Question

Which one of the following orders correctly represents the increasing acid strengths of the given acids?

(a) HOClO < HOCl < HOClO₃ < HOCIO₂

(b) HOClO₂ < HOClO₃ < HOClO < HOCl

(c) HOClO₃ < HOClO₂ < HOClO < HOCI

(d) HOCl < HOClO < HOClO₂ < HOClO₃

Answer 1

Correct option (d) HOCl < HOClO < HOClO₂ < HOClO₃

Explanation :

As the number of oxygen atom increases, an increasing amount of electron density shifts from Cl atom to more electronegative O atom. Hence as the oxidation number of Cl atom increases, the amount of actual positive charge on Cl atom increases which in turn attracts the electron density from O - H bond. hence the O -H bond is weakened and proton is easily released and acidity increases.