Question

Order the following considering their boiling point in an aqueous solution.

1) pentan-2-one
2) pentan-2-ol
3) 2-aminopropanoic acid

The answer key says the order (increasing) is,
1 < 2 < 3 and states 1 only have weak permanent dipole dipole forces and Van der Walls forces.

But isn't there any chance that the Carbonyl group of an aqueous solution of a ketone(or even an aldehyde) can make H bonds with the H^+ ions in water?

So can we simply order them considering the reason the answer key states?

I think 3 should have the highest boiling point as it can make more than 1 H bond and what about the other two?

Answer 1

*the Oxygen atom in the Carbonyl group

Answer 2

You are right about 3. It does have the highest boiling poin; the key agrees with you. But the ketone has no to little chance of H bonding with another ketone molecule while the alcohol does which is why it is ketone<alcohol<aminoacid

Answer 3

But isn't there any chance that the Oxygen atom in the ketone molecule can make H bonds with the H^+ ions in water,not with another ketone molecule?