Question

Which is stronger $\mathrm{HClO}\mathrm{or}{\mathrm{HClO}}_2$?

Answer 1

Hypochlorous acid ($\mathrm{HClO}$):

1. It occurred when Chlorine dissolves in water and is partially dissociated form Hypochlorite (${\mathrm{ClO}}^{-}$).
2. It is an effective antibacterial and related compounds such as Sodium hypochlorite ($\mathrm{NaClO}$) and Calcium hypochlorite ($\mathrm{Ca}{\left(\mathrm{ClO}\right)}_2$) can be found in many commercial bleaches, deodorants, and disinfectants.

Chlorous acid (${\mathrm{HClO}}_2$):

1. In its pure state, the compound is unstable, disproportionating to Hypochlorous acid ($\mathrm{Cl}$ oxidation state $+1$) and Chloric acid ($\mathrm{Cl}$ oxidation state $+5$).
2. It is a powerful oxidizing agent, though it had the tendency to be disproportionate, which counterparts its oxidizing potential.

Strongest compound: Chlorous acid is stronger than the Hypochlorous acid. The reasons are explained below:

1. The oxidation state of the central Chlorine atom is more in the case of Chlorous acid ($+3$) as compared to the Hypochlorous acid ($+1$) which means the higher oxidation state has a more acidic nature.
2. According to the Lowry-Bronsted theory, ${\mathrm{ClO}}^{-}$ has minimum stability that attracts more Hydrogen ions which becomes the strongest base, and conjugate acid $\mathrm{HClO}$ is the weakest acid.
3. The oxidation number of the central atom increases with the number of Oxygen atoms that indicating that the stability of ${\mathrm{HClO}}_2$ is more than the $\mathrm{HClO}$ due to a more resonance structure.
4. Chlorous acid has a high acid strength because of the more positive charge on the chlorine atom, causing more electronegative molecules to drag electrons away from a Hydrogen atom. It means the electron density increases as the number of Oxygen atoms increases.