MHTCET 11 Apr 2026 Shift 1 Paper

Concept:Wurtz reaction couples alkyl halides using sodium metal in dry ether, but tertiary alkyl halides fail due to steric hindrance and elimination.Explanation:In Wurtz reaction, two alkyl halide molecules react with sodium to form a higher alkane:$$2R-X + 2Na \rightarrow R-R + 2NaX$$This reaction works best with primary alkyl halides.For example:$2\mathrm{CH}_3\mathrm{Br} + 2\mathrm{Na} \rightarrow \mathrm{CH}_3-\mathrm{CH}_3 + 2\mathrm{NaBr}$$2\mathrm{C}_2\mathrm{H}_5\mathrm{Cl} + 2\mathrm{Na} \rightarrow \mathrm{C}_2\mathrm{H}_5-\mathrm{C}_2\mathrm{H}_5 + 2\mathrm{NaCl}$Option A, $(\mathrm{CH}_3)_3\mathrm{CCl}$ is tert-butyl chloride, a tertiary alkyl halide.Due to high steric crowding, tertiary halides preferentially undergo elimination with sodium, giving an alkene instead of the coupled product.Therefore, Wurtz reaction is not possible with $(\mathrm{CH}_3)_3\mathrm{CCl}$.Answer:Option A: $(\mathrm{CH}_3)_3\mathrm{CCl}$