Question
1.6 g of pyrolusite was treated with 60 mL of normal oxalic acid and some H2SO4. The oxalic acid left undecomposed was made up to 250 mL,25 mL of this solution required 32 mL of 0.1 N potassium permanganate (KMnO4). Calculate the percentage of pure MnO2 in pyrolusite.