The conjugate base of H2SO4 (sulfuric acid) is HSO4– (hydrogen sulfate ion).
When sulfuric acid (H2SO4) donates a proton (H+), it forms the hydrogen sulfate ion (HSO4–). This process can be represented by the following chemical equation:
H2SO4 → H+ + HSO4–
In this reaction, H2SO4 acts as an acid by donating a proton, and HSO4– is its conjugate base. The conjugate base is the species that remains after the acid has donated a proton.