chemical will come on anode and what will happen to the cathode? A chemical will come, this is called electrolysis. So what do we do in electrolysis? With the help of electricity, chemical changes. Chemical. Now here is NaCl, I am saying, Chlorine brother, come, will it come? No. Will it come if I say? You have to put electricity, what will you have to put? Electricity. So what are we doing by applying electricity? Basically, understand simple. I tell you that I have a weaker. In that, I have made one rod positive, and one rod negative by applying battery. By applying plus and minus of battery. This is plus of battery and this is minus. So think what will happen, So think what will happen if I here A plus, focus please, chapter A, where did it go? Switch off. Listen, let's go, one, two, listen, suppose here is a plus and b minus chemical, then the plus one will go here and the minus one here, this is called electrolysis. What do you say? Bring chemical changes with the help of electricity. Whatever work you can do, we are doing it with the help of electricity. So if whatever will be made here, whatever will be made here, what is coming here? Sodium. What is coming here? Chlorine. So we will say this is the product of electrolysis. What is this? Chlorine gas is a product of electrolysis Sodium metal is a product of... Did you understand what I said? You must have understood what I said We used electrical energy When cells convert electrical energy to chemical energy We call it electrolytic cell Did you understand what I said? If you understood, then you have to read Product of electrolysis What do you have to read? Product of electrolysis You have to remember this I am explaining, you have to see NCRT also, from here the question comes in the exam In NCRT, you have to remember the reactions in electrolysis See what is written, like if we take molten NaCl If we take NaCl, then we will get sodium on cathode and chlorine gas on anode And this will be the reaction, you have to remember the reaction See again, if we have taken aqueous NaCl, this is the melted salt This is the water salt, then hydrogen gas will be found on anode Chlorine gas will be found on cathode and these are its reactions Means this whole topic has to be remembered, I am also helpless in this, what should I tell Yes, I am telling you the extra point, this question can come in your mind, see What can come? Pay attention If there is aqueous here, then H2O will be there. So, from H2O, hydrogen gas is being obtained here. What is being obtained? And here, chlorine gas is being obtained. But, oxygen gas can also be obtained. H2O also contains oxygen. So, why is oxygen gas not being obtained? What did I say? Why is oxygen gas not being obtained? There is a reason behind it, over potential. What is the reason? So, remember this point in your mind. If someone asks you a question in the aqueous area, who should ask? A question should come on aqueous NaCl. that on aqueous NaCl, there is chlorine gas and hydrogen gas why? why am I not getting oxygen gas? because if there is water, there will be oxygen as well so what will be the reason? over potential required what will we say? over potential required what is over potential? like there is chlorine gas, what is here? so why can't there be oxygen gas? so what will we say? over potential required what will we say? over potential required so we don't have to give over potential we need over potential so you have to remember this product of electrolysis now we have two laws Product of electrolysis has two laws If we have product of electrolysis So we have two laws on product of electrolysis Faraday's law I will explain it to you in easy way See, now the story is Suppose this is your electrochemical cell Electrolytic cell Where one is positive and the other is negative You are putting A plus and B minus here Plus goes here and minus goes here So how much will be collected here Or how much will come out of here That is called product of electrolysis So how much weight will be accumulated here That weight directly depends on How much charge you have given Here the battery is connected So what flow is there from the battery? Charge How much charge you have given Here we will say weight is directly proportional to What does charge mean? Current is charge upon time So weight is directly proportional to current into time Simple thing, the longer you give current The more weight will be accumulated here Now here comes a constant z Z means electrochemical equivalent I will teach you what Z means, don't worry, everything is written here Z means electrochemical equivalent Z also has a formula, what is Z formula? Z formula is, you have to write the atomic weight of the person you are talking about Write 96500 and write N here, what do you have to write? N 96500, what do you have to write here? N So if I tell you, suppose I say that for copper plus 2, what did I say? For copper plus 2, I have to write Z So atomic weight of copper is around 63 63.5 is the atomic weight which will be given in the exam Then 96500 and how much is n? plus 2 n means number, remember n is electron so 2 in x it is easy to find z, see it is written weight proportional to charge z is constant and this charge is I into t and z means electrochemical equivalent to find z, atomic weight is 9600 n where n means number of moles of electron like if a question comes in the exam that tell me in copper plus 2, how many faradays, how many faradays charge? leave everything, I am telling you in 1 in 1 mole this much, 9600 coulomb we call this f, what do we call this? f suppose a question comes in the exam How many Faraday are there in this? We call it F. We call 9600 F. 9600 is F. So, we say that in copper plus 2, there are 2 moles. How many moles are there? 2 moles. So, how much is there in 1 mole? 9600. So, how much will be there in 2 moles? I have told you this extra question. This is our topic. This is our topic. I am saying this topic is done. Read the definition and then I will tell you what I was teaching next. It states that the weight of product during electrolysis is directly proportional to the charge supplied. What was the first law? Now, there is a question that comes in the exam many times How much charge will be there from zinc to zinc plus 2 and 2 electrons? Let me remind you something 1 mol means 1F What does it mean? And 1 mol means 96500 coulomb This is a new question, not the previous one, don't relate it to the previous one The question is, how many moles are charged in it? 2 moles So, we will say 2 moles, how many moles are there? So, what will 2 moles mean? Charge is equal to 2 moles How much is the charge? 2 moles It means 2 faraday, what will it mean? Because 1 mol means 1 faraday, so 2 moles means 2 faraday And you can write it like this 2 into f value, 9 6 So I am telling you, such questions are also given in the exam How many faraday are there? 2 faraday You have to put f instead of e How many chance are there to put f value? Such questions are also given in the exam So this was our easy topic First law of faraday Electrolysis, whose law is it? Electrolysis, law of electrolysis Product of electrolysis is the first law Second law I am telling you, you can define it yourself Second law is this, second law of faraday Second law is that, suppose this is a cell Then this second electrolytic cell, this third, this fourth You have given a lot of cells If you put many cells in series Then the weight here will be W1 Here the amount will be W2, here the amount will be W3, here the amount will be W4 So W1 is directly proportional to E1 W2 is of E2, W3 is of E3 Now you will say what is E1, E2, E3? This is called equivalent weight I will tell you the meaning of E Equivalent weight. Weight equivalent. Equivalent weight. Now how do we get this? So there is a formula to get E. Divide atomic weight by n. Atomic weight? Didn't understand? I will explain what it means So if we take out the concept from here This is the second law Second law says When number of Write it yourself I am telling you When number of electrolytic cells connected in series Then weight of the product of electrolysis Is proportional to equivalent weight Proportional to Now if I say W1 by W2 If I divide these two, what will be the answer? E1 by E2 If I get a question, I will show you the question There is no big deal in the definition, the question is One cell and another cell, two cells, it is the second law Both are connected in series In series, the charge is same and the current is also same And we say, its weight is 4 grams And this is zinc, what is this? There are zinc plus 2 ions here And we don't know its weight But we know that it is copper, what is this? Copper plus 2 So, take out W2, then you will say, okay son W1 by W2 is equal to E1 by E2 You will say, I know W1, I have to get W2 out. What does E1 mean? Atomic weight by N. So how much is the atomic weight of zinc? I don't know. Find out about zinc quickly. Google search. Genuine atomic weight. 65, keep quiet. So I will say, W1 is zinc, right? So 65 by N. What does E mean? Atomic weight by N. So what will I say? 65 by N. 65 by N. And how much is N? Copper's plus 2 means 2. What does E2 mean? Copper's atomic weight by N. E means this. So copper's is 63.5. And what is the value of N? 2. What is the value of N? 2. So this will be cut. Answer is 65 by 63.5. So we have an equation. 4 by W2 is equal to 65 by 63.5. From here, W2 will be easily removed. That is what Faraday's second law of electrolysis. If I show you in notes, you will get scared. It is written in English. So write what I said. You can write it in tough English if you want This is a slightly tough English Again, the second law is slightly tough English It is written, the mass of different Wait, please The mass of different, this was different The mass of different ions liberated at electrode When the same amount of electricity is placed through different electrolytes Are directly proportional to their chemical equivalent weight Their chemical equivalent You see, the mass of different ions liberated at electrode When the same, leave it Remove it You can write it like this The mass of different ions liberated at electrode when many connected in series Leave everything, I won't do it. I'm giving you two options. Firstly, I'm saying it with my mouth. I'm not writing. I don't have time. Please, sorry for that. The mass of different ions liberated at electrode when the number of electrolytic cells connected in series I'll cut this. Are directly proportional to their chemical equivalent Wait, this is one way, the other is same too same W1 by W2, E1 by E2 This is the second law of Faraday's Now what is in this chapter? Batteries In batteries, we have to remember reactions I have already made a video on youtube about batteries I am not able to do it in batteries, I have already put that trick in I am telling you a topic, pay attention The topic is rusting What is it? Rusting or Corrosion, have you heard? Corrosion means fighting, rusting means fighting On iron, on iron Why is rusting happening? Rusting happens because in the presence of air and water Bonnie- HEY! You want to throw your shoes and hit them? I am saying this continuously for more than an hour. Without keeping quiet, with the same intensity. Full of dedication. Do you know why? To make a good career. I am working hard. Listen to me. And you, talk, talk, talk. What's the benefit? And before you, I have taken 7 classes continuously. I have taken 7 chapters today. One shot, one shot, one shot. 7 chapters. This is the 7th. With the same intensity. I am hungry, thirsty, and dry. Corrosion, there are classes after this. Corrosion, rusting, and fighting. Why? Because oxygen, water, and metal react with each other. Metal reacts quickly with oxygen and water. And they get damaged and become weak. So to save them, people paint them, apply grease. And the most dangerous method is galvanization. Galvanization is a sacrificial method. What happens in this? A zinc is a reactive metal. Zinc is reactive. Like an iron pillar. And we want to avoid a war on iron. So we will make a thin layer of zinc. We will make a layer of zinc. Whenever there is a reaction, it will happen with zinc. And if it is damaged, we will remove it. We will apply another zinc. If it is damaged, we will remove it. So zinc sacrifices itself. This is called galvanization or sacrificial method. So, rusting is not an important topic, so there is no need to discuss it further. This chapter ends here. Batteries are on YouTube. Watch it with a trick. This is the end of this chapter. one May you prosper. This is my blessing and this is my love.

Here you have to pay attention to the chemical I will show you electrochemical cell So we are studying electrochemical cell What happens in electrochemical cell? You generate electricity from chemicals You generate means you convert electricity You convert chemical energy into electricity energy How? You take a box You put some chemical in it You put copper sulphate in it Here you put zinc rod Here you put copper rod And you connect from here And here is bulb or voltmeter, whatever it is, it will burn. What will happen? It will burn.

You put chemicals, you get electricity. Now friends, to complete this circuit and to keep it neutral, what did I say? To complete the circuit and to keep it neutral, we put in the middle, it is called salt bridge.

What does salt bridge do? It completes the circuit and keeps it neutral. What does it keep? Neutral.

Why is its name salt bridge written in it? Because it contains salt, KCL. This is called saturated solution.

The solution we make, we make it in gelatin or in agar agar jelly. What did I say? KCL is a salt.

What is KCL? Salt. Who makes this salt? In gelatin or in a jelly called Agar-agar. Thick paste.

We make it thick. Why thick? So that the salt doesn't fall.

And here we also apply cotton. You will say, sir, we don't understand. Let me read you a little about salt bridge. If we read about salt bridge, what will you see?

It is inverted YouTube. This is an inverted YouTube. Joining two half cells, which joins half of them. Containing saturated solution.

of electrolytes such as KCL, KNO3 It has electrolyte solution or KCL or KNO3 and it is written that the saturated solution is generally taken in agar agar and in gelatine I have told you that it is made in gelatine or agar agar Understood? So YouTube, this salt bridge is inverted YouTube and what is added in this YouTube? Salt, what is added? Salt and who makes the solution of salt?

Agar agar or in gelatine friends Now friends we understood this salt bridge I have also understood the function of salt bridge I have told you the function of salt bridge, pay attention The function of salt bridge is, now it will be written I am disappointed, it didn't come Here it is, where is the function of salt bridge? It is missing, here it is, function of salt bridge It came, complete the electrical circuit It completes both the circuits and maintains the neutrality I told you, to keep it neutral and to complete it We use salt bridge Now friends, what happened, we did nothing We used chemicals and we got electricity So this is called electrochemical cell Now friends, you will have to pay attention to some things. Here, the zinc is the rod of zinc. The zinc rod melts. What did I say?

The zinc rod melts. How does it melt? The zinc removes two electrons from inside and oxidizes itself.

What does it do? Oxidation. That means, the zinc oxidizes and the zinc rod melts.

The copper below goes up. Why do they go up? Because when Zinc melts, it will produce two electrons Those two electrons, the two electrons that have come out, they go from here to here Electron is a negative particle, so to get this negative particle, the copper plus 2 inside goes up and gets accumulated So this copper plus 2 goes up, takes two electrons, becomes copper zero and will do its own reduction It is called reduction, okay? So on one side there is oxidation, on the other side there is reduction So from here the electrons will go this way, and we know, we have studied in physics, if our electron is going this way then our current will come this way that means the flow of electron is from zinc to copper and the flow of current is from copper to zinc ok friends, there are some more things which you need to understand everything is clear, is the recording happening or not? everything is clear, pay attention pay attention, so this one is called anode and this one is called cathode here anode is negative and cathode is positive the way to remember is, left hand side will be oxidation, this is my left hand This right and left side will be oxidation, we will call it anode and it will be negative So oxidation is happening in the left, it is called anode and it is negative See this is known as lone, what is known as lone This is called electrochemical cell, so you can see that the current is applied for the emitter The current flow is shown here, the electron flow is shown here If you see in the salt bridge, then you will not see KCL and KNO3, this is very small written This is very small written, I will show you again KCL and KNO3 are shown in the salt bridge So this is a proper setup, I have told you the trick, I have told you everything, that is electrochemical cell So we just finished electrochemical cell and I hope that if you are paying attention to my words then I have not left out any point I have also covered salt bridge Even it was not necessary to tell that it is made of gelatin I have told you that function of salt bridge also I have told you Now friends the next topic is your electrode potential Now understand what is electrode potential When we were taking utensils like this We were taking utensils like this remember So we were saying that here is the rod of zinc And we were saying that here will be zinc plus 2, you know Zinc will be plus 2 right So what happens is, let's talk about something, let's say there is a solution here And suppose there is a rod here, or anything, we call it an electrode So if there is a charge separation between them, anywhere, let me teach you from a physics point of view You must have read in physics, wherever there is a plus or minus, there is an electric field from plus to minus And suppose there is a distance here, suppose D, you must have read V potential, potential is equal to electric field into distance If there is an electric field at a distance, there will be potential as well That means, there will be a separation of charge at any place There will be a separation of charge, plus or minus, so there will be potential as well So friends, we are going to study here, I will cover all the points here We are going to study electrode potential here Now, what is electrode potential?

Read it Due to separation of charge between electrode metal and solution That means, the solution and the metal that we have added, we did not understand The solution and the metal, there will be a separation of charge And due to the separation of charge, there there is development of potential, which is called electrode potential what is he trying to say? he is trying to say, let me explain to you that here and here, this is the solution and this is metal electrode this is metal, zinc metal there will be a separation of charge between them and due to the separation of charge, potential will be created here we call that electrode potential anyone has any problem? so I have taught you electrode potential, it is very easy we were talking about electrode potential so due to separation, you can read it yourself, you will understand it by yourself now see, we will read in our syllabus for now That is standard electrode potential What is the definition of standard electrode potential?

Here we take concentration of 1m 1m means that Molarity will be 1 Concentration is this much Concentration means molarity It will be 1 If I write concentration of zinc sulfide If I write concentration of 1m It means that this is standard case For standard case, electrode potential is called E0 Standard electrode potential is called E0 Did you understand? Now let's talk about work If we talk about Oh man Now we will talk about our cell. If you remember, there are two parts of our cell. If you remember two parts of our cell, one is this and the other is this. Here are two parts, one on the left and one on the right.

So this will also have electrode potential. And this will also have electrode potential. So if I want to find out the whole cell, then for the whole cell, we use from the right one, we have to minus the left one.

Or on the right, we have reduction. From the reduction one, we have to minus the oxidation one. Many children will have a question, why do we have to minus?

Because at one place, oxidation happens. What happens at the other end? Reduction.

Both are different things, so we have to minus them. If both have reduction, what would we do? Plus.

Or if both have oxidation, what would we do? Plus. But one has oxidation and one has reduction, so we have to minus them.

That means, if we minus the left one from the right one, that means, if we minus the value from here to here, then we will get the electrode potential of the whole cell. For example, if I take a question in a fun way, I will tell you that there is a box here and there, and this is our setup, there is a rod here and there, and this bulb is burning. And he said that the value here is 2.314V And the value here, the e0 here is 1.073 Minus He gave us values like this And he said tell me how much will be the whole cell So you will say that the e0 cell is very easy e0 of right minus e0 of left You will minus the left one from the right one What does this mean friends? You will minus 2.314 Here is one more minus, extra minus, from minus 1.073 If you minus it, then whatever answer you get, will come out of the whole cell So what is the electrode potential?

Due to separation of charge, potential is created It will be created in the left and right as well If you minus both, then you will get the potential of the whole cell That is a very simple and very interesting topic Now friends, we are going to talk about a small thing, we are going to talk about SHI The full name of SHI is Standard Hydrogen Electrode What is this? Understand It is the device that measures the half Cell Electrode Potential What does this mean? It means that Assume Pay attention Some new You made a new Electrochemical cell You made a new Electrochemical cell And you have to Find out the Electrode potential Of this one So its value Is found out by She Who knows? She So what is she?

What is she? She is a device That measures The half Cell Electrode Potential of Cell Now this is a small thing She doesn't know much But still See how the diagram is She is a device You don't have to study it How does she become? I am giving you an idea out The idea is, let's take a glass and make a hole here So that we can put hydrogen gas inside Here we have a platinum wire and a platinum foil And here in this beaker, we take the solution of SCL This is platinum and this is also platinum This foil is platinum Now this is the solution of SCL We have taken SCL as 1M 1M means standard And from here we will leave wiring for connection We will connect from here That is she Just remember some conditions I will tell you the condition, see she is like this We leave a gap here so that we can put hydrogen gas inside This will be the wire of platinum, here platinum foil coated with finely divided platinum Platinum is coated on the foil of platinum Hydrogen gas is being put inside the pressure for one time What am I saying?

Hydrogen gas is being put inside the pressure for one time Did you understand? It is written here, it is a reference electrode, for reference Reference means, with the help of this, we will extract the other ones And the special thing about this is, it can be anode and cathode It is a reference electrode, it can be anode and cathode It can be anode and cathode, that is the most important thing And the second thing is, look that here platinum wire, platinum foil, hydrogen gas has to be put on 1 bar pressure only can you understand me? say 1 bar or we will call it 1 ATM also now friends, what is special here? that here you have to maintain 1M SCL solution whatever SCL solution will be, it will be 1M means if someone asks you, tell me 2 conditions for she so the first condition is that you have to keep hydrogen gas on 1 bar pressure so hydrogen gas is being put on 1 bar pressure so pressure must be 1 bar and what is the second condition? 1M SCL solution and son, the most important thing I will tell you It has zero volts.

What happens? Because it is a reference electrode. Reference means exactly reference line.

It has zero volts. What is its value? Zero. Understood? So, the work of she is to give the value of any half cell.

And this is the arrangement of she. You don't have to do anything more than this. For she, the matter is over. There is no tension. Now, I will tell you some small things here, friends.

It is written, disadvantage of she. See, 1M SCL is difficult to maintain. He is saying that 1M SCL is required and 1M SCL is difficult to maintain. Who knows, it may become 1.1. What happens?

It may become 1.1. One bar pressure, it is difficult to maintain. He says, brother, one bar pressure should be there. when it becomes 1.1 bar then it is difficult thirdly, easily get poisoned in the presence of small impurity. If something small comes from somewhere, then it gets spoiled.

It doesn't work properly. So, easily get poisoned. It becomes useless.

It becomes poisonous. Do you understand? If something small comes from somewhere, then it has to be run in a very special condition. In a very special condition. Do you understand?

So, we have finished this by reading about Sheet. Now, my friends, the next topic is Nurse Equation. Now, you will have a question in your mind that when do we use Nurse Equation? Look, we were reading back now that concentration should be 1. But if 1 concentration is not there, then what will happen? If concentration is not equal to 1. If it is not 1, then it is not a standard case.

Then we use Nernst equation. Nernst equation is, if we are reading what we have used in our NCERT repeatedly. If your concentration is not 1, suppose the value is written 0.01.

This is not 1. Suppose 0.02 is written. This is not 1. If it is not 1, then you cannot apply the previous concepts. Now you have to apply a new formula. So we keep the temperature 298 Kelvin or 25 degrees. So when the temperature is 298 Kelvin or 25 degrees Celsius and there is no 1 value, then we use this formula.

E cell. E cell. What is E cell? Nernst equation.

E cell is equal to E naught cell, the old one. Minus 0.0591 and log QC. Now what is QC? Let me teach you how to get it. For example, if A plus B gives C plus D.

So what do you have to do to get QC? Do you see C? Let me teach you how to get QC with a reaction. Suppose this is zinc.

This is zinc plus 2. Suppose this is copper plus 2 and this is copper 0. If a question asks you to get QC, then to get QC, remember the equilibrium of class 11. You have to remember that in this case, you have to always take ions. So the concentration of ions, the value given in the question, you have to write it up. and divide product ions up and reactant ions down we have to take ions only, ions means the ones with plus the ones with plus or minus, we have to take them only the simple ones, the ones with zero, we don't take them in QC suppose the question is, copper value is 0.01 m and zinc value is 0.04 m so what I do is, I write 0.04 I write 0.04 here, and what do I write in place of copper?

0.01, I write 0.01 so it is very simple to get QC so QC you understood, log is log value, that is it now you have learnt to get E0, E right minus E left Now the question is N, what is N? If you know, I am explaining you about N Look carefully about N If you remember, basically Zinc goes to 2 and leaves 2 electrons Copper goes to 0 with 2 electrons So, how many electrons are there in between these two? The condition is that the reaction should be balanced.

Here is one zinc, here is another zinc, here is one copper, what is here? So, how many electron moles are involved in the balanced reaction? Here is 2, how many are there here?

2. So, n equals to 2. So, the reaction should be balanced first. Then you have to see how many electron moles are there next to the electron. And how many numbers are there next to the electron. So, the answer to this question is 2. So, I have taught you how many electrons are involved in the balanced equation.

How many electron numbers are involved? The moles that we call it So you understood this? So this is called the Nernst equation Now my dear students, keep a small note You are moving forward Very simple and easy thing Where are the slides? I can't find them Here they are Equilibrium constant from Nernst equation Now friends, if you don't remember the equilibrium chapter a little, don't be afraid I have taught you how to write QC See, there are some special things about equilibrium Whenever we talk about equilibrium, we have to write KC to our QC That is, we will write KC to the QC Have you written it?

When we talk about equilibrium, you have to write KC to the QC And let's zero this cell That means this thing will be zero So this is zero. That's it. Now from here, if you want, if you bring this part here, then what will be minus? Plus. So our enote cell plus 0.0591 by n log Kc.

Kc will come in place of Qc and this will become the formula. Do you know what we read? Do you know the name of this topic?

Kc means equilibrium constant. We read this topic, friends, equilibrium constant. Equilibrium constant from the Nernst equation.

How did we reach equilibrium constant from the Nernst equation? That is a very important topic. Question comes on it in exams. Sometimes it comes, but it's tough because you have to put anti-log in it. I hope all clear.

Those who are watching online, please write all clear in the comments. My heart will be happy Those who are watching online, please Look, pay attention here The topic is Representation of electrochemical cell I had told you left hand side Oxidation Anode Negative So, follow the same method Like he said This is our electrochemical cell Of zinc and copper How will you represent it So, you will not do anything like this Zinc Say Zinc plus 2 You have to show this by pulling the line That the zinc is in Zinc plus 2 And there are two lines in between These two lines are salt bridge Do you remember salt bridge Which was in the middle Zinc plus 2 from this side Then in between a salt bridge And copper plus 2 Copper zero and in between two lines are drawn, this topic is called representation of electrochemical cell and this question is often asked in one number in exam, so you will take care of this now my dear children, next topic is gives free energy now you will think what is gives free energy, see carefully this was in your 11th, but I will revise it here, see two things, one will be delta G, this will be delta G so delta G formula is minus N, we know what is N E, we know what is E and F I will tell you here this E is this one, E cell, to find this E you have to use the Nernst equation Delta G is the Gibbs free energy where you know the meaning of N Now which is this E? This is the Nernst equation This E is derived from the Nernst equation and F means 96500 Coulomb This is called Faraday constant 96500 Coulomb, this is the value If someone tells you to find Delta G you have to find N first and then you have to find E How will you find E? Through Nernst equation which was E cell is equal to E naught cell minus 0.0 Now there is Delta G naught Delta G naught is the standard Gibbs free energy 90% of the questions are the same, because it is very tough.

First you know the n, then you get the NURSE equation, then you get E, then you add F. This is a little tough. This is easy.

Why? Because here, delta G naught is standard. So you have to use minus n, then E naught here. E naught.

And you know how to get E naught of cell. How do you get E naught of cell? Do you remember? Here, the E naught will come out from this.

E right minus, or E reduction minus E. So this one is easier. And F means, you know, there are two types of questions.

There will be two types of questions in Gibbs free energy. One is only delta G. So to get only delta G, you have to get E, in the NURSE equation.

Guys, what will happen? Delta G naught, which is standard. So the standard one is easy. Why is it easy?

Because the E note that has to be taken out here, will come out from E right minus E left. Or E reduction minus E oxidation. So this one is easy and this one is a little tough. Is it clear to everyone?

Very good. Now my friends, the next topic in this chapter is about electrolytes. What are electrolytes, friends?

As you can see here, Na plus Cl minus, NH4 plus OH minus, H plus Cl minus, all these are electrolytes. So what are electrolytes, friends? Those who have plus and minus in them, we call them electrolytes.

What do we call them? Electrolytes. Now friends, here you have to understand the types of electrolytes. We have two types of electrolytes. See, one is strong electrolyte and weak, so first types of electrolyte, we are studying strong electrolyte strong electrolyte is salt, your salt is strong electrolyte, why?

because when we put it in water, it will dissolve completely so completely dissociate, what does dissociate mean? breaking, the one which breaks completely in water, we call it strong electrolyte the one which breaks completely in water, what will be its name? strong electrolyte, keep this in mind then like NACL, KCL, now we have weak electrolyte it is gone, wait, I am only saying this See, this is the one that is down there.

I am saying where did it go? One is our weak electrolyte. Weak is the one that doesn't break completely.

Don't go by name, that it is strong, how can it break? The strong one will break completely. And the weak electrolyte do not completely dissociate. Like this one.

It doesn't break completely. If you put it in water, then 10% breaks, 20% breaks. It will not break completely. 100% will never break. Salt breaks 100%.

That's why it is a strong electrolyte. Weak one that doesn't break completely. Now friends, we are going to talk here. We are talking some basic things that you have studied in physics.

I don't think you should study all this yourself. See, you must have studied the formula of resistance in your childhood. 2 minutes left, what is resistance formula?

R is equal to Rho L by A where Rho means resistivity, R means resistance, L means length, A means area Now listen to me when we are reading It is written that Reciprocal of resistance is conductance Resistance means resistance, conductance means conducting So conductance and resistance will be opposite So Reciprocal means the opposite of resistance will be conductance So conductance is 1 by resistance So for conductance we use G as 1 by R So remember G is equal to 1 by R Similarly what will be conductivity? Reciprocal of resistivity Resistivity means resistance, what does it mean? Conductivity means conducting So what will be conductivity?

Reciprocal of resistivity This is resistivity, stop, this is conductivity, both are opposite. resistivity, stop, conductivity, conduct, both are opposite. So what have we learnt till now?

We learnt that G is conductance which is 1 by R. This is kappa, kappa is conductivity which is 1 by resistivity. We were just going to learn two things and nothing else.

Now friends, here you will understand a very simple topic. See, the name of the topic is relation between conductance and conductivity. See, here is a vessel.

What is a vessel? What is special about this vessel? We will give it a name later. But the special thing about this utensil is that here are two rods The distance between them is L and the area is A. What is the area?

A So L by A is called cell constant. What is it called? Because its length and area will never change So its name is L by A is equal to cell constant.

L by A is called cell constant And this is G star. Its name is G star. So G star means L by A.

Now look carefully Resistance rho L by A. I am doing this protocol. 1 by R, 1 by rho, A by L Did I do it the other way round? I did it the other way round. So I will say 1 by R is G.

What will I say? G. Kappa. and what is this? a by l, what is this?

next time I will send l here and a down so what will become of kappa? k will become g l by a, didn't understand? l up and a down so kappa will become g l by a now tell me honestly instead of g, what did we say? g star so kappa means conductivity, kappa means what is conductivity? conductance into my cell constant conductivity is equal to conductance into my cell constant so keep a small relation in mind relation between conductance and conductivity conductance and conductivity it was a very simple topic friends, then we will move ahead quickly No need to be scared, chapter will be completed, no tension, just these slides are here Now friends, let me remind you of some definitions See what is the definition?

A word is written here, conductivity So what does conductivity mean? Kappa How will you define kappa? So now I have told you that the formula of kappa is G, means conductance L by A So let me tell you, suppose the vessel you have taken is a cube, what is a vessel? Cube And the side of this cube is 1, how much is the side?

1 So what will be its volume? Volume will be 1 cube, how much will be the volume? YOKIDAKA! If its side is 1, then its area will also be 1. Do you know? And its volume will also be 1. Do you know?

If the side of the cube is 1, then the area will also be 1. And if you find the area of any face, then it will be 1. And how much will the volume be? If I find the area of any face, then it will be 1. So, we said, if our cube has a length of 1, then what is the length? 1. And what is the area?

1. Do you know what L by A was? G star. We were saying L by A to G star. Oh man, I won't go so far back.

I won't go so far back. This L by A was called G star So this was our GxG star So if length becomes 1 and area becomes 1 then your conductivity will be equal to conductance So it is written there What is conductivity? It is the conductance of 1 unit cube, 1 unit of electrolytic solution If there is 1 unit cube, means length is 1 and area is also 1 and volume is also 1 then K will be equal to G So conductivity is conductance Now it is written on dilution When we will do dilution then conductivity decreases Kappa's value decreases, dilution means adding water If we add water, if we dilute then K's value will decrease What will be K's value? Decrease.

Why? Because number of ions per unit, volume decrease Number of ions decrease, what did I say? Number of ions decrease So because number of ions decrease, what will happen? Conductivity also decreases By adding water, number of ions decrease and by adding number of ions, conductivity decreases Now friends, next topic is molar conductivity The name of the topic is molar conductivity friends and molar conductivity is nothing You have studied conductivity you divide it by molarity, how?

by molarity, so this is called molar conductivity and the symbol is lambda m what is the symbol of this? make it lambda or make it pi, what should I make? I am explaining, see you make pi and write m below and say there was conductivity, I divided it by molarity so conductivity per unit molarity is molar conductivity some people write it like this, lambda m conductivity by molarity, understood? so when we divide conductivity by molarity, then it will be called molar conductivity, if we open molarity then what will happen?

what is our formula friends? Our formula is kappa upon the molarity. Molarity means, mol upon the volume. So, this volume will go up.

Mol upon the volume will go up. Now, friends, pay attention here. Keep in mind that mol conductivity depends on volume.

How does it depend? If I do dilution, dilution means adding water. You imagine, my friends, my dear children, if I add water, what will happen?

If I add water and dilution, what will happen? Please pay attention. If you add water, what will happen by adding water? K value will decrease.

K value. But volume will increase. What will increase? And in order to increase volume, volume increases a lot.

In order to increase volume, me the molar conductivity will increase. Molar conductivity. So molar conductivity always increases. What did I say?

By dilution, molar conductivity increases a lot. Reason? Volume. Volume is directly proportional If you increase the volume, then molar conductivity will also increase That means dilution reduces conductivity Molar conductivity Did you understand? Molar conductivity increases, you will notice this, please I request you Now my dear students, there is an important topic here Which is likely to come in the exam, there is no tension What is written here is variation with dilution Now I told you that dilution means adding water Friends, I just told you that dilution means adding water Adding water Now let's talk logically If we talk about conductivity, it will decrease, we know But molar conductivity will increase Now remember one word, concentration and dilution Remember this word, both are inversely proportional If we are increasing the dilution somewhere, then we are reducing the concentration If we are diluting, then the concentration will be decreasing, these are opposite to each other So don't take tension, understood?

So here we are studying variation in molar conductivity with dilution It says that how will the change in molar conductivity, lambda m, with dilution happen? That is, when we add water What to add? When we add water So pay attention, what we are doing here, look at this side We are increasing the dilution on this side What is written? Increase dilution By increasing dilution, we are adding water And I told you that when dilution increases, concentration decreases Dilution increases, concentration decreases So here is molar conductivity and here is dilution What is this going for?

This is written as root concentration Here is written as root concentration But what we have to keep is that we are adding water So I know that by adding water, molar conductivity increases So it increased But here it increased by a shock This graph is of strong electrolyte This graph is for KCL And this graph is for weak electrolyte weak electrolyte means C-S-C-D-C-O-H so we thought that we should increase it for strong increase it for weak too, but why increase it for weak? so we will say, why anomalous behaviour in weak electrolyte? anomalous means weird, what does it mean?

why increase it in weird way? here it is increasing a little, and here it is suddenly what is happening here? attack so we thought that by dilution, molar conductivity increases but why increase it for weak? so the reason behind this, I am explaining to you, study it yourself what is the reason? I am explaining to you, study it yourself, I will show you the slide leave it, I am explaining the reason, see Our strong electrolytes, strong means KCL or salt, NACL, KCL These are already 100% broken, 100% All the people here are already working But what happens here in the weak side?

In the weak side, 10% are broken, that is 10% people are working But when we add water, what will we add? Water When we add water, do you know what happens? Now there are 10% people who were working When we add water, it will start to break more If it breaks more, then the remaining 90% that were not broken Now they will also start to break, because of which new ions will be produced What will be produced?

And as new ions are produced, the conductivity will increase suddenly So in strong electrolyte, people are already working And in weak electrolyte, 10% are working And 90% are sitting somewhere, like in the pot In the pot, there are 10% people who broke down And 90% were sitting somewhere in the corner And as soon as the rain started, people started breaking down New number of ions were created and suddenly the conductivity increased I am teaching you the written version, wait a second The slides are missing because it hangs I will buy a new one, I am waiting for some money Wait, I am not joking, I will buy a new one It hangs a lot, but it is still expensive 3-3 lakhs in 2 years, now it has been 2 years and 2.5 years Its screen time is over, don't you understand screen time? I'll show you. Where is it?

See the reason. See the reason. In case of weak electrolyte on dilution, degree of dissociation increase.

Degree of dissociation means breaking. What does it mean? Breaking.

In weak electrolyte, people were not broken before. Now, it will start breaking. In weak electrolyte, hence, number of ions increase. Number of ions. Which leads to increase in molar conductivity.

Due to which, molar conductivity increases. In case of strong electrolyte on dilution, there is no increase in number of ions. Here, the number of ions doesn't increase but by adding water, the motion increases.

That's why the conductivity increases. See, it's increasing in both. Increasing in the weak. Reason?

New number of ions. New number of? It's increasing in the strong but less.

Why? By adding water, the motion increases. See, it's written, due to dilution, the force of attraction between the ions decrease and movement of ions increase. So, it's increasing in the strong.

Reason? Because of movement. Increasing in the weak. Reason?

Because of the arrival of new number of ions. It's increasing in both. Tell me, why is it increasing in the strong? because of movement, did you understand?

so this was a very important topic, then we will move forward now a small topic is Kohar Laws Law, what is this? Kohar Laws Law, you pay attention when we apply Kohar Laws Law, pay attention like we were reading in the back we were reading that here is molar conductivity and here is concentration so this point is called zero concentration and the opposite name of this is infinite dilution so friends, on infinite dilution or zero concentration zero concentration or infinite dilution We use the Kohler's law. Where is it?

We use the Kohler's law. When does the Kohler's law work? When it works on infinite dilution or zero concentration. You don't need to read all this. I am explaining what it says.

It says, what does it say? It is written in rough. Fair one on the next page.

It is not important to read this. You don't understand what I am explaining. It says, if it is lambda m and we have reached zero.

Where have we reached? Zero concentration. Then you will have to write lambda m naught. Read this zero. If you are on zero concentration.

And someone says to you that you have to find out the value of this Weak electrolyte value And you are given something separately CS3 COO-NA+. and its value is 40, and someone has given this as well, the value of SCL is 10, and someone has given this, lambda M0, we have to find this, keep listening, we have given NACL, value 12, so it is saying, if you have given some values like this, if you have given some values like this, and you want to get this, then how can you get it? So we will pick up CS3O- from here, we will pick IN, so first we will need 40, then we will pick H, because we want this and H, so we will need 10, But When we take 40 and 10, then we get 1 Na and 1 Cl extra.

What is NaCl? So we have to minus NaCl here. So we have to do minus 12. So 38 out of 50. That means, how much is the value of COH in CS3?

38. That means we can subtract ions by doing plus minus and get our answer. This is called Corrallois law of independent migration. I will explain its definition to you. See, I have already explained this to you.

We call it zero concentration or infinite dilution. You don't have to understand this. I have asked the same question above.

Now I will explain its definition. It states that at zero concentration or infinite dilution zero or infinite the molar conductivity of electrolyte is equal to the sum of the conductance of the cation and anion you can find the answer of cation and anion by adding plus minus did you understand? if you want to find the answer you still didn't understand what else can I explain the definition is sum of the conductance of the cation and anion if you want to find the answer of zero concentration then that's it this is a small thing now we are moving forward here is alpha alpha is alpha is in 11th class it is called degree of dissociation means breaking weak electrolyte breakage is known by alpha like I said, my alpha is 1 1 means 100% here, what does it mean? 100% if I said my alpha is 1 by 2, then it means 50% I said my degree of dissociation is 1 means all the particles have broken I said my degree of dissociation which is alpha alpha means degree of I said my alpha is 1 by 2 means 50% particles have broken we have read about alpha in the solution chapter now see the method of removing alpha normal molar conductivity has to be kept up and keep the infinite one below, didn't you understand? I said, my normal molar conductivity is 40 and my infinite one is 80 and my infinite one is 80 so how much alpha will I get?

40 by 80 which means 1 by 2, which means my particle is broken by 50%, so you can get alpha by this way no problem for anyone, no problem now my friends, we are going to study electrolysis what are we going to study? electrolysis and I am explaining what is electrolysis, see we take a device, the name of the device is electrolytic cells what is the name of the device? electrolytic cell this device, which is called electrolytic cell, how does it make?

Take a button. We will call one anode and the other cathode Here anode is positive and cathode is negative Anode will have oxidation and cathode will have reduction I am saying it again, here anode is positive, don't put a loan here Loan is not right everywhere Here anode is positive, cathode is negative Here oxidation and here reduction What happens is We put batteries with anode and cathode, like we did here, plus and minus What chemicals do we put in it? Suppose we have NaCl here, Na plus and Cl minus So see this is plus, so a person with minus will go to plus And who will go to minus?

Will go to plus That means a chemical will come on anode and what will happen to the cathode? A chemical will come, this is called electrolysis. So what do we do in electrolysis? With the help of electricity, chemical changes. Chemical.

Now here is NaCl, I am saying, Chlorine brother, come, will it come? No. Will it come if I say? You have to put electricity, what will you have to put?

Electricity. So what are we doing by applying electricity? Basically, understand simple.

I tell you that I have a weaker. In that, I have made one rod positive, and one rod negative by applying battery. By applying plus and minus of battery. This is plus of battery and this is minus. So think what will happen, So think what will happen if I here A plus, focus please, chapter A, where did it go?

Switch off. Listen, let's go, one, two, listen, suppose here is a plus and b minus chemical, then the plus one will go here and the minus one here, this is called electrolysis. What do you say? Bring chemical changes with the help of electricity.

Whatever work you can do, we are doing it with the help of electricity. So if whatever will be made here, whatever will be made here, what is coming here? Sodium.

What is coming here? Chlorine. So we will say this is the product of electrolysis. What is this? Chlorine gas is a product of electrolysis Sodium metal is a product of...

Did you understand what I said? You must have understood what I said We used electrical energy When cells convert electrical energy to chemical energy We call it electrolytic cell Did you understand what I said? If you understood, then you have to read Product of electrolysis What do you have to read? Product of electrolysis You have to remember this I am explaining, you have to see NCRT also, from here the question comes in the exam In NCRT, you have to remember the reactions in electrolysis See what is written, like if we take molten NaCl If we take NaCl, then we will get sodium on cathode and chlorine gas on anode And this will be the reaction, you have to remember the reaction See again, if we have taken aqueous NaCl, this is the melted salt This is the water salt, then hydrogen gas will be found on anode Chlorine gas will be found on cathode and these are its reactions Means this whole topic has to be remembered, I am also helpless in this, what should I tell Yes, I am telling you the extra point, this question can come in your mind, see What can come? Pay attention If there is aqueous here, then H2O will be there.

So, from H2O, hydrogen gas is being obtained here. What is being obtained? And here, chlorine gas is being obtained. But, oxygen gas can also be obtained. H2O also contains oxygen.

So, why is oxygen gas not being obtained? What did I say? Why is oxygen gas not being obtained?

There is a reason behind it, over potential. What is the reason? So, remember this point in your mind.

If someone asks you a question in the aqueous area, who should ask? A question should come on aqueous NaCl. that on aqueous NaCl, there is chlorine gas and hydrogen gas why?

why am I not getting oxygen gas? because if there is water, there will be oxygen as well so what will be the reason? over potential required what will we say?

over potential required what is over potential? like there is chlorine gas, what is here? so why can't there be oxygen gas?

so what will we say? over potential required what will we say? over potential required so we don't have to give over potential we need over potential so you have to remember this product of electrolysis now we have two laws Product of electrolysis has two laws If we have product of electrolysis So we have two laws on product of electrolysis Faraday's law I will explain it to you in easy way See, now the story is Suppose this is your electrochemical cell Electrolytic cell Where one is positive and the other is negative You are putting A plus and B minus here Plus goes here and minus goes here So how much will be collected here Or how much will come out of here That is called product of electrolysis So how much weight will be accumulated here That weight directly depends on How much charge you have given Here the battery is connected So what flow is there from the battery? Charge How much charge you have given Here we will say weight is directly proportional to What does charge mean? Current is charge upon time So weight is directly proportional to current into time Simple thing, the longer you give current The more weight will be accumulated here Now here comes a constant z Z means electrochemical equivalent I will teach you what Z means, don't worry, everything is written here Z means electrochemical equivalent Z also has a formula, what is Z formula?

Z formula is, you have to write the atomic weight of the person you are talking about Write 96500 and write N here, what do you have to write? N 96500, what do you have to write here? N So if I tell you, suppose I say that for copper plus 2, what did I say? For copper plus 2, I have to write Z So atomic weight of copper is around 63 63.5 is the atomic weight which will be given in the exam Then 96500 and how much is n? plus 2 n means number, remember n is electron so 2 in x it is easy to find z, see it is written weight proportional to charge z is constant and this charge is I into t and z means electrochemical equivalent to find z, atomic weight is 9600 n where n means number of moles of electron like if a question comes in the exam that tell me in copper plus 2, how many faradays, how many faradays charge?

leave everything, I am telling you in 1 in 1 mole this much, 9600 coulomb we call this f, what do we call this? f suppose a question comes in the exam How many Faraday are there in this? We call it F. We call 9600 F. 9600 is F.

So, we say that in copper plus 2, there are 2 moles. How many moles are there? 2 moles. So, how much is there in 1 mole?

9600. So, how much will be there in 2 moles? I have told you this extra question. This is our topic.

This is our topic. I am saying this topic is done. Read the definition and then I will tell you what I was teaching next. It states that the weight of product during electrolysis is directly proportional to the charge supplied. What was the first law?

Now, there is a question that comes in the exam many times How much charge will be there from zinc to zinc plus 2 and 2 electrons? Let me remind you something 1 mol means 1F What does it mean? And 1 mol means 96500 coulomb This is a new question, not the previous one, don't relate it to the previous one The question is, how many moles are charged in it? 2 moles So, we will say 2 moles, how many moles are there? So, what will 2 moles mean?

Charge is equal to 2 moles How much is the charge? 2 moles It means 2 faraday, what will it mean? Because 1 mol means 1 faraday, so 2 moles means 2 faraday And you can write it like this 2 into f value, 9 6 So I am telling you, such questions are also given in the exam How many faraday are there? 2 faraday You have to put f instead of e How many chance are there to put f value?

Such questions are also given in the exam So this was our easy topic First law of faraday Electrolysis, whose law is it? Electrolysis, law of electrolysis Product of electrolysis is the first law Second law I am telling you, you can define it yourself Second law is this, second law of faraday Second law is that, suppose this is a cell Then this second electrolytic cell, this third, this fourth You have given a lot of cells If you put many cells in series Then the weight here will be W1 Here the amount will be W2, here the amount will be W3, here the amount will be W4 So W1 is directly proportional to E1 W2 is of E2, W3 is of E3 Now you will say what is E1, E2, E3? This is called equivalent weight I will tell you the meaning of E Equivalent weight. Weight equivalent.

Equivalent weight. Now how do we get this? So there is a formula to get E. Divide atomic weight by n. Atomic weight?

Didn't understand? I will explain what it means So if we take out the concept from here This is the second law Second law says When number of Write it yourself I am telling you When number of electrolytic cells connected in series Then weight of the product of electrolysis Is proportional to equivalent weight Proportional to Now if I say W1 by W2 If I divide these two, what will be the answer? E1 by E2 If I get a question, I will show you the question There is no big deal in the definition, the question is One cell and another cell, two cells, it is the second law Both are connected in series In series, the charge is same and the current is also same And we say, its weight is 4 grams And this is zinc, what is this? There are zinc plus 2 ions here And we don't know its weight But we know that it is copper, what is this?

Copper plus 2 So, take out W2, then you will say, okay son W1 by W2 is equal to E1 by E2 You will say, I know W1, I have to get W2 out. What does E1 mean? Atomic weight by N. So how much is the atomic weight of zinc?

I don't know. Find out about zinc quickly. Google search.

Genuine atomic weight. 65, keep quiet. So I will say, W1 is zinc, right? So 65 by N.

What does E mean? Atomic weight by N. So what will I say? 65 by N.

65 by N. And how much is N? Copper's plus 2 means 2. What does E2 mean?

Copper's atomic weight by N. E means this. So copper's is 63.5. And what is the value of N? 2. What is the value of N?

2. So this will be cut. Answer is 65 by 63.5. So we have an equation. 4 by W2 is equal to 65 by 63.5.

From here, W2 will be easily removed. That is what Faraday's second law of electrolysis. If I show you in notes, you will get scared.

It is written in English. So write what I said. You can write it in tough English if you want This is a slightly tough English Again, the second law is slightly tough English It is written, the mass of different Wait, please The mass of different, this was different The mass of different ions liberated at electrode When the same amount of electricity is placed through different electrolytes Are directly proportional to their chemical equivalent weight Their chemical equivalent You see, the mass of different ions liberated at electrode When the same, leave it Remove it You can write it like this The mass of different ions liberated at electrode when many connected in series Leave everything, I won't do it. I'm giving you two options. Firstly, I'm saying it with my mouth.

I'm not writing. I don't have time. Please, sorry for that.

The mass of different ions liberated at electrode when the number of electrolytic cells connected in series I'll cut this. Are directly proportional to their chemical equivalent Wait, this is one way, the other is same too same W1 by W2, E1 by E2 This is the second law of Faraday's Now what is in this chapter? Batteries In batteries, we have to remember reactions I have already made a video on youtube about batteries I am not able to do it in batteries, I have already put that trick in I am telling you a topic, pay attention The topic is rusting What is it? Rusting or Corrosion, have you heard?

Corrosion means fighting, rusting means fighting On iron, on iron Why is rusting happening? Rusting happens because in the presence of air and water Bonnie- HEY! You want to throw your shoes and hit them?

I am saying this continuously for more than an hour. Without keeping quiet, with the same intensity. Full of dedication. Do you know why? To make a good career.

I am working hard. Listen to me. And you, talk, talk, talk. What's the benefit?

And before you, I have taken 7 classes continuously. I have taken 7 chapters today. One shot, one shot, one shot. 7 chapters. This is the 7th.

With the same intensity. I am hungry, thirsty, and dry. Corrosion, there are classes after this.

Corrosion, rusting, and fighting. Why? Because oxygen, water, and metal react with each other. Metal reacts quickly with oxygen and water. And they get damaged and become weak.

So to save them, people paint them, apply grease. And the most dangerous method is galvanization. Galvanization is a sacrificial method. What happens in this? A zinc is a reactive metal.

Zinc is reactive. Like an iron pillar. And we want to avoid a war on iron. So we will make a thin layer of zinc. We will make a layer of zinc.

Whenever there is a reaction, it will happen with zinc. And if it is damaged, we will remove it. We will apply another zinc. If it is damaged, we will remove it.

So zinc sacrifices itself. This is called galvanization or sacrificial method. So, rusting is not an important topic, so there is no need to discuss it further.

This chapter ends here. Batteries are on YouTube. Watch it with a trick.

This is the end of this chapter. one May you prosper. This is my blessing and this is my love.

Transcript for:Electrochemistry Key Concepts

Transcript for:
Electrochemistry Key Concepts