 Okay, let's start the quiz. The first question is in front of you. The result of some test on a colorless liquid XR shown. The liquid has a boiling point 102 degree Celsius. Universal indicator turns green. Universal indicator turns green. Okay, universal indicator is used for identify acid and bases that turns green. And boiling point is given to you. Can you tell me what is the substance among this? Okay, you have to think it is related to the chapter 1. This question is related to chapter 1. If you think you can get the answer. Boiling point is 102 degree Celsius. Okay, so answer of this question is. Okay, let's see how many of you can do this. Okay, my dear student answer was D. Okay, if you remember I gave you, do you remember, I don't remember whether I explained that in other groups, in other classes. If I and our people remember I told you whenever you add impurity in water, whenever you add impurity in water, boiling point decreases or decreases? Boiling point decreases or decreases? Tell me. Boiling point increases. So you have 102 degree Celsius. So mostly it would be the salt water, NACL acquires. And second thing they have given green color. So green color in universal indicator is because of the neutral solution. NACL is neutral in, neutral. You all know that what is the color of universal indicator if it was acid, if it was acid what will be the color? Yes, acid gives red color and base gives, and base gives blue color. So the infusion they have given, if base was given then it was a blue color but they have given green color means it is a neutral solution. So you have to think like that. Okay, so answer is D. If anyone has any doubt please ask. If anyone has any, should I show the question? Should I show the question? No? Okay, one minute. I thought it is clear to all of you but one student has asked, this is the question. Okay, so you can see here boiling point is 102. So answer is sodium chloride salt solution. On, on adding the impurity if you remember I explained in the class, if on adding impurity boiling point increases. So boiling point goes from 100 to 102. Universal indicator turns green. So universal indicator turns green in a neutral solution. Only neutral solution you have this. FNL boiling point is 78 degrees Celsius. This is not the answer. You know that FNL is bearing your, like alcohol is bearing your sanitizer. Alcohol boiling point are very less that's why they are highly volatile. That's why they are highly volatile. Okay, so answer is D. I hope you understood this. Okay, fine. So next question is, okay, Abhishek who is leading Abhishek NPR, NPR Saina. Good Abhishek. Okay, moving to the next question. Blue solid X is soluble in water. Which method is used to obtain a pure solid X from aqueous solution? Blue solid X is soluble in water. Which method is used to obtain a pure solid X from aqueous solution? You have 20 more seconds, 25 seconds. Okay, students please don't discuss any other thing. Which process you will use to purify the liquid to get the pure crystal? Okay, answer for this question is B. 45 of you got the right answer. Okay, so answer was very easy. Okay, anyone has any doubt please ask. We have, okay, why? So, see, question number two is this. A blue solid X, see, solid is given to you and which is soluble in water. Okay, water soluble. Just take an example of salt solution. If you have a salt solution, how can you get the pure crystal of solid? I explained you this in class. Do you remember I explained this in class? If you have a salt solution and you keep on heating the salt solution after some time, you will get the crystal and when you get the crystals, stop. So, that is known as crystallization. Just remove the whole water and then leave it for cooling. That process is known as crystallization. I explained this thing when I was explaining you the saturated, unsaturated, super saturated solutions. So, crystallization is the technique used. Any doubt student to obtain the pure salt? Okay, what will happen if I ask you one question? Let's say I have the sugar here. Let's say I have a sugar solution. And if I keep on heating, if I keep on heating and I'm not stopping the burner and if it goes continuously, what will happen? Are you going to get the sugar? So, can I drive? Yes, tell me. So, you won't get the sugar because the sugar will start caramelizing as well. Yes. So, you will get a black powder in that case. So, no one can say it is like only evaporation. The process, that's why we will not get sugar. If we want to get the pure solid, we need to use the chromatography. Understood? Okay, fine. Anyone has any doubt? Please ask. No doubts. Okay, we will see the leader board. Okay, students, I would tell you once more that please don't write unnecessary messages because I am not able to read if someone really has any doubt in this. So, please don't discuss anything other than what we are doing here, other than the patients. If you have doubt in questions, you can write it there. Question number three, a mixture is separated using the apparatus shown to a mixture you have. You can see there is a funnel filter paper you have. Filter paper and funnel and mixture is poured into that. What is this mixture? Now, you have to think what is there in that mixture. I would help you a little bit. Sir, the font is very small. Sir, it's very small. That's why I am reading. A mixture is separated using the apparatus shown. You have a container, there is a funnel, there is a filter paper and mixture is poured over that. What is the mixture? Aqueous copper chloride and copper. A option. Aqueous copper chloride and sodium chloride. B option. Ethane and methane. C option. Ethanol and water. D option. Okay. So, most of you have answered it right only. Thus see how to do this question. It is again a very easy question. See. Okay. Just a minute. Third question is this one. A mixture is separated. So, apparatus is given. You know, you need to. That mixture can only be separated which is a combination of some solid and some liquid. Which is a combination of solid and liquid that only will get retained over the filter paper. Okay. Aqueous copper chloride and copper is the only answer because copper is solid and copper chloride is solution. Copper chloride is solution. Copper chloride and NaCl will not work because both are solution. Both are solution. Ethane and methane both are gases. Ethanol and water both are liquid. Won't work. Understood? Could I move to next one? Okay. Okay. Next question is. So, first we will see the leader board. Who is leading now? Radha. Those who are talking. Those who are chatting on this chat box. Please don't do that. I am not able to read the messages. Okay. So, we will see the next question. Ethanol is made by fermentation. Ethanol is made by fermentation. How is the ethanol obtained from the fermentation mixture? Ethanol is nothing but the alcohol. It is made by the fermentation. How is the ethanol obtained from the fermentation mixture? Okay. Most of you are right. Fermentation is the process of preparation of ethanol with the help of, let's say you have the, you must have heard that. Okay. Who can tell? You have a glucose. Okay. Glucose you have and there are the enzymes called as these or enzymes are used to ferment the glucose and get the ethanol and carbon dioxide. This process is used and in that process the way of obtaining alcohol is fractional distillation. Fractional distillation is used in those processes where the boiling point difference is very less. When the mixture has the components and those components have a very less boiling point difference, then only where you use the fractional distillation. This is the last warning students. If you keep on chatting here, I will, I will remove all of you. Those who are chatting, please don't chat. If you have anything related to the questions, then only you can write there. Okay. So, Arthur is leading. Okay. Next question. Which of, which two methods can be used to separate a salt from its solution in water? Which two methods can be used to separate a salt from its solution in water? Crystallization, decanting, distillation, filtration. You know all these four processes you have already learnt in your class 8 or 7. You know all these things. What is the distillation? What is decantation? What is filtration? What is crystallization? Okay. So, what, what processes we can use to separate salt from its solution? Please underline, please read this word salt from its solution. Okay. So, I think what is the answer? Okay. Answer is B. Very good. Answer is B. 37 have answered. Okay. Students, I told you one process I already told you in previous question. If you want to separate, you can use the crystallization. One process is also distillation. Distillation will also give you the salt and water. Yes. Any doubt students? Okay. Suddenly settling its animation and removing the, okay, fine. Any, any doubt? Why not decantation? Very good question. Bharat, that's why I told you, please read the word solution. Decantation is used where you have insoluble thing. Then that insoluble thing settle down. If you put us, if you have a sugar water, if you have a sugar and water. So, in that sugar solution, your sugar will not get settled down. Yes. Did you understand? One student asked Bharat. Did you understand? Okay. Good. Moving to the, okay. We'll see the next question. Okay. Fast process is Monisha. Good Monisha. Saurav is, okay. Akur is not leaving his place. Okay. Now, still we have so many questions. Okay. This is really very, I know that the font is very small, but listen to me carefully. A solid mixture contain an ionic salt, X. Okay. And a covalent organic compound Y. Okay. Okay. Now, two students suggest methods of separating the mixture as shown. In method one, shake with water and then filter it. Method two is shake with ethanol and then filter it. Which method of separation are likely to work? I want to tell you one thing in this question that you all know that like dissolves like. I use this word many times in class. I want to help you here. Yes. Sir, I couldn't read the thing properly. I read now. The solid, okay. It's fine. It's hard to connect with the reading. So that's why I read the question. It's so fast. Like so slow. Okay. Fine. Okay. Okay. One thing. Listen, listen. From next time, I actually read the question. You could have been. That was quite less for the question. Okay. No problem. First, okay. We'll see the question. Let's see what, whether you understood or not. I think time was less for all of you. Okay. So that's not an issue. Now see, the question was this. Can you, can you see my screen now? Or should I zoom in? Is it fine? A solid mixture contains a solid mixture containing x and organic solid y. This solid is nothing but x and y. And this x and y, there are two methods. Two students are there. One is suggesting that add water and filter. Other is suggesting add ethanol and filter. You know, ethanol is an organic compound. Ethanol is an organic compound. And your water is, water is inorganic. Water is inorganic. Okay. As I told you, like dissolves like. Like dissolves like means water will dissolve the salt, ionic salt. Because water is a polar compound, ionic salt is a polar compound. So water is, you all know that NACL get dissolved in water. Because water is a polar, it dissolves the NACL. Similarly, ethanol can dissolve the covalent compound. That is nothing but an organic compound. Ethanol cannot, if you put a salt and ethanol, you know, it will, it can't dissolve that. Salt and ethanol can't be, can't form a solution. So what will happen if you put a water on this filter paper? Sorry, one minute. Okay, see. If you put filter paper here, see. If you put filter paper and water, so the solution which is, which is we call it like a filtrate, filtrate will have your salt. Filtrate will have your salt and water. And your organic compound will get deposited here. This is organic compound. That is organic compound. It is nothing but Y. If you do like this, your Y will come with the filtrate. Y plus ethanol will come here. And here you will get the salt. So both the ways are fine. Both the ways are correct to separate X and Y. Okay, students, if you have any doubt, please ask. Because there are so many messages. If you have doubt, now write, now type your doubt if you have any doubt. No doubt, sure. Okay, this concept will be used in other questions also. So if you have any doubt, please ask now only. Okay, fine. So moving to the next one. Okay, I'll read the question pass in now from now on. So you can show your PPT. So it's clear in that. Okay, so, okay, you let me know whenever you feel like font is very small, I will show my PPT in that case. Okay, but you have to tell me at that time only. So can you just show it so? No, no, then they have to start this thing also, no? In 90 meter also. Okay, see all questions are not like that. If there is some question which has a really small font, I will definitely go for the PPT in that case. Okay. So what's the most important CD option, so that was hard to. Pardon? So we couldn't see the options clearly. Okay, fine, fine. Okay, now, now you will not face this issue. Let's move to the next question. I'll read question for you. Please listen to me and I'll read options also. Neftaline and iron filings cannot be, okay, there is a word cannot, okay? Cannot is very small in font. Neftaline and iron filings cannot be separated by the method of solvent extraction, solvent extraction sublimation, magnetic separation and filtration. Please mute your mic, all of you please mute your mic. Cannot, there is a word cannot, okay? Neftaline and iron filings cannot be separated by method of solvent extraction, sublimation, magnetic separation and filtration. I told you cannot, there is a word cannot. Monisha, why you didn't listen? Why is cannot small? I will tell you why later. Okay, then if you are marked wrong means you have made the mistake. Okay, 33 students, someone asked me sir why you have written the word cannot or why cannot is small. Actually this question was MCQ based. There were the multiple correct answers but to make the, but I wanted to give this question to you so that you understand the concept. So I made it the single correct. Okay, now see. What is there in the question? Just one minute. Question is this. Neftaline and iron cannot be separated by method of, you know solvent extraction, solvent extraction is nothing. Let's say neftaline. I told you neftaline is an organic compound, like dissolves like organic compound. Iron filings are the metal. If you put some organic substance you can dissolve neftaline in that but iron filings cannot be dissolved. So this is the only method. Okay, this is the one of the method. They are asked cannot be separated. This, by this method you can separate. Second is sublimation. Sublimation you can separate because neftaline are the, neftaline is sublimable substance. Magnetic separation can be used but filtration won't work because both are solid. How you can separate? Both are solid. Answer is D. Understood? Okay, Talvi, what doubt you have? Yes, Talvi, please ask what doubt you have. Yes, no, no, you can't separate it by D. That was the question. You cannot separate. You know, if you have a neftaline balls, these are the neftaline balls and let's say you have the iron balls. Iron balls are, let's say I am representing with the brown colour. So if you put in the filter paper also, how can you separate them? It cannot be separated by filter paper. Understood? So filtration is not the technique. So this is the answer. They are asked cannot be separated. Talvi, is it clear? Talvi, please respond. Okay, fine. Yeah, okay, okay, okay. Thank you. Now we are moving to the next question. If anyone has still, if anyone still has any doubt, please ask. Next question we'll see. First we'll see the readable. Okay, good Monisha. Next question. The font size is very small. Yes, yes, I'll show. Yes, yes, I'll show it. I'll show it. Okay, so question is this. Please read the question carefully. Methanol CS, this is the question. Please read it carefully. Methanol CSPOH and ethanol are miscible liquids. Which diagram shows the apparatus that is used to obtain methanol from mixture of ethanol and methanol? So could you scroll down and show us the options? Oh, these are options only ABCD. These diagrams are option. These diagrams are option. Okay, okay, fine. Now I'll show you the, how to do the question. Okay, fine. What is the answer of this question? Tell me. It's very easy question. So B is the answer. Yeah, B is the answer. Why B? Because these are the liquids which are having the almost equal boiling point or boiling point differences very less and these two are the liquids only. So A, we can't use because A is used for solid and liquid separation. B, we can use only heating won't work because both will evaporate and the last option is used. The last option why I gave this question, you know, last option is very interesting. Whenever there is a water, whenever there is a water in any salt and you want to remove that, you use this technique. I am again repeating, whenever there is a water and you want to remove that, you use this technique. What you do? You provide heat from this end. So what will happen? Water will evaporate and report to this tub. It will report to this tub and then later on it will report in over the test tube by the downward displacement of water or if there is some oxide, let's say copper oxide is there. If there is a copper oxide and you want to remove the oxygen from copper oxide, just heat it. So oxygen will report on the top of this. Understood? Students, did you understood? Did you understand this? Okay. Moving to the next one. Fine. Please read the question carefully. Okay. Should I show in the PPT or is it visible? Yes sir. Yes sir. PPT. PPT. Okay. PPT, PPT. One minute. I'll show it. I'll show it. One minute. Okay. See, a mixture of sulfur and iron filings needs to be separated. I think you can read the question. So I'm not reading it. Please tell me the answer. If you're done. Okay. Still people. Easy. Okay. Good. Still it's a small font. Maybe font. Okay. Should I zoom in? Thank you, Gandhaar. Sir, this is fine but the real question font is small. Okay. Sir, it hangs up. Okay. Thank you, student. So what is the answer of this question? The first time we do have any doubt. I'm not able to see the leaderboard. Do you have any doubt? Answer is B. Do you have any doubt? If anyone has any doubt, please ask. Okay. No. Oh my God. So many answers. Okay. Please. Everyone should not. Okay. No doubts. I present the option B but then the software shows wrong answer. No. I think answer. Okay. Let's see what is the answer. Sulfur is their solubility in water. Okay. They are given. What is the possible technique for sulfur and iron filings using water? Can you do that? No. No. Both are not soluble in water. You know, you can use only that technique which can dissolve one thing and other remain and other remain insoluble like using a carbon disulfide. Carbon disulfide is again it is a non-polar. It will dissolve the sulfur. I told this thing in chapter one. I told you sulfur can dissolve. Carbon disulfide can dissolve sulfur but it can't dissolve iron filings. So this is the correct way and using the magnet, magnet will extract the iron filings but not the sulfur. This is also correct. The answer is B only. Any doubt? Okay. We will move to the next question. First we will see the leaderboard. Okay. 40 students have marked it right. Good students. Now we are moving to the next one. Resurve is leading. Shrejan goes for KRM. Very good Shrejan. Okay. Next question is in front of you. Should I show you PPT again? PPT or this? Let's say PPT. PPT. Okay. Fine. Fine. PPT is in front of you. Please write the answer. A mixer one contains hand and water. Mixer two contains salt and water. Which method of separation could we use to obtain each of the required product from each mixer? Okay. This question is very good question. Okay. Please read the option carefully and then answer. In as hung sir. I'm not able to answer. Sanya what to do now? Please replace it. There is only one option. Please replace it and do. Yeah. These questions are very big. You need to understand that and but I by while I explain you this. Okay. I think it's time sir. Yes. Yes sir. Okay. What did? So do you need? Okay. Anyone wants explanation? So the answer is D. Fine. Anyone want explanation? Please tell me. Yes or no? Yes. Okay. Okay. One minute sir. No sir. No sir. No. Anyone who wants? Okay. Yes. Someone has written yes. Contains salt and water. Salt and sand and water. Salt and water to obtain the sand. Okay. Try to understand. You want to recover the sand from the water. You know the filtration is the best technique. Please put your mic. Students or those who please don't on your microphone. So obtain sand filtration is the best technique you know and by the filtration what you're going to get. So filtration are there in option C and D. Okay. Fine. Next is to obtain water also filtration is best. Why you want to go for the distillation. Distillation is used when the boiling point if you if there is no other option left with you filtration is the best technique. Okay. So by filtration you can separate both salt and water. So I told you crystallization will give you the salt. But now why I told this mission is very important. Whenever you want to recover the solvent I am repeating my statement again. Whenever you want to recover the solvent you go for the distillation because in the distillation there is a tube if you have if you have one question again in which the distillation apparatus was given. So there is a tube in the distillation chamber. This tube will recover all your solvent. This tube will recover all your solvent. That's why answer is D. Is it clear someone ask Satyam or someone ask this question. Is it clear Sivam? Okay. Thank you. Fine. Moving to the next one. Okay. Good. So leaderboard just we'll see the leaderboard. Oh, Srejan is fast. Okay. Please read the question carefully. The table gives the solubility of four substances. Do you need? Can you read this or should I show? No problem. I will show it. Yes. Tables give the solubility of four substances in ethanol and in water. The mixture containing all four substances added to the ethanol still and filtered the solid residue is added to water still and filtered filtrate and evaporated is evaporated to dryness living the white solid which is the white solid. Please take your time and answer this question. Okay. Jager please put your mic on you. Okay. Please let me know if time get over. So time's up. Okay. Time's up. Okay. See question is very easy and it's a very good question. So tell me what you mean by Mahatma Gandhi. I didn't understand that. Something you have written here. Okay. So table gives the solubility of four substances. Okay. Fine. Four substances are there. Okay. Now we'll write ABCD let's say four substances in ethanol and water. Now a mixture containing all four substances added to ethanol if I put into ethanol ethanol is a some solvent and still and filtered. So I put in put into the ethanol. Okay. I stood it and I filtration will let's say I filter it. Okay. Once I filter it. Once I filter it. What is they are saying the solid residue is added to water. Okay. I have taken this thing to the water not the down thing. This means that the thing which I'm taking is insoluble in ethanol. Is it clear because they have said that the solid residue is added to water state and filtered. So now I am adding this solid. I'm adding this solid into water. This is the water. Okay. And it is mixed properly and in the next process the filtrate is evaporated to dryness. Now again the filtrate here you are using the filtration again. Okay. Now filtrate you are taking to the dryness. This you are taking for the dryness leaving a solid behind. Now you got some solid. This solid is white solid. Now tell me what is that nature of white solid. So I think you understood this question that white is obtained by the by the residue of of the filtered ethanol residue of filtered ethanol means this solid is definitely not soluble in ethanol. So I will write insoluble in ethanol insoluble in ethanol and this solid is passed through the filter paper. See this this means solid is soluble in water soluble in water. Okay. What is the answer then? Solid is soluble in water. Water is this soluble and insoluble. Answer is B. Please check. Is it clear? Yes, sir. Okay. I hope you understood this question. Okay. We'll see the leader board first. 22 people have answered it right only. So I think you understood this question. If anyone has any doubt, please ask. Okay. Fine. So we are moving to the next question. Are you already? Any doubt? No. Please read the question carefully. PPT? Do you think? Okay. Please read the question carefully. A student carries out an experiment to prepare pure magnesium sulphate crystal. This is again a very good question. I have given more time for this question. Okay. Because this is very good question, please take your time and answer this question. Vibha. Why are you discussing all those things? Vibha. Okay. Did I explain? Time is not yet up. Okay. Fine. Sorry. Please let me know. So time is up. Okay. Fine. So question is very easy. You know, a student carries carries out an experiment to prepare pure magnesium sulphate crystal. Okay. Anyone want me to explain this question? Please tell first. What's the answer? Okay. I think you must have got the answer. It is, I think it's the answer is filtration. See. Yes. How to do this question? Okay. Anyone has any doubt? Tell me. Tell me. One minute. Please mute your mic. No doubt. No doubt. Anyone who wants me to explain? No one? Should I move to the next question? Okay. Me. Yes. Next question. Please. Okay. Please explain. Someone is asked. See. Magnesium carbonate. Magnesium carbonate when add to the dilute sulphuric acid. H2SO4. This is the sulphuric acid. Okay. Now what they have given? He adds magnesium carbonate until no precipitate. Now this is very, very important question. He add magnesium carbonate. This person is keep on adding the magnesium carbonate in this container in this beaker. He is keep on adding. Which process should he use the next stage? Why I give the, why I put this question in the today's class. They have, you have to think like what will be the next step? Next stage will be what? You know magnesium carbonate when he is going to add, he is let's say after sometime they have given that he will add till no more react. So after some point of time you know what will happen? When no more magnesium will react, how you are going to detect that? Actually some magnesium will get deposited here. Some magnesium carbonate will get deposited. That's how he will going to know that no more magnesium is dissolving. You know this is the actually practically based question. Practically what we do? We keep on adding magnesium carbonate. Once we notice that please put your mics on mute. Once you notice that no more magnesium carbonate is dissolving then you stop the process. Now when you want what is the next process? The next process is you need to filter this. You need to filter this so that you can remove this magnesium carbonate and you get this, this is nothing but magnesium sulphate. You can get the magnesium sulphate, pure magnesium sulphate. Understood? This is the process to make one salt from the other. Here you use the magnesium carbonate to prepare magnesium sulphate but the first process is to filter this is nothing but extra, this is nothing but extra magnesium carbonate. So I put filtration, it's showing us wrong answer. It's showing wrong? Are you sure? All of you are getting wrong answer? Sir it happened to me also sir before. Oh no one minute we'll see that. Okay fine see. Sir I got filtration and I got it right. Okay I think then what can I do tell me students and sir you can see in front of you it see only, only nine students. Oh my god. Okay students did you really understood this question? Did you really understand this question or not? Anyone who still has, oh my okay anyone has any doubt? Please no I now I understood okay anyone who still has any doubts or why do we, one minute sir why do we keep on adding? Yes it is given in the question, very good question. See someone has asked, someone has asked sir why we keep on adding this? I told you you are using magnesium carbonate to prepare magnesium sulphate and my dear student how you will get to know that all sulphuric acid is has reacted. How you got to know? You keep on adding, you keep on adding. At one point of time your salt will stop dissolving. Your salt it is same like it is same like you are adding a you are adding a sugar, you are adding sugar in water. If you add sugar in water then sometime it will keep on dissolving, keep on dissolving, keep on dissolving but at, at one point when you add a single sugar crystal that will report in the bottom that will not get dissolved. That is how you get to know that this is the saturation limit. After this you won't, you can't dissolve a single sugar crystal. Similarly you keep on adding and and once you get to know that no more carbonate is dissolving that is how you get to know the whole sulphuric acid has reacted. Now no more sulphuric acid is left in the container. So this is the way we, we convert one salt into another. Understood? Understood or not? Someone asked this question. Did you understand this? I mean we can also add limited amount then filter. No. Okay listen for us. You, if you add the limited amount let's say, let's say you add 5 gram. Let's say you add 5 gram but that 5 gram is getting dissolved completely then what you are going to filter? What you are going to filter it is dissolved. It is same like let's say 36 gram can be dissolved in 20 degree Celsius temperature 36 gram of sugar can be dissolved. Now if you dissolve 25 gram at 20 degree Celsius your 25 gram will completely dissolve then what you do with the filter paper in that case everything will pass from that. Understood? Kanuvi you are disturbing class I'm telling you. Please don't type anything. Okay it gets dissolved but it's okay. Any other doubt? No? Please try to understand I can't read the messages if you keep on chatting. Okay so next question is in front of you. Please read the question carefully before answering. Which of the following pair of gases cannot be separated by diffusion method? Diffusion you know I explained you when one gas goes from one place to another or a higher concentration thing goes to the lower concentration that is called as diffusion. You have one minute 15 seconds left. You have to think properly which gas can be diffused. How you can separate? There is a purpose of giving you the more time in this question. Monisha you have to think. There is a sulphur dioxide and hydrogen CO2 and N2O. You have a little bit idea of periodic table. Little bit idea what comes first what comes after that and till atomic number 10 I think all of you have idea till atomic number 10. If you know till atomic number 10 only you can answer this question very easily. Okay Monisha then you can answer how to use I explained in the class. You think how diffusion can help you separating two things. Okay you have to what you are saying to Moe is to I will see either you are disturbing your right in English only. Okay so answer for this question is CO2 and N2O. Let's see how many of you have answered this. Oh good 22. Fine see the question was very easy. You know what was the question. Okay you know very easy question why I told you if you remember hydrogen helium lithium okay hydrogen helium lithium beryllium boron carbon nitrogen oxygen chlorine neon you would need till this only. You know carbon the diffusion if you remember I explained that thing diffusion is nothing but movement of particles movements of movement of molecules. Okay so if the molecule is bigger let's say you have this this much this the size of molecule is this much and size of molecule is this much which will run fast tell me which will run fast a or b which will run fast a or b a will run fast okay someone has written b also so a will run fast b will not run fast because it is a is a small okay now if a is a small particle that can I say that after some time a will report here but we will reach here only so by this way you can separate a and b by this way you can separate a and b this is nothing but separation similarly you have to think in gases also which gas is having a huge molecular mass difference and which is having the same molecular mass if mass is same if mass is same they won't be separated by diffusion you see the only this option where the carbon is having combined with two oxygen and two nitrogen is combining with oxygen in this case the mass are same CO2 masses those who know little bit about the atomic number this is 6 atomic number 6 oxygen atomic number is 8 so mass of CO2 is mass of CO2 is atomic number just multiply it with 2 carbon 6 multiplied by 2 okay it is nothing but 12 12 is the mass of carbon and 1632 is the mass of oxygen that is 44 mass of N2O is mass of N2O is nitrogen mass nitrogen atomic number 7 mass is 14 14 plus 14 plus oxygen mass is atomic number 8 mass is 16 16 it is 44 in this case only you can't separate through the diffusion because both will run with same speed you can't separate them students did you understand this how what how someone has written how nitya you have written how nitya do you have any doubt okay fine so we'll go to the next question okay students please don't write unnecessary messages okay now who is leading very good Sreejan now we are going to have a next question please read the question carefully okay you need PPT or is it fine so we need PPT yes a constituent of a heterogeneous mixture contains XYZ in this mixture if mixture is XY take on X as us take on X can be separated using magnetic separation from Y if Y and Z mixture is taken it can be separated using distillation which of the following mixture can be XYZ DIA Prateek can you please stop so are there any more questions one more question we have sir time's up okay fine answer for this question is A why A this mixture had constituent a heterogeneous mixture XYZ XY can be separated by magnetic separation means one should be magnetic so iron is magnetic salt is not magnetic Y and then mixture is taken can be used as distillation distillation will be used when there is a salt and water if there is a salt and water something is soluble soluble thing is whenever there is a soluble thing we use the distillation the salt and water is there answer is A students if you have any doubt please ask any doubt no okay students now we are going to do the last question iron magnetic yes iron is magnetic cobalt is magnetic nickel is magnetic okay now the last question you can read it in your 90 meter only greasy spots can be removed from clothes by evaporation sublimation fractional distillation dissolving in a suitable solvent oh good Tannavi good Arithya oh 1.33 oh very good okay so last 10 seconds I think you can relate this question with your practical practical you see that when there is a greasy spot how you remove that okay that is nothing but the solvent extraction oh three students have made them say it is solvent extraction but still it's a good graph okay now we are going to see the result and tell me according to you who won the game who won this quiz tell me fast okay jagrav season monish jagrish okay fine region jagra only three votes we are getting okay just give me one second I'll show you the result okay jagra there are too many votes for jagra okay see let's see who won this and the result goes okay I think it's jagra only oh good jagra good congratulations okay students hope you learned something today about the separation technique yes or no have you learned something okay good good okay thank you student we'll again have this center one next week bye thank you thank you bye thank you sir thank you so bye okay so thank you sir some yes someone was saying something yes okay my dear student you know whenever the questions are big whenever the questions are covering more area I can't increase font otherwise it will you can't read the full question understood thank you sir okay thank you bye thank you