Question
Chemistry Question on Electrochemistry
If E°Fe2+/Fe = -0.441 V and E°Fe3+/Fe2+ = 0.771 V, the standard emf of the reaction: Fe + 2Fe3+ → 3Fe2+ will be:
A
0.441 V
B
1.753 V
C
1.212 V
D
0.211 V
Answer
1.212 V
Explanation
Solution
(i) Fe²⁺ → Fe (Reduction) with E° = -0.441 V = +0.441 V (Given standard electrode potentials (E°) :- E°Fe/Fe²⁺ = -E°Fe²⁺/Fe° = +0.441 V)
(ii) 2Fe³⁺ → 2Fe²⁺ (Reduction) with E° = 0.771 V
Overall Reaction:
Fe + 2Fe³⁺ → 3Fe²⁺
Cell Potential (E°cell):
E°cell = +0.441 V + 0.771 V = 1.212 V
So, the correct option is (C): 1.212 V