(i) Ethyl benzene when treated with ${\mathrm{KMnO}}_4$ and $\mathrm{KOH}$, undergoes oxidation to produce potassium benzoate. The potassium benzoate when treated with an acid forms benzoic acid.

(ii) Cyclohexanol is oxidized by $\mathrm{mathrm}{\mathit{C}\mathit{r}\mathit{O}}_3$ to cyclohexanone. Cyclohexanone when treated with semicarbazide produces cyclohexanone semicarbazone.