Zaymiey

🧪 Chemistry  ·  Haloalkanes & Haloarenes  ·  NEET & JEE

Chlorobenzene reacting with chloral (trichloroacetaldehyde) in the presence of sulfuric acid yields:

Answer: DDT (a persistent insecticide).

  • A DDT (a persistent insecticide)
  • B BHC (benzene hexachloride)
  • C Freon-12 (a refrigerant)
  • D chloroform (an anaesthetic)

Correct answer: A. DDT (a persistent insecticide)

Explanation: This condensation of two chlorobenzene molecules with chloral produces DDT, once a widely used insecticide.

SN2: one stepNu-CX-backside attackNuC+ X-Inversion of configuration(Walden inversion)SN1: two stepsCX-slow: leaving group exits+CcarbocationNu-Planar intermediate givesracemisation (both faces attacked)

SN2 proceeds in a single step with backside attack and inversion of configuration, while SN1 forms a planar carbocation intermediate first, leading to racemisation.

Concept context

Study carbon-halogen compounds: how they are made, how they react via SN1/SN2 and elimination, their stereochemistry, and their environmental impact.

Read the full Haloalkanes & Haloarenes notes →