Question #3. (Marks 30) A gas mixture is flowing at m = 100.0 kg/s contains 80 mol % methane, and 20 mol% ethane. a) Find molecular weights of each species. Reference your source (e.g. if you use your textbook, you can say FRB Table B.1) Without doing any calculation, estimate the mass fraction of ethane. Explain how you did the estimate. (5+ 5 = 10 marks) b) What is the molar flow rate of each species, n; and of the total the stream, ni [=] g-mol/s. What is the average molecular weight (MW) of the stream? (5 + 5 = 10 marks) c) What is the mass flow rate of each species mi? Confirm that the sum of the mass flow rate of each species is 100.0 kg/s. (5 + 5 = 10 Marks)