An ore containing 24% solid inert and 76 mol% iron pyrites (FeS2) is roasted in the presence of dry air at 500 °C and 1 atm. Considering the given reactions that take place as:
2 FeS2(s) + 15/2 O2 (g) → Fe2O3(s) + 4SO3 (g) (1) ,2 FeS2(s) + 11/2 O2 (g) → Fe2O3(s) + 4SO2 (g) (2)

Dry air is fed to the furnace in twenty five percent excess of the amount theoretically needed to oxidize all the sulfur(S) in the ore to Sulfur trioxide. An Iron disulfide oxidation of eighty percent is obtained, with forty percent of the FeS2 converted forming Sulfur dioxide and the rest forming sulphur trioxide. A a solid stream and a gas streamleave the roaster. Compute the molar composition and volumetric flow rate of the gas leaving the roasting oven per kilo mol of ore roasted?