Question
3.2 g of pyrolusite (MnO2) was treated with 50 mL of 0.5 M oxalic acid and some sulphuric acid. The oxalic acid left undecomposed was raised to 250 mL in a flask. 25 mL of this solution when treated with 0.02 M KMnO4 required 32 mL of the solution. Find the percentage of MnO2 in the sample.
Given: Atomic mass of Mn is 55 g mol−1