Compound P is neutral, Q gives effervescence with NaHCO 3 while R reacts with Hinsberg’s reagent to…

$\mathrm{Q}$ is giving effervescence with sodium bicarbonate, it means $\mathrm{Q}$ contain carboxylic acid functional group. The compound $\mathrm{R}$ is reacting with Hinsberg's reagent and giving solid which soluble in sodium hydroxide means $\mathrm{R}$ contain primary amine functional group. Hence, The compound $\mathrm{P}$can be a secondary amide. The overall reaction is shown below.