Question

why do nitric acid HNO3 only reacts with Mn and Mg. why it do not react with other metals to release H2 gas

Answer 1

Explanation:

Technically, metal + acid ----> metalsalt +water. But when we look atHNO3, it has a tendency to form H2O and not H2 when it reacts with metals. ... Hence, when Mg/Mn reacts withNitric acid to form a salt and H2O, but the H2O is quickly (almost instantaneously) reduced and converted to H2 gas.

Answer 2

Answer:

Hydrogen gas is not evolved when a metal reacts with nitric acid. It is because HNO3 is a strong oxidising agent. It oxidises the H2 produced to water and itself gets reduced to any of the nitrogen oxides (N2O, NO, NO2).