Which of the following compounds is correctly named as a phenol derivative?

• A. $C_3{H}_7\mathrm{OH}$ is named phenol.
• B. $C_2{H}_5\mathrm{OH}$ is named phenol.
• C. $C_6{H}_5\mathrm{OH}$ is named phenol.
• D. $C_6{H}_{6}O$ is named ethanol.

Answer: (C)

Verified step by step guidance

1. Understand that phenol is a specific compound where a hydroxyl group (-OH) is directly attached to an aromatic benzene ring, not to an aliphatic carbon chain.
2. Identify the molecular formulas given and relate them to their structures: for example, C6H5OH corresponds to a benzene ring (C6H5) with an -OH group attached, which defines phenol.
3. Recognize that C3H7OH and C2H5OH represent alcohols with hydroxyl groups attached to saturated carbon chains (propyl alcohol and ethyl alcohol, respectively), so they are not phenol derivatives.
4. Note that C6H6O is not a standard formula for ethanol; ethanol is C2H5OH, so this formula likely corresponds to a different compound and is not phenol.
5. Conclude that the compound with formula C6H5OH is correctly named phenol because it matches the definition of a phenol derivative: an -OH group bonded directly to an aromatic ring.