 First one is B2O3 boron trioxide, boron trioxide, right on it is the and I tried off, the other is also like, we are doing only the important one, right on next, boron trioxide B2O3, this is an anhydride of, anhydride of orthoboric acid, orthoboric acid is H3BO3, H3BO3 when you heat this, it converts B2O3 plus H2O3, so since water molecule element is here, that is why this is the anhydride of this, okay what the molecule is? So why do we call it orthoboric acid? Where is the orthoboric acid? Ortho orthoporic acid is just the name of it, there is no answer for this, this is the name of it, we have to up, what is your name? Ortho something, no what is the answer for this one? What is the answer for this one? Is it the same thing, all the compounds like all non-organic compounds that have ortho and all of that and that. Ortho is a sub student product that is defined in organically, when the group is attached to ortho because of the pollution defect, here we don't have such things. Sir believe in inorganic, you have some compounds that stuff with ortho or omega or something. So those are just names? There are just names, no reason. So we have many things to memorize here, right So try to keep it confined, for a very important reason, in organic chemistry there are positions defined ortho-paradise, so we have ortho, you can also answer that question, why is it un-serving also, understood this. So benzene if you write on this, why this is ortho, what is the answer for this one? The chemistry way you cannot do like this, try to understand that way. So ortho-poric acid, B2O3 first of all it is an anhydride of ortho-poric acid, this is important. They ask this, the anhydride of S3BO3 is water, that is B2O3, okay, important. Another method is what, boron when reacts with water, sorry O2, it forms B2O3, preparation of this. This compound we also call it as, you can also ask why is it un-serving. It is, it is a white crystalline solid, right on top, it has affinity towards water, yes, hygroscopic in nature, right on the reaction B2O3 plus H2O, hygroscopic in nature B2O3 plus H2O forms HbO2, metabolic acid, worldwide meta compounds. No. How do you form this? Which one? Ortho-poric acid, how do you do that, what is the preparation time? BbO2. It is just see, there is a reaction of decomposition at different different temperature. So at different different temperature, you will get different different compounds. So you will see that, okay, and that is important of the temperature dependent reaction that is. This is at more temperature. This is at more temperature. This is just boron we have, so around 600 Kelvin we are using. And that one? It is high temperature only, so that will be around 400 to 500, 450 around here. So this is high temperature, like what? Reaction of this one, B2O3 with water, B2O3 with H2O gives HbO2. HbO2 that is metabolic acid. HbO2 again oxide B2O3 and boron. It gives HbO2 first, this further reacts with water and forms HbO3. So this is the reaction, the overall reaction is this. It depends upon what temperature, what amount of water you are taking. So it requires a higher temperature than orthobolic acid? No, because whatever temperature we use here, we have a little temperature. Otherwise this will not form, this will stay. The temperature is more than this one over here. See you said this one is 600 and that one is 4. This is the temperature here and here is lesser than this. Orthobolic acid makes a right on, next compound is borax. Borax is N2B4O7 sodium tetra borax. Borax N2B4O7 sodium tetra borax. It can be obtained from boric acid, that is H3BO3. H3BO3 reacts with Na2CO3 and it forms Na2B4O7 plus H2O plus CO3. Sir, but now this is boric acid. This one, orthobolic acid and boric acid both are same thing. H3BO3 is orthobolic acid or simply boric acid. B2O3 is boric oxide, boric anhydride oxide. So this is right on both. It is boric acid or we also call it as orthobolic acid. Na2CO3 forms Na2B4O7. It can also obtain from polymanide mineral. Also obtained from polymanide mineral. So this is Ca2B6O11, formula it is important for polymanide. Ca2B6O11 plus Na2CO3. It forms Na2B4O7 plus CaCO3 plus CaCO3 and sodium metaborate NaBO3, which is polymanide mineral. Now you see, there is a compound called prismatic borase. The formula for this, they have asked this question Na2B4O7. It is the hydrated form, take a hydrated form. It is prismatic borase, Na2. Octahedral form of prismatic borase. Another one is octahedral form. Octahedral borase is Na2. It is Na2. Octahedral borase is Na2B4O7.5H2O. Borase glass is the anhydrous form, that is Na2B4O7. Borase glass is the anhydrous form, that is Na2B4O7. Okay, next slide down. Octahedral is anhydrous form. Next slide down. Action of heat, or we also call it as heating effect. Action of heat. This is very important for example. Depending upon the temperature, the product will be different. Okay, action of heat. I'll write down the reaction. If you have Na2B4O7.10H2O and when you heat this, it converts into the anhydrous form and the temperature around we are using. What is Na2B4O7? Na2B4O7 and the temperature here we are using around 900 degree Celsius. All this water molecule goes off and we get the anhydrous form. Okay, further if you heat this, 740 degree Celsius, converts into sodium metaborate, NaBOP, boric anhydride. Boric anhydride, boric anhydride, amps with copper sulphate and forms blue colour complex of, blue colour complex of metaborate. Blue colour complex of copper metaborate. Okay, so colour, this is the boric's big test we call it. The boric's big test, right? So copper gives you blue, iron gives you green colour that you write down. Fe gives you green colour, nickel gives you brown. So you make it react to the FES? Yes, CuS4 plus B2O3. And case of FES? FES. Solution of iron. Iron gives you green, nickel gives you brown. Okay, next one more reaction we have of boric's. I'll write down the whole reaction here. NaS4 plus, this is copper it forms CuBO2 whole twice, NaBO2 whole twice. Okay, the reaction of boric's you write down with HCl. It forms H3BO3, we have seen this reaction. We can use HCl4, we can also use H2SO4 for this purpose. S3BO3. Further, you heat this with NaOH, forms sodium metaborate, which is NaBO2. Sir, what is boric's like boric's glass or plasma? It is anhydrous simply, B2O3. Na2B4O7. There's no boric's glass. Anhydrous one. S3BO3, if you heat at 100 degrees Celsius, this is also important. S3BO3, if you heat at 100 degrees Celsius, it forms HBO2. Further, if you heat this at 160 degrees Celsius, it forms H2B4O7. This is metaboric acid, and H2B4O7 is tetra boric acid. S3BO3, heated strongly, it converts into B2O3, boric anhydride, which on reduction, we have seen this in NaM potassium. It gives you boron. Boron, when heated with nitrogen, gives you boron anhydride. Boron anhydride is also obtained with boron, where it is heated with NH4CF. Sir, what temperature is that? Generally, very high temperature we use, around 700 degrees Celsius. All these reactions are very important, temperature also. What is the structure of Na2B4O7? Na2B4O7.NH2, what is the structure? This molecule, this is the actual bonding. This is the structure. This is the Na's attack in those two. This is again a complex compound. The structure of this part, right on next, helites of boron, helites BX3, helites of boron. Right on boron forms helites of BX3 type, BX3 type. What is the hybridization of this BX3? SP2. This is SP2, trigonal planar. BX3 is SP2 hybridized trigonal planar. Right down, these helites are covalent in nature, covalent in nature. And why it is covalent? Because it is small size of boron. Small size of boron. It has more covalent. High-polarizing. Yes, please. It will be 0. Right, next write down. Next write down, covalent in nature, because it is small size. It has low boiling point. It has low boiling point. And the boiling point increases with, increases increases with the atomic number of halogen. What is the electron deficient molecule? Lewis acid in nature. Behaves as a Lewis acid. Okay, so if you one thing, what is the order of Lewis acid in behavior of this? BR3, BCL3, BBR3 and BI3. Order, BBR3. BI3, what is Lewis acid? X7, which one has maximum tendency to accept? Order should be what? This is the order of Lewis acid. But this is wrong. Why the order is maximum for BI3? This is the other order. What is the order of Lewis acid in behavior of this? That is wrong. But then, F3 will take the thing and then you can accept it like that. This is wrong. So B, C, L, B will be the most acidic, then BF3, then BBR3, then BBR3. What is the answer? B, C, L, B is the highest. Who is B? C, L, B is like the most acidic. Why not have it? B, L is the most acidic. The reason for this is, I didn't tell you. This is P5, P5, backward. P5, P5, backward. That is the problem. The concept is that you won't understand. You will ask what is the name of the orthoboric. What happened? I didn't sit off. You don't have to read the name. You have to understand the concepts. Whatever it is there to memorize, you have to remember it correctly. What is the P5, P5, backward. Basically, we awaited P5. How many times of backward we have? P5, P5. Any example of P5, P5? B, C, L, B, B, B, B, B, B, B, B, B, B, B, B, B. So you need to take like... Like this one. T, L, B, L. No. No, so it will never come unless you can... Unless... It is coming next. So we only... In this molecule we have P5, P5, backward. This donut is like drawn to the vacant D orbital. P5, P5, backward. See actually what happens in VF3, do it as it is tendency to accept electron pair. Right? Accept electron pair. Now this boron has vacant P orbital. I have discussed this in pre-ordering properties. Right? Yeah, I am going to discuss this. Boron has three long pair. Right? Sorry, protein. And since boron has one vacant P orbital, so this protein has tendency to donate this lone pair into the P orbital of this boron. This P orbit, this lone pair is present in P orbital of chlorine. And this is also P orbital of boron. The vacant P orbital is of boron. Okay? So this is what? Since it donates electrons, it is back bonding. Since the bond has been formed already. And then this electron pair it on X. Right? So it is back bonding. And since P orbital is involved, so it is P and P. The bond has pi characteristics. So it is P5, P5, back bonding. Okay? Of this kind of back bonding, decreases the electron deficiency of this boron. Since you have a 6th half, you donate 30 of 8 to the boron. Right? So electron deficiency of right. Now, this kind of back bonding is maximum in BF3. If you talk about BI3, so PI3 may will have like this. We have electron pair presence in P orbital. This is the P orbital. Right? Or here on P orbital. That is why the overlap is not possible. This is if compatible, so overlap is possible there. Right? So here we have the best overlap. This molecule is least electron deficient. Least electron deficiency means the tendency to accept electron is minimum. And here the order is big one. Very important. Okay?