Question

How does acidified permanganate solution react with: 

i. iron (II) ions 

ii. SO₂ 

iii. oxalic acid?

Answer 1

i. Acidified permanganate solution oxidizes iron (II) salt to iron (III) salts.

MnO₄^- + 8H⁺ + 5Fe²⁺ → Mn²+ + 4H₂O + 5Fe³⁺

ii. It oxidizes sulphur dioxide to sulphuric acid.

2MnO₄^- 5SO₂ + 2H₂O → 5SO₄^2- + 2Mn²⁺ + 4H⁺

iii. It oxidizes oxalic acid to CO₂ and H₂O.

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