predictions.

ExperimentalmeasurementsofVaughanandCollins$[$Ind$.$Eng.

Chem.,$34,885(1942)]$forthepropane$$isopentanesystem$,$at$167$F

and$147$psia,showapropaneliquid$-$phasemolefractionof$0\mathrm{.}2900$in

equilibriumwithavapor$-$phasemolefractionof$0\mathrm{.}6650.$Calculate:

$($a$)$TheK$-$valuesforC$3$andiC$5$fromtheexperimentaldata.

$($b$)$TheK$-$valuesofC$3$andiC$5$fromRaoult$$slaw$,$assumingvapor

pressuresat$167$Fof$409\mathrm{.}6$and$58\mathrm{.}6$psia,respectively.

Comparetheresultsof $($a$)$and$($b$).$Assumingtheexperimental

valuesarecorrect,howcouldbetterestimatesof theK$-$valuesbe achieved?Torespondtothisquestion,comparetherigorousKi$$

giLfiL$=$fiV totheRaoult$$slawexpressionKi$$Ps

i$=$P$.$