Brine is electrolysed using inert electrodes. The reaction at the anode is _____.


Brine is a saturated solution of Sodium chloride in water. It contains a substantial amount of chloride(Cl-) ions compared to hydroxyl (OH-) ions.


Reduction potential value of Chlorine (Cl2 + 2e 2Cl-) is 1.36V whereas that of Oxygen (O2+ 2H2O + 4e 4OH-) is 0.40V.So O2 gas should be oxidized at anode instead of Cl2.


But since the amount of Cl- ions are much more than OH- ions, so Cl- ions are preferentially oxidized at the anode to liberate Cl2 gas.

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