In the following reaction, HCO3- (aq) + H2O(l) -> CO3^2- (aq) + H3O+ (aq)
HCO3- is an acid and H2O is its conjugate base.
H3O+ is an acid and CO3^2- is its conjugate base.
H2O is an acid and CO3^2- is its conjugate base.
HCO3- is an acid and CO3^2- is its conjugate base.
H3O+ is an acid and HCO3- is its conjugate base.