Amines practice · Mixed difficulty

Option B (Gattermann reaction) is correct because the reaction of arenediazonium chloride with Cu/HCl to form aryl chloride is known as the Gattermann reaction.

Option D (All the above) is correct because primary, secondary, and tertiary amines can all react with $NaN{O_2} + HCl$ to form alcohols or related products.

Option A (Diazotisation followed with coupling with phenol) is correct because aniline undergoes diazotization followed by coupling with phenol to form a dye, while benzylamine does not.

Option A (Liebermann’s nitroso test) is correct because it is specifically used to detect secondary amines, forming a green solution that turns blue upon addition of acid.

Option D (${\mathrm{C}_6}{\mathrm{H}_5}\mathrm{C}{\mathrm{H}_2}\mathrm{N}{\mathrm{H}_2}$) is correct because the phenyl group is separated from the amine by a methylene group, reducing the electron-withdrawing effect compared to aniline.

Option A (A, B, C) is correct because primary aliphatic amines, urea, and amides react with $HCl + NaN{O_2}$ to liberate $N_2$ gas.

Option C (Hofmann) is correct because the Hofmann degradation reaction converts amides into amines with one less carbon atom.

Option C ($Y$) is correct because it is a tertiary nitroalkane, which does not have an alpha-hydrogen and therefore cannot exhibit tautomerism.

Option A (3) is correct because carboxylic acids, phenols, and compounds with active methylene groups can be methylated by diazomethane.

Option C (Aniline) is correct because aniline, being an amine, has a lone pair of electrons on the nitrogen atom, making it a better proton acceptor compared to the other options.

Option A (Urea) is correct because potassium cyanate reacts with ammonium sulphate upon heating to produce urea.

Option D ($\mathrm{CH_3NH_2}$) is correct because methylamine is soluble in dilute HCl, reacts with NaNO2 to release nitrogen, and the resulting solution smells of wood spirit (methanol).

Option A (In acidic (strong) medium aniline is present as anilinium ion) is correct because in a strongly acidic medium, aniline is protonated to form the anilinium ion, which is meta-directing due to the positive charge on the nitrogen.

Option C (Wöhler’s synthesis of urea from NH4CNO) is correct because it disproved the vital force theory by synthesizing an organic compound (urea) from inorganic starting materials (ammonium cyanate).