 Yes, hello. Good evening, guys. Can you hear me? Yes. So, okay, I'll wait for a couple of minutes more, only 27 of you are there. Okay, so guys, today we are going to do three chapters. I have prepared the slides for alcohol as well, but these three chapters only it took around 50 slides. So I doubt we'll be able to finish this 4850 slides and more than like more number of sites required for today's session. Okay, if it is there, then we'll add up, right, we'll add the slides into this. But as blog biomolecules polymers definitely will try to finish it today itself, because I was going through the plan the plan that you have now that is the older plan. And according to that plan, we are going to finish the portion on 23rd of Feb, if you see, right? Right. So we have to go a bit fast. I think Feb 7th and or Feb 10th max to max will have the class for this crash course. So that's why we'll try to finish these three chapters today. Okay, I have taken most of the theories in this. Okay, because this need to revise. You know, so theories I have taken properly. Questions are also there. Okay, as block I have taken a few questions of Bunsen classes module. It's a solved questions I did not get the unsolved one so I have taken that so that we can go through the questions also. Okay, so biomolecules polymers and as blog will finish today. Next class also I'll tell you what all chapters will do. Okay. So like half of the things we have done last class only as block. Today we are going to start with sodium here. Okay, so sodium and the compounds of sodium. First one is sodium monoxide. Okay, preparation how it is obtained. I'll just tell you the key points here if you want you can write down in short anyways you're going to get this notes. Okay. So that also from there also you can revise. So first of all, any to is a white amorphous solid. Okay, this property, you should know how it is prepared. It is prepared by heating any to O2 sodium peroxide and O2 O2, or sodium nitrate Na NO3, the sodium peroxide and sodium nitrate you heat with sodium itself. It converts into sodium monoxide and into gas. This reaction is important sodium nitrate on reaction with sodium releases nitrogen gas. Okay. It reacts with water violently forming NaOH right energy releases in this process on heating over 400 degrees Celsius it disproportionates to give peroxide and metallic sodium this reaction is also important. Over 400 disproportionation takes place third one. Okay, with liquid ammonia it forms sodium and sodium hydroxide. Okay, the formation of sodium hydroxide is pretty common in this particular compound that is any to work. Okay, so important point in this, the evolution of end to is important. Okay, and decomposition takes place sodium metal gets involved this is also important to you. Okay, so the next one you see. Sodium hydroxide NaOH sodium hydroxide is commonly called caustic soda we all know, therefore used as a purifier it is prepared by electrolytic process. Okay, there are two electrolytic methods commonly used for the preparation for hydroxide when it's gastro-chelinal cell. Right. In this what happens we have to diaphragm actually what you have to keep in mind in castor channel cathode is made up of mercury reaction is this. Which forms soda amalgam and then this go into the inner compartment if you go through NCRT there that you know explanation is given here. There are two compartments in the outer compartments cathode is made up of mercury where the reduction takes place NaHg forms sodium amalgam and then this go into the inner compartment the anode is made up of graph idea. Where this oxidation takes place. Okay, sodium amalgam removed from the cell, it is then decomposed in a separate cell by water giving NaOH hydrogen and mercury. And mercury is re-circulated so here this anode and cathode thing you must remember what metal we use for this particular things and then cathode. Okay. Next sodium carbonate like it exists in various forms and hydro sodium carbonate is soda ash. Soda ash. Monohydrated form.H2O crystal carbonate heptahydrated 7H2O. It is manufactured by Solvay ammonia soda process name is important. Not for Jay, but in Bitsat need all these exams ask this question okay Solvay or ammonia soda process in this process bring that is a solution of salt. Ammonia and carbon dioxide are the raw materials chemical reactions involves this. Ammonia carbon dioxide and water forms ammonium bicarbonate with react with NaCl forms sodium bicarbonate NH4Cl evolves and on heating the sodium bicarbonate it gives an hydrous form of Na2CO3. Okay. Ammonia Solvay process cannot be used for the production of K2CO3 since KHCO3.