This creates the hydronium ion (H3O+ = conjugate acid of water) and the dihydrogen phosphate ion (H2PO4- =conjugate base of H3PO4).Click to see full answer. Considering this, what is the conjugate base of h2po4 -? Answer and Explanation: The conjugate base of H2 PO4 – is HPO4 -2. The removal of a proton (H+1) from a conjugate acid gives us its conjugate base.Beside above, is hco3 an acid or base? HCO3- (known as bicarbonate) is the conjugate base of H2CO3, a weak acid, and the conjugate acid of the carbonate ion. HCO3- acts as a base when mixed with a compound that is more acidic than itself (larger Ka) and as an acid when mixed with a compound that is more basic than itself (smaller Ka). Also, is hpo4 a base or acid? H2PO4- and [HPO4]2- H2P04- is an acid and when it is in water it forms a hydronium ion and HPO4-, which is the conjugate base.What is the conjugate base of h3po4?In this case the conjugate base of the phosphoric acid is the dihydrogen phosphate anion, HPO-.