Question
Question: When nitrogen can be formed directly by decomposition of ammonium nitrate, why do we start with ammo...
When nitrogen can be formed directly by decomposition of ammonium nitrate, why do we start with ammonia chloride in the laboratory?
Solution
We must have to remember that nitrogen is a chemical element and nitrogen compounds are nitric acid, ammonia, etc. are used as important compounds in industries. It is a nonmetallic element because of its high electronegativity and usual gaseous form and also nitrogen has a lack of solid form. At STP (standard temperature and pressure) two nitrogen atoms combine to form dinitrogen (N2) , an odorless gas.
Complete step by step answer:
We must have to know that in the laboratory method of preparation nitrogen is prepared by the reaction of ammonium chloride (NH4Cl) with sodium nitrate (NaO2). This is heated and small amounts of water is added to this reaction. The product is ammonium nitrate (NH4NO3) and sodium chloride (NaCl). This reaction is a double decomposition.
We can write the chemical equation for this chemical equation as,
NH4Cl+NaNO2→NH4NO3+NaCl
The ammonium nitrate (NH4NO3) formed here decompose to form nitrogen and water vapor, see the below equation,
NH4NO3→N2+2H2O
Ammonium chloride is sublimed when heated so we add small quantities of water that prevent subliming.
If we start with ammonium nitrate (NH4NO3) initially, ammonium nitrate is heated, this reaction is very fast and this leads to explosive.
That’s why we start with ammonium chloride (NH4Cl) in the laboratory to prepare nitrogen.
Note: We must remember that the ammonium nitrate is not an explosive on its own but it is oxidized when oxygen is at surround and this creates a violent explosion and generates heat, nitrogen oxides also. When Ammonium nitrate is stable at STP. It is an important fertilizer. Ammonium nitrate is not a health hazardous substance.