Which functional group characterises the alcohol family of compounds?

Correct Option

The correct option is -OH.

Explanation

Functional groups are specific substituents or moieties within molecules that are responsible for the characteristic chemical reactions of those molecules. Organic compounds are categorized into different families based on the specific functional group attached to the carbon chain.

Option Analysis

• -OH is Correct: The -OH group is known as the hydroxyl group. It is the defining functional group for the alcohol family of compounds (e.g., Methanol, Ethanol).
• -CHO is Incorrect: The -CHO group characterizes the aldehyde family (e.g., Methanal, Ethanal).
• -COOH is Incorrect: The -COOH group characterizes the carboxylic acid family (e.g., Ethanoic acid).
• -NO2 is Incorrect: The -NO₂ group characterizes nitro compounds (e.g., Nitrobenzene).

Key Takeaway: The presence of a hydroxyl group (-OH) attached to a saturated carbon atom is the primary characteristic of alcohols.