moles of SO2 produced = mass of SO2 / molar mass of SO2 = 899 g / 64.066 g/mol = 14.03 mol

Using balanced equation

moles of O2 = (11 mol of O2 / 8 mol of SO2) x 14.03 mol of SO2 = 19.3 moles

mass of O2 = moles of O2 x molar mass of O2 = 19.3 moles x 15.999 g/mol = 308.8 g or 0.309 kg

moles of Fe2O3 = (2 mol of Fe2O3 / 8 mol of SO2) x 14.03 mol of SO2 = 3.508 moles

mass of Fe2O3 = moles of Fe2O3 x molar mass of Fe2O3 = 3.508 moles x 159.69 g/mol = 560.2 g or 0.560 kg