1011. Solving a chemistry problem

6. A sample weighing 0.1210 g of a sulfur-containing organic compound was burned in a stream of O2, and the released SO2 was absorbed by a solution of H2O2 (H2O2+SO2 → H2SO4). To titrate the resulting acid, 20.5 ml of 0.1070 N was used. KOH solution. Calculate the mass fraction of S in the compound (in %).