HCO3- + H2O ---><--- H2CO3 + OH- 
HCO3- + H2O ----><--- CO3-2 + H3O+ 
Dihydrogen Phosphate is H2PO4-1 
H2PO4-1 + H2O ---><--- H3PO4 + OH- 
H2PO4-1 + H2O ---><--- HPO4-2 + H3O+ 
HIDROGEN PHOSPHATE IS HPO4-2 and for it you've got: 
HPO4-2 + H2O ---><--- H2PO4-1 + OH- 
HPO4-2 + H2O ---><--- PO4-3 + H3O