Explanation:
$$ HOCl(=O)_3 $$ ......perchloric acid,$$ Cl(+VII) ;pK_a \cong −15 $$ . Its salts are called perchlorates...
$$ HOCl(=O)_2 $$ ......chloric acid, $$ Cl(+V) ;pK_a \cong −1 .$$ Its salts are called chlorates...
$$ HOCl=O $$ ......chlorous acid, $$ Cl(+III) ;pK_a=+1.96 $$. Its salts are called chlorites...
$$ HOCl $$ ......hypochlorous acid,$$ Cl(+I) ;pK_a=+7.53 .$$ Its salts are called hypochlorites...
Increasing oxygen substitution on the chlorine atom INCREASES acidity. Hypochlorite salts are the active ingredients of bleach....a potent oxidant...
$$ ^−OCl+2H^++2e^−\rightarrow Cl−+H_2O $$
And of course, we also got $$ HCl $$, hydrochloric acid with $$ Cl(−I) $$; its salts are called chlorides...