Q$10.$ A solution has the following composition, expressed as mole fraction: ethane, $0\mathrm{.}0025$; propane, $0\mathrm{.}25$ ; isobutane, $0\mathrm{.}185$ ; n$-$butane, $0\mathrm{.}560$ ; isopentane, $0\mathrm{.}0025.$ In the following, the pressure is $10$ bars. Use the equilibrium distribution coefficients from the DePriester nomograph $($Chem$.$ Eng. Prog. Symp$.$ Ser., Vol. $49,$ issue $7,$ pp$.1(1953)$ and Chemical Engineers' Handbook, $5^{th}$ ed$.,$ Fig. $13-6$b or any other higher Eds.$),($i$)$ calculate the bubble and dew points. If the solution is flash vaporized to vaporize $40$ mol$\%$ of the feed, $($ii$)$ calculate the composition of the products. If the solution is differentially distilled to produce a residue containing $0\mathrm{.}80$ mole fraction $n-$butane, $($iii$)$ calculate the complete composition of the residue and the $\%$ of the feed which is vaporized.