# What is the conjugate base of HBr?

The conjugate base of any acid is the acid less ${H}^{+}$, hence bromide, $B {r}^{-}$ ion is the conjugate base of $H B r$.
So what is the conjugate base of ${H}_{2} O$, of ${H}_{2} S {O}_{4}$, of $H S {O}_{4}^{-}$, and of hydroxide anion, $O {H}^{-}$? Remember to conserve both mass and charge.