Question

Balance the following equations by oxidation number method
i) K₂Cr₂O7 + KI + H₂SO₄ → K₂SO₄ + Cr₂(SO₄)₃ +I₂+H₂O
ii) KMnO₄ + Na₂SO₃ → MnO₂ + Na₂SO₄ + KOH
iii) Cu+ HNO₃ → Cu(NO₃)₂ + NO₂+ H₂O
iv) KMnO₄ + H₂C₂O₄ + H₂SO₄ → K₂SO₄ + MnSO₄ + CO₂ + H₂O

Answer 1

Oxidation Number Method:

1) We will find the Oxidation Number of each element undergoing change in Oxidation state .
Then, we will find the magnitude of Change in the respective elements per required no. of reactant.

2) Then, we will criss-cross themagnitude of change in ON to alternate elements.

3) After that, we will easily balance the other ekements /Molecules by Atomic Conservation.


For Calculation see pic.