Question

Among the following the correct order of acidity is:

Options

• HClO₂ < HClO < HClO₃ < HClO₄

• HClO₄ < HClO₂ < HClO < HClO₃

• HClO₃ < HClO₄ < HClO₂ < HClO

• HClO < HClO₂ < HClO₃ < HClO₄

Answer 1

HClO < HClO₂ < HClO₃ < HClO₄

Explanation:

This is because the acid strength increases with the increase in the oxidation state of the halogen or number of oxygen atoms. Higher oxygen atoms stabilise the conjugate base more due to resonance, thus making the acid stronger. Hence, perchloric acid (HClO₄) is the strongest acid, while hypochlorous acid (HClO) is the weakest among them.

So, the correct option is HClO < HClO₂ < HClO₃ < HClO₄.