Question

Identify the acid which matches the following description from (i) to (v)

1. The acid which is used in the preparation of a non-volatile acid
2. The acid which produces sugar charcoal from sugar
3. The acid which is prepared by catalytic oxidation of Ammonia
4. The acid on mixing with lead nitrate solution produces a white precipitate which is insoluble even on heating
5. The acid on mixing with Silver nitrate solution produces a white precipitate which is soluble in excess Ammonium hydroxide

Answer 1

Identification of acid

1. The acid which is used in the preparation of a non-volatile acid is Sulfuric acid$\left({\mathrm{H}}_2{\mathrm{SO}}_4\right)$ $\mathrm{NaCl}\left(\mathrm{s}\right)+{\mathrm{H}}_2{\mathrm{SO}}_4\left(\mathrm{aq}\right)\stackrel{<200°\mathrm{C}}{\to }$${\mathrm{NaHSO}}_4+\mathrm{HCl}$
2. The acid which produces sugar charcoal from sugar is Sulfuric acid$\left({\mathrm{H}}_2{\mathrm{SO}}_4\right)$ ${\mathrm{C}}_{12}{\mathrm{H}}_{22}{\mathrm{O}}_{11}\left(\mathrm{s}\right)+{\mathrm{H}}_2{\mathrm{SO}}_4\left(\mathrm{aq}\right)+1/2{\mathrm{O}}_2\left(\mathrm{g}\right)\to 11\mathrm{C}\left(\mathrm{s}\right)+{\mathrm{CO}}_2\left(\mathrm{g}\right)+12{\mathrm{H}}_2\mathrm{O}\left(\mathrm{g}\right)+{\mathrm{SO}}_2\left(\mathrm{g}\right)$
3. The acid which is prepared by catalytic oxidation of Ammonia is Nitric acid$\left({\mathrm{HNO}}_3\right)$ In Ostwalds process of preparation of Nitric acid, catalytic oxidation is by the reaction; $4{\mathrm{NH}}_3\left(\mathrm{g}\right)+5{\mathrm{O}}_2\left(\mathrm{g}\right)\underset{800-900°\mathrm{C}}{\overset{\mathrm{Pt}}{\to }}4\mathrm{NO}+6{\mathrm{H}}_2\mathrm{O}$
4. The acid on mixing with lead nitrate solution produces a white precipitate which is insoluble even on heating is Sulfuric acid$\left({\mathrm{H}}_2{\mathrm{SO}}_4\right)$ $\mathrm{Pb}{\left({\mathrm{NO}}_3\right)}_2\left(\mathrm{aq}\right)+{\mathrm{H}}_2{\mathrm{SO}}_4\left(\mathrm{aq}\right)\to {\mathrm{PbSO}}_4\left(\mathrm{s}\right)+2{\mathrm{HNO}}_3\left(\mathrm{aq}\right)$
5. The acid on mixing with Silver nitrate solution produces a white precipitate which is soluble in excess Ammonium hydroxide is Hydrochloric acid$\left(\mathrm{HCl}\right)$. $\mathrm{HCl}\left(\mathrm{aq}\right)+{\mathrm{AgNO}}_3\left(\mathrm{aq}\right)\to \mathrm{AgCl}\left(\mathrm{s}\right)+{\mathrm{HNO}}_3\left(\mathrm{aq}\right)$

hence the acids are identified.