Is a carbonyl functional group an acid, base, or neither?

Carboxyl group " "


Amine " "


Aldehyde " "


Ketone " "|||In order for something to be an acid it must be a proton (H+) donor, and to be a base, it must be a proton acceptor.





Carboxyl, Aldehyde, and Ketones are all Carbonyls, so see below.





Carboxyl groups are acids- look at carboxylic acids and amino acids. They have O=C-O-H. That last H can be dropped fairly easily.





Amines- these are basic, with the Nitrogen trying to grab loose hydrogens off of other molecules.





Aldehyde- Typically neutral, however, in the right circumstances, a H from the next carbon down can get passed up and put on the end of the carboxyl group, making it available for donation. Thus Aldehydes can act as weak acids in the right conditions.





Ketones- can be weakly acidic for the same reason as aldehydes, but are not as acidic.