3. (15 points) Forty-five lbm of a gas mixture consisting of 20.0%CO2,55%N2, and 25.0% H2 (mass composition) are placed in a cylinder with a volume of 300ft3. a) What is the average molecular mass of the gas? (Ans: Mave=6.7) b) If the gas flows in a pipe at the same temperature and pressure as that of the cylinder at the rate of 350ft3/min, what is its molar flowrate, in kmols/min? (Hint: The density of the gas depends only T and P.) (Ans: n=3.5 kmols/min)