(Q3-8) A mixture contains 55 mol% isobutane, 25 mol% isopentane, and 20 mol% n-hexane is at 30 psia. This mixture is flashed at 582.74R where 80 mol% of the feed is evaporated and at these conditions Kic4 = 3.1718, Kics = 1.051, and Knco = 0.3169. The fraction of isopentane in the feed recovered in the vapor phase is None of the given answers. 0.7878 0.8278 O 0.8078