Question

Hydrogen is not evolved when a metal react with concentrate nitric acid. Why?

Answer 1

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)

Hope this helps...

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