Question

__________________can be used with dilute nitric acid to produce hydrogen gas.

Answer 1

• Nitric Acid is a very strong oxidizing agent.
• It oxidizes the Dihydrogen Gas produced during the reaction with metals to Water. That is why Nitric Acid cannot be used for the preparation of hydrogen gas.
• However, metals like Magnesium still produce hydrogen gas but with very dilute nitric acid. Only 1% dilute and cold nitric acid reacts with magnesium to liberate hydrogen gas.
• $\mathrm{Mg}+\underset{\mathrm{Nitric}\mathrm{acid}}{2{\mathrm{HNO}}_3}\to \underset{\mathrm{Magnesium}\mathrm{nitrate}}{\mathrm{Mn}{\left({\mathrm{NO}}_3\right)}_2}+{\mathrm{H}}_2\uparrow$

Therefore, nitric acid can be used with dilute nitric acid to produce hydrogen gas.