Why metals except Mn and Mg don't release Hydrogen gas when they react with Nitric Acid, also state the chemical equation when metals such as sodium etc, except Mn and Mg react with HNO3

Asked by Trisha Gupta | 27th Sep, 2021, 02:37: PM

Expert Answer:

Metals also react with nitric acid, but hydrogen gas is not evolved, because nitric acid is a strong oxidising agent. So, it oxidises the hydrogen to water and itself gets reduced to any nitrogen oxide.
However, magnesium and manganese react with dilute nitric acid to evolve hydrogen gas.
Very dilute about 1% acid reacts with Mg and Mn at room temperature to give nitrates and hydrogen gas.
Mg + 2HNO3 → Mg(NO3)2 + H2 ↑
        (V. dil)
Mn + 6HNO3 → Mn(NO3)+ H2 ↑

Answered by Ramandeep | 27th Sep, 2021, 03:11: PM

Queries asked on Sunday & after 7pm from Monday to Saturday will be answered after 12pm the next working day.