Describe the preparation,properties,and uses of $HCl$.

(N/A) Preparation: In the laboratory,$HCl$ is prepared by heating sodium chloride with concentrated $H_{2}SO_{4}$.
$NaCl + H_{2}SO_{4} \xrightarrow{420 \ K} NaHSO_{4} + HCl$
$NaHSO_{4} + NaCl \xrightarrow{823 \ K} Na_{2}SO_{4} + HCl$
$HCl$ gas can be purified by passing it through concentrated $H_{2}SO_{4}$.
Properties:
Physical Properties: It is a colorless gas with a pungent smell.
It liquefies easily to a colorless liquid (boiling point $189 \ K$) and freezes to a white crystalline solid (freezing point $159 \ K$).
It is highly soluble in water and ionizes as follows:
$HCl(g) + H_{2}O(l) \rightarrow H_{3}O^{+}(aq) + Cl^{-}(aq), \ K_{a} = 10^{7}$
Its high value of dissociation constant $(K_{a})$ indicates that it is a strong acid in water.
Chemical Properties: $HCl$ reacts with $NH_{3}$ to give white fumes of $NH_{4}Cl$.
$NH_{3} + HCl \rightarrow NH_{4}Cl$
When three parts of concentrated $HCl$ and one part of concentrated $HNO_{3}$ are mixed,aqua regia is formed,which is used to dissolve noble metals like gold and platinum.
$Au + 4H^{+} + NO_{3}^{-} + 4Cl^{-} \rightarrow AuCl_{4}^{-} + NO + 2H_{2}O$
$3Pt + 16H^{+} + 4NO_{3}^{-} + 18Cl^{-} \rightarrow 3PtCl_{6}^{2-} + 4NO + 8H_{2}O$
Hydrochloric acid decomposes salts of weaker acids,e.g.,carbonates,hydrogen carbonates,and sulphites.
$Na_{2}CO_{3} + 2HCl \rightarrow 2NaCl + H_{2}O + CO_{2}$
$NaHCO_{3} + HCl \rightarrow NaCl + H_{2}O + CO_{2}$
$Na_{2}SO_{3} + 2HCl \rightarrow 2NaCl + H_{2}O + SO_{2}$
Uses:
$(i)$ In the production of chlorine,$NH_{4}Cl$,and glucose (from corn starch).
(ii) For extracting glue from bones and for purifying bone black.
(iii) In medicines and as a laboratory reagent.