JEE Main · 2025 · 29 Jan 2025 · Shift 1 · Compounds Containing Nitrogen

Among the nitrogen compounds shown, benzylamine (${\mathrm{C}}_6{\mathrm{H}}_5\mathrm{C}{\mathrm{H}}_2\mathrm{N}{\mathrm{H}}_2$) is the most basic: its lone pair sits on an $s{p}^3$ nitrogen insulated from the aromatic ring by the $-{\mathrm{CH}}_2-$ spacer, so it stays fully available for protonation, unlike amines where the nitrogen lone pair conjugates into the ring or an amide carbonyl.

Molar mass of benzylamine $=7(12)+9(1)+14=107{\text{g mol}}^{-1}$.
Moles in 1.0 g $=1.0/107=9.34\times 10^{-3}\text{mol}$.

Benzylamine reacts with HCl 1:1, ${\mathrm{C}}_6{\mathrm{H}}_5\mathrm{C}{\mathrm{H}}_2\mathrm{N}{\mathrm{H}}_2+\mathrm{HCl}\to {\mathrm{C}}_6{\mathrm{H}}_5\mathrm{C}{\mathrm{H}}_2\mathrm{N}{\mathrm{H}}_3^{+}\mathrm{C}{\mathrm{l}}^{-}$, so moles of HCl consumed $=9.34\times 10^{-3}\text{mol}$.

Mass of HCl $=9.34\times 10^{-3}\times 36.5=0.341\text{g}=341\text{mg}$.