WHAT IS THE BASICITY OF CARBONIC ACID?
H2CO3- 2 , It all depends on how much hydrogen atoms the acid has.
Dissociation equation of carbonic acid : H2CO3 --> 2H+ (aq) + CO3- 2 (aq)
Here, two replaceable hydrogen ions, so it is dibasic
Remember basicity is the number of replaceable hydrogen ions in the acid molecule.