Explanation:
The acids in question are oxoacids of chlorine:
- HClO — Hypochlorous acid
- HClO₂ — Chlorous acid
- HClO₃ — Chloric acid
- HClO₄ — Perchloric acid
Trend:
Acidity of oxyacids increases with:
- Increase in the oxidation state of the central atom (Cl)
- Increase in number of oxygen atoms, due to increased electron-withdrawing effect (stabilizes the conjugate base)
Oxidation states:
- Cl in HClO = +1
- Cl in HClO₂ = +3
- Cl in HClO₃ = +5
- Cl in HClO₄ = +7
So, acid strength increases in the order:
\(\boxed{HClO < HClO_2 < HClO_3 < HClO_4}\)
Correct Answer:
\(\text{Option 1: } HClO < HClO_2 < HClO_3 < HClO_4\)