Mixture of CO2 and CO is passed over red hot graphite when 1 mole of mixture changes to 33.6 L (converted to STP). Hence, mole fraction of CO2 in the mixture is

Let, CO2 = x molThen,    CO = (1 - x) molCO2+C⟶2COx mol                   2x molTotal CO after passing over hot graphite = (1 - x )  +  2 x = 1 + x 22.4 L at STP = 1 mol∴ 33.6 L at STP = 1.5 mol∴ 1 + x = 1.5⇒x = 0.5Thus, CO2 = x = 0.5 molCO = 0.5 molXCO2=0.5