11. Use the following acid-base reaction of identify the acid, base,conjugate acid and conjugate base. *

\mathrm{HC}_{2} \mathrm{H}_{3} \mathrm{O}_{2(\text { aq) }}+\mathrm{H}_{2} \mathrm{O}_{(1)} \rightarrow \mathrm{C}_{2} \mathrm{H}_{3} \mathrm{O}_{2}^{-} \text {(aq) }+\mathrm{H}_{3} \mathrm{O}_{\text {(aq) }}^{-}