16. Solution to Chemistry Problem

31. To plot a calibration graph in Aotn-CMn coordinates, 11.0 12.0 13.0 14.0 15.0 ml of a standard solution containing 1.25 mg/ml Mn were placed in 250.00 ml volumetric flasks and Mn was oxidized to MnO4-. The optical density was measured relative to a solution containing 12.5 mg Mn in 250 ml and the obtained Aotn: 0.2 0.4 0.6 0.8 1.01. A 0.5 g sample of ore was dissolved and the solution was diluted to 1000 ml. Mn was oxidized to MnO4- in 50 ml of the filtrate and the solution was diluted to 250.00 ml. The relative optical density was measured as when plotting the calibration graph. Calculate w(Mn,%) if AotnX=0.320.