Please be very explicit in your development. Thank you!

1.9 Atomic and molecular weights of some common substances are listed in Appendix Tables A-1 and A-1E. Using data from the appropriate table, determine (a) the mass, in kg, of 20kmol of each of the following: air, C, H2O,CO2. (b) the number of lbmol in 50lb of each of the following: H2,N2,NH3,C3H8