Question

(a) Write the equation for:
(i) the preparation of hydrogen chloride from sodium chloride and sulphuric acid. State whether the sulphuric acid should be concentrated or dilute.
(ii) the preparation of ammonia from ammonium chloride and calcium hydroxide.
(iii) the reaction of hydrogen chloride with ammonia.

Answer 1

(i) Sodium chloride reacts with concentrated sulphuric acid to form sodium hydrogen sulphate and hydrochloric acid. The equation is as follows:

$\mathrm{NaCl}+{\mathrm{H}}_2{\mathrm{SO}}_4\to {\mathrm{NaHSO}}_4+\mathrm{HCl}$

(ii) Ammonium chloride reacts with calcium hydroxide to form ammonia and calcium chloride. The equation is as follows:

$2{\mathrm{NH}}_4\mathrm{Cl}+\mathrm{Ca}{\left(\mathrm{OH}\right)}_2\stackrel{∆}{\to }{\mathrm{CaCl}}_2+2{\mathrm{H}}_2\mathrm{O}+2{\mathrm{NH}}_3$

(iii) Ammonia reacts with hydrogen chloride to form ammonium chloride. The equation is as follows:

${\mathrm{NH}}_3+\mathrm{HCl}\to {\mathrm{NH}}_4\mathrm{Cl}$