Fe2O3(s) + 3CO(g) -----> 3CO2(g) + 2Fe(s)
mass of iron = 198.5 g of iron
atomic mass of iron = 55.845g/mol
moles of iron = mass/Atomic mass
= 198.5g/55.845
= 3.5545 moles Fe
moles of carbon monoxide
= 3.5545 moles Fe x 3 moles CO
2 moles Fe
= 5.3317 moles CO
molar mass of CO = 12.01 + 16 = 28.01g/mol
mass of carbon monoxide reacted
= moles x molar mass
= 5.3317 x 28.01
= 149.34g
grams of carbon monoxide needed to react with an excess of iron(II)oxide to produce 198.5g of iron is 149.34g CO