What volume of air at 1 atm and 273 K containing 21% of oxygen by volume is required to completely burn sulphur (S8) present in 200 g of sample, which  contains 20% inert material which does not burn. Sulphur burns according to the reaction18S8(s) + O2(g) → SO2(g)

In 200 g sample,20% inert material and 80% is S8∴Mass of S8 in sample = 200×80100=1600gMoles of S8 = 16032×8=0.62518S8+O2→ SO2Number of moles of O2 required according to reaction=0.625 × 8 = 5 molesVolume of O2 required = 22.4 ×5∴Vol. of air required = 22.4 × 5 ×10021=533.33L