Why is an external emf of more than `2.2V` required for the extraction of `CI_(2)` from brine?

Explanation

`2Cl^(-)(aq)+2H_(2)O(l) to 2OH^(-)(aq)+H_(2)(g)+Cl_(2)(g)`
For the given reaction, value of `DeltaG^(@)` is + 422kJ.
Using `DeltaG^(@)= -nFE^(@)`, the value of `E^(@)= -2.2 V`.
Therefore, an external emf greater than 2.2 V is required for the extraction of `Cl_(2)` from brine.