Question: 1 litre of co2 is passed through red hot coke?
Answer: x/22.4 moles of CO2 will produce 2x/22.4 moles of CO. Thus, the final volume of gases will include the leftover CO2 and newly formed CO. Thus, 0.8 l of CO are formed. And 0.6 l (= 1- x = 1- 0.4) of CO2 are left over.