Question

Name a gas which is always produced when a reactive metal reacts with a dilute acid. Write a chemical equation supporting your answer.

Answer 1

Hydrogen gas (${\mathrm{H}}_2$) is produced as a byproduct when dilute acids(${\mathrm{H}}_2{\mathrm{SO}}_4$,$\mathrm{HCl}$) reacts with reactive metals such as Alkaline metal or Alkaline earth metal ($\mathrm{Mg},\mathrm{Al},\mathrm{Zn}...$)

For example:

Reaction of Sodium ($Na$) with Hydrochloric acid ($\mathrm{HCl}$), Hydrogen gas (${\mathrm{H}}_2$) is produced as a byproduct. Chemical reaction is as follows.

$\underset{\mathrm{Sodium}}{2\mathrm{Na}\left(\mathrm{s}\right)}+\underset{\underset{\mathrm{acid}}{\mathrm{Hydrochloric}}}{2\mathrm{HCl}\left(\mathrm{aq}\right)}\to \underset{\underset{\mathrm{chloride}}{\mathrm{Sodium}}}{2\mathrm{NaCl}\left(\mathrm{s}\right)}+\underset{\mathrm{Hydrogen}}{{\mathrm{H}}_2\left(\mathrm{g}\right)}$

When Aluminium ($\mathrm{Al}$) reacts with dilute Sulphuric acid (${\mathrm{H}}_2{\mathrm{SO}}_4$), Hydrogen gas (${\mathrm{H}}_2$) is produced as a byproduct. Chemical reaction is as follows.

$\underset{\mathrm{Aluminium}}{\mathrm{Al}\left(\mathrm{s}\right)}+\underset{\underset{\mathrm{acid}}{\mathrm{Sulphuric}}}{2{\mathrm{H}}_2{\mathrm{SO}}_4\left(\mathrm{aq}\right)}\to \underset{\underset{\mathrm{sulphate}}{\mathrm{Aluminium}}}{{\mathrm{Al}}_2{\left({\mathrm{SO}}_4\right)}_3(\mathrm{s}})+\underset{\mathrm{Hydrogen}}{3{\mathrm{H}}_2(\mathrm{g}})$