Question

Write the balanced chemical equation for the laboratory preparation of hydrogen chloride gas.

Answer 1

Chemical reaction for laboratory preparation of HCl

• For the production of Hydrogen chloride gas, the two main reactants are used, these reactants are sodium chloride and Sulphuric Acid.
• This process is known as Leblanc process.
• The reaction that takes place, at a temperature less than $200°\mathrm{C}$ :

$\underset{\mathrm{Sodium}\mathrm{chloride}}{\mathrm{NaCl}\left(\mathrm{s}\right)}+\underset{\mathrm{Sulphuric}\mathrm{Acid}}{{\mathrm{H}}_2{\mathrm{SO}}_4\left(\mathrm{aq}\right)}\stackrel{<200°\mathrm{C}}{\to }\underset{\mathrm{Sodium}\mathrm{Bisulphate}}{{\mathrm{NaHSO}}_4\left(\mathrm{s}\right)}+\underset{\mathrm{Hydrogen}\mathrm{chloride}\mathrm{gas}}{\mathrm{HCl}\left(\mathrm{g}\right)}$

• The reaction that takes place at a temperature above $200°\mathrm{C}$ :

$\underset{\mathrm{Sodium}\mathrm{chloride}}{\mathrm{NaCl}\left(\mathrm{s}\right)}+\underset{\mathrm{Sulphuric}\mathrm{acid}}{{\mathrm{H}}_2{\mathrm{SO}}_4\left(\mathrm{aq}\right)}\stackrel{>200°\mathrm{C}}{\to }\underset{\mathrm{Sodium}\mathrm{sulphate}}{{\mathrm{Na}}_2{\mathrm{SO}}_4\left(\mathrm{s}\right)}+\underset{\mathrm{Hydrogen}\mathrm{chloride}\mathrm{gas}}{\mathrm{HCl}\left(\mathrm{g}\right)}$