Question

How does nitric acid react with metals?

Answer 1

• Metals react with nitric acid (${\mathrm{HNO}}_3$) to produce hydrogen gas (${\mathrm{H}}_2$).
• Nitric acid is an extremely powerful oxidizer. As a result, it oxidizes the hydrogen gas produced during the process to produce water (${\mathrm{H}}_2\mathrm{O}$) and nitrogen oxide ($\mathrm{NO},{\mathrm{N}}_2\mathrm{O},{\mathrm{NO}}_2\mathrm{etc}.$)
  For example: $\mathrm{Cu}+4{\mathrm{HNO}}_3\to \mathrm{Cu}{\left({\mathrm{NO}}_3\right)}_2+2{\mathrm{H}}_2\mathrm{O}+2{\mathrm{NO}}_2\uparrow$
• Magnesium ($\mathrm{Mg}$) and manganese ($\mathrm{Mn}$) produce hydrogen gas when they react with very dilute nitric acid.
  For example: $\mathrm{Mg}+2{\mathrm{HNO}}_2\to \mathrm{Mg}{\left({\mathrm{NO}}_3\right)}_2+{\mathrm{H}}_2\uparrow$