AIIMS 2018 Chemistry Acidity of Phenols MCQ Question
Assertion : Ortho nitro phenol is more acidic than meta nitro phenol
Reason : Ortho nitro phenol has more –I effect than meta nitro phenol
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
Correct Answer
Detailed Explanation
The statement is false because, while the nitro group (–NO₂) does exhibit a –M (mesomeric) effect at the ortho position, it primarily exerts a –I (inductive) effect, which stabilizes the negative charge on the phenoxide ion formed upon deprotonation of ortho-nitrophenol. However, the ortho derivative is not more acidic than the para derivative due to steric hindrance and intramolecular interactions that can destabilize the anion. Other options are incorrect as they either misinterpret the effects of the nitro group or do not provide a definitive answer.
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