Solution :HClO DECOMPOSES to give `Cl_(2)` and WATER. `HClO_(2)` undergoes auto-oxidation to give HClOand `HClO_(3)`. `HClO_(3)` is stable only in dark. In presence of light, it releases CHLORINE and therebyacts as OXIDIZING agent. `HClO_(4)` is very stable one, hence obtained in pure FORM.