Chromium, cobalt, vanadium and manganese chemistry

MANGANESE

Mn can exist in a number of oxidation states, but is most stable in an oxidation state of +2, +4 or +7

In the +7 oxidation state it exists as the intense purple ion MnO₄⁻.
This can be reduced to the pale pink Mn²⁺ by Fe²⁺ in acidic solution:

MnO₄⁻ + 8H⁺ + 5e^– → Mn²⁺ + 4H₂O

Fe²⁺ → Fe³⁺ + e^–

MnO₄⁻+ 8H⁺ + 5Fe²⁺  → Mn²⁺ + 5Fe³⁺  +  4H₂O

The redox titration of C₂O₄^2- (oxalate) with MnO₄⁻ in acid solution (autocatalysed reaction)

C₂O₄^2-  → 2CO₂ + 2e⁻

5C₂O₄^2- +2MnO₄^–  + 16 H⁺ →10 CO₂ + 8 H₂O + 2 Mn²⁺

Pages: 1 2 3 4