(CH 3 ) 2 CHCHO has a lower boiling point than CH 3 CH 2 CH 2 CH 2 COOH.

(CH3)2CHO has a lower boiling point than (CH3)2CHCH2CH2COOH because the latter contains a carboxylic acid group, which can form hydrogen bonds, significantly increasing its boiling point compared to the ketone, which cannot form hydrogen bonds as effectively.

(CH 3 ) 2 CHCHO has a lower boiling point than CH 3 CH 2 CH 2 CH 2 COOH.

(CH3)2CHO has a lower boiling point than (CH3)2CHCH2CH2COOH because the latter contains a carboxylic acid group, which can form hydrogen bonds, significantly increasing its boiling point compared to the ketone, which cannot form hydrogen bonds as effectively.