Question

what is the conjugate base of HSO−4 ?

Answer 1

Although it has a negative charge, it will never accept a
H
+
to form
H
2
S
O
4
(sulfuric acid) . That is because sulfuric acid is a strong acid and completely disassociates in water.
Therefore, the sulfate ion (
S
O
2
−
4
) is the conjugate base of
H
S
O
−
4
.