CHE 425 (Fall 2010) __________________ LAST NAME, FIRST Optional set 1 (Show all your work)Note: Your answers must be correct to 3 significant figures and have the appropriate units.I. A mixture contains 55 mole % isobutane and 45 mole % isopentane is at 30 psia. The K valuesfor these compounds can be obtained from ln K = A/T2 + B + C ln P where T is in oR and P is in psiaCompound A B CIsobutane -1,166,846 7.72668 -.92213Isopentane -1,481,583 7.58071 -.931591) The vapor mole fraction of isobutane at the bubble point of 527.6oR is ___________ 2) The liquid mole fraction of isobutane at the dew point of 549.7oR is ___________ 3) The mixture is flash at 536.0 oR, 30 psia where V/F = 0.4, then the mole fraction of isobutane (iC4) in the liquid phase is __________ II. A liquid containing 50 mol % benzene and 50 mol % toluene is subjected to a flashvaporization process at a pressure of 760 mmHg where the temperature inside the flash drum is95oC. At 95oC, Pbenzeneo= 1176.8 mmHg, Ptolueneo= 476.87 mmHg (4) The mole fraction of benzene in the exit liquid is ____________III. A homogeneous reaction A  P takes place inside a porous cylindrical catalyst with radiusR. The two ends of the catalyst particle are impermeable to A so diffusion is only in the rdirection. The length of the catalyst particle is L = 1 cm. The effective diffusivity, De, of A withinthe catalyst is 1.210-7 m2/s. The concentration of A within the catalyst is given byCA = CAo[0. 20+sinh(rR)] , where CAo = 0.10 kmol/m3 and R = 1.00 mm(5) The molar flux of A at r = R/2 is __________ (6) The consumption rate of A within the catalyst is __________IV. An ethanol-water separation is achieved in a distillation column at 1 atm. Feed flow rate is5,000 lb/hr. The distillate contains 90 wt% ethanol, and the bottoms contain 5 wt% ethanol.Assume theoretical trays, a total condenser, a partial reboiler, and saturated reflux.7) The minimum number of equilibrium stages (including the reboiler is) ________ 8) If the reflux ratio R is 1.8, the enthalpy H’ of the upper operating point D’ in Btu/lb is _____ 9) If the feed contains 30 wt% ethanol and H’ = 1,200 Btu/lb, the condenser duty is___________ 10) If the feed is saturated liquid with 30 wt% ethanol and the enthalpy of W’ =  100 Btu/lb,then the enthalpy of the upper operating point D’ in Btu/lb is__________11) If the feed is saturated vapor at 190oF, then the minimum reflux ratio is__________12) If the feed is saturated liquid, the enthalpy H’ of the upper operating point D’ is 1100 Btu/lb,and the enthalpy of W’ is  100 Btu/lb then temperature of the feed in oF is__________V. A saturated vapor mixture of benzene and toluene containing 40 mole percent benzene is to beseparated into an overhead product containing 98 mole percent benzene and a bottom productcontaining 2 mole percent benzene. Benzene and toluene mixture may be considered as ideal.Use optimum feed plate.ln Psat = A  B/(T + C) P where T is in K and Psat is in kPaCompound A B Cbenzene 14.1603 2948.78  44.5633toluene 14.2515 3242.38  47.180613) If the feed is at 420 K, the feed pressure is __________ 14) Consider an equilibrium tray at 415 K and the liquid mole fraction of benzene leaving thetray is 0.3, the vapor mole fraction of benzene leaving the tray is____________ 15) If the reflux ratio is 3.0 and the liquid mole fraction of benzene leaving an equilibrium tray is0.3, the vapor mole fraction of benzene entering the tray is____________ 16) If the reflux ratio is 3.0 and the vapor mole fraction of benzene entering an equilibrium trayis 0.35, the liquid mole fraction of benzene leaving the tray isVI. A feed with q = 0.4, consisting of 100 mol/s phenol and cresols, is separated in a platecolumn with a total condenser and a partial reboiler. Assume CMO with a reflux ratio of 3. Thefollowing compositions and relative volatilities are givenCompound Feed, mol% Distillate, mol% Bottoms, mol% Relative volatility1) Phenol2) o-cresol3) m-cresol40253594.24.51.35.2 1.301.000.7017) The mole fraction of o-cresol leaving the column in the bottoms is ____________ 18) The mole fraction of phenol in the liquid stream leaving the top (first) tray is ____________ 19) The mole fraction of o-cresol in the liquid stream leaving the top tray is ____________20) The liquid flow rate in the stripping section of the column is ____________ 21) The vapor flow rate in the stripping section of the column is ____________ The mole fraction of phenol and o-cresol in the liquid stream leaving the second tray are 0.8945and 0.0680, respectively.22) The mole fraction of phenol in the vapor stream entering the second tray is ____________ 23) The mole fraction of o-cresol in the vapor stream entering the second tray is ____________ VII. 10,000 lb/hr of saturated liquid at 1 atmosphere is fed into an adiabatic flash drum operatingat 0.1 atmosphere. The feed stream is a binary mixture of 29 wt% ethanol and 71 wt% water. 24) The temperature in the flash drum is ____________ 25) The mole fraction of ethanol in the vapor phase is ____________VIII. (26) The degree of freedom for an equilibrium stage with feed and heat transfer for 10 components is____________IX. 1000 kg/hr of a saturated liquid with 30 wt% ethanol in water is fed into a distillationcolumn. We desire a distillate composition xD = 0.90 mass fraction ethanol and a bottomscomposition xB = 0.02 mass fraction ethanol. Reflux is return as a saturated liquid with a refluxration of 1.5. The column is adiabatic with a partial reboiler and a total condenser. The enthalpiesof ethanol-water system are given belowh(kJ/kg) = 114x2  279x + 393 = enthalpy of saturated liquid mixtureH(kJ/kg) =  1614y + 2676 = enthalpy of saturated vapor mixturex, y = mass fraction of ethanol in the liquid and vapor mixture, respectively27) The condenser duty in kJ/hr, QC, is ____________ 28) If QC = 2.0×105 kJ/hr, determine the reboiler duty, QR, in kJhhr ____________X. Consider an air cooler where the flow rate of water is large compared to the air, and theeffectiveness, , of the cooler is known to depend on the flow rate of air according to the relation,  ~ ( )0.3airm-&. The air inlet