2. (20 points) Atomic and molecular weights of some common substances are listed in Appendix Table A-1 and A-1E. Using data from the appropriate table, determine a. The mass, in kg, of 10 kmol of each of the following: air, HO, Cu, SO2. b. The number of lbmol in 20 lb of each of the following: Ar, H2, N2, C.