Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A) : Treatment of bromine water with propene yields 1-bromopropan-2-ol.
Reason (R): Attack of water on bromonium ion follows Markovnikov rule and results in 1-bromopropan-2-ol.
In the light of the above statements, choose the most appropriate answer from the options given below :
Assertion (A) : Treatment of bromine water with propene yields 1-bromopropan-2-ol.
Reason (R): Attack of water on bromonium ion follows Markovnikov rule and results in 1-bromopropan-2-ol.
In the light of the above statements, choose the most appropriate answer from the options given below :
- (A)Both (A) and (R) are true but (R) is NOT the correct explanation of (A)
- (B)(A) is true but (R) is false.
- (C)Both (A) and (R) are true and (R) is the correct explanation of (A)✓ Correct
- (D)(A) is false but (R) is true.
Answer: (C)
Solution
Propene and bromine water first form a cyclic bromonium ion. Water, present in large excess, opens the ring by attacking the more substituted carbon, which carries the greater share of positive charge, placing the hydroxyl on C-2 and the bromine on C-1 to give 1-bromopropan-2-ol. This Markovnikov opening is the mechanism the reason states, so the assertion is true, the reason is true, and the reason is the correct explanation of the assertion.
JEE Main · 2021 · 31 Aug 2021 · Shift 1 · Single correct option