What a net ionic equation that occurs in a Na2HPO4/NaH2PO4 buffer solution when a small amount of HCl is added
HPO42- (aq) + H2O(l) H2PO4-(aq) + H3O+(aq)
HPO42- (aq) + H2O(l) H2PO4-(aq) + OH-(aq)
H2PO4-(aq) + OH-(aq) HPO42- (aq) + H2O(l)
HPO42- (aq) + H3O+(aq) H2PO4-(aq) + H2O(l)