Answer: CnH2n+2O.
- A CnH2nO
- B CnH2n-2O
- C CnH2n+2O
- D CnH2n+1O2
Correct answer: C. CnH2n+2O
Explanation: A saturated alcohol adds one O to an alkane, so its formula is CnH2n+2O.
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.