A gas mixture consisting of 50 mol% methane and 50 mol% inert gas at 10 atm (1013 kPa) enters a reactor at 422.2 K at a volumetric flow
rate of 6 dm3 s"1. 

Calculate (a) the concentration of methane at the reactor inlet in mol dm 3 and (b) concentration of methane in the reactor outlet if the conversion of methane in the constant volume rector is known to be 75%.