JEE Main · 2026 · 02 Apr 2026 · Shift 2 · Practical and Analytical Chemistry

Reduction of the nitro group of $p$-nitrotoluene by $\mathrm{Sn}/\mathrm{HCl}$ followed by base gives $p$-toluidine, whose amino group is then acetylated by acetic anhydride. The acetamido group steers the incoming bromine to the position ortho to itself and meta to the methyl, and final hydrolysis strips the acetyl group, so the product P is 2-bromo-4-methylaniline, $\mathrm{C}{}_7\mathrm{H}{}_8\mathrm{BrN}$, of molar mass $186\mathrm{g}\mathrm{mo}{\mathrm{l}}^{-1}$ with one bromine per molecule. In the Carius estimation each mole of P yields one mole of AgBr:

The mass of silver bromide precipitated is $1$ g.