How many moles of FeC2O4 are required to reduce one mole of KMnO4 in acidic medium?

1. 3/5

2. 1/5

3. 5/3

4. 5

Concept Videos :-

#5 | Stoichiometry
#6 | Questions on POAC
#13 | Calculation of % composition & % Purity

Concept Questions :-

Equation Based Problem

(3) 

3KMnO4+5FeC2O4+24H+5Fe3++10CO2+3Mn2++3K++12H2O\

  1. Ferrous is oxidized to ferric state
  2. Carbon and hydrogen are converted to CO2 and H2O
  3. All the metallic ions are converted to sulphates
  4. Write the equation keeping in mind that the valency of of iron in ferric state is 3, that of K and Mn is one and two respectively as
  5. FeC2O4 + KMnO4 + H2SO4 = K2SO4 + MnSO4 + Fe(SO4)3 + H2O + CO2
  6. FeC2O4 is oxidized and KMnO4 is reduced. Hence the main reaction is
  7. Fe2+ → Fe3+ (removal of 1 electron)

Mn7+ → Mn 2+ (addition of 5 electrons)

In order to balance multiply (Fe2+ → Fe3+) by 5

Now you know that there should be 5 FeC2O4 molecules. Write that and balance the rest.

Difficulty Level:

  • 21%
  • 23%
  • 45%
  • 13%