The first and second members, respectively, of the ketone homologous series are:

Correct option is B

The correct answer is (B) propanone, butanone.

Explanation:

The ketone homologous series consists of compounds with the general formula CₙH₂ₙO, where the carbonyl group (C=O) is attached to two alkyl groups.

1. Propanone (Acetone):
• The first member of the ketone series.
• Chemical formula: CH₃COCH₃.
• Simplest ketone, with two methyl groups attached to the carbonyl group.
2. Butanone:
• The second member of the series.
• Chemical formula: CH₃COC₂H₅.
• Contains one ethyl group and one methyl group attached to the carbonyl group.