CBSE Class 12 · 2018 · d and f Block ElementsShort Answer

Complete and balance the following chemical equations:
(a) Fe²⁺ + MnO₄⁻ + H⁺ →
(b) MnO₄⁻ + H₂O + I⁻ →

Answer: (a) 5Fe²⁺+MnO₄⁻+8H⁺→5Fe³⁺+Mn²⁺+4H₂O. (b) 2MnO₄⁻+H₂O+I⁻→2MnO₂+2OH⁻+IO₃⁻.

Solution

(a) Acidic medium:

5F e^{2 +} + Mn O_{4}^{-} + 8 H^{+} \to 5F e^{3 +} + M n^{2 +} + 4 H_{2} O

(b) Neutral/faintly alkaline medium — iodide is oxidised to iodate:

2Mn O_{4}^{-} + H_{2} O + I^{-} \to 2Mn O_{2} + 2O H^{-} + I O_{3}^{-}

CBSE Class 12 Board · 2018 · Subjective