Which conjugate pair is suited best to make this buffer? Which conjugate pair is suited best to make this buffer? Phosphoric acid H3PO4 and dihydrogen phosphate ion H2PO4− Formic acid HCOOH and formate ion HCOO− Carbonic acid H2CO3 and bicarbonate ion HCO3− Phenol C6H5OH and phenolate ion C6H5O− Monohydrogen phosphate ion HPO42− and phosphate ion PO43− Acetic acid CH3COOH and acetate ion CH3COO− Dihydrogen phosphate ion H2PO4− and monohydrogen phosphate ion HPO42− Ammonium ion +NH4 and ammonia NH3 Lactic acid CH3CH(OH)COOH and lactate ion CH3CH(OH)COO− Bicarbonate ion HCO3− and carbonate ion CO32−