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 act as a strong  oxidizing
(i)What will be the pH range of the solution formed by ‘B’ and why?.
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Answer 1

A is nitrogen; because nitrogen is the largest constituent of air. B is ammonia, C is nitrogen dioxide and D is nitric acid (nitric acid is a strong oxidising agent).

When nitrogen is heated with hydrogen in the presence of a catalyst, following reaction takes place:

$\star \: \sf{N_2+3H_2 \rightarrow 2NH_3}$

When nitrogen is heated with oxygen, we get nitrogen dioxide

$\star \: \sf N_2 + 20_2 \rightarrow 2NO_2$

When nitrogen dioxide is treated with water, we get nitric acid

$\star \: \sf NO_2+H_2 O \rightarrow HNO_3$

This non-metal belongs to Group 15.