To determine the correct order of acidity among the given oxyacids of chlorine, we need to understand the relationship between the number of oxygen atoms and acidity.$\\$The acidity of oxyacids generally increases with the increase in the number of oxygen atoms attached to the central atom. This is because more oxygen atoms lead to greater stabilization of the conjugate base through resonance and inductive effects.$\\$Let's analyze the given oxyacids:$\\$• $$HClO (hypochlorous acid)$\\$• $$HClO$_2$ (chlorous acid)$\\$• $$HClO$_3$ (chloric acid)$\\$• $$HClO$_4$ (perchloric acid)$\\$The order of acidity is determined by the number of oxygen atoms:$\\$• HClO has 1 oxygen atom.$\\$• HClO$_2$ has 2 oxygen atoms.$\\$• HClO$_3$ has 3 oxygen atoms.$\\$• HClO$_4$ has 4 oxygen atoms.$\\$Therefore, the correct order of acidity, from least acidic to most acidic, is:$\\$HClO < HClO$_2 <$HClO$_3 <$HClO$_4 \\$This corresponds to Option 2.