Match the compounds in Column I with their characteristic test(s)/reactions(s) given in Column II. Indicate your answer by darkening the appropriate bubbles of the \(4 \times 4\) matrix given in the ORS.

A-r; B-p, q; C- p, q, r; D-p
Sodium fusion extract gives Prussian blue when nitrogen is present alongwith carbon. Phenolic group and carboxylate gives positive \(\mathrm{FeCl}_3\) test - white precipitate comes with \(\mathrm{AgCl}\).
Hydrazone formation occurs effectively at \(\text{pH} \approx 4.5\). The reaction proceeds in that condition only when \(\mathrm{H}^{+}\)concentration is merely sufficient to activate. As \(\mathrm{H}^{+}\)concentration raises, sufficient molecule of hydrazone gets converted into hydrazonium which is not nucleophilic and reaction becomes impossible. Further, low concentration of \(\mathrm{H}^{+}\)(in the case of hydrolysis of 2, 4-dinitrophenyl hydrazonium bromide) is not effective to proceed elimination (rate determining step).

If it is assumed that the given hydrazonian bromiate is the result as salt main \(\mathrm{HBr}\) is used as acid catalyst. Remember! hydrazone formation involves first addition and then elimination (res). In the second step substitution dominates over elimination ( \(\mathrm{HBr}\) is not a dehydrating reagent mutually).