8.2.
Representative surface acidic functional groups are carbonyl, carboxyl, phenolic hydroxyl, and lactone groups.
Which functional groups are the most acidic?
The carboxylate is resonance stabilised to a very significant extent, as the negative charge on oxygen is delocalised extensively between 2 electronegative oxygens. This makes the carboxylate very stable, hence carboxylic acid is the most acidic functional group.
How do you know if a functional group is acidic or basic?
There are two key features of an acidic functional group: the presence of a hydrogen atom that can dissociate from the group (H+), and the ability of the remaining atoms to delocalize the resulting negative charge via resonance.
