(i)
The reaction of an aldehyde with Tollen's reagent (ammoniacal \(AgNO_3\)) results in the reduction of the aldehyde to a carboxylate anion, and the silver ion is reduced to metallic silver. The chemical equation is:
\[
\text{CH}_3\text{CH}_2\text{CHO} + \text{Ag(NH}_3\text{)}_2^+ \rightarrow \text{CH}_3\text{CH}_2\text{COOH} + 2\text{Ag}
\]
(ii)
The reaction of an aldehyde with zinc amalgam (Zn-Hg) in the presence of hydrochloric acid (HCl) undergoes reduction to the corresponding alkane. The chemical equation is:
\[
\text{RCHO} + \text{Zn-Hg} \xrightarrow{\text{HCl}} \text{RH}
\]
(iii)
When chlorobenzene is reduced with hydrogen in the presence of palladium on barium sulfate \((Pd-BaSO_4)\), it produces benzene. The chemical equation is:
\[
\text{C}_6\text{H}_5\text{Cl} + \text{H}_2 \xrightarrow{\text{Pd-BaSO}_4} \text{C}_6\text{H}_6 + \text{HCl}
\]
(iv)
In this reaction, nitriles (RCN) undergo reduction with diisobutylaluminum hydride \((AlH(i-Bu)_2)\) to form the corresponding amine. The chemical equation is:
\[
\text{RCN} + \text{AlH(i-Bu)}_2 \rightarrow \text{RCH}_2\text{NH}_2
\]
(v)
When acyl chloride (R-CCl) reacts with anhydrous aluminum chloride \((AlCl_3)\), it undergoes a Friedel-Crafts acylation to form an aromatic ketone. The chemical equation is:
\[
\text{R-CCl} + \text{AlCl}_3 \rightarrow \text{R-C=O-Ar}
\]