Question

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

(a) Identify A, B, C and D 

(b) To which group of periodic table does this non-metal belong?

Answer 1

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 dioxide 
• 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 dioxide is passed into water in the presence of air it gives an Nitric acid 

NO₂ + H₂O → HNO₃ 

b) Nitrogen belong to group 15