Given below are two statements :
Statement (I) : Alcohols are formed when alkyl chlorides are treated with aqueous potassium hydroxide by elimination reaction.
Statement (II): In alcoholic potassium hydroxide, alkyl chlorides form alkenes by abstracting the hydrogen from the -carbon.
In the light of the above statements, choose the most appropriate answer from the options given below :
Statement (I) : Alcohols are formed when alkyl chlorides are treated with aqueous potassium hydroxide by elimination reaction.
Statement (II): In alcoholic potassium hydroxide, alkyl chlorides form alkenes by abstracting the hydrogen from the -carbon.
In the light of the above statements, choose the most appropriate answer from the options given below :
- (A)Both Statement I and Statement II are incorrect
- (B)Statement I is incorrect but Statement II is correct✓ Correct
- (C)Statement I is correct but Statement II is incorrect
- (D)Both Statement I and Statement II are correct
Answer: (B)
Solution
Aqueous potassium hydroxide supplies a high concentration of hydroxide ions that act as a nucleophile, so alkyl chlorides are converted to alcohols by nucleophilic substitution, not by elimination; the statement that credits alcohol formation to elimination is therefore wrong. In alcoholic potassium hydroxide the ethoxide-rich medium favours the base acting as a proton abstractor: a hydrogen is removed from the -carbon while the chloride departs, and the alkyl chloride is converted to an alkene by elimination. The statement about alcohol formation by elimination is thus incorrect while the statement about alkene formation by -hydrogen abstraction in alcoholic KOH is correct.
JEE Main · 2025 · 04 Apr 2025 · Shift 2 · Single correct option