Question

Which of the following orders is incorrect regarding oxyacids of chlorine and the hydrogen acids?

• A. Thermal stability: $HClO<HCl{O}_2<HCl{O}_3<HCl{O}_4$
• B. Acidic strength: $HClO<HCl{O}_2<HCl{O}_3<HCl{O}_4$
• C. Oxidising power: $HClO<HCl{O}_2<HCl{O}_3<HCl{O}_4$
• D. Reducing power: $HF<HCl<HBr<HI$

Answer 1

The correct option is C Oxidising power: $HClO<HCl{O}_2<HCl{O}_3<HCl{O}_4$

The oxidation state of chlorine in $HClO,HCl{O}_2,HCl{O}_3,HCl{O}_4$ is $+1,+3,+5$ and $+7$ respectively. Since, the oxidation state of $Cl$ in $HCl{O}_4$ is the highest, it should have the highest oxidising power. But here, stability plays an important role. Lower the stability, more is the oxidising power.