[(5Fe2+) + (MnO4-) + (8H+)]
--
[(5Fe3+) + (Mn2+) + (4H2O)]

(titrating with KMnO4)

How do I reduce the speed of Fe2+ oxidation? e.v is +1.52

I have found out that since e.v. is +1.52, i can add something with less than 1.52 e.v so that the mno4 would be 'wasted' on it, such as zinc with an e.v of 0.77.

I do not know what is the most feasible thing to do. Perhaps I can add sodium which is more reactive?

Which would oxidise faster? Sodium or Zinc (in terms of activation energy)

Question

[(5Fe2+) + (MnO4-) + (8H+)] 
--> 
[(5Fe3+) + (Mn2+) + (4H2O)] 

(titrating with KMnO4)

 How do I reduce the speed of Fe2+ oxidation? e.v is +1.52

I have found out that since e.v. is +1.52, i can add something with less than 1.52 e.v so that the mno4 would be 'wasted' on it, such as zinc with an e.v of 0.77. 

I do not know what is the most feasible thing to do. Perhaps I can add sodium which is more reactive? 

Which would oxidise faster? Sodium or Zinc (in terms of activation energy)