Amphiprotic species.

An amphiprotic substance is one that can either donate a proton (act as an acid) or accept a proton (act as a base)
Below are some examples of amphiprotic substances.
HCO3- can act as an acid (donating a proton), as shown on the right.
Or HCO3- can act as a base (accepting a proton)
HSO4- can act as an acid (donating a proton), as shown on the right
Or HSO4- can act as a base (accepting a proton)
H2O can act as an acid (donating a proton)
Or H2O can act as a base (accepting a proton)

Write the reactions of HCO3- with OH- and HCO3- with H3O+

Solution

Write the reactions of HSO4- with OH- and HSO4- with H3O+

Solution

Write the reactions of H2PO4- with OH- and H2PO4- with H3O+

Solution