The correct statements about the oxoacids, HClO _ 4 andHClO are,

(i)  ${HClO}_{4} ⇌ {H}^{+} + {ClO}_{4}^{-}$

${ClO}_{4}^{-}$  is resonance stabilized anion.

$HClO ⇌ {H}^{+} + {ClO}^{-}$

$∴ {HClO}_{4}$ is more acidic then $HClO .$

(ii)   ${Cl}_{2} + {H}_{2}O \to HClO + HCl$

(iii)  ${HClO}_{4}$ The central atom is ${sp}^{3}$ hybridised.

 The central atom is ${sp}^{3}$ hybridised.

(iv)  ${HClO}_{4} + {H}_{2}O \to {H}_{3}{O}^{⊕} + {ClO}_{4}^{-}$ since ${H}_{2}O$ is accepting ${H}^{+}$ from ${HClO}_{4}$ so ${H}_{2}O$  is stronger base compare to ${ClO}_{4}^{-}$.