Match List I with List II
| List I | List II |
| A. Methyl n-propyl ketone | I. Prop-2-enal |
| B. Acetaldehyde | II. 4-Nitrobenzaldehyde |
| C. Acrolein | III. Pentan-2-one |
| D. p-Nitrobenzaldehyde | IV. Ethanal |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → A-III, B-IV, C-I, D-II
The common names of aldehydes come from the acid they give on oxidation; common names of ketones name the two alkyl groups on the carbonyl carbon. In IUPAC names the –e of the alkane is replaced by –al (aldehydes) or –one (ketones), counting the longest chain with the carbonyl carbon.
A. Methyl n-propyl ketone — This matches III. Pentan-2-one. \( \ce{CH3COCH2CH2CH3} \): a five-carbon chain with C=O at C-2.
B. Acetaldehyde — This matches IV. Ethanal. \( \ce{CH3CHO} \): two carbons, aldehyde group at the end.
C. Acrolein — This matches I. Prop-2-enal. \( \ce{CH2=CHCHO} \): three carbons, CHO at C-1 and a double bond from C-2.
D. p-Nitrobenzaldehyde — This matches II. 4-Nitrobenzaldehyde. The para position is C-4 counted from the carbon carrying –CHO.
Shortcut: A-III appears in Options (1) and (2); B-IV (acetaldehyde = ethanal) leaves only Option (2).