Amphiprotic substances can act as an acid in one reaction and a base in another. The bicarbonate ion reacts with water to produce two different results. HCO3-(aq) + H2O(l) H2CO3(aq) + OH-(aq) HCO3-(aq) + H2O(l) CO3-2(aq) + H3O+(aq) Explain how these two reactions can minimize the change in pH (when a small amount of a strong acid or based is added) in a system containing the bicarbonate ion.