Question

Which from the following is a correct decreasing order of boiling points for following organic compounds ?

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

Hint:

Boiling point order follows hydrogen bonding: acid, then alcohol, then ketone, then aldehyde.

Answer 1

The Correct Option is B

Step 1: Rank by force strength
Acid dimer H-bonding, then single H-bonding in alcohols, then dipole-dipole in carbonyls.

Step 2: Order the carbonyls
The ketone carbonyl is more polarised than the aldehyde carbonyl, so ketone is above aldehyde. This gives option (B).

Final Answer:
The order is carboxylic acid, alcohol, ketone, aldehyde, option (B). \[ \boxed{\text{Acid} > \text{Alcohol} > \text{Ketone} > \text{Aldehyde}} \]