Question 60. Given below are two statements.
One is labelled as Assertion A and the other is labelled as Reason R.
Assertion A: Aryl halides cannot be prepared by replacement of hydroxyl group of phenol by halogen atom.
Reason R: Phenols react with halogen acids violently.
In the light of the above statements, choose the most appropriate option.
(1) Both A and R are true but R is NOT the correct explanation of A
(2) A is false but R is true
(3) A is true but R is false
(4) Both A and R are true and R is the correct explanation of A
Answer: (3)
Explanation:
In phenols, the -\mathrm{OH} group is directly attached to the aromatic ring.
The \mathrm{C}-\mathrm{O} bond has partial double bond character due to resonance.
Because of this, the hydroxyl group of phenol cannot be replaced by a halogen atom to form aryl halides.
Hence, Assertion A is true.
Phenols do not react violently with halogen acids to give aryl halides.
Therefore, Reason R is false.