question_answer

What is the standard reduction potential \[(E{}^\circ )\] for \[F{{e}^{3+}}\to Fe\]? Given that:         [JEE Online 08-04-2017] \[F{{e}^{2+}}+2{{e}^{-}}\to Fe;{{E}^{o}}_{F{{e}^{2+}}/Fe}=-0.47V\] \[F{{e}^{3+}}+{{e}^{-}}\to F{{e}^{2+}};{{E}^{o}}_{F{{e}^{3+}}/F{{e}^{2+}}}=+0.77V\]

A)  -0.057 V                              

B)  + 0.30 V

C)  - 0.30 V                               

D)  + 0.057 V