Question

Among the following, the correct order of acidity is

• A. $HCl{O}_2<HClO<HCl{O}_3<HCl{O}_4$
• B. $HCl{O}_4<HCl{O}_2<HClO<HCl{O}_3$
• C. $HCl{O}_3<HCl{O}_4<HCl{O}_2<HClO$
• D. $HClO<HCl{O}_2<HCl{O}_3<HCl{O}_4$

Answer 1

The correct option is D

$HClO<HCl{O}_2<HCl{O}_3<HCl{O}_4$

The acidic character of the oxoacids increases with increase in oxidation number of the halogen atom i.e., $HClO<HCl{O}_2<HCl{O}_3<HCl{O}_4$. The can be explained on the basis of relative stability of the anions left after removal of a proton. Stability of the anions left after removal of a proton. Since the stability of the anion decreases in the order : $Cl{O}^{4-}>Cl{O}^{3-}>Cl{O}^{2-}>Cl{O}^{-}$, acid strength also decrease in the same order.