# What is the formula of the conjugate acid of HSO_4^-?

${H}_{2} S {O}_{4}$.
The conjugate acid of a species is simply the original species PLUS a proton, ${H}^{+}$. As with all such exercises, both mass and charge are CONSERVED. What do I mean here?
Can you tell the conjugate acid of sulfate ion, $S {O}_{4}^{2 -}$, and the conjugate acid of ${H}_{2} S {O}_{4}$?