Hydrogen peroxide solution (20 mL) reacts quantitatively with a solution of KMnO 4 (20 mL) acidified with dilute H 2 SO 4 . The same volume of the KMnO 4 solution is just decolourised by 10 mL of MnSO 4 in neutral medium simultaneously forming a dark brown precipitate of hydrated MnO 2 . The brown precipitate is dissolved in 10 mL of 0.2 M sodium oxalate under boiling condition in the presence of dilute H 2 SO 4 . Wr

Step-by-step solution

I 2KMn O 4 + 3 H 2 S O 4 + 5 H 2 O 2 → K 2 S O 4 + 2 Mn S O 4 + 8 H 2 O + 5 O 2 I I 2KMn O 4 + 3 Mn S O 4 + 2 H 2 O → 5 Mn O 2 + K 2 S O 4 + 2 H 2 S O 4 I I I Mn O 2 + Na 2 C 2 O 4 + 2 H 2 S O 4 → Mn S O 4 + Na 2 S O 4 + 2 CO 2 + H 2 O Reaction (III) ⇒ mM of Na 2 C 2 O 4 = 10 mL × 0.2M = 2 mM = mM of Mn O 2 Reaction (II) ⇒ mM of K MnO 4 = 2 × 2 5 = 4 5 mM Reaction (I) ⇒ mM of H 2 O 2 = 4 5 × 5 2 = 2 mM 2 mM of H 2 O 2 = 20 mL × M H 2 O 2 M H 2 O 2 = 0.1 M