From a hydrogen peroxide (diluted in water) a sample of 1.00 g is removed, acidifing it with H2SO4 and then titrated with a solution of 0.20 M of KMnO4, requiring 17.6 mL of KMnOH. What is the percentage of H2O2 contained in the bottle?

Answer 1

5H2O2 + 2KMnO4 + 3H2SO4 = 5O2 + 2MnSO4 + K2SO4 + 8H2O
millimols KMnO4 used = mL x M = 17.6 mL x 0.2 M = ?
Convert to mmols H2O2 = ? mmols KMnO4 x (5 mols H2O2/2 mols KMnO4) = ??
Change mmols H2O2 to mols (divide by 1000)
grams H2O2 = mols H2O2 x molar mass H2O2 = ?
%H2O2 = (grams H2O2/1.00 g sample)100 = ?
NOTE: This is the %H2O2 in the diluted sample. It is not the %H2O2 in the bottle, before dilution, and without know the dilution factor one may not calculate how much is in the bottle of H2O2.