Question

why HNO3 does not give hydrogen ?​

Answer 1

Answer:

This is because Nitric acid ( HNO3 ) is a powerful oxidising agent , and the oxygen formed due to its decomposition oxidises the hydrogen to give water thus defeating the purpose of the reaction .

Answer 2

$\huge\mathfrak\red{AnsWer}$

Nitric acid(HNO3) is a strong oxidising agent.

The Hydrogen gas produced during its reaction with metal gets oxidised to H2O, hence no hydrogen gas is produced.

Instead it evolves nitric oxides such as  NO2,NO etc.

For Eg:

Cu(s) + 4HNO3(aq)--->Cu(NO3)2(aq) + 2NO2(g) + 2H2O(l)