Determine the equilibrium constant at 255 K for the following reaction under acidic conditions.
4H+ (aq) + MnO₂ (s) + 2Fe²+ (aq) ———› Mn²+ (aq) + 2Fe³+ (aq) + 2H₂O(1)
The two half-reactions are:
MnO₂ (s) + 4H+ (aq) + 2e¯¯ ———› Mn²+ (aq) + 2H₂O(1) E* = 1.23 V
Fe³+ (aq) + e, Fe²+ (aq) E³ = .0.770 V