Q35 / 150 · MHT CET 2026 (20 April Shift 2) · Chemistry
In Finkelstein reaction, which one of the following reagents is used?
- AHI in dry acetone
- Correct answerBNaI in dry acetone
- CNaOI in dry acetone
- DNaI in dry ether
Solution
The Finkelstein reaction is a halogen exchange reaction used for the synthesis of alkyl iodides from alkyl chlorides or alkyl bromides.
The reaction involves treating an alkyl chloride or bromide with sodium iodide (NaI) in dry acetone.
$R-X + NaI \xrightarrow{\text{dry acetone}} R-I + NaX \downarrow$
where $X = Cl, Br$.
Sodium iodide is soluble in dry acetone, whereas sodium chloride and sodium bromide are insoluble and precipitate out. This precipitation drives the forward reaction according to Le Chatelier's principle.
Answer: NaI in dry acetone
The reaction involves treating an alkyl chloride or bromide with sodium iodide (NaI) in dry acetone.
$R-X + NaI \xrightarrow{\text{dry acetone}} R-I + NaX \downarrow$
where $X = Cl, Br$.
Sodium iodide is soluble in dry acetone, whereas sodium chloride and sodium bromide are insoluble and precipitate out. This precipitation drives the forward reaction according to Le Chatelier's principle.
Answer: NaI in dry acetone
Hence, the correct answer is option: 'B'.