In the extraction of chlorine from brine ............

a. $∆{\mathrm{G}}^{⊝}$ for the overall reaction is negative.

b. $∆{\mathrm{G}}^{⊝}$ for the overall reaction is positive.

c. ${\mathrm{E}}^{⊝}$ for the overall reaction has a negative value.

d. ${\mathrm{E}}^{⊝}$ for the overall reaction has a positive value.

Choose the correct option

1. (a, b)
2. (b, c)
3. (c, d)
4. (a, d)

Hint: For electrolytic cell, Ecello value is negative.

Electrolysis of brine solution is used to extract chlorine. Overall chemical reaction occurring in this process and the value of $∆{\mathrm{G}}^{⊝}$ can be shown as

For the given reaction, value of $∆\mathrm{G}°$ is 422 kJ
Using $∆\mathrm{G}°=-\mathrm{nFE}°$, the value of $\mathrm{E}°=\mathrm{E}°-2.2\mathrm{V}$.
Therefore, $∆\mathrm{G}°$ for the overall reaction is positive and E° has negative value.

The reaction is non-spontaneous and with the help of external process, in this case electricity is an external source which is used.

With the help of electricity non-spontaneous reaction is converted into spontaneous reaction in the electrolytic cell.