Rank the following compounds in order of increasing acidity:

Amines are basic. Diethyl amine is a base. So, it will have lowest acidity. Alcohols and ketones are slightly acidic. So, they will be more acidic than amines.

Acetone is less acidic than ethanol. This is because, on deprotonation negative charge is obtained on electronegative atom ‘O’ in ethanol. On the other hand, in acetone, negative charge is obtained on ‘C’ atom in acetone.

2,4-pentadione is more acidic than acetone as deprotonation of reactive methylene group produces carbanion which is stabilised by resonance.

Propanoic acid is more acidic than 2,4-dipentadione as they have higher acidity than ketones.

Trichloro acetic acid is more acidic than propanoic acid. This is because, the Cl atom removes the electron density from carboxylate ion and increases stability.

The order of increasing acidity of the given compounds is,