Answer: 95%.
- A 100%
- B 84%
- C 42%
- D 95%
Correct answer: D. 95%
Explanation: Rectified spirit is the constant-boiling (azeotropic) mixture of about 95% ethanol and 5% 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.