Conjugation between unshared electron pair on oxygen and aromatic ring in phenoxide ion results in:
Correct answer: D. All of these
- A. Shorter C - O bond distance
- B. Stable base
- C. Stronger acidic character
- D. All of these
Explanation
In phenoxide ion, the unshared electron pair on the oxygen atom participates in resonance with the aromatic ring, creating a conjugated system. This resonance imparts partial double bond character to the C-O bond, shortening its bond length. The delocalization of charge across the ion stabilizes the phenoxide ion, making it a more stable base compared to other alkoxide ions. This increased stability of the conjugate base (phenoxide ion) enhances the acidic strength of phenol. Therefore, all the given statements (shorter C-O bond distance, stable base, stronger acidic character) are correct, making 'All of these' the right choice.
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About Alcohols and Phenols
Alcohols are classified as primary, secondary or tertiary and studied through their hydrogen bonding, acidity, oxidation and reactions with active metals, acids and halogenating agents. Phenols require separate treatment because the hydroxyl group is attached to an aromatic ring, making their acidity and electrophilic substitution different from ordinary alcohols.
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