Question

Which is stronger $HClO$ or $HCl{{O}_{2}}.$

Answer 1

We know that the Lowry-Bronsted concept, a strong acid has a weak conjugate base, and a weak acid has a strong conjugate base. Now, let us consider the stabilities of the conjugate bases. These anions are stabilized to a greater extent.

Complete answer:
We can use the concept of stability of the conjugate base of the particular acid in order to compare their acidic strength. We can say that the more stable the conjugate base, more will be the acidic strength of the related acid. Conjugate bases can be stabilized by effects like inductive effect and hyperconjugation. It has a lesser attraction for protons and will behave as a weaker base. Consequently, the corresponding acid will be most vital because the weak conjugate base has strong acid and the strong conjugate base has weak acid and vice versa.
$\underset{Hypochlorus~~Acid}{\mathop{Cl-O-H}}\,\underset{~~~~~~~~~~~~~~~~~~~~~~~~~~~Chlorus~~Acid}{\mathop{~~~~~\And ~~~~~O=Cl-O-H}}\,$
We can see that chlorine atom in Hypochlorous acid only have any oxygen atom bonded with chlorine atom but Chlorous acid, Chloric acid and Perchloric acid have one, two and three oxygen atoms doubly bonded with chlorine atom respectively in addition to the singly bonded oxygen atom. These oxygen atoms that are doubly bonded with chlorine will withdraw the electron density from the chlorine atom because oxygen is more electronegative than chlorine. The acid is much stronger if the number of oxygen atoms is more. In $HCl{{O}_{3}}$ and $HCl{{O}_{2}},\text{ }HCl{{O}_{3}}$ has more oxygen therefore it is more acidic.

Note:
Remember that the conjugate bases that will be formed as the dissociation of hydrogen atoms will take place in aqueous medium. Now depending upon the stability of the conjugate bases, the stability of acids will be decided because as the conjugate base is more stable.