Which among the following is the conjugate base of $\mathrm{HClO}_4$ ?
Which among the following is the conjugate base of $\mathrm{HClO}_4$ ?
$\mathrm{ClO}_4^{2-}$
$\mathrm{ClO}_4$
HCl
$\mathrm{ClO}_4^{-}$
Solution
Conjugate base is formed when a BronstedLowry acid donates a proton.
$\mathrm{HClO}_4+\mathrm{H}_2 \mathrm{O} \rightleftharpoons \mathrm{H}_3 \mathrm{O}^{+}+\mathrm{ClO}_4^{-}$
$\therefore \quad$ Conjugate base of $\mathrm{HClO}_4$ is $\mathrm{ClO}_4^{-}$.