 Yeah. Hello. Okay. Now you see next carbides. Okay. I'm this in J. They have asked question a couple of times. Write down in this. If you look at the formation of carbides here. Lethium is the only metal among all the metals. Which reacts directly with carbon. And forms carbides of. Li2 C2 type C2 type carbides direct reaction. Okay. This card wide is I nick other metals forms carbides, but they do not react with that directly with carbon. Like you see if you talk about sodium. Sodium reacts with acetylene to form carbides which is any plus C triple bond C minus minus. One more important reaction is what this is the salt of acetylene. And when you dissolve this in water. It converts into hydroxide NaOH two molecules of it. And we get acetylene back. Done. Let him reacts directly with carbon to form carbides because of the high lattice energy of lithium carbide. Both cations if you see ni plus. And C2 two minus both cations are anions are very small. And hence they have a very high lattice energy because of that only it forms. So you must remember this lithium again you see the first element has abnormal property. The lithium is the only alkali metals which reacts directly with carbon and forms carbides. Okay. So this is one important reaction Li2 C2 I nick type of carbide forms high lattice energy because of the small size of carbocation. Sorry, cation and. Okay. Now the another compound we have that is carbonates and bicarbonates. Right on alkali metals forms carbonates of M2 CO3 type carbonates of M2 CO3 type. And if you look at the reaction how this carbonate forms like for example if you talk about Li we can also form this with halide like LiCl plus Na2 CO3. It converts into 2 NaCl plus Li2 CO3. Or we can also have hydroxide LiOH 2 LiOH impact. Plus CO2. So it forms Li2 CO3 plus H2O. We can also obtain carbonates by the dissociation of bicarbonates Na at CO3. When you heat this we're talking about bicarbonates also your carbonates and bicarbonates right down. So when you heat this bicarbonate Na at CO3 to Na at CO3 impact it forms Na2 CO3 plus H2O plus CO2. So by heating bicarbonates also we can get this. Preparation of bicarbonate you see will take hydroxide NaOH and this hydroxide we allow this to react with CO2. It forms carbonates Na2 CO3 and H2O. And this carbonates we again circulate carbon dioxide into this like for example the reaction is Na2 CO3 plus H2O. And we add CO2 here it forms NaH CO3 to NaH CO3. This is how the bicarbonate forms okay. So both reactions are important here for carbonates and bicarbonates. Right on one note here lithium does not form. Lithium does not form a solid bicarbonates. Lithium does not form a solid bicarbonates. Due to due to its less electropositive nature okay. If you compare the stability of bicarbonates like you see right down the stability of bicarbonates first we'll see carbonates. The stability of carbonates bicarbonates increases down the group. Why it happens I'll tell you first of all write down the order. We have Li2 CO3 is less than stable then Na2 CO3 then we have K2 CO3 RB2 CO3 CS2 CO3. This is the order we have electropositive why this happens because as we go down the group you see top to bottom. Electropositive character increases electropositive character increases when electropositive character increases the tendency to form electropositive iron is more and that will stabilize the carbocation. Sorry, the carbonate iron CO3 to minus iron will stabilize it right so write down as we go down the group the electropositive character increases. And hence the stability of carbonate also increases. As we go down the group the stability of the electropositive character increases and hence the stability of carbonate also increases. See there are multiple factors here if you look at this compound is carbonate and if you consider the size here bond length. As we go down the group the size increases bond length increases bond length increases so stability should be less, but that is not the factor here. The factor is not size, but the factor is electropositive character because both are contradictory to each other. One is electropositive character and other one is size the bond length, both are contradictory. So bond length Li2 CO3 should be the most stable one. According to electropositive character it is full right, reversed, exactly reversed. So since both are contradictory to each other. So in such cases thus the result becomes experimental it depends upon which factor is the dominating factor. And in the book the answer that is given the order that is given that is given according to that dominating factor only. Okay, so here we can say on the length or the size of the you know the ions here that is cation basically. Electropositive corrective dominates over the size of the ion, and hence we have the answer according to the electropositive nature, which is this given here. Right, so this kind of thing will be there in, you know, in organic chemistry. Once one particular logic gives you one particular answer, another logic gives you another answer. Okay, so you should know this fact that at what point what logic is dominating what logic prevails. And according to that only we can write down the answer. Okay, so here you need to think about what you need to think about the electropositive character, not the size. Okay, one more thing you can understand over here. Calculate ion is a big ion right the size of carbonate ion is large CO32 minus. So one logic we also have here that bigger an ion or cation is stabilized by some suppose you're bigger and I'm so bigger and I'm is a stabilized by bigger cation and bigger cation is stabilized by bigger. So CO32 minus this negative charge is a stabilized by the bigger ion that we have. And among this you see CS plus is the biggest and we have that's why CS CO3 is the most stable one. Okay, write down these carbonates are these carbonates are highly stable towards heat, except Li2 CO3. Okay, again you see the change we have for Li2 CO3 again abnormal behavior right all carbonates are what stable towards heat, but not Li2 CO3 Li2 CO3 easily decomposes into its oxide and CO2 right. Li2 CO3 is easily decomposable. When you hit this into Li2 O and CO2, but all other carbonates are relatively more stable. Okay, quite stable. These carbonates are soluble in water. These carbonates are soluble in water and solubility increases as the size increases size of cation solubility increases as the size increases. Look at the reaction here, M2 CO3 plus H2O, it forms hydroxide MOH plus CO2, so H2CO3. This is alkaline in nature base we have no alkaline. That's why we also say aqua solution of carbonates is alkaline in nature. Aqua solution of carbonates are alkaline. Next point write down except lithium, except lithium, all other metals forms except lithium, all other metals forms solid bicarbonate, solid bicarbonate, and these bicarbonates are soluble in water. Now, next slide down we'll see few properties of lithium, which we call it as abnormal behavior of lithium. Heading right down abnormal behavior of lithium. Why it shows abnormal behavior? The reason is small size. So these are the reasons for for this behavior that is abnormal behavior. Small size. Okay. And high polarizing effect. All these are because of small size only. High polarizing effect. Least number of electron electrons in the inner shell, in the inner shell, maximum ionization energy, maximum ionization energy. All these factors we have for abnormal behavior of lithium. What are the abnormal behaviors properties? Okay, so first property here write down it is like it forms nitride of N3N type direct reaction with nitrogen. Okay. Nitrate if you talk about LiNO3, lithium nitrate. When you heat this, it gives a mixture of N2O2 and Li2O. Okay. But if you have any other metal nitrates, for example, we have the balance reactions for LiNO3, we have 4NO2 plus O2 plus 2 Li2. When you look at the nitrate of other metals like NaNO3 and when you heat this, it forms from nitrate it forms nitrite that is NaNO2 and O2 releases. So you see here both are nitrates only, lithium nitrate and sodium nitrate, but this gives nitrogen dioxide. This does not produce nitrogen dioxide. It does not form nitrite here. It forms oxide, but it forms nitrite, sodium nitrite. Very important reaction we write down here. Lithium when heated with NH3, lithium when heated with NH3, when heated with NH3 forms imide. Okay. Forms imide. So Li with NH3, it forms imide to Li we have. It forms Li2NH, NH plus H2. This we call it as imide, the general name, lithium imide or simply imide. But any other metal if you have, for example, if you take Na, Na you heat with NH3, it forms imide that is NaNH2, sodium imide NaNH2. So imide, lithium forms, it forms imide. One last point we write down. Bicarbonate of lithium is known in solution. Solid bicarbonate, lithium does not form. Okay, always keep that in mind. Bicarbonates of lithium is known in solution, but bicarbonates of other metals are known in solid state. Bicarbonates of lithium is known in solution, but other bicarbonates are known in solid state. Now, there are few compounds of sodium that we need to discuss. So write down the heading. Compounds of sodium. Compounds of sodium. There are few compounds of sodium. You should know the formula of this, like the common name when we have chili salt, Peter. Its formula is Na Na3, sodium nitrate, cryolite. What is the formula of cryolite? Na3, ALF6, globbers salt, globbers salt. The formula is Na2SO4, it is a decahydrated form of sodium sulfate, .10H2. If you write exams like, you know, some CT, Bitsat, okay, Manipalano, they'll ask these questions that what is cryolite? What is the formula of cryolite? Okay, like this. Gropel salt. Another one is soda feldspar. Soda feldspar is NaAlSi3OA, soda feldspar. Next one is borax. Borax is an important compound. Na2B4O7.10H2O. We'll discuss this again in Boron family, that is group 13 elements. Borax we also call it as tinkal. Same name. Tinkal is nothing but in Hindi we call it as Suhaga. That's the Hindi name. Okay, Borax tinkal in Hindi it is Suhaga. SUHAGA. Done. Next you see the preparation of sodium. Two methods we have for this. We have two methods for this mainly. First one is Castner's process. See as far as preparation is concerned and the properties that we discussed, the order and all of carbonates, pycarbonates, okay, halides, what kind of halides, its forms, hydroxides, okay, oxides, stability order, you know, bond length and all, those things, the order part that we discussed, those things are more important in this, okay. It's not like you do not ask questions from properties part, but if you look at the relatively, if you look at the importance, okay, those kind of order and the reasons, no, reasons for a given order, okay. Those things are more important here. In Castner's process, what happens? Okay, give me a second here. Okay, fine. So in this what you do, we'll discuss about the compound first. Just you wait for this. We have a compound here of sodium, that is sodium hydroxide, means those compounds that have given you like cryolite, lower salts, chelisolic pitanol, for that you just need to know the formula, okay, there's no preparation and all, just you need to know the formula. Other compounds like sodium hydroxide, the preparation is important, okay, so other compounds you write on, sodium hydroxide, first we finish this, okay. Sodium hydroxide. Sodium hydroxide, we have two, three methods of preparation, like the first one we have, we call it as causticization process, the preparation method we have causticization process. We also call it as Gauss's process, G-O-S-A-G-E, Gauss's process, not much important. We'll just write down two, three points here, okay. So in this what happens, causticization process, write down, this process involves the reaction between sodium carbonate and slagged lime, sodium carbonate and slagged lime, very simple reaction. We take 10% Na2CO3, Na2CO3 and this is allowed to heat with CaOH whole twice, it forms hydroxide NaOH plus CaCO3. The next method of preparation we have electrolytic process, electrolytic process, write down. Nowadays, sodium hydroxide is prepared by, sodium hydroxide is prepared by the electrolysis of aqueous solution of sodium chloride. Electrolysis of aqueous solution of sodium chloride NaCl. The biggest advantage of this process is what we get very pure NaOH, means in comparison to the other method, we get pure form of NaOH, impurities are very less. We also get hydrogen and chlorine as the byproduct, which is also a valuable product, like hydrogen and chlorine are also very useful products we have, which we get here as a byproduct, which is also very useful. So write down in this process, we get H2 and Cl2 as a byproduct. Now, could you tell me, aqueous solution of NaCl means what? If I ask you, aqueous solution of NaOH, could you tell me, sorry NaCl, could you tell me what all ions are present in this solution? Yes, aqueous solution of NaCl means what, what all ions are present? Yes, we have Na plus, we have Cl minus, H plus and OH minus. Okay. So if you look at the overall reaction here, the overall reaction is we have NaCl plus H2O, simply it forms NaOH plus H2 plus Cl2. This is the reaction we have. How this reaction happens, if I write down the Inic equation here, the Inic equation is 2Na plus 2Cl minus, then we have 2H, sorry 4H plus, or simply H2O, let it be as it is. This is the reaction we get. Chlorine evolves at anode. This comes out at anode and hydrogen evolves at cathode. See, if you try to understand the process of electrolysis, it's very simple. I'll explain you here, what is electrolysis? In electrolysis, what happens? We'll take this ion in a, you know, in a container, we have a setup over there. Right, so we have a container, roughly I'm drawing this, don't draw this, okay. In this container, we have two electrodes present, right. And here, yes, we have a container. In this container, we'll take the solution, the solution which we need to electrolyze. Means, in this solution, we have all those ions present, Na plus, Cl minus, H plus, and OH minus, okay. These two are electrodes, correct. Now, what we do, we connect these electrodes with an external source of current, battery, okay. So this is the positive end of the battery, this is the negative end of the battery. This rod becomes positively charged because it's connected to the positive end. And this becomes negatively charged, connected to the negative end, correct. So when there is charge on the electrode, then these electrodes attracts the oppositely charged ion towards its side. For example, this positive electrode, this will attract the Na plus ion, sorry, Cl minus ion and OH minus ion towards this side. It will attract both. So both ion will go towards the electrode and try to get, you know, oxidize or reduce over there, okay. Similarly, this negative ion also attract Na plus and H plus towards this side. So both Cl minus and OH minus is going towards the electrode, but the oxidation, obviously it is anode. So anode, we know oxidation takes place and this is what cathode and cathode reduction takes place. But it's not like that both ion, Cl minus and OH minus will get oxidized over here. Oxidation of only one ion possible and that depends upon the oxidation potential of that particular ion. The one which has higher oxidation potential has high tendency to get oxidized, okay. These things in detail you will study in electrochemistry class as well, right. What I'm telling you here, both will compete with each other, but only one will get oxidized. Na plus and H plus similarly, both will compete with each other, but only one positive charge ion will get reduced, okay. So here what happens at anode, at anode oxidation of chlorine takes place because the oxidation of chlorine is easier than to that of OH minus. The two Cl minus will get oxidized, converts into Cl2 and electron releases. Similarly, cathode what happens, Na plus and H plus, H plus will get reduced because at cathode reduction takes place. Two H plus will take two electron, converts into H2. Hence you see hydrogen and chlorine gas evolves in this reaction. So they also ask this question that chlorine evolves at which electron? So chlorine at anode, hydrogen at cathode. We have Na plus and OH minus ion which combines and forms sodium hydroxide. Understood. Any doubt in this electrolysis? So this is done in electrolysis. For electrolysis we have two types of cell which we are not going to discuss. I'm just writing down the name. Nelson diaphragm cell. It is not at all important. Okay, just ignore this one. Second one we have Castner-Kellner cell. Okay, it is given in NCRT. If you want, you can just go through once. Castner-Kellner cell. Okay, just go through once. The entire process is this only. Just we have here some cathode. I know there are two compartments in this. It is given in NCRT. So let's read this out. So this is the preparation methods of NaOH, that is sodium hydroxide. Few properties of sodium hydroxide will finish today. Okay, we have few more minutes. We'll do it. So write down the properties next. Write down. It is soluble in water. Highly soluble in fact. Soluble in water. And this process is exothermic. So we have two types of it. NaOH decomposes into its elements at high temperature around 1300 degrees Celsius. 2 Na plus O2 plus H2. 2 Na plus O2 plus H2. Correct. Few reactions of acid. Write down reaction with acid and acidic oxides. So for example, you know, this reaction is very simple. NaOH plus H2SO4 or HCl, Na2SO4 plus H2O. Solve plus this. Dibasic acid here. Acidic oxides, for example, if you take carbon dioxide NaOH, CO2 is an acidic oxide. It forms Na2CO3 plus H2O. Reaction with non-metal COC. You can balance the reaction. Here also you can balance the reaction. Balanced reaction I do not always write. I just write down the reaction. Okay. Reaction with non-metal. This reaction is also not balanced. Is it fine now or not? If I multiply this, I have to do it now. 2H4, 4, sulphur is 1, sulphur is 1, oxygen is balanced. 2 NaOH CO3, H2O, acid. Reaction with non-metal. So there are a few reactions which is important here. Like you see this. 2 NaOH, this one is important. 2 NaOH plus Br2. It forms NaBr plus NaOBr, I'm sorry. NaBr plus NaOBr plus H2O. This reaction you see, 6 NaOH plus Br2 gives 5 NaBr plus NaBr O3 plus 3H2. You see two different reactions with the same reactant. The difference in these two reactions are this NaOH is cold and concentrated. But this one is hot and concentrated. And that is why it is important. Temperature, we get different product here. Okay. Reaction with phosphorus here you see. 3 NaOH plus P4 plus 3H2O. When you heat this, it forms 3 NaH2PO2 and Ph3 evolves. Ph3 is phosphine. Important. Phosphine evolves in this reaction. Write down next, it reacts with ammonia salt. Ammonia salt and ammonium salt basically. And releases ammonia and releases ammonia. For example, ammonia salt we have NH4Cl. Okay. NaOH plus NH4Cl. It forms obviously it forms NaCl plus H2O plus NH3. Ammonia releases in this with all ammonia salt. Similarly you see reaction with metal. The last one, the reaction with metals. With zinc you see ZN plus 2 NaOH. It forms sodium zincate. Sodium zincate is Na2ZNO2H2 releases. Sodium zincate. With aluminium 2Al plus 2 NaOH in presence of water. It forms 2 NaAlO2 plus H2O. This compound is sodium meta-eliminate. If you take tin then sodium is standard. Two conditions here, the last two reaction. You see SN with NaOH. It forms Na2SNO2 plus H2. This is sodium stanite. If you again take here 2 NaOH. It forms in presence of H2O. It forms Na2SNO3 plus H2. This is sodium stanite. This is also possible when you take it as excess. This is the two reaction we have here. This is it for today. Copy this down. I would request all of you for your assignment hydrogen chapter. Centre module you finish completely. This is your assignment for the week. Centre module hydrogen chapter. In this only few things are left. I would request all of you to read NCRT for sodium bicarbonate. Same thing we have some properties. Sodium carbonate Na2CO3. NCRT for this. That is it. In this we have one solvay ammonia sort of process. That is important. I want you to finish these two before the next class. We will start with alkaline arithmetic. Have you done this previous one? I am done. Finish the assignment. See you in the next class. Take care.