Question

Give reasons: 

E° value for the Mn³⁺/Mn²⁺ couple is much more positive than that for Fe³⁺/Fe²⁺.

Assign reason for each of the following:

E° for the Mn³⁺/Mn²⁺ couple is much more positive than for Fe³⁺/Fe²⁺.

Answer 1

1. The standard electrode potential (E°) for Mn³⁺/Mn²⁺ is more positive than for Fe³⁺/Fe²⁺.
2. Mn³⁺ is less stable and easily reduces to Mn²⁺, making its E° more positive.
3. Fe³⁺ is relatively more stable and does not reduce as easily to Fe²⁺.
4. The higher positive E° value for Mn³⁺/Mn²⁺ means Mn³⁺ is a stronger oxidizing agent than Fe³⁺.
5. This difference arises because Mn³⁺ has a greater tendency to gain electrons and revert to the more stable Mn²⁺ state, while Fe³⁺ has comparatively less tendency to get reduced.