 fine already no through what happened through what happened okay fine so first question is in front of you mainstream volume second you showed in the powerpoint yes I can you show it okay this is the question mainstream volume of liquids is fundamental aspect of experimental chemistry the diagram shows three different features of the records used for which rose type okay Vibha we can't increase the font because the question is that much big so I can't increase font more than this yes sir no it says time's up there was so less time time yes that's why I told you see time it's very easy so but you didn't show yes so so so we had to read the question by that time the time okay time was 30 seconds time was 30 seconds I so can we do this one please no redo why you why you want to redo no 30 second was allotted because it is very efficient they ask which is the burette which is which is measuring cylinder if you know you could have answered but if you don't know there is no other option you have so I knew the answer but the time we had to read the question we have to read the question to know the answers so I knew the answer but next time could you please make the font big so it's all it hurts okay fine fine say listen only this question has 30 seconds you have to switch tabs and come in that it's small and then you have to open the slide that's a lot of time sir okay fine no problem listen answer of this question is a okay why a this is the burette burette is used for the burette is used to measure the volume added in the solution whenever we add something in a in a big container you in the in the container if you put the burette over burette what happens burette can you can control the flow of liquid okay in acid base reaction generally we use burette so this is known as burette this is known as measuring cylinder and this is known as burette in this tip we need to serve the solution from burette because exact volume we needed for a small volume let's say 25 ml and all we can exactly measure from the burette so answer is a any doubt students no doubt okay now next question this is the only question which has 30 seconds rest all you can do it fast okay there is one more question because for 40 seconds time limit so please read the question carefully and you have time please you see the time first okay and Christians are big because you can see that if I want to show the diagram Christians could be like this only now I will show you screen again the question isn't okay first we'll see the okay this is the reading I will show you Christians just after this okay if you have again if you want to see Christian this is the next Christian it is in front of you okay now if you want to see screen this is the screen please let me know once time once time got over please let me know once time get over time time over very good so answer for this question is answer for this question okay what is that if you see properly this is increasing here so this is 17.5 and you always write the reading that you have a lower miniscule there is one thing called as lower miniscule okay whenever in the laboratory when you go so you always write the lower miniscule so you take reading from this point and this this point is reading is nothing but but 17.8 reading is 17.8 okay now here if you see the reading 30 32 34 reading is 34 17.8 and 34 C is correct answer is C okay fine moving to the next question we'll see the leaderboard and oh it's very disappointed 20 students only have answered this question right why students it was not that tough question okay it was easy question but yes the font was so small and then okay now don't say font was not a large question so that's a screen share screen you can see that if you zoom in you lose a solution try it yourself okay students this is only which can I do I can one start and I will show you the PPT in next moment only completely fine sir okay fine next we are going to I'll show you Christian immediately after showing that I'll show you the PPT immediately after showing the question so Pratham is leading again fine good Pratham give it up next question is it front of you if I am showing the screen if you want to see question number three is this please see question number three solid P melts at exactly 60 degree Celsius and boils at exactly 310 degree Celsius solid two dissolves in ethanol and shows a green color and a yellow color when analyzed using paper chromatography which row is correct please don't make mistakes why I've given these type of questions because I know that many of you just overlook the question okay please let me know once time get over okay don't please read question carefully I think last time if all of you those are marked A because you have not read that values properly that's why you marked A in last question so please read the question carefully okay time's up okay fine P melts at exactly 60 now this question uses two concept P melts at exactly 60 and boils at exactly 310 pure substance you all know that pure substance has pure substance has fixed melting point and boiling point fixed melting point and boiling point so this is a pure substance so contains only one substance so P contains only one substance so only possible answer seems is D only possible answer is D okay let's check solitude is all in ethanol and shows green color and yellow color if two spots are observed if two spots are observed this means that if two spots are observed means definitely Q is a mixture of two substances this means two is having more than one substance answer is D hope you understood this and it out and it out no chart would we go to next one okay 29 have answered it right good students keep it up next question is in front of you first I'll show you the leaderboard sir to move fast you can do all tabs okay I see don't worry I'll show you it fast only it will take hardly two seconds okay now are you already for next question I'm showing you the next question so next question is in front of you pure S2O boils at 100 degree Celsius and freezes at 0 degree Celsius here what is the melting point and boiling point of water after addition of potassium chloride please read question carefully and then answer why why you miss click I don't know last time also you said miss click I think is it clear tell me okay fine I think it times up yes no sir sir oh still not please let me know okay fine so which has pure boiling boils and oh sorry someone has written times up why so now okay fine question number it's a hundred degree Celsius and zero degree Celsius now pure water boils you know that when you add impurity when you add impurity in any liquid okay it's melting point decreases and boiling point increases so boiling point will go to 103 degree Celsius and melting point decreases to minus 3 degree Celsius answer for this question is a am I clear to all of you okay fine so yes yeah basically the range of the temperature increases with impurity right range of temperature increases yes exactly but it is in the range if it is a impurity is in the range but definitely boiling point will increase slightly understood that whenever there are impure substances you can say that it is not a fixed temperature but definitely the temperature of boiling point will increase similarly I explained in the class and I think I explained some in some center are also whenever whenever it is like just a minute yes whenever you add salt in water it boiling point increases whenever you add salt in water it's melting point decreases that's why you can preserve fish fish enough you know the what what you generally be used to preserve fish or the this person who wants to preserve fish what they do they put the salt in water and then they praise it so the melting point of ice get reduced so you can preserve fish or these food items for longer time and similarly if you want to increase temperature of the substance you add some boiling point you add some salt understood any doubt in this it is very basic concept but I can see only 20 students have answered it right okay fine next question already fine moving to the next question oh fine region is leading very good region moving to the next one this is the question oh sorry I think you can see the question in fact a student carry out an investigation of different plant extract using paper chromatography the experiment setup experiment setup he uses is shown below paper pencil line solvent where should he place the sample of plant extract like where should he put plant extract to observe the chromatogram or to get the chromatogram okay students these revise your notes in time do questions solve all the there are so many I told you in the last class also 9 INR 9 students that attempt questions it is given in the whatever you want to do the chromatography you put your sample on this pencil line you put your sample on this pencil line what happens your solvent goes up your solvent goes up when the solvent goes up it will take your dot also in the upward direction so whatever things which are more soluble in your whatever things which are more soluble in your solvent things are the component component which are more soluble in soluble in solvent the things which are more soluble will report will report higher in the chromatogram will report higher in chromatogram in chromatogram what does this mean what does this mean like if I have mixture of A and B on this dot if I have mixture of A and B and if a is more soluble if a is more soluble so could you tell me if after from I get this chromatogram let's say I get this chromatogram and the two dots are this and the second dot is somewhere this and this is your pencil line can you please tell me can you please tell me which is which dot is A and which dot is B which dot is A the top one or the bottom one the red one red one is A and this one is B because it can't travel more so this is the chromatography one question I will ask you there will be one question so to tell you that do you know retention factor those who don't know for them I'm telling you retention factor there is something called as retention factor what is the retention factor formula I'm telling you now it will be used in one of the yes we I did not tell you retention factor in class that's why I'm telling you now in next class I will take that okay I will tell you the retention factor is next in next class okay so retention factor is nothing but if you have things going up if you have things going up retention factor you know it this is a chromatogram and in your chromatogram this is the level of your solvent this is nothing but your chromatogram this is chromatogram after chromatography you get this and this is your level of solvent level of level of solvent your solvent will reach at this point. So, what is the retention factor distance moved by distance moved by component distance moved by component component component a in like a or b whatever you want to calculate let us say you want to calculate retention factor of a so you will write distance moved by component a from baseline from baseline divided by divided by distance moved by solvent front distance moved by solvent front distance moved by solvent you can say from baseline please remember this formula please remember this formula if you want to know what is this formula if let's say this distance is x where your solvent has moved and your a has moved to distance y if this is the distance moved by the a and this is distance y and this is nothing but baseline this is nothing but baseline so formula is retention factor of a retention factor of a is nothing but what is the formula tell me what is the value of retention factor of a distance moved by component in from the baseline how much distance it moved y by x or x by y y by x or x y y okay students right the y by x okay I can be I know that you didn't learn that's why I try to learn now retention factor is y by x or x by y it is okay all of you nine INR nine students right what is the distance move x by y or y by x okay distance moved by component a is nothing but x and distance move sorry distance move by component is nothing but y because I'm talking about come a a has moved to this point till this point a has moved that's why it is y by x not x by y is it clear to all of you okay no problem Monisha but did you understand answer is y by x this formula will be used in one of the question we are be ready okay now next question is okay is it clear to all of you could I move to next question okay answer for this on the pencil line you put that dot in the pencil line answer is a and this is a retention factor which you are going to use in question number seven okay to be ready for that now next question is in front of you first we'll see the leaderboard okay students moving to the next question this is the next question paper chromatography are used to determine if a band preservative x is present in four samples obtained from four different package food labor ABCD okay 90 code I will tell you okay okay student one once can get all things let me know so okay double one two double zero one double seven okay so now now see answer of this is what if you see paper chromatography ABCD four things are four samples you have and this is the chromatogram this is the movement of your x actual x which is banned substance actually you know chromatography is used in the food industries it is used in the food industry and in drugs and for drugs also we use so what happens in pharmaceutical it is used a lot so if this is a band substance definitely a band substance has how many component can you tell me band substance has how many component one or two it has two components it is to it definitely have two component because a band substance is giving you two dots in a chromatogram so if I say the band substance is having a mixture of A and B definitely it is having a A and B in it okay so it is having A and B now see whether a is that whether a okay A and B are already used so I will write it like why okay I'll write like M and N the two in the band substance you have two components M and N okay if you see the A A is not having it is having M but it is not having M means it is not your band substance it is not X X is not there if you see the B it is having and also see the same level it is having M also see it is also on the same level so yes B is the answer C C is having M C is having M but not N is not having N because it is slightly in the upper side then actual N is so it is not answer B is definitely not the answer because it is having only N not M so answer for this question is B let us see how many of you have done this question right did you understand first tell me did you understand this yes sir all of you yes sir okay fine I'll show you the answer okay I'll show you the result fine very it's not that bad 367 answer is right okay Anuya you know like has covid has covid okay fine so next question I'm going to show you now be ready for that okay this is the next question four different label TQ RS are produced in a chromatogram as shown below this is the solvent front this is the baseline which die has RF value point seven I already told you I will ask in question number seven about RF value this RF value what solvent front I told you last class solvent front I told you I last question question number five that am I told you students if you have any doubt please ask so but you haven't given the values huh it's not required I will tell you when I solve this question just think students it's very easy question have you done okay please let me know one time get over okay fine student answer for this is I Monisha you asked her what is solvent front I told you you have a baseline your solvent is moving up the height where your solvent the maximum height of your solvent is the solvent front from the baseline your solvent moves to highest point of the chromatogram that is nothing but solvent front but your mixture which you are taking may not remove till the solvent front it will go along with the solvent but not till the highest point now they have given RF as point seven RF is nothing but distance traveled by by your let's say what they have given label TQ RS chromatogram okay distance traveled by component divided by distance of solvent front distance of solvent front from baseline in last last question also I've written the same formula solvent front from baseline okay so if you see point seven is the answer which distance it seems like a point seven if this is the distance one where is the point seven I think it should be around this this distance should be point seven so this much is the this one is the point seven so here you have to just there's no point value given but you have to imagine where you will get the point seven value the point seven correspond to this s so answer is a okay again I'm repeating this is the point seven if it is one centimeter because if I assume it as one centimeter if I assume it as one centimeter RF is point seven means distance of component move this point seven from the baseline this is the baseline from the baseline your distance move to be point seven is it clear to all of you here you need to think which is the point seven okay what is the value correspond to this point any idea any guess what is the point what is the RF value for this point RF value for this point so maybe point two maybe point two so you need to guess yes it is point two maybe point two point two point five point two five like that understood yes the answer definitely know that from baseline and it will always be one centimeter no it's not one centimeter I have assumed my dear I'm just saying that I'm just saying that if I consider this as a X and if I consider this as a Y according to my formula it is X by Y I can definitely say that Y is 70% X is 70% of Y I can surely tell that okay if you don't want one centimeter assume it as 100 centimeter if Y is 100 centimeter and RF is point seven so definitely RF is point seven means your X must be 70 centimeter am I clear to you yes I got it it is not that same one centimeter just assume it okay a Monisha it is around eight point eight you know this this is around point eight this is around point nine like that yes I understand these are very close close close values yes it's the distance of solvent front that means the top of the solvent right yes top of the solvent yeah you know what happens I told you solvent so the rest of it is clearly not point seven because it's much more the top of the solvent sorry repeat the top of the solvent of PNQ is much higher even though the bottom of it is at the same level as S but the top is much higher so it's not PNQ rate one minute can you repeat your can you repeat what you want to say this is the solvent front now tell me what please repeat in P in P your dot is moving till point B understood you know I meant to say that like the distance that the dot travels is it at the top of the ellipse or is it in the middle of the ellipse okay fine it should be middle of the ellipse okay otherwise this also it's not justified for this answer also understood yeah it is the middle of ellipse okay Monisha did you understand actually the C&A are very close to each like you can get confused with the C&A but best answer would be A yes tell me I just want to say that this is slightly unfair because it's slightly hard to guess whatever yes I understand that I understand that if you see this value and if you see this okay so I can say that this distance is if you I understand your point this is not it is slightly greater than 70% of this if this is the hundredth thing if this is the hundredth thing it is slightly greater than 70 you can say 75 or 80 I understand your point but answer is this understood if you measure with a scale also but we don't need to measure you need to get the best answer okay I want to tell one more thing yes so this is the only only way you can do this question understood Monisha and it's most it's okay fine but you should understand the concept it's fine if you got it wrong because actually those who have marked it see they are not absolutely wrong but fine there is some because you don't have the measurement to do there it's fine don't worry okay moving to the next question okay fine next question is in front of you a student has been given a sample of amino acid to analyze by chromatography as part of the investigation the student will have to use the locating agent to make the colorless amino acid spots visible the RF value is then calculated to identify the amino acid which row described the correct step locating agent I told about I said something about locating agent in class we use locating agents now what is the purpose of that and which step okay this is the one technique which is not given in detail in NCRT because most of you are having NCRT it is not given in detail even RNR 9 students have not this in detail that's why I took chromatography everything distillation fraction distillation you have in detail but chromatography they don't talk about much about chromatography but it is very important okay fine okay it's time's up not yet okay RNR is having different syllabus what happened what happened which concept is not clear tell me Tanya can you please speak up what happened Tanya please unmute your mic okay you are getting questions wrong that's what I'm saying please please if you remember I explain so many things in last class and that's why I'm taking the this this is the topic which we have discussed in class chromatography if you remember I told you about the locating agent whenever the substance which is not colored whenever the substance which is not colored we use the locating agent to get because there are sometimes if you want to separate A and B then sometimes you want to separate A and B and you put it in the chromatography or in the if you run chromatography for that A and B get separated A is having some point B is having some point but what happens sometimes they don't show different colors so what we do we put some locating agent we spray some locating agents there so spray on the surface of the solvent okay sorry spray on the chromatogram not on the solvent spray on the chromatogram not before experiment after experiment you do if you put before experiment what problem may cause or what problem might happen if you put before if you put before before chromatography what problem could happen please tell me it might shift yes because you need to separate A and B if you put locating agent also that will show its other point third point okay we don't want to increase more things in the mixture we want only A and B to get separated so spray the chromatogram spray on the chromatogram chromatogram is called when you get when you are done with the chromatography then the thing that you got is called as chromatogram then compare the RF value to the known amino acid what happens once you got this dot let's say after putting the after putting the spray you are getting this dot as red dot you are getting this red dot once you put the spray now you will check with the data which you have which are available with you when you calculate RF value for this dot let's say RF value comes out to be point three five point three five four so you will compare like which Molly which compound is having the RF value point three five four example if I have A and B I get a boiling point of A is equals to 100 degree Celsius what what can I say about A can I say like it is more likely to be water can I say it is more likely to be water because boiling point is 100 degree Celsius yes or no similarly similarly whenever RF value you are getting let's say point three five four you will compare with the known data if something has RF point three five we will say your mixture is most likely to have that compound so compare the RF value to that known amino acid okay this is probably the last question for the chromatography okay any doubt in this any doubt in this answer answer is B okay students next picture is in front of you please be careful okay one minute okay so here here you have the result 17 were right okay be ready for next question so in many cases you have to think everything I like there are chances that I can't tell everything in class but you need to think you apply the concept it's common sense that if you add if you add locating agent before the chromatography it may be a problem in chromatography what happened Raghav Raghav any any doubt every chemistry I just have a feeling that Jagrav comes first every time and in maths class he used like some kind of shady ways to get there okay now see we are going to the next question are you already okay Jagrav is leading I think he's coming is again okay we'll see what will happen I don't know okay next question is in front of you it's very easy question but it is having very less time now this is not at all related to chromatography but just your imagination you need to imagine now here you need to use your imagination students how you can get 4 if you have to if you have to how you can get 4 okay hands up yes sir okay very easy question you have this shape and you want to make it as a filter you know this is this is how you make the filter how you do the filtration in lab you have us this thing this is a filter paper you turn it like this and the next step you fold it in this way and you put it like this you make it like this and in next step you put finger inside this this area where you can see there is a gap you will get filter paper like this so answer for this question is a so this is totally imagination based question not no chemistry at all let us see how many of you have done this question right 22 only yes what happened okay next question the same as a huh the same what happened no she's not same as a these also okay I'll show you wait yes see the piece of paper huh sir D is just the piece of yeah it is single piece of paper that's what I told you please see the option carefully very good next question hello Salute W is soluble in water which matter of separation can be used to obtain W from at first solution Monisha asked to re-explain okay Monisha I will explain it after this question okay Monisha after this time over answer for this question is solution W yellow solid W is soluble now soluble there are two options with where you can get confused that's why I add distillation and crystallization but you need to get the solid only you are not interested in collecting the liquid so answer will be crystallization not distillation so answer is D Monisha and I'll show you the question number okay just give me one second student just one minute just one minute I'll show you I'll show you one video if I could show you just one minute the switcher stop okay students one minute one minute I'll share my screen okay please please one minute okay just a minute if I see I can see some video I will tell you it's very easy just a minute okay yes so I'll show you one video in that you can understand it it's very easy to understand okay please with your mic students okay hope you can see my screen now and there is a filter paper you can see just a minute okay this is the filter paper you have okay you need to think like how this is the circle of paper okay please try to understand what you have done what she has done they see Monisha Monisha did you understand this is it clear now yes sir okay so this is how we make the filter paper okay if you want to see the question it was efficient this is the answer you have folded it one more time that's it okay fine next question is okay students next question is in front of you okay here also you people have done very bad in this question also okay we'll see the leaderboard first okay fine now Jagrab is again leading okay fine so we are moving to next question good Jagrab next question is in front of you the diagram below illustrates the experimental setup to carry out distillation which are the correct labels for point A and B on the condenser I don't think you have much time you have just 60 seconds for this question please let me know once time get over sir I lost connection can you repeat the code okay now code I don't one minute I'll show you code one minute 6500 wrong this wifi excuse me sir we have muted so you got muted so screen froze that means oh sorry sorry I just wanted to see the result first I just wanted to see the result first if I'm 24 or 24 sorry 29 34 33 students okay it is very good question very easy also see see this is the question you know you add water from this and and your answer is adding water at point A water in at A and water out at B answer is B okay why it is like that because you know that what happens the temperature at this point is very high temperature is very high and yet yes what happened tell me okay temperature is very high temperature is very low so when you add water your water goes up it is with the water has some pressure so it goes up and it take most of the heat or it takes heat from the okay not from this path sorry by mistake I'm wrong it goes on this path it goes in this path and take and will be taken out from B point B is it clear because you need to extract maximum heat if you do like other way round if you and if you put water inside B through B and if you take out take it out from A then water will not going to get more heat from the your distillation chamber or this distillate condenser it will not condense your solution much that's why we do this process hope you get you got the point any any doubt any doubt no A or D because in one there will be no water in the other there will be too much water that the thing will burst okay one minute what can you repeat okay please please who is this Satvik stop sharing click on source and save change to present yes change to present okay one minute who is this okay students don't worry I'm going I'm showing you the screen in one minute okay can you hear me can you hear me now we are moving to the next question sorry yes sir moving to the next okay someone has some doubt in that previous question please ask if you have any doubt yes any doubt someone ask something like sir with what will it water that will burst or something like that no no doubts fine we are moving to the next question it can be neither A or D because in one there will be no water and in the other there will be too much water that it will burst no no why it will burst why it will burst like it is not yeah it is going in the outer no sir like in A the voice is breaking your voice is breaking my dear I can't hear you sir can you hear me now yes yes yes tell me yes sir I was just saying that in A the thing might break because there's so much of water there's no place for water to exit why okay it is like this try to understand okay try to understand it won't break why it won't break because it is in the outer side it is going in the outer side okay there is a this is the condenser try to understand this is the condenser which is going like this and your water is going inside like this your water goes in this path and since it is there is nothing in this this is completely vacant so it goes like this and it come out like this understood it won't burst at all no sir but what if both sides are water in then it will burst yeah then then it will burst that's what I was saying okay any doubt answer is B okay next so someone has marked A also okay now this is the result fine we are moving to the next question the diagram below illustrates okay fine next question sorry okay you know don't worry I want to see how many of you are in the second and third position I want to see all of you first three position I want to check so let's let us see what will happen and you also check like whether you have improved or not okay I have given questions which are literally tougher also I know now here you need to think a lot lot means okay it's a very tricky question you might not think in that direction but let us see what will happen just please let me know once time get over okay is it clear to all of you should I explain this question okay students please don't check okay is it should I explain sir time's not up okay fine now it time's up I'll explain in this question yes so answer for this question is A answer for this question is A very good question why it is A because you are having HCL here and you are having ammonia here now I want to ask from you people I want to ask from you people which is heavy HCL is heavy or ammonia is heavy think and tell me which is heavier if you can answer this question right you will definitely get answer in next step which is heavier ammonia or HCL okay I am getting mixed answer ammonia or HCL if you see the periodic table HCL is heavy okay we have done some questions related to that this is heavy sir it's HCL yes and it is lighter so or it is lighter now see if something is heavy now it is nothing but diffusion is taking place diffusion now tell me which will diffuse more both are diffusing both are diffusing which will diffuse more heavier one or lighter one heavier one will diffuse less lighter one will diffuse more I told you in the last class also the thinner person can run fast then the fat person HCL won't diffuse much but your but NS3 will diffuse a lot so that NS3 NS3 will travel more distance than HCL so precipitate that is ammonium chloride will form somewhere around A so answer is A students you are chatting continuously did you understand this question or not answer is A salt will form near to A is it clear yes students do you have any doubt okay fine next question okay next question is you will have you will not having much time for this please attempt it fast okay question is this evaporation spawn okay fine no problem it is I have already clicked you have 30 more seconds 15 more seconds okay fine it is very easy question 15 more seconds okay fine students I will explain this question now so okay time is up if you want to see the result answer is B answer is B how evaporation is used liquid into vapor not above room temperature A is as spawn just solid P viruses diffusion fusion is melting boiling is vapor above room temperature SP SPQ SPQTR SPQTR answer is 2 any doubt students do you have any doubt no next question is in front of you students be ready for that if you want to see the leader board you can see it very good Srijan jagra, vihan, gandhar very good okay next question iodine temperature given iodine sulfur see water pure water ice and common salt okay students please answer it fast 20 have already answered so far don't make mistake this time okay students while you are worried about jagra I don't know if let's say first of all if he is playing very good second thing let's say if he is boating why you are worried you should not be worried about someone other because if someone is sitting if someone is sitting it is because he is creating problem for him or if someone is creating or he or she is creating problem for him or her so why you people are worried okay fine answer for this is iodine iodine is nothing but sublimation iron plus sulfur mixture of two elements S see water I told you it has salt salt plus water higher boiling point higher boiling point so answer is scheme pure water 100 degree Celsius Q ice plus common salt only option left is P temperature below 0 degree Celsius that is nothing but melting point they want to say R S T P Q P R S T okay R S T Q P sorry Q P answer is A hope you understood this any doubt any doubt no last question okay last question it is very easy question okay very good jagra Srijan Bihar Ganga very good last question last question is in front of you mixture of Z N C L 2 and T V C L 2 can be separated by okay this is the last question anyways very easy question but you need to think little bit in this you need to think little bit in this you can go with the elimination option also if you are getting confused okay fine students it is last 15 seconds okay option is option option is there okay fine option is correct okay students answer for this question is answer of this question is crystallization B destination is not carried out for the solid and liquid sublimation is always applicable for sublimable substance adding acetic acid won't work adding acetic acid won't work okay because both are soluble in acetic acid so it won't give you any answer it won't give you any of the salt so answer is crystallization what you do once you once you heat it P B C L to get dissolved in water because it is soluble in water or it soluble in hot water once it get dissolved you can remove that in C L 2 then you can use crystallization technique so crystallization is the answer let us see how many of you got this 25 B option they might have got confused so today's result is this okay students we will see who won okay very good shri chan, vimhaan, jagra, siddhaan, gandhaar very good shri chan siddhaan, gandhaar, vimhaan and jagra very good okay keeping up students very good jagra congratulations thank you if you have any doubt please ask no doubts sure okay students thank you okay don't worry don't worry if you think like jagra it comes first every time don't worry you you see second third position are also there don't worry okay bye students okay no problem thank you sir thank you so amazing cause bye bye bye roman thank you so this is through okay through bye thank you