Eθ(Cl2/Cl-)= 1.36V

e(Fe3+/Fe2+)= 0.77-0.0592 * LG(0.0 1/0. 1)= 0.83v

e(Cl2/Cl-)= 1.36-0.0592 * lg2 = 1.34v

e = 1.34v-0.83v = 0.5 1V

The electromotive force of the primary battery is 0.51v.

2(Fe^2+)+Cl2=2(Fe^3+)+2(Cl^-)