Which of the following is propiophenone?
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → \( \ce{C6H5COCH2CH3} \)
Alkyl phenyl ketones are named by putting the name of the acyl group in front of the word phenone.
In propiophenone the acyl group is propionyl, \( \ce{CH3CH2CO-} \), joined directly to the benzene ring, so the compound is \( \ce{C6H5COCH2CH3} \). Its IUPAC name is 1-phenylpropan-1-one.
In the same way, acetophenone is \( \ce{C6H5COCH3} \) (acetyl + phenone).
NCERT (2026-27 edition):
8.1.1 Nomenclature – “The common names of ketones are derived by naming two alkyl or aryl groups bonded to the carbonyl group. … Alkyl phenyl ketones are usually named by adding the name of acyl group as prefix to the word phenone. For example”
