An equimolar mixture of ethane, propane, n-butane, and n-pentane undergoes a flash vaporization process at 150F and 205 psia. Determine: (a) The vaporization fraction in the process. b) The amounts of the liquid and vapor products per mole of feed. c) The compositions of the expected products. d) Is it possible to recover 70% of the ethane in the vapor phase in this single flash stage at other conditions, without losing more than 5% of nC4 in that phase?