Question

Among the following, the CORRECT increasing order of acidity:

विकल्प

• HCIO < HCIO₃ < HCIO₂ < HClO₄

• HClO₄ < HClO₃ < HCIO₂ < HCIO

• HClO₃ < HClO₄ < HCIO₂ < HCIO

• HCIO < HCIO₂ < HClO₃ < HClO₄

Answer 1

HCIO < HCIO₂ < HClO₃ < HClO₄

Explanation:

With increasing halogen oxidation state, the acid strength of halogen oxoacids increases.

Also, the increasing order of charge delocalization in the anions of oxoacids of chlorine is, \[\ce{ClO^- < ClO^-_2 < ClO^-_3 < ClO^-_4}\].

The stability of the ion improves as charge delocalisation grows, but the basicity of the anion diminishes. As a result, ClO⁻ is the strongest base, whereas \[\ce{ClO^-_4}\] is the weakest. A weak base can be converted into a powerful conjugate acid and vice versa. As a result, the weakest acid is HClO (conjugate acid of ClO⁻), whereas the strongest acid is HClO₄ (conjugate acid of \[\ce{ClO^-_4}\]).

Thus, the correct increasing order of acid strength is:

HCIO < HCIO₂ < HClO₃ < HClO₄