Answer: CCl4.
- A CCl4
- B CH2Cl2
- C CHI3
- D CHCl3
Correct answer: A. CCl4
Explanation: Carbon tetrachloride (CCl4), sold as pyrene, was used to smother fires as its dense vapour cuts off oxygen.
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.