 Next write down the compounds of ammonia. So the compounds of nitrogen the compounds of nitrogen. The first compound is ammonia and history right down. It is the most important hydrides of nitrogen and it can be prepared by the following method. Most important hydrides of nitrogen and can be prepared by following method. The first method we have when ammonium salt ammonium salt is heated with caustic soda heated with caustic soda or slagged like slagged like all these are reactions. Okay, so you see the reaction is ammonium salt means what we have NH4Cl is the ammonium salt heated with caustic soda caustic soda we can take or slagged like anyone we can take any OH CO OH whole twice it gives NH3 plus NaCl plus H2 this is the product we get. Similarly, when this is heated with CaOH whole twice again we'll get CaCl2 NH3 forms and we'll get H2O okay. This reaction like ammonia can also be prepared by urea with the help of urea. The second one you write down urea also forms ammonia when treated with caustic soda. So urea is NH2 CO NH2 when treated with caustic soda that is NaOH it forms NH3 two molecules of it plus Na2 CO3 sodium carbon right. So with the help of urea with the help of ammonium salt. Okay, two methods we have done the third one is the very common. That is Haber's process Haber's process industrial method of preparation is this the first method we use for the preparation or production in small scale. This is for the small scale production the first one not important. Small scale production okay Haber's process is used for industry. This is the industrial method actually and in this process the nitrogen is obtained by the reaction of N2 with H2 it is a reversible reaction in presence of iron as a catalyst. Okay around 500 degrees Celsius forms two molecules of NH3. This reaction is an exothermic reaction delta H is less than zero for this reaction. Okay, property right down it is a colorless gas lighter than air colorless gas lighter than air and pungent smell. It is highly soluble in water and why so hydrogen bonding highly soluble in water since it can form hydrogen bonding. Okay, the boiling point and melting point of ammonia right on the next line the boiling point and melting point of ammonia is more than is more than to the other hydrides. Belongs to the same group other hydride belong to the same group the reason is again same hydrogen bonding. It also behaves as a Lewis acid right don't represent so behaves as a Lewis acid. So we all know all these things there is nothing new into this but there are some reactions which are important and which probably we haven't done yet. So reactions of NH3 and this reaction is based question they ask index like for example suppose if I'm taking excess of NH3 and it reacts with chlorine Cl2. Here this ammonia is excess reacts with Cl2 then it forms nitrogen with NH4 Cl this is one reaction. But in the same reaction if you take chlorine as excess and it's 3 plus Cl2 this question they have asked many times in the exam. If there's this chlorine is excess then it forms nitrogen trichloride and Cl3 plus HCl. You must remember that the difference between the two reactions. The reaction of aqueous ammonia we also see suppose we have a pretty chloride FeCl3 plus NH4 OH aqueous ammonia. This gives FeOH whole price plus salt of ammonia that is NH4 Cl. Okay this is the reaction we have similarly if you have AlCl3 similar kind of reaction we have metal chloride with aqueous ammonia. Aqueous ammonia is NH4 OH only and this 3 plus water gives NH4 OH this gives AlOH whole price plus NH4 Cl. The next slide down it forms a white precipitate. It forms a white precipitate with mercury chloride aqueous ammonia forms a white precipitate with mercury chloride and a gray precipitate with mercury chloride. White with mercury, gray with mercury. Reaction you see HgCl2 mercury chloride plus aqueous ammonia NH4 OH this gives Hg plus Hg NH2 Cl. Wait just a second this Hg won't be there. You will get Hg NH2 Cl plus NH4 Cl right NH4 Cl plus H2 2 molecules of H2. This is amido-mercury chloride this compound is amido-mercury chloride the color is white precipitate. But when you take mercury chloride that is Hg2Cl2 plus NH4 OH this gives you a mixture of mercury and amido-mercury chloride NH2 Cl plus NH4 Cl plus 2H2O. So this mixture it gives gray precipitate okay we can also prepare urea from ammonia okay. So right down one point here ammonia reacts with carbon dioxide ammonia reacts with carbon dioxide and forms ammonium carbamate. And forms ammonium carbamate which decomposes to give urea which decomposes to give urea. The two molecules of NH3 reacts with CO2 it gives this first ammonium carbamate COO NH4 and this H2O molecules comes out and it converts into NH2 CO and H2O that is urea. This compound is ammonium carbamate ammonium carbamate okay. So ammonia we have discussed reaction also we have seen then we see the next thing here that is oxides of nitrogen oxides of nitrogen nitrogen like we know. It forms a number of oxides okay the first one we are going to discuss here is dinitrogen oxides dinitrogen oxides. We also call it as nitrous oxide the structure is N2O and this we also call it as laughing gas. What is the oxidation number of nitrogen here oxidation number of nitrogen. Plus one okay minus two plus one plus two okay it is prepared by it is prepared by hitting ammonium nitrate hitting ammonium nitrate okay. So NH4 NO3 if you heat this you'll get N2O plus two molecules of H2O okay nitrous oxide okay. Now this NH4 NO3 we can prepare by the reaction of sodium nitrate that is NaNO3 and it's react it reacts with ammonium sulfate which is NH4 2 SO4. The product we get here two molecules because of NH4 NO3 plus we'll get Na2 SO4 Na2 SO4. Now when you heat this also so you'll end up getting nitrous oxide some properties of N2O you write down next. The first one it is a colorless and testless gas colorless and testless. The second one it is soluble in cold water it is important this one is important okay put a stomach over there soluble in cold water cold water. But insoluble in hot water insoluble in hot water third one it gets contaminated with it gets not the third one in the same line you write down next. It gets contaminated with nitric oxide that is NO in bracket you write down ammonia and water vapor at high temperature. It gets contaminated with nitric oxide ammonia and water vapor so we'll have a layer of nitric oxide that's why it does not react okay. The next line in this you write down to remove nitric oxide we use ferrous sulfate solution to use nitric oxide we use ferrous sulfate solution and to remove ammonia and water vapor. We use concentrated as to a support they have asked this question both information is important to remove ammonia and water vapor. We use concentrated as to a support okay. Now the last thing in this what is the structure of N2O what is the structure of N2O N2O structure you can do is draw the structure okay and it is when you draw the structure you'll get N double bond N double bond O. Where here we have the positive charge on nitrogen and here we have the negative charge with two lone pair of this nitrogen and oxygen has two lone pair on it. And it's a resonating structure if you draw this comes over here so it N triple bond and single bond O oxygen we have three lone pair negative charge and this will have the positive charge so this is the resonating. Okay it's just also sometimes they ask an example.