The suffix -one indicates which functional group?

The suffix -one indicates which functional group?

• A. Alcohol
• B. Aldehyde
• C. Ketone
• D. Carboxylic acid

Answer: (C)

In naming organic compounds, the ending tells you what functional group is present. The suffix -one indicates a ketone, meaning the molecule has a carbonyl group (C=O) that is bonded to two carbon atoms. This is distinct from other common endings: -ol for alcohols, -al for aldehydes (where the carbonyl is at the end of the chain and attached to at least one hydrogen), and -oic acid for carboxylic acids (which feature a carboxyl group -COOH). A ketone’s carbonyl is typically internal rather than terminal, which is why the ending used is -one, as in propanone (acetone).

In naming organic compounds, the ending tells you what functional group is present. The suffix -one indicates a ketone, meaning the molecule has a carbonyl group (C=O) that is bonded to two carbon atoms. This is distinct from other common endings: -ol for alcohols, -al for aldehydes (where the carbonyl is at the end of the chain and attached to at least one hydrogen), and -oic acid for carboxylic acids (which feature a carboxyl group -COOH). A ketone’s carbonyl is typically internal rather than terminal, which is why the ending used is -one, as in propanone (acetone).