Answer: Acetic acid.
- A Methane
- B Acetic acid
- C Ethene
- D Propanol
Correct answer: B. Acetic acid
Explanation: Strong oxidation of ethanol by acidified KMnO<sub>4</sub> produces acetic acid.
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.