Value of standard electrode potential for the oxidation of `Cl^(-)` ions is more positive than that of water, even then in the electrolysis of aqueous sodium chloride, why is `Cl^(-)` oxidsied at anode instead of water?

Explanation

Under the condition of electrolysis of aqueous sodium chloride, oxidation of water at anode requires over potential So, `Cl^(-)` is oxidized at anode instead of water Possible oxidation half cell reactions occuring at anode are
`Cl^(-)(aq)rarr(1)/(2)Cl_(2)(g)+e^(-),E_("cell")^(@)=1.36V`
`2H_(2)O(l)rarrO_(2)(g)+4H^(+)(aq)+4e^(-) E_("cell")^(@)=1.23V`
Species hav ing lower `E_("cell")^(@)` cell undergo oxidation first than the higher value but oxidation of `H_(@)O` to `O_(2)` is kinetically so slow that it needs some ov ervoltage.