Answer: NaI in dry acetone.
- A AgF in MeOH
- B NaI in dry acetone
- C KBr in water
- D HI gas
Correct answer: B. NaI in dry acetone
Explanation: Finkelstein reaction: RCl + NaI → RI + NaCl. The reaction is driven forward because NaCl is insoluble in dry acetone and precipitates out.
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.