 Is it recording now? Yes, it's recording now. But again, I think it is not reflecting on everyone's side. It's reflecting here and I think kids are also saying yes. Yes, yes, yes, I can see that. Yes, yes, started now. Okay. Okay, fine. Yes, so we were talking about some division of marks, right? So your comprehension type of question like case study base questions, those are going to cover 25% of the total marks, right? Okay. Another 25% is going to cover with the writing skill and grammar. Okay, so you have to be very careful while writing sentences. Okay, while writing your answers, you can't avoid some, you can't miss some words, you can't leave incomplete sentences. Okay, so because after all that is going to cover your 25%, right? Next, 50% is going to cover from your textbook, right? Literature textbook and the knowledge what you have, what are you going to represent in your writing book, okay, in your exam. So pay attention properly in all these aspects. Okay. Okay. Yeah, this is in English but this footage will be applicable for science also. No, this is not only for English. Okay. This is the general, like, what should I say for physics, chemistry, biology, science paper, okay? Yeah, okay. Now, okay, what is the pattern of the question? What is the pattern of your paper? So your full paper would be divided into four parts, four sections, A, B, C, D, right? In section will have all the MCQs, one, two, twenty, objective based question, in that you will have some MCQs, some assertion and reason types of question. Okay, basically each question will carry your one mark. Now, section B, section, in section B, we will have short six answer type questions, okay, carrying two marks. Then in section C, we have three marker questions, right? Here we have seven questions. And in section D, we have three long answer questions, okay? Here your comprehensive type of question must be there, maybe one second. Yeah, okay, sorry. So in section D, you have all five marker questions, passage reading, case study type of question, everything would be here, okay? So today we are going to start our revision from acid basis and salt. In this chapter also, in this chapter also, you have the division mark division criteria is approximately one plus one plus three, okay? Or sometimes this would not be there, you will have directly five marker of passage reading questions. So you have to pay attention in each and every theoretical part of this chapter. Meanwhile, we will do some questions also here, the past year questions and we will discuss how to solve case study sort of questions and assertion and reason types of questions, okay? Yeah. Okay, so let's start. Acid, we all are very well aware about the acids, right? So labric-defined acid is a compound which contains what, which contains one or more hydrogen atom, replaceable partially or completely by metal, right? To produce a salt, okay? Is it only the metal? Is it only the metal? The hydrogen atom can be replaced only by metal, okay? Aditya knows, Surya knows, then which other thing can replace your hydrogen? Manisha, okay, no problem, fine. Salt can replace, is it? Okay, no, no, no, Surya, see here. Any acid, suppose you have HCl, you have H2SO4, okay? So what, what do we have? We have these replaceable hydrogens, okay? These hydrogens can be replaced by metals, okay? If you have any metal here, then this metal is going to make salt, right? Like MCL, MCL2 maybe, M is just a random metal, okay? Aditya and Pratik, you are saying base, okay? We'll discuss, yeah? Okay, next, what is here? We have sulphate, so MSO4, correct? Let's see how base HCl plus NaOH, so what's happening? This hydrogen is going to replace by this sodium, correct? So it gives NaCl and H2O, right? So ultimately, what's happening? Hydrogen is going to replace by a base, right? Yes. Okay, so let me define that the compound which contains one or more hydrogen item, replaceable partially or completely by a metal to produce salt, okay? Then acids are the substances which have SAR in taste, right? They have SAR taste, they turn blue litmus to red. One second, yeah, they turn blue litmus to red. So the short form I have given you guys, if you remember, ABR, correct? Acid turned, guys, is this pen colour okay? Is, okay, I think this green one is better. Okay, Aryan, I just saw your message. Wait, okay, wait, we'll discuss ABR. What I'm saying, ABR, that means acid turns blue litmus to red, right? Blue litmus solution, blue litmus paper to red, okay? Yeah, Aryan, but Na is a metal. Huh, Aryan, that's why I told that metal is only going to replace hydrogen ion from the acid, right? The same thing only I told, Aryan, okay? So ABR, that means acid turned blue litmus to red. Done, now we will see some common examples of acids. Here I have written common mineral acid. What does it mean by mineral acid? What are the examples of mineral acids? The acid which can be prepared by minerals, right? Which is available in the form of minerals which can be prepared by minerals, right? Okay, good, correct. So mineral acid examples are HCl, H2SO4, HNO3, yes, very good, correct? And H2CO3, you know, yes, H2CO3, okay? H2CO3 is the carbonic acid, right? Okay, out of all these four acids, you know, all these three are strong acid. Strong acids, right? Only the one weak acid, only the one carbonic acid is the weak acid, right? Correct, good, Aryan, very good. H2SO4, HCl, HNO3, HSO3, H2CO3, Aquaregia, good, very good. Yes, Aquaregia is what? Aquaregia is combination of HCl and HNO3, right? And what do we say Aquaregia? What is the common name of Aquaregia? What is the common name of Aquaregia? Royal water or King's water, okay? Yes, regal water is also there, correct? Royal water, King's water, the combination or the composition I should say 3 is to 1. That means you have three part of HCl and one part of HNO3, okay? This is the Aquaregia, okay? Good guys, very good. Yes, the ratio is 3 is to 1. HCl and HNO3, three part of HCl and one part of HNO3, right? Any doubt in Aquaregia, no? Okay, okay. Next, so we were talking about some common mineral acids. Now let's see some common organic acids, okay? Organic acids means what? Organic acids are the acid which we obtain from living things. Natural substances. Very good, natural substances, some living organisms, decay of some, what should I say, some organisms, right? Okay, good. So examples of organic acid, still so many people are joining. Acetic acid. Very good, acetic acid. Ethanoic acid. Ethanoic acid. Oxalic acid. Wait, wait, wait, wait, I have to write all of this. Oxalic acid, okay. Acid, ethanoic acid, acetic acid and ethanoic acid is the same thing, right? Yes, ma'am. And yes, correct, good. And ethanoic acid is the same thing. Lactic acid, oxalic acid. Oxalic acid. Lactic acid. Lactic acid. Tartaric acid. Yes. Manisha, formic acid, Agni tartaric acid, yes. Shabita, methanoic acid, very good. Formic, wait, wait, wait, wait, formic acid, then. Malic acid. Malic acid, very good example. One minute, methanoic acid. Formic acid and methanoic acid is the same thing, yeah. Okay. What else? Malic acid. Yes. Malic acid, then. Escorbic acid, yes. Escorbic acid. Okay. Citric acid, isn't it? And guys, do remember citric acid and scorbic acid, not the same thing, okay. Citric acid, nitric acid, no, no, no, no. Nitric acid is in mineral acid, ethano3, right? Yes, yes, here we are going through organic acid. It's okay. Then you know some uric acid, have you heard about it? uric acid, folic acid, folic acid, right? Where do you get folic acid? You all are aware, okay? Where do you get folic acid? What is the source of folic acid? Pyruvic acid, yes, yes, correct. Pyruvic acid is also the example, correct. Guys, do you remember the source of folic acid? Just use your general knowledge, you know where do we get folic acid? No, no, not the follicles, no. It is related to vegetables. In ants, we have formic acid, this one, this one. Olig acid we have in olive oil, okay? Olig acid is also the good example. Hmm, folic acid, you know, folic acid we get from green and leafy vegetables. Green and leafy vegetables, yes, yes. Akshita, correct, very good. Escorbic acid is your vitamin C. Okay, mostly people get confused between citric acid and ascorbic acid. Okay, guys, come back to the point. Stop discussing here. One second, still some people are joining. Yes, okay, so we have got so many organic acids, okay? Let's discuss the sources of these acids. Let me check if I have written everything here. Yeah, I have written. Okay, so in vinegar, what do we have? In vinegar, we get acetic acid, right? Acetic acid, correct. In oranges and lemon, we have citric acid and some amount of ascorbic acid as well. Okay, so citric acid. Then in tamarind and grapes, tartaric acid. Tamarind. Good. In tomato, which acid we have? Very good, good. Manu, who has answered me on the mic? Prabhat Kumar, ma'am. Okay, okay, Prabhat, correct, correct answer. Aditi, yes. Aditi, shares. Aninket, oxalic acid in the tomato. Correct, then sour milk. Yes, lactic acid in sour milk, right? Okay, then next. Next, in ant, in ant sting, these sting and hair of nettle plants. Methanoic acid or formic acid, correct. Who is not on mute? So then please keep your mic on mute, beta. Hmm, okay. Yes, formic acid or methanoic acid, okay. Both are the same thing. They have same molecular formula. Yes. Next, what we have? Olive oil, we have oleic acid, right? Yes, Arya Navya Purva, correct, correct. Olic acid, then in gastric juice, in gastric juice. Yes, very common acid, HCl, right? HCl, correct. Then, then what is remaining? Apple, yes, apple, apple. Tell me, tell me. Nehakshita, yes, correct. Malic acid, very good. Next, one minute. Somebody asked me some question. Aryan, I mentioned mineral acid. Oh, Aryan, HCl is the mineral acid. I know what is, I know your doubt, okay. It's a mineral acid, okay. Aditya, yes, ascorbic acid. Source of ascorbic acid is the citrus fruits, okay. Yeah, vitamin C citrus fruit. The best source is kiwi. Okay. Next, in fat, do you know in fat which acid is available? Yes, Aniket. Fatty acids? Fatty acid is there, but they have more specific name. Steric acid, steric acid. Or if you don't remember any name, then you can write fatty acid as well. No problem in exam, okay. Steric acid or fatty acid? Fine. In rancid butter, which acid do we have? In rancid butter, you know, in rancid butter, we have butyric acid. No, no, no, no, beta. Lactic acid, we have in sour milk, okay. Yes, butyric acid. It's okay. It's just for your knowledge, okay. Yes, I think these things are, you should have not taught in the school because obviously it's not given in NCAT, it takes root. But knowledge is always good for health, yeah. Right? Okay. Uric acid. Very good. Uric acid. Then fresh fruit and vegetables. This is important, guys, okay. I don't know whether you guys have learned it before or not. In fresh fruit and vegetables, which acid is available? Melanoic acid. Melanoic acid. No, no, no, no. In fresh fruits and vegetables, we have high content of vitamin C, ascorbic acid. Okay. Ascorbic acid. This I should have written here. This is the short form of acid I'm writing here, okay. You don't use in your award exams. Yes. Yes. In all fruits and vegetables. Yes. In obviously, if I talk about Apple, so in Apple, the major constituent, you will have malic acid, but you will have vitamin C as well over there. And then the highest source of the vitamin C or ascorbic acid is Kiwi. Okay. Oh, good question. If I'm pronouncing your name, right? Ralph. Ralph. Okay. Okay. Yeah. So Ralph, your question is butter comes from milk. And why it doesn't contain lactic acid. Okay. Very good question. So, you know, lactic acid is the constituent of what? Sore milk, right? Okay. And butter has a different composition, but we are not talking about butter here. It is rancid butter. That means, you know what? When your butter react with atmospheric oxygen, it converts into butyric acid. Now, again, the question, what is the composition of butter? So butter is having a long chain of hydrocarbon, not like petrol and all those things. Okay. But butter and oil has a long chain of what? Hydrocarbons. It is unsaturated sort of. Okay. So when it reacts with atmospheric oxygen, it converts into butyric acid. Okay. Unsaturated hydrocarbon. It converts into what? Butyric acid. That's why we are using the term here, rancid butter. Okay. Navya. Navya. What happened, beta? Repeat. Okay. So butter, butter, ghee, what should I say? Oil. All these things are, these things are made up of what? Long chain of hydrocarbon. Okay. So they have different, different constituents, right? The oil is saturated hydrocarbon. Ghee is unsaturated hydrocarbon. Okay. So when ghee or butter reacts with the atmospheric oxygen, it forms butyric acid. It forms butyric acid. Okay. Right. And milk is not the composition of long chain hydrocarbon. That is why there are different acids in milk and butter. Okay. Milk is the part of what? Fat and water. That fat has the different carbon atom chain. Okay. I'll put up a good question by the way. Next green vegetables, green and leafy vegetables. You know now. Okay. And which acid do we have here? Foilic acid. Yes. Yes. Correct. Foilic acid. So you should eat so much of green and leafy vegetables. We run oxalic acid is there in green. Green. Yes. Yes. Oxalic acid is also there. But you know, in leafy vegetables, we have major content of foilic acid. If you see, if you ask with your parents also know, they might have heard somewhere if some person has deficiency of iron, doctors suggest them to eat spinach. And what should I say? Fenugreek leaves. Okay. Why? Because they are rich in, in the content of folic acid and folic acid helps to increase iron. Right. Yes. Correct. Fenugreek is a methi. I mean, I don't know what to say in other language. Yeah. It's methi. Hey, guys. Do you know if there is a, there is one area, methi kere in Bangalore. So I heard that, that is their areas based on the name of methi. Is it methi kere? Methi kere something like that. Really? Seriously no Surya. Oh, okay. Kere means lake. Okay. Okay. Then it must be having some different reason. Okay. Coming back to the font. Yeah. Yes. Yes. Correctly. Forgot this bark wood and tree. T in this we have Tannic acid. Okay. Tannic acid. Tannic acid. Okay. Now we are done with all the assets and their sources. We have to do so many things. So now we need to increase our speed. Basicity of an asset, basicity or proto city of an asset. Okay. Yeah. Yeah. I got it. Basicity of an asset. What does it mean? Basicity, that means the number of replaceable hydrogen atom in one molecule of an asset. Okay. Or the number of hydrogen atom, which can neutralize hydroxide ion from the base, which can neutralize the number of hydro, hydroxide ion of the base. Right. That is known as as basicity of an asset. Remember. Okay. So now according to the basicity, that means what, how much hydrogen ion replaceable hydrogen ion is present in your asset. True. Right. According to this definition, we have different, different kind of basicity of the asset. Right. Let's say, we have mono basic asset. We have die basic asset. I can say that monoprotic or mono basic anything is fine. Okay. Monoprotic assets. Or mono basic asset. Anything is fine. Then dioprotic assets. And polyprotic assets. Now monoprotic asset, we all are very well aware. Right. HCl, HNO3, HI, HBR, anything is fine. Correct. These are what? Monoprotic asset. Now, dioprotic asset, H2CO3, Navya, yes, but the classification has came in the previous year board exams. Basicity of the asset and what would I say? Classification of asset based on the basicity or protocity. Yeah. Okay. Hmm. So if you have done in your school now, then it's better to go with that. Okay. Yes. Yes. I know that it's not there. Hmm. Okay. Let's continue. So dioprotic, we were talking about H2SO4 and one minute. I want H2SO4. Yeah. H2SO4, H2CO3 and another asset. Hmm. If you guys remember, help me. H2SO3. Yes. H2SO3. Okay. Just pay attention here. See now I'm going to write some new asset examples. Okay. H2SO3. This is dioprotic asset. Okay. H2SO3. Now next what we have polyprotic acid in polyprotic acid. Best example we have H3PO4 phosphoric acid. Please pay attention here now. Okay. H3PO4 I have written in the column of what polyprotic acid. That means it has, why I have written it like this because it has three replaceable hydrogen atom. Three replaceable hydrogen atom, right? Three hydrogen ion, sorry. Three hydrogen ion can replace or can neutralize your three OH negative ion from the base, right? Okay. Now if I write here H3PO3. What is the basicity of H3PO3? This is phosphorous acid. Yes. That's the important thing here. Okay. H3PO3 should come under the category of dioprotic acid. Okay. Okay. It is dioprotic acid because only two hydrogen can be released from here. One second. Another window has got open by mistake. Okay. Can you explain again basicity of acid? Sure. Basicity of the acid means what? The number of replaceable hydrogen atom in one molecule of an acid. Here you can say basicity or, basicity or proto-city of an acid. Okay. So number of replaceable hydrogen atom in one molecule of an acid. For example, HCL. In one molecule of HCL, it can give only one H plus ion. So its, its basicity is for only one. Why? Because, because this hydrogen ion only, it can utilize only one OH negative ion. Isn't it? Right. This hydrogen ion can utilize only one OH negative ion. So the basicity of this acid is OH negative. You know what? Ideally what is the meaning of basicity? Basicity that means the hydrogen ion released from an acid which can neutralize the hydroxide ion released from a base. Okay. Which can neutralize the hydroxide ion released from a base. Right. So one molecule of HCL can neutralize how many molecules of a base. One mole or one molecule of HCL can react with only one molecule of a base, anion. Right. Or it can utilize only one hydroxide ion. Right. This is basically our basicity. How can you write it in the exam? So any definition you can follow. The first one is what? Number of replaceable hydrogen present in one molecule or number of hydrogen ion produced in an aqueous solution by one molecule. Anything you can follow. Right. Prabha, did you understand now? Okay. Good question Aditya. We will discuss when we talk about the strong and weak acid. Okay. We will discuss this. Okay. Yes. Next. One second. Hmm. Any other doubt? Okay. Okay. If I'm pronouncing it right. Aditya Pratik. I need, I need answer from all of you, beta. I'm waiting for your messages. Guys, what are you doing? Are you sleeping? If I'm pronouncing it right. This topic is important for board. So I can't say very important for board because I have seen just one question in past 10 years of the board exam paper. But I feel if the question is there, it's better to learn. Right. And even the question was related to H3PO4 and H3PO3, something like that only. So Purva, if I can tell you Purva, is it fine? Purva, do you have any doubt? Did you understand what is the meaning of the city beta? Now we will see some uses of acids in which we are very well compensated. Now we will see some uses of acids in which we are very well comfortable. You all know uses of all the acids. Right. But here we are also going to discuss some important uses which you might have not studied or which you might have forgotten. Okay. So let's see here. Now some uses of acid. The first one is hydrochloric acid. Tell me some very rare use of hydrochloric acid. It is used for making oxide films from steel objects. Very good. Correct. Yes. Good. Correct. Then it is used for making die stuffs. Die stuffs. Correct. Yes. Yes. In textile industry is correct. So what are the uses? Uses we have the very common use cleaning metallic items. Cleaning. Metallic items. Then die stuffs. Textiles. Food and leather industries. Very good. In tanning industries and in printing industries you know in printing industry also we use hydrochloric acid too for the like die purpose. Okay. Or for the tanning purpose you can say printing industry. Okay. Next. Sulfuric acid. So the most popular use of sulfuric acid. For making of fertilizers. Yes. Most important use of sulfuric acid. Production of fertilizers. Wait. Sulfuric acid is mostly used in car batteries. And nitric acid mostly used in fertilizers and explosives. Okay. Somebody was telling me, wait, wait, wait, who was there? I can't see the name. Okay. Somebody was asking me TNT the hydrochloric acid can be used in preparation of TNT. TNT is tri-nitro toluene. Okay. So hydrochloric acid. No. We use sulfuric acid. Sorry. Nitric acid. Okay. In explosives. Explosives. I'll come to that point. So first sulfuric acid. Sulfuric acid we use in fertilizers. Yes. We can make sulfuric acid from the sulfuric acid. Fertilizers. I should try to make fertilizers. Fertilizers. Chemicals. Pains. Pains. Dyes. And explosives. Explosives. Explosives. And car batteries. Okay. Nitric acid. Nitric acid. HNO3. Nitric acid. We use in fertilizers and explosives. Okay. Again, manufacturing of fertilizers. And explosives. What do you have to write? To manufacture fertilizer and explosives. Like what? TNT. Okay. Okay. Okay. Okay. Okay. Okay. Okay. Okay. What do we have? DnT. DnT. DnT. This is Trinitropoluene. Next. Acetic acid. Acetic acid you know very well all right. We use like as a vinegar in cooking and then we use as a food preservative. We use in a vinegar in cooking and obviously as a food preservative right. Food preservative. Okay. Okay. Next now let's start basis. Basis are what? Basis are the Kristal Gl久.יפ here is the which have bitter taste and they are soapy in touch, right? They are soapy in nature. Yes, Aditya. Done, my dear. Basis are bitter in taste and soapy touch. They have soapy touch and then the term red to blue. Very good. Correct. Red to blue. So what we have learned a short form for this? R, B, R. No. B, R, B. Wait. B, R, B. B, R, B. Right. Baseturn red to blue. That means baseturns red litmus paper to blue. Right? Okay. Now you know that if suppose I have a gas, ammonia gas, if suppose I am talking ammonia gas and I am saying that ammonia is highly alkaline, like highly basic. Okay. Will it be able to turn red litmus paper to blue? No. Meghana answered me. Prabhat answered me. I am waiting for others answer. You know, guys, we are 75. Okay. And I just have received two or three answers. Good. Right. Right. Because this NH3 gas cannot convert red litmus paper to blue. So what is the very important thing here? This NH3 needs an aqueous medium. NH3 needs an aqueous medium. Yes, Surya, it is a gas. Read your question properly, beta. Okay. Listen to your question properly. So NH3 needs a NH3 gas, ammonia gas needs some aqueous medium. Aqueous medium means what? The medium of water. Correct. Then only it will be able to get one hydrogen ion from here. Right. It will accept hydrogen ion from here and it will convert into ammonium ion and H4 positive. And this ammonium ion is basic. It will turn red litmus paper to blue. Right. Okay. Good. Correct. Yes. Good. That was also a question in some year of board exam. I don't remember exactly the year. But yeah, that was a question that why dry NH3 gas cannot convert red litmus to blue. Okay. Let's go. Acidity of a base. Again, the cement. So many examples. Guys, please keep your mic on mute. Guys, please keep your mic on mute. Mahadev is ready. Okay, it's okay, I have muted. Yes, Surya, Ma'am can pure NH3 exit in the liquid form without water. No, no, no, no, you know what NH3 is highly highly alkaline alkaline what should I say highly soluble in water, it is highly soluble in water. So if it gets like exposure into just a little bit amount of water molecule around it, it will absorb the water molecule. Okay, yes, correct, correct Aditya, you got it now. Okay, so here we are talking about acidity of a base acidity that means it is equal to the number of hydroxide ion it is equal to the number of hydroxide ion furnished by or released by released by a base in its aqueous medium after what after a dissociation after complete dissociation, right. So we have mono acidic base mono acidic base very simple example what do we have NaOH KOH why because the release only one OH negative ion one molecule will release only one OH negative ion correct diacetic something went wrong CaOH twice acetic very good calcium hydroxide magnesium hydroxide right then then we have triacetic guys I need example for triacetic from you aluminum hydroxide very good and and good very hydroxide huh okay correct good excuse me okay then okay one example I'll give you here be OH thrice okay be OH thrice or on hydroxide okay next now some bases and their use this is very simple we all are very well aware about the examples of base and their uses yes name is also the correct example aditya very good um excuse me now can you yes for the second I just want to copy those assets yes it's sure yeah thank you okay now we are going to discuss some use of bases some industrial use of bases so what are the common bases we know we know very well sodium hydroxide potassium hydroxide calcium hydroxide magnesium hydroxide and and one base which is very weak and which is very common no problem okay yeah so NaOH this is what sodium hydroxide sodium hydroxide is used for the production of this soap right using manufacture of soap soap paper these two are very important use of NaOH okay synthetic fibers or you can say as rayon yes rayon and this is rayon okay guys please don't get confused then calcium hydroxide is used for the production of leaching powder huh wait wait wait let me finish sodium hydroxide first okay okay so these are some uses of sodium hydroxide guys what is the common name of sodium hydroxide do you know caustic soda caustic soda very good caustic soda okay the sodium hydroxide is what caustic soda correct good now this is also known as what your caustic soda now the next turn is for potassium hydroxide potassium hydroxide now what is the common name of potassium hydroxide yes rayon also has a fire extinguishing correct okay yes caustic potash correct shahdhuli if i'm pronouncing it right correct answer beta purva correct prabhat correct caustic potash okay there was again a question based on caustic potash the question was super duper easy but they have given the name caustic potash instead of ko8 so students were getting confused what is it exactly okay so do remember all their names general common names caustic potash caustic potash yeah and this also we use in soap preparation and you can say in alkaline batteries yes this we use in alkaline batteries okay yeah next what we have calcium hydroxide calcium hydroxide ca OH twice guys it's COH twice this we use in a bleaching powder which prabhat has already told us right bleaching powder manufacture of bleaching for powder yes mam it's also used in white washing right yes yes correct correct correct and this also be used in softening of hard water okay bleaching powder softening off but bleaching powder is used no ma'am for softening of hard water but this is used in the preparation of bleaching powder now so we instantly prepare that and use in the in the softening of water because caustic potash sorry caustic potash calcium hydroxide is stable but but it will be the uses of bleaching powder no ma'am but it will be in the uses of calcium hydroxide as well calcium hydroxide will also be used in the softening of hard water softening of hard water just remind me towards the end of the class okay i'll just tell you the reaction okay then you will understand how the sequence goes from ca OH twice to bleaching powder and then the softening of hard water it instantly prepare the bleaching powder and then it's often the bottom next um yes the very important use we forgot neutralizing acids so i right ma neutralizing ma'am one minute ma'am one doubt you have it tell me ma'am for production of bleaching powder they are adding cl2 also no ma'am so it becomes cao cl2 so how then we can use that as uses of calcium hydroxide ma'am softening of hard water very good doubt beta one minute i'll explain neutralizing acid in the soil one second huh yeah guys what is the common name of this calcium hydroxide slaked lime slaked lime correct where should i write okay so what is the name pravada i think you asked me the doubt right okay you know pravada we when we soft uh what should i say when we soften hard water with the help of this calcium hydroxide that is known as lime softening okay that is known as lime softening when you have higher content of chlorine in the water okay then that time this calcium hydroxide react with the chlorine and form the bleaching powder and then it's softened that is a different process but there is another process in which only calcium hydroxide simply can be used to soften the water without any formation of bleaching powder okay that is known as lime soda ash softening okay calcium hydroxide and then what what we are using soda ash what is the chemical formula of soda ash don't tell me guys chemical formula of soda ash yes correct correct correct correct like that now i'm asking formula of soda ash na2co3 iron tendon very good hmm yes so this is this process is known as what lime soda ash softening of water okay aditi you have sent me something wait but uh i have to see oh now it's visible oh my god okay so aditi your message is what ma'am is in the washing soda used for hmm good question aditi yes so aditi see here you know uh when we have uh what should i say bleaching powder the main purpose of bleaching powder is what use as a disinfectants okay we use bleaching powder as in the disinfectants for the purification of water basically right but it's uh what should i say if the water is very hard if the water is very hard then it can be used as a softening purpose but that water will not be drinkable okay water will convert into the soft water but that water will not be drinkable okay so that's why we don't recommend that that bleaching powder should be used in the softening of water okay and also you know what what it will do it will form precipitates into the water why because the calcium salt what it is going to form in the water that will not be soluble right yeah hmm okay good uh okay next we have uh classification of acids and bases so guys classification of acids and bases you know very well i'm not going into the too much of detail right as we have a lot to do uh so let's discuss the superficial things this presentation is also available in learnest so you guys can refer refer the full presentation from there okay so on the basis of origin of acids acids are divided into organic acid and mineral acid mineral acids are also known as what uh inorganic acids correct and organic acids are derived from living organisms and all we have already discussed about it right on the basis of strength bases are classified into strong base and weak base acids are also classified into strong acid and weak acid don't worry at all okay so strong bases are what those which completely dissociate into its ions in aqueous solution that's the important thing in aqueous solution right uh weak bases are the bases which cannot dissociate completely but dissociate partially into the aqueous solution the best example is nh4 OH and strong bases uh for the strong bases we have examples like koH naOH right yeah now on the basis of the concentration acids can be classified into dilute acid and concentrated acid dilute acid and concentrated acid right you know what this division or this classification is based on the comparison comparative study okay this is a comparative study when you have no concentration of acid in the aqueous solution that will be your comparatively dilute solution right vice versa for concentrated acid okay similarly you can classify bases also okay come back to the another point on the basis of number of hydrogen number of hydrogen ion present in the acid monoprotic monoprotic diprotic diprotic and polyprotic okay so surya i think you got your answer here polyprotic if it has three replaceable hydrogen it can be known as triprotic okay yeah uh yeah so so diprotic monoprotic triprotic and polyprotic that also we have discussed depends upon how many replaceable hydrogens you have right now the basic me on the basic of the number of hydroxyl ion or hydroxide ion mono basic di basic tri basic poly basic that also we have discussed right okay next hmm now we have the first question 15 ml of water and 10 ml of sulfuric acid are to be mixed in a beaker okay instead the method what should we follow and uh what is this process called so tell me the first answer what should we follow what should be the method you can tell me in short beta i know it's uh it will take time to write here okay prabad first neepurva first answer very good beta yes correct so what do you have to write here the acid to be added slowly answer a the acid to be added slowly in water to prevent what to prevent to prevent the mixture to be splashed right the mixture to be splashed okay this reaction is highly exothermic you know right so the reaction is what the reaction is highly exothermic guys i can't see your messages right now because i'm writing here so if you have any doubt now you can unmute and ask okay the reaction reaction is highly exothermic therefore constant cooling should be done right therefore constant cooling should be done now what is the next what is this process called so you all are very well aware now i saw a few answers yes shares glass beaker from the breaking very good beta correct this could be again another reason ma'am can you see uh arian arian yes but i know uh but you know what's happening with me i can't uh focus on both the sides if i'm writing here and you know my handwriting yeah right so if i'm writing on uh board here i can't pay attention on my phone yes okay so this process is known as what dilution so you have to write properly okay just don't leave with the dilution word this process is dilution okay next now we have indicators okay indicators mean what which indicates the presence of acid or base in a solution right so the first indicator what we have litmus paper litmus solution litmus paper it is obtained from a plant known as lichen lichen plant correct and you know very well that we extracted from the lichen plant and then we have different different kind of uh uh what i say methods like litmus solution litmus paper right okay coming to the next point so other examples are what red cabbage turmeric and colored petals of what colored petals of flower known as petunia if i'm pronouncing it right then hydrangea grensium is it right i'm pronouncing it right i'm it's more like geranium geranium okay yeah thank you uh there are three flowers and one red cabbage and turmeric so these are what and litmus also these are what natural indicators these come under the category of natural indicators right obviously because it is available naturally correct out of this uh i don't yeah this year we do not we didn't do fees to fees classes now so if we meet next year now then i'll show you red cabbage experiment if i have done this with indra another guys or ypr guys i don't remember but if we meet next year we'll do this experiment okay it's very beautiful so so so many the shares i'm coming back to this that point as well those also comes in the category of natural indicator only beta don't worry okay yeah yes yes next what we have all factory indicator all factory indicators are also part of the natural indicator only okay it depends upon what depends upon the order order of the uh what you what do you have your substances right so it shows change in order not actually it shows okay but the order changes in acidic medium or in basic medium that's how it indicates onion clove and vanilla vanilla is also there okay so the order remains in the substance if you are having acidic medium but if you use these substances in the basic media then what happened then order goes off right okay so these are some natural indicators apart from this we have some synthetic indicators also synthetic indicators you know the name one is phenolphthalein and another one is what phenolphthalein and most common indicator i'm asking phenolphthalein and methyl orange very good and what is the color of phenolphthalein in acidic medium yes correct very good the color of phenolphthalein in acidic medium is it is completely colorless and pink in a basic medium very good correct and what is the color of methyl orange i must have included it somewhere yeah it's here correct yes so it is phenolphthalein is what colorless usually it is colorless indicator in acidic medium also it remains colorless and in basic medium it is what in basic medium it gives pink color a very beautiful pink color it gives i have used it in so many times in titration yeah okay methyl orange methyl orange yes orange yeah red yellow okay so usually methyl orange gives a red or orange color or pink color in acidic medium okay and yellow color in basic medium pink or red right bright red turmeric you know it's it remains yellow in acidic medium and becomes red in basic medium right red litmus paper and two litmus paper you guys are aware yes aditya wait correct correct correct guys okay so don't worry this presentation is uploaded over there and i will share this full pdf file as well okay if you have missed something then don't don't worry at all but yes you can ask me to scroll it up or to scroll it down yes so define olfactory indicator and name two of the substances of olfactory indicators yes kulsum you have raised hand yeah do you want to ask me something yes so define olfactory indicators and name any two olfactory indicators so we we just have learned about it how will you answer it in the exam what are the keywords for this those substances whose smell or order changes in acidic medium or basic medium so answer for a by the way this was the question of 2015 and the question what we have done before that was also from 2015 so those substances whose smell guys i'm not able to see your messages wait now please hold on let me finish this changes in acidic medium and basic medium or sorry or basic medium are called as olfactory indicator called as olfactory indicators right example onion vanilla clove okay yeah okay now see the next question is super duper easy right choose the strong acid from the following H2SO4 yeah H2CO3 and HNO no H2SO4 and HNO3 yes H2SO4 and HNO3 correct hey wait somebody asked me one question does red litimus and blue litimus paper turns to neutral in purple in neutral solution yes arian yes that happens yes arian okay it happens even we are going to see one question based on this okay the question is related that you will have one litimus paper only and then you have to identify acid base and neutral okay so this technique will will be useful in that question okay next acid base indicators done then another problem what we have a gas produced in the laboratory is highly soluble in water a gas produced in laboratories highly soluble in water it's colorless solution turn it's colorless solution turns pink when a few drop of phenolphthalein is added to it what is the nature of this gas oh so simple all of you uh can answer me for this base yes only one two three four five six seven answer please guys yes Ranjini Gaur Siddharth Arun Dati Karek Navya yes Varsha Aniruddh Aryan Tandon where are you and Neha where are you Aditi Avni Anike guys are you sleeping what's going on now it's good okay so that definitely nature of the color is nature of the gas gas is what base right basic it's basic okay done so answer for this is gas is basic in nature okay gas is basic in nature and you know what is the gas that's ammonia yeah because ammonia is only highly soluble basic gas okay okay next that was the question of 2014 chemical properties of acid and bases right so uh acid react with metal to form salt and hydrogen gas current acid react with metal to form salt and hydrogen gas aditya when NH3 react with water it gives ammonium ion ammonium ion NH4 positive okay yeah yeah next acid plus metal form salt and water like HCl plus zinc gives ZNCl2 plus hydrogen gas right you can refer all these reactions all are very easy see the last one this is the formula of acetic acid acetic acid react with zinc to form zinc acetate and hydrogen gas zinc acetate and hydrogen gas okay you know what when this reaction happens so obviously there is a gas released how will you detect that the reaction is reaction has got over or how will you detect that the gas is hydrogen what is the test name here to detect the hydrogen yes correct correct are you in our guys are you sleeping answer me here where are you are you having your snacks yes yes correct yes navya akshita navya flim correct uh shrusti correct so we have the test name is pop test pop test okay when we use a burning candle or burning is finger in front of the test tube okay it burns with a pop sound if if the gas is what if the gas is hydrogen gas because hydrogen burns with a pop sound right okay so this pop test again we are going to see in some question now chemical properties as we are learning chemical properties of acid and bases so what happens when men are base react with a metal again when a base react with a metal it forms salt and hydrogen gas simple right okay so next what we have see the question here to ml of sodium hydroxide solution is added to to a few pieces of granulated zinc sodium hydroxide to granulated zinc okay taken in the test tube when the content are warmed a gas evolved okay which is bubbled through the soap solution before testing write the equation chemical equation involved here and uh what is the name of the gas detected in the test tube then name of the gas which has evolved and the name of the gas which will be evolved when the same metal react with dilute or a strong acid oh I can see so many messages are there really one let's see okay okay okay yes sodium zinc zinc will be formed correct yeah yeah correct but what will be the reaction beta you have to tell me the reaction how are you going to write this uh in exam uh you know this is the question of 2018 I guess yeah this is the question of 2018 and marker yes okay so see how will you write this okay when the sodium hydroxide solution is heated with the zinc granules and all well the reaction will be the reaction will be NaOH plus ZN gives ZN Na2 ZNO H plus H2 gas very good when NaOH solution is heated heated with granulated zinc okay now guys you know they don't repeat so many questions okay they repeat the question then they create a sound little bit of twist in the question correct what I'm talking about the board exams and the examiners right okay so if there is twist the question what kind of twist they can create see in this question they might ask that why do we use this granulated zinc or what should we use the granulated zinc or the chips of zinc or the powdered zinc or or metal strip of zinc so what can what have we have to use or what should we use the first preferable is very good aditya correct first preferable is preferable thing is powdered zinc if you do not have powdered zinc in the option then granulated zinc then uh the small chips of zinc metal or then the last one should be what last one is the zinc metal okay because the granulated or the powdered zinc that means the surface area of zinc is increasing so there will be more surface area provided to react with your acid or base correct so zinc metal then sodium zinc it and hydrogen gas are formed sodium zinc it hydrogen hydrogen gas are formed equation is what to NaOH plus this Na2ZnO2 plus H2 yeah you must be thinking ma'am how do you know that two molecules of NaOH would be required because I remember the formula of sodium zinc Na2Zn plus ZnO2 Na2ZnO2 this is the formula right so here I need two sodium so I just have kept two here okay yeah two NaOH plus Zn gives Na2ZnO2 and hydrogen gas now what is the test for hydrogen oh god I don't have a space okay so see here the test I'm writing here again I'll erase it will it be fine Surya what is the question ma'am ma'am could you show how it is formed during the reaction means what to Surya I couldn't understand can you unmute and how do we obtain this formula Na2ZnO2 like how is it obtained during this reaction how do we are a simple thing see what happens first it will form Na positive and OH negative right this OH negative is going to react with zinc but here we have zinc and here we have sodium sodium is more reactive than zinc definitely right so sodium will try to pull OH towards sodium and zinc will try to pull OH towards zinc right now in this condition what is going to happen it will break OH bond will break from here okay OH bond will break and then this H plus ion will again react another H plus ion of the OH okay and this NaO NaO will react with your zinc okay then that's how it form this formula sodium zincate got it okay thank you yeah okay be welcome so let's do the pop test okay guys now I need to increase our speed because it's 5-2 and we have to do solves bit slide I'm doing by the way right now oh my god I'm doing 21 21st slide and you know what we have 15 sides I guess okay what is the pop test or the test for hydrogen test for hydrogen you know what a splint or what is a burning candle we can help near the opening of test tube burning is splint or a burning candle once again is to be held near opening of test tube obviously where the gas is releasing okay then the stopper is removed then the stopper is removed to expose the splint to the gas right the stopper is removed if the gas is flammable or if the gas is hydrogen the splint will burn with pop sound correct if the gas is hydrogen splint will burn with with pop sound okay so this thing proves that hydrogen gas burns with the pop sound now what they have given us what they have asked us in the last percent is the name of the gas which will evolve when the same metal react with the dilute or a strong acid so let's say the same metal zinc is reacting with H2SO4 and it forms what ZNSO4 ZNSO4 plus hydrogen gas again right here we have to burn it and remember when we have written NOH reaction right NOH with zinc that also we have to heat a bit okay we have to warm the test tube okay okay next you know that the metal which can displace hydrogen from the dilute acid is known as active metals like sodium potassium zinc iron and all right so the active metal which lies above the hydrogen in activities is only those can replace hydrogen okay those are more reactive as compared to hydrogen and those can replace hydrogen from the acid and in the result the hydrogen gas evolved right okay next this one is important attention oh sorry none the slides yeah metals that lie above hydrogen are electropositive in nature but aren't even metals like mercury and copper even though the light below hydrogen aren't they also electropositive yes correct they are also electropositive in nature but if you go top to bottom electropositivity decreases yes okay so okay it's there is no issue if you want to remove this word this word for me you can remove it no worries okay you can say simply that the metals before hydrogen they are more active than the hydrogen or you can say they are more electropositive than the hydrogen okay are more electropositive I should write here okay yes more electropositive in nature yeah thank you so their atom can lose electron very easily okay yeah next if the dilute nitric acid is used okay in the place of HCl dilute nitric acid okay HNO3 is used in the HCl or is used in the place of HCl or S2S4 hydrogen gas will not be evolved why you know why because the nitric acid is very strong oxidizing agent and it oxidizes hydrogen into water okay then what happened because it converting it is converting hydrogen into water so your contain your final content should have what and instead of hydrogen right okay and see it oxidizes hydrogen into water and itself gets gets reduced to an oxide of nitrogen such as nitrogen di nitrogen oxide nitrogen monoxide nitrogen dioxide okay okay so usually all the metals sorry usually metal does not release hydrogen in presence of nitric acid what is the reason because it is very strong oxidizing agent but there are few metals like magnesium manganese they react with dilute nitric acid and they release HNO3 because they reduces the power of oxidizing power of HNO3 okay okay guys next slide yes when acid react with metal carbonates carbonates when acid react with shabita not only magnesium and manganese not only magnesium and manganese okay because the metal which reduces oxidizing property of the HNO3 will produce hydrogen because manganese and magnesium they are what should I say they reduces the oxidizing property of HNO3 okay next when acid react with metal carbonates okay sodium when react with carbonates it from carbon dioxide guys do remember whenever you have carbonates bicarbonates carbonates anything okay definitely in end of the reaction this acid base reaction you will have carbon dioxide okay because the CO3 is going to form CO2 okay yeah so Na2CO3 reacts with HCl2 from NaCl and H2O similarly NaHCO3 which is metal bicarbonate sodium bicarbonated it is it reacts with HCl2 from NaCl CO2 and H2O okay okay the next thing you know what the x-shell chalk marble they all contain calcium carbonate right so they also react with acid okay see the marble also react with acid so if you see that acid has got spilled over the marble or something you will see some bubbles will come out over there because that marble is reacting with your concentrated acid part okay next if the person is suffering from acidity then okay obviously if the person is suffering from acidity then he what he doctor advice to take baking soda right yeah I don't remember but suppose if suppose we do not have baking soda then what other thing we can we have in the case of acidity this is my question from you yes milk of Magnesia correct there was something else yes milk of Magnesia is fine yeah milk of Magnesia is fine but there was something else let me just think is that what is that if the person oh no sorry my mistake you know the question was if the person has like suffering from that de-sting or angsting and if you don't have soda at home what can you use to treat it what should be the first thing yeah that was the question I have seen any idea any guess Surya de-sting or angsting contain formic acid and if you are using saliva saliva is also slightly acidic yes Aditya my question is you know what if you do not have NaHCO3 if you do not have sodium bicarbonate at home baking soda if you don't have yes so Surya Aryan both are right and shares water and dilute acid no shares that you can't you can't use dilute acid water is fine but you can't use dilute acid okay yes Ranjini but where will you search the leaves leaves of dog plant over there yeah Prishin Prishin's the nice name if I'm pronouncing it right yes yes now it is fine correct guys yes we can use toothpaste and we can use we can use toothpaste and we can use soap okay the best option is what soap okay soap and toothpaste we can apply over that area where the burning sensation is happening right next explain the action of dilute hydrochloric acid on the following chemicals so magnesium ribbons sodium hydroxide and crush excel you guys know very well and you can answer it by your own okay after this class I'm going forward milk doesn't contain lactic acid beta sour milk contains lactic acid okay but even though milk will also increase acidity because it is sometimes hard to digest lactose from the milk that increases acidity okay it's not like that milk contains lactic acid milk doesn't contain salt milk contains lactic acid okay next chemical properties in this we have lime water test there was again a question wait yeah see on passing excess carbon dioxide gas through the lime water the first on milky and then becomes colorless explain why right all the chemical equation in the reaction involved so so see on passing excess of carbon dioxide through the lime water first of all what would be the reaction of carbon dioxide through lime water this is also known as lime water test test for CO2 right on passing SO2 gas evolved through the lime water okay evolved through the lime water on passing S carbon dioxide gas through the lime water it converts into calcium carbonate calcium carbonate is what calcium carbonates are insoluble like precipitates okay so that's why our solution becomes milky right now if we pass excess of carbon dioxide then what happens calcium carbonates water and carbon dioxide they all will react and it forms calcium bicarbonate calcium bicarbonate which is soluble in water so your milky appearance goes off right okay so this should be the complete answer for this on passing excess of carbon dioxide gas through milky through lime water first it turns to milky and then it becomes colorless because it forms calcium bicarbonate soluble in water okay very good guys correct good now it is again related to the same thing what we have learned I'm going to the next part now what is universal indicator what is universal indicator you know very well right what is universal indicator universal indicators that means the indicator or the mixture of synthetic indicators which is used to find the pH of the solution right answer for a mixture of synthetic indicators I didn't change the change the color of the spin indicators which is used which is used to find pH of solutions right and it results it gives results in wide range of pH pH 1 2 3 4 5 6 up to 14 it gives it shows change in color right so this is the basically universal indicator right the chemical equation in one the preparation of sodium hydroxide so this is actually belongs to the salt part but let's discuss it here as well very good guys arian yes aditya yes akshita good correct beta so nacl the b part is what equation are what equation can we write nacl common salt which is used to prepare sodium hydroxide and this process name is what chloralkali nacl plus h2o and what do we do we provide electricity electricity right and it converts into chlor chlorine alkali NaOH and and hydrogen gas okay so chloralkali process this is known as chloralkali process where why because it prepares chlorine as well as NaOH this chlorine can be further used to prepare bleaching powder okay yes correct guys next oh this was the question of my god this was the question of 2012 the previous one instead the following instead the reason for following statements okay so guys i'm going a little fast now because i have to increase my speed now okay the stain of curry the stain of curry on a white cloth become radish brown when our soap is scrubbed on it okay when our soap is scrubbed on it and it turns yellow again when the cloth is washed with the plenty of water so what happens in this condition like how this happened why this happens because when we rub soap over the cloth okay when we rub the cloth with the soap soap contains NaOH so that curry turns into yellow color because turmeric react with the sodium hydroxide and gives yellow color correct and then when we wash it off with the plenty plenty of water again the soap part or the basic part removed it's removed from the turmeric so it comes comes back to the previous color correct so how will we write it answer for the first one turmeric react with sodium hydroxide present in the soap to form form red color red color compound it turns yellow again because sodium hydroxide becomes very sodium hydroxide will be diluted in case of lot of water right it turns yellow it turns yellow again because NaOH becomes very diluted or NaOH will be very diluted I should write properly here somebody's asking something with lot of water in that yeah any question beta next curd should not be kept into the copper vessel why oh my god Aditya very good curd consists of lactic acid and react with a metal yes ralf correct ralf sorry yes correct so the curd should a curd contains lactic acid which react with the copper vessel or the brass vessel right and and the taste of curd changes so it should not be kept into the copper vessel or brass vessel right because curd contains lactic acid this was a question of 2016 okay 2016 question curd contains lactic acid and it reacts with with copper and brass so where should we store curd then okay so we should store curd in glass yes glass container correct ma'am could we also write a reason as curd reacts with or copper and brass and or reduces harmful salts which can cause like food poisoning which will cause food poisoning oh no no no that salt doesn't cause food poisoning long term consumption of will disturb your stomach okay yeah okay what is done to be protected so we should store curd in in glass container okay curd should be the store in glass container uh guys this I have tried personally myself seriously we should not store curd even in steel container I know the steel is alloy and it doesn't react but still I felt that the taste of curd gets changed if I store it for a day or two yeah plastic is Surya again I I didn't find plastic good for that curd store it I found glasses very well like no no no you know Aryan what happens that protective layer of aluminum oxide is also very thin if sometime you scratch it with the spoon not that layer will come out and then aluminum oxide is not good for health okay Aryan seriously Adityan still reacts with them in the beginning how Surya that matka is also the good option yeah okay guys coming back to the point it's fight 24 neutralization reaction you know neutralization reaction is again so simple base and acid react to form salt and water so when a base react with acid it it will form a respective salt and water okay neutralization reaction takes place when the effect of base is null filled by the acid and vice versa obviously correct so if suppose you have a red litmus paper and you are using a basic solution so red litmus paper will be turned to blue correct now if you are using a neutral solution that blue litmus paper will be turned to purple right the blue litmus paper will be turned to what purple why because you are using a neutral solution no no aria there is no compulsion like that okay don't worry if if we are not able to finish it the salt part i will do in the next class it's not compulsory arian it's not compulsory don't worry i have planned i have planned according to that but it's not compulsory right okay now do you know here do you know here what i was thinking to tell you hmm it's related to your uh neutralization reaction uh no problem navya so here do you know here what i was thinking to write that uh what how to dilute an acid okay you know very well that it is advisable to add acid into water add acid into water to dilute it right not water into acid you know the reasons right because it is very exothermic reaction we we have to prevent the splash right we have to stop splashing of the acid if you add water into acid it will splash out yes it can also break the beaker correct correct next so it's okay then leave it next yes reaction uh of metal oxide with acids reaction of metal oxide with acid any example from you guys salt and water release are guys i'm asking reaction of metal oxide with acid any example you can give me arm yes shabita very good thank you you are the one only who answered me HCl plus calcium oxide it gives CaCl2 plus H2O right next example it could be your CaO plus H2SO4 right it will give you CaSO4 well NaCl plus HCl no NaOH plus HCl NaOH beta it's a base and we are talking about metal oxide NaOH is a base beta isn't it right you can use MgO NaO anything is fine H2SO4 it gives MgSO4 plus water what is this possible NaO plus HCl NaO plus HCl is theoretically it is possible practically it is not possible okay because sodium oxide is highly unstable it will immediately react with the water to form NaOH right so theoretically it's not possible oh sorry what did i say practically it is not possible yeah okay but you know the formula is also for NaO it's not NaO actually it should be Na2O Na2O okay Na2O plus HCl so it gives NaCl plus H2O and obviously it should be your HCl yeah done it is balanced but it is theoretically possible thing right next reaction of non-metallic non-metallic oxide with a base now you all are aware of this thing that metallic oxides are what metallic oxides are known as basic oxides metallic oxides are known as basic oxides right and non-metallic oxides are acetic oxides correct non-metallic oxides are acetic oxides so what's happening here non-metallic oxide CaOH twice how something wrong i think i have pasted here non-metallic oxide okay what could be the reaction with non-metallic oxides oh sorry non-metallic oxide with a base it's right non-metallic oxide with a base so carbon dioxide with a base okay calcium hydroxide it gives calcium carbonate and water so non-metallic oxide react with a base and it forms salt and water that that that says that your non-metallic oxides are acetic in nature right acetic in nature because they produce salt and water okay next huh no root purva C the Ca is CaOH is the base and non-metallic oxide is the carbon dioxide okay yeah carbon dioxide next huh yeah what will you observe when sulphur dioxide is passed through water and lime water yes this question was there in 2016 or 2015 exam yeah so uh what will you observe when it is passed through sulphur right seriously good very good okay waiting for others answers okay yes correct so see here the first question answer the A part it will form sulphurous acid it is sulphurous acid okay see here uh sulphurous acid form okay so here SO2 plus H2O gives H2SO3 okay H2SO3 you know it is sulphurous acid right when this SO2 is passed through the lime water then what then what will happen SO2 lime water is you know Ca Ca OH twice Ca OH twice correct it converts into what Ca SO3 calcium sulphide SO3 is what sulphide and H2O so calcium sulphide pH 80 okay remember one thing whenever SO2 react with water it gives you some compound based on SO3 some compound based on SO3 which have combination of SO3 okay SO3 is what SO3 is basically known as your sulphide ion SO3 2 minus sulphide DE right SO4 2 minus you know sulphate S2 minus is sulphide sulphide got it no confusion aditya you can calculate it so oxidation number beta it is 2 minus oxygen and it is 2 plus here now calculate the oxidation number of sulphur you will get its valency minus 6 plus 2 sulphur is plus 4 here I guess plus 4 or minus 4 1 minute minus 6 minus 4 sulphur is plus 4 here okay yeah next okay guys so I think from the pH solution we will be doing in the next class okay I don't know when we have next class schedule I just take the schedule the next topic is written for the next class but I will change it and from the pH we will be doing in the next class okay okay everybody did you understand any question any doubt anything ma'am you said that at the last we will tell the formula of that bleaching powder and welcome ma'am welcome baby uh uh prabhath you be in the class one minute okay initially what was the topic never the topic was metals and non-metals okay now we will be continuing from the pH and then we will continue from the metal like means we end this stop end this chapter then we will do metals yeah okay uh prabhath your doubt is uh welcome ralph ralph and rancini navya are in thank you guys welcome bye bye enjoy your day hope you understood everything thank you shares akshita shabita bye bye beta bye shalini bye avni bye navya bye arian bye bye anishka bye nahi ha nahi nisha sorry bye nisha bye ananya yes so prabhath you were asking something beta yes ma'am ma'am I was asking you said that you'll tell that the last of the class the formula of bleaching powder and okay how it is formed let's discuss that thank you rukpur wow very nice compliment so sweet of you and feel free to ask your doubts you can post your doubts in the forum okay or you're in respective whatsapp group or moxtra group okay edin bye bye nanthini welcome so uh prabhath see the question was bleaching powder formation and cleaning of water or softening of water something like that I remember right yes ma'am see here if suppose you have you know in water we have certain ions correct yes ma'am yes if your water is very hard in your water if you have calcium magnesium what is the composition of hard water the salt of calcium and magnesium correct yes ma'am so I'll share the another screen here wait so you know what happens when you use uh calcium hydroxide calcium hydroxide with your hard water what happens hard water if the water contains amount of chlorine if water has some amount of chlorine it forms it reacts with chlorine it forms cao cl2 okay it forms cao cl2 and then uses then it uses for the softening of water cao uh cl2 I guess something like that is it yeah yeah okay then we use it for the softening of water now you know what when bleaching powder is used uh is has been treated with the water anything hard water soft water anything is fine the main purpose of bleaching water is what the disinfectant if you leave the disinfectant part as well that's fine but what will happen when it gets dissolved in the water it will release some amount of chlorine in the water right so now what happened with softening of water your water is not uh is having high content of chlorine still this water is not drinkable are you getting my point are you getting my point hello Prabha yeah so so what is our purpose the purpose is the water will be disinfectant like water will be completely free from the jumps but it is not drinkable so we use calcium uh not the calcium hydroxide we use this bleaching powder for the disinfectant purpose right okay yes this is the way of softening of water but usually calcium hydroxide you ask the ma'am how can we use calcium hydroxide for that so calcium hydroxide is used with the sodium pycarbonate and it's softened the water that process is known as lime soda uh water softening if you remember I do yeah ma'am right okay now tell me again what is your doubt beta cleared ma'am done okay fine fine so Prabha is done thank you ma'am any question are you are welcome beta any question any doubt okay guys enjoy enjoy new year bye bye see you soon the next class yeah bye okay