oxoacid containing a chlorine series

The relative acid strength increases in the following order: hypochlorous acid < chlorous acid < chloric acid < perchloric acid. The oxidation state of the chlorine increases with an increase in the number of oxygen atoms in the acid. As the number of oxygen in the acid increases the strength of the acid increases since the more electronegative oxygen atoms removes electron density from the chlorine atom as shown by the blue arrows. The delta positive charge on the chlorine atom increases with an increase in the number of oxygen atoms in the acid. This attracts more electron density away from the OH bond, weakening the O-H bond and increasing the bond polarity. The increase in bond polarity leads to the proton to be transfered easier which is an increase in the acid strength. The stabiltiy of the oxoanions also affects the strenght of the acid. The more oxygens the oxoanions have, the more stable the oxoanion since the negative charge can be delocalised over a larger number of oxygens.