Question

Why is E for Mn³⁺/Mn²⁺ redox couple more positive?

Hint:

A higher E° value indicates a greater tendency for reduction — Mn\textsuperscript{3+} is readily reduced due to instability in aqueous medium.

Answer 1

Step 1: Mn³⁺ has a high charge density and causes strong hydration, making it less stable.
Step 2: Due to instability, Mn³⁺ has a high tendency to gain an electron (i.e., get reduced).
Step 3: Hence, the redox potential (E°) becomes more positive for the Mn³⁺/Mn²⁺ couple.