# For a given acid, what is its "conjugate base"?

The conjugate base of an acid is simply the parent acid MINUS a proton, ${H}^{+}$.
So the conjugate base of chloric acid is $C l {O}_{3}^{-}$. I have simply subtracted ${H}^{+}$ from $H C l {O}_{3}$ and CONSERVED mass and charge.
You might try this rigmarole with the other questions you have asked. Conjugate acid: add ${H}^{+}$. Conjugate base: remove ${H}^{+}$