The standard electrode potential for the half-reactions Fe³⁺/Fe²⁺ and Sn⁴⁺/Sn²⁺ are +0.77 V and +0.15 V respectively. The EMF of the cell where these half-reactions are coupled is:

+0.92 V

+0.92 V

0%

-0.92 V

-0.92 V

0%

+0.62 V

+0.62 V

33.33%

-0.62 V

-0.62 V

66.67%