A non-metal A which is the largest constituent of air, when heated with H2 in 1:3 ratio in the presence of catalyst (Fe) gives a gas B. On heating with O2 it gives an oxide C. If this oxide is passed into water in the presence of air it gives an acid D which acts as a strong oxidising agent. (a) Identify A, B, C and D (b) To which group of periodic table does this non-metal belong?

Soln:

a)

Non-metal a is nitrogen because it is the largest constituent of air which constitute around 78% of the gases.. B is Ammonia, C is Nitrogen-di-oxide and D is Nitric acid.

When heated with H2 in 1:3 ratio in the presence of catalyst (Fe) following reaction takes place. 3N₂+3H₂ 2NH₃

On heating Nitrogen with O2 it gives nitrogen-di-oxide N₂ +3O 2NO₂

When nitrogen-di-oxide is passed into water in the presence of air it gives an Nitric acid NO₂₊ H₂O HNO₃

b)

Nitrogen belong to group 15