Explanation

The general formula CnH₂nO corresponds to ketones, where a carbonyl group (C=O) is bonded to two alkyl groups.

This formula is consistent with ketones but not with carboxylic acids, ethers, or carbolic acid (phenol).

Carboxylic acids: CnH₂nO₂

Ethers: CnH₂n+₂O

Alcohols: CnH₂n+₂O