What's the order of oxidising strength of the oxyacids of Chlorine? What I have been told is that the acidity of the four oxyacids of Chlorine increase in the order $\ce{HOCl} &lt; \ce{HClO2} &lt; \ce{HClO3} &lt; \ce{HClO4}$.

I have also been told that the oxidising strength goes in the reverse order. In my knowledge acidic strength should increase with oxidising strength. Where am I going wrong?

For your reference, the Ka values of the acids are as follows:


$\ce{HOCl} = 2.9 \times 10^{-8}$
$\ce{HClO2} = 1.1 \times 10^{-2}$
$\ce{HClO3} = 5.0 \times 10^2$
$\ce{HClO4} = 1 \times 10^3$
For many acids, the proton $\ce{H+}$ is the oxidizing agent. For example, in the oxidation of zinc with $\ce{HCl}$, the oxidizing agent is $\ce{H+}$.

$$\ce{Zn + 2H+ -&gt; Zn^{2+} + H2}$$

However, for some acids, the conjugate base (anion) is also an oxidant (and usually a more powerful oxidant than $\ce{H+}$. The oxyacids of chlorine are all oxidizing agents through their anions, as is nitric acid and some others:

$$\ce{Zn + 2H+ + 2OCl- -&gt; Zn^{2+} + H2O + 2Cl-}$$

In the above example, hypochlorite is the oxidizing agent. For the oxyacids of chlorine and others, the strength of the oxidizing agent is independent of the strength of the acid.