Answer: Phenol.
- A Ethanol
- B Methanol
- C Phenol
- D Ether
Correct answer: C. Phenol
Explanation: Phenol forms 2,4,6-tribromophenol as a white precipitate with bromine water.
The phenoxide ion's negative charge spreads into the aromatic ring through resonance, lowering its energy and making phenol give up its proton more easily; an alkoxide ion (from a plain alcohol) has nowhere to delocalise the charge, making alcohols far less acidic.
Concept context
Oxygen-containing organic compounds. Understand the acidic nature of phenols, reactions of alcohols (dehydration, oxidation, esterification), and properties of ethers. Includes industrial applications and named reactions.