Question

Draw a labelled diagram and explain the laboratory preparation of hydrogen chloride gas. Give the balanced equations.

Answer 1

Reactants: Sodium chloride and concentrated sulphuric acid.

Reaction and conditions: The reaction takes place as follows:

\[\ce{\underset{Sodium chloride}{NaCl} + \underset{Sulphuric acid}{H2SO4} ->[\lt 200^\circ C] \underset{sulphate}{\underset{Sodium hydrogen}{NaHSO4}} + \underset{chloride gas}{\underset{Hydrogen}{\text{HCl}_{(g)}}}}\]

Above 200°C, sodium sulphate is formed.

\[\ce{NaCl + H2SO4 -> NaHSO4 + HCl_{(g)}}\]

\[\ce{NaCl + NaHSO4 -> \underset{Sodium sulphate}{Na2SO4} + HCl}\]