Answer - H2PO4 conjugate base is HP(O^-2)4.
Let's now examine the bronsted-lowry concept. The bronsted-lowry notion states that two acids' propensities to give protons can be used to compare their respective strengths. Similar to this, the propensities of two bases to make protons are compared to determine their relative strengths. The conjugate base is the material that forms after an acid loses a proton (H+), and conjugate acid is the substance that forms after a base receives a proton (H+).
As a result, we learned that removing H+ from a molecule results in the formation of the conjugate base. To restore electrical neutrality after the removal of a proton, the remaining substance acquires a negative charge. HP(O^-2)4 is thus the conjugate base of H2PO4.
H2PO4 Conjugate Base
H2PO4 conjugate base is HP(O^-2)4. Both a conjugate base and a conjugate acid are created from an acid and a base, respectively.