100 kmol/h of a feed (z) composed of 25 mol% n-butane, 40 mol% n-pentane, and 35 mol% n-hexane is flashed. If 80% (by moles) of the n-hexane is in the liquid at 400 K, what is the pressure (P) and the liquid (xi) and vapor (yi) compositions? Obtain K-values from the above table. (Hint: Calculate bubble point and dew point pressures first to get an estimate for an initial input value for equilibrium pressure in the flash calculations.)

In(K)=a/T2+az+azln(P)+a4/P2+as/P Tin K, P in kPa methane ethylene ethane propylene propane isobutane n-butane isopentane n-pentane n-hexane n-heptane ai -90,389 -185,209 -212,114 -285,026 -299,595 -360,138 -395,234 -457,279 -470,645 -549,044 -621,544 a2 a3 a4 9.9730 -0.8951 2,846.4 9.5411 -0.8468 2,042.6 9.6178 -0.886 2,331.8 9.4141 -0.8787 2,267.6 8.6372 -0.7698 0 9.5073 -0.9221 0 9.8124 -0.9646 0 9.3796 -0.9316 0 9.0527 -0.8914 0 8.6021 -0.8463 0 8.0651 -0.7954 0 as 0 0 0 0 47.602 0 0 0 0 0 0