fall 2003 2 - DEC 1 4 2005 Midterm Exam#2 ChBE 2100 Fall...

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Unformatted text preview: DEC 1 4 2005 Midterm Exam #2, ChBE 2100, Fall 2003, p. 1 ChBE 2100 Chemical Process Principles Fall 2003 Midterm Exam #2 October 8, 2003 Printed name: (Please write your name on the back of the last page of the exam too) Note that there are 4 problems, each worth different amounts for a total of 100 points. Note also that there are some tables at the end of the exam that you may find useful. Please read the questions carefully. This examination is closed book. However, you are allowed one 8.5" x 11" piece of paper (one side only) with any information you want on it. These notes must be your own and may not be copied from another person. You are also allowed to bring a calculator, although programmable calculators and wireless devices are prohibited. To receive full credit on each problem, you must present your solution clearly. For each problem, start with the (appropriate) full form of the balance equation(s) needed to solve the problem. Label all variables, equations and diagrams. Include a brief word description to explain each step in your problem. Numerical answers without units or explanations will not receive credit. I pledge that l have abided by the above rules and the Georgia Tech Honor Code. I have neither given nor received inappropriate aid on this exam. Signed: Problem 1 ___/25 Problem 2 __/15 Problem 3 ___/25 Problem 4 ___/35 Total __/100 MAY 19 2004 RESERVE DESK i5 ‘ . \ "ii’rii J J Midterm Exam #2, ChBE 2100, Fall 2003, p. 2 Problem 1 (25 points total) (a) (6 points) A bottle contains a liquid phase and a gas phase in equilibrium. The gas phase contains 98% species A, 1.9% species B and 0.1% species C. The liquid phase contains 0.4% species A, 33.6% species B and 66% species C. To make vapor-liquid equilibrium calculations, for each species would you use Raoult’s law or Henry’s law? (Circle the correct answers) (i) Species A: Raoult’s law Henry’s law (ii) Species B: Raoult’s law Henry‘s law (iii) Species C: Raoult’s law Henry’s law 38'“ (b) (12 points) Naphthalene is initially a liquid at 100 °C and 1 atm in equilibrium wp air. It is then heated at constant pressure through its boiling point at 217 °C until it reaches a final temperature of 230 °C. (i) At the final temperature, what phase is the naphthalene in? solid liquid gas (ii) At the initial temperature, is the gas phase saturated with naphthalene? (E yes no (iii) How would the pressure (P) need to be changed to bring the naphthalene at its l A l final temperature to reach the dew point? - decrease P not change P increase P (iv) What is the vapor pressure of naphthalene at the boiling point? atm (v) At the initial temperature, how large is the vapor pressure (P'inmao compared to l l l the boiling point vapor pressure (P bp)? P initial < P bp P initial = P bp P initial > P bp 4+7 11“} (vi) If another compound is dissolved in the liquid naphthalene, how will that affec the naphthalene boiling point? decrease it not change it increase it E (c) (4 points) A gas containing an equimolar mixture of ethanol and water (i.e., steam) is cooled until its dew point. At this temperature the vapor pressure of ethanol is greater than for water. In the liquid phase, how does the mole fraction of ethanol (Xethanol) compare to Water (xwater)? Xethanol < Xwater Xethanol = xwater Xethanol > Xwater (d) (3 points) List three ways in which the Alaska pipeline was designed to address @ environmental concerns. 1. 2. 3. Midterm Exam #2, ChBE 2100, Fall 2003, p. 3 Problem 2 (15 points) (a) Calculate the vapor pressure of benzene at 15.4 °C using only the following data. - Antoine equation constants: A = 6.89272, B = 1203.531, C = 219.888 (where P has units of mm Hg and T has units of °C). Show your work! mm Hg U59 (b) Calculate the vapor pressure of benzene at 15.4 °C using only the following data. - Vapor pressure at 7.6 °C, P' = 40 mm Hg I Normal boiling point, pr = 80.1 °C mm Hg (c) Which answer is probably more accurate? part (a) is more accurate part (b) is more accurate both are equally accurate ® Midterm Exam #2, ChBE 2100. Fall 2003. p. 4 Problem 3 (25 points) On a hot summer’s day in the swamps of the Okefenokee, the thermometer reads 40 °C. the barometric pressure is 1.01 atm and the relative humidity is 90%. At a rate of 10 m3/min, air is fed into a compressor, which condenses some water. The air leaving the condenser has been cooled to 5 °C and compressed up to a pressure of 3.29 atm. This air is then heated at constant pressure back up to 40 °C. (a) Draw and label the process diagram for this problem. (b) What is the volumetric flow rate of liquid water leaving the compressor? liters/min (c) What is the volumetric flow rate of air at the end of the process? 3 . m /mm (d) What is the relative humidity of the air at the end of the process? % (e) What is the dew point of the air at the end of the process? °C ,5 $‘\ 99% who Midterm Exam #2, ChBE 2100, Fall 2003. p. 5 Midterm Exam #2, ChBE 2100, Fall 2003, p. 6 Problem 4 (35 points) A storage vessel is filled a liquid mixture initially with the follow mass fraction composition: 43.6 mass% toluene, 44.4 mass% styrene and the balance liquid iodine (assumed to be non-volatile). Nitrogen is bubbled through this liquid at a temperature of 115 °C. The N2 flow rate is 90 moles/min. The gas leaving the bubbler is saturated with toluene and styrene vapors and contains 25 mol% N2. (a) Draw and label the process diagram for this problem. (b) What is the initial pressure of the vessel? mm Hg (0) What is the initial mole fraction of toluene in the vapor phase? (d) What is the initial mass flow rate at which toluene leaves the bubbler? kg/min Midterm Exam #2, ChBE 2100, Fall 2003, p. 7 Table 13.1 (Continued) W SG 4 Compound Formula Mol. Wt. (20°/4°) Tm (°C)” Sodium Na2S203 158.11 1.667 — thiosulfate Sulfur S8 256.53 2.07 1 13 (rhombic) Sulfur S3 256.53 1.96 119 (monoclinic) Sulfur S02 64.07 — — 75.48 dioxide Sulfur S03 80.07 -—- 16.84 trioxide Sulfuric H2804 98.08 1.8341” 10.35 acid . Toluene C7 H; 92.13 0.866 — 94.99 Water H20 18.016 1.00" 0.00 m-Xylene Cngo 106.16 0.864 —47.87 o-Xylene Cngo 106.16 0.880 —25.18 p-Xylene Cngo 106.16 0.861 13.26 Zinc Zn 65.38 7.140 ‘ 419.5 AHm(Tm )c'j Afiv(Th)eJ (mfyd kJ/mol Tb(°C)" kJ/mol TC(K)f Pc(atm)‘ kJ/mol ' _ _ _ _ — —1117.1(c) 10.04 444.6 83.7 — — 0(6)- 14.17 444.6 83.7 — — +0.30(c) 7.402 - 10.02 24.91, 430.7 77.8 —296.90(g) 25.48 43.3 41.80 491.4 83.8 —395.18(g) 9.87 Decomposes at 340°C — — —811.32(l) - 907.51 (aq) 6.619 110.62 33.47 593.9 40.3 +12.00(l) +50.00(g) 6.0095 100.00 40.656 647.4 218.3 —285.84(1) ~241.83(g) 11.569 139.10 36.40 619 34.6 -25.42(l) + 17.24(g) 13.598 144.42 36.82 631.5 35.7 -24.44(1) + 18.99( g) 17.11 138.35 36.07 618 33.9 ~24.43(l) 17.95(g) 6.674 907 114.77 — — 0(c) (433)” kJ/mol —390;9(1) - 3947.9(g) —4551.9(1) —4594.5(g) —4552.9(1) —4596.3(g) —4552.91(1) —4595.2(g) MM Hydrogen sulfide Iodine Iron Lead Lead oxide Magnesium Magnesium chloride H28 34.08 12 253.8 Fe - 55.85 Pb 207.21 PbO 223.21 Mg 24.32 MgClz 95.23 — —85.5 4.93 113.3 7.7 1535 11.3372”? 327.4 9.5 886 1.74 650 2.32525“ 714 2.38 15.1 5.10 11.7 9.2 43.1 —60.3 184.2 2800 1750 1472 1 120 1418 2w; 18.67 373.6 88.9 —19.96(g) — 826.0 —— 0(c) 354.0 — — 0(C) 179.9 — 0(0) 213 — — —219.2(c) 131.8 — —— 0(c) 136.8 — — —641.8(c) —562.59(g) Appendix B Table B.3 Vapor Pressure of Water“ Example: The vapor pressure of liquid water at 43°C is 6.230 mm Hg T(°C) 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 4.579 4.613 4.647 4.681 4.715 4.750 4.785 4.820 4.855 4.890 1 4.926 4.962 4.998 5.034 5.070 . 5.107 5.144 5.181 5.219 5.256 Liquid 5.294 5.332 5.370 5.408 5.447 5.486 5.525 5.565 5.605 5.645 water 5.685 5.725 5.766 5.807 5.848 5.889 5.931 5.973 6.015 6.058 6.101 6.144 6.187 6.230 6.274 6.318 6.363 6.408 6.453 6.498 6.543 6.589 6.635 6.681 6.728 6.775 6.822 6.869 6.917 6.965 7.013 7.062 7.111 7.160 7.209 7.259 7.309 7.360 7.411 7.462 7.513 7.565 7.617 7.669 7.722 7.775 7.828 , 7.882 7.936 7.990 8.045 8.100 8.155 8.211 8.267 8.323 8.380 8.437 8.494 8.551 8.609 8.668 8.727 8.786 8.845 8.905 8.965 9.025 9.086 9.147 10 9.209 9.271 9.333 9.395 9.458 9.521 9.585 9.649 9.714 9.779 11 9.844 9.910 9.976 10.042 10.109 10.176 10.244 10.312 10.380 10.449 12 10.518 10.588 10.658 10.728 10.799 10.870 10.941 11.013 : 11.085 11.158 13 11.231 11.305 11.379 11.453 11.528 11.604 11.680 11.756 11.833 11.910 14 11.987 12.065 12.144 12.223 12.302 12.382 12.462 12.543 12.624 12.706 15 12.788 12.870 12.953 13.037 13.121 13.205 13.290 13.375 13.461 13.547 16 13.634 13.721 13.809 13.898 13.987 14.076 14.166 14.256 14.347 14.438 17 14.530 14.622 14.715 14.809 14.903 14.997 15.092 15.188 15.284 15.380 18 15.477 15.575 15.673 15.772 15.871 15.971 16.771 16.171 16.272 16.374 19 16.477 16.581 16.685 16.789 16.894 16.999, 17.105 17.212 17.319 17.427 20 17.535 17.644 17.753 17.863 17.974 18.085 18.197 18.309 18.422 18.536 21 18.650 18.765 18.880 18.996 19.113 19.231 19.349 19.468 19.587 19.707 22 19.827 19.948 20.070 20.193 20.316 20.440 20.565 20.690 20.815 20.941 23 21.068 21.196 21.324 21.453 21.583 21.714 21.845 21.977 22.110 22.243 24 22.377 22.512 22.648 22.785 22.922 23.060 23.198 23.337 23.476 23.616 \DMQQUI kWNHO 25 23.756 23.897 24.039 24. l 82 24.326 24.471 24.617 24.764 24.912 25 .060 26 25.209 25.359 25.509 25.660 25 .812 25.964 26.117 26.271 26.426 26.582 27 26.739 26.897 27.055 27.214 27.374 27.535 27.696 27.858 28.021 28.185 28 28.349 28.514 28.680 28.847 29.015 29.184 29.354 29.525 29.697 29.870 ‘ 29 30.043 30.217 30.392 30.568 30.745 30.923 31.102 31.281 31.461 31.642 30 31.824 32.007 32.191 32.376 32.561 32.747 32.934 33. 122 33.312 33.503 31 33.695 33.888 34.082 34.276 34.471 34.667 34.864 35.062 35.261 35 .462 32 35 .663 35.865 36.068 36.272 36.477 36.683 36.891 37.099 37.308 37.518 33 37.729 37.942 38.155 38.369 33.584 38.801 38.018 39.237 39.457 39.677 34 39.898 40.121 40.344 40.569 40.796 41.023 41.251 41.480 41.710 41.942 35 42.175 42.409 42.644 42.880 43.117 43.355 43.595 43.836 44.078 44.320 36 44.563 44.808 45.054 ' 45.301 45.549 45.799 46.050 46.302 46.556 46.811 37 47.067 47.324 47.582 47.841 48.102 48.364 48.627 48.891 49.157 49.424 38 49.692 49.961 50.231 50.502 50.774 51.048 51.323 51.600 51.879 52.160 39 52.442 52.725 53.009 53.294 53.580 53.867 54.156 54.446 54.737 55.030 40 55.324 55.61 55.91 56.21 56.51 56.81 57.11 57.41 57.72 58.03 41 58.34 58.65 58.96 59.27 59.58 59.90 60.22 60.54 60.86 61.18 42 61.50 61.82 62.14 62.47 62.80 63.13 63.46 63.79 64.12 64.46 43 64.80 65.14 65.48 65.82 66.16 66.51 66.86 67.21 67.56 67.91 44 68.26 68.61 68.97 69.33 69.69 70.05 70.41 70.77 71.14 71.51 45 71.88 72.25 72.62 72.99 73.36 73.74 74.12 74.50 74.88 75.26 46 75.65 76.04 76.43 76.82 P 77.21 77.60 78.00 78.40 78.80 79.20 47 79.60 80.00 80.41 80.82 81.23 81.64 82.05 82.46 82.87 83.29 48 83.71 84.13 84.56 84.99 85.42 85.85 86.28 86.71 87.14 87.58 , 49 88.02 88.46 88.90 89.34 89.79 90.24 90.69 91.14 91.59 92.05 Table BA Antoine Equation Constants” log p‘ = A — B ‘ ' ‘ ° 10 T+C pmmmHg, TmC Example: The vapor pressure of acetaldehyde at 25°C is determined as follows 1600.017 25 + 291.809 l0810 Pémoayc) = 800552 — = 2.9551 : PE.H.0(25°C) = 1023551 = 902 mm Hg Compound Formula Range (C) A B C Ethylene glycol C2H602 50.0 to 200.0 8.09083 2088.936 203.454 Ethylene oxide C2H40 0.3 to 31.8 8.69016 2005.779 334.765 1,2—Ethylenediamine CszNz 26.5 to 117.4 7.16871 1336.235 194.366 Formaldehyde HCHO — 109.4 to ~22.3 7.19578 970.595 244.124 Formic acid CH202 37.4 to 100.7 7.58178 1699.173 260.714 Glycerol C3H803 183.3 to 260.4 6.16501 1036.056 28.097 n-Heptane n-C7H16 25.9 to 99.3 6.90253 1267.828 216.823 i-Heptane i—C7H16 18.5 to 90.9 6.87689 1238.122 219.783 l-Heptene I) C7H14 21.6 to 94.5 6.91381 1265.120 220.051 n-Hexane n—C6H14 13.0 to 69.5 6.88555 1175.817 224.867 1' -Hexane i-C6H14 12.8 to 61.1 6.86839 1151.401 228.477 1-Hexene C6le 15.9 to 64.3 6.86880 1154.646 226.046 Hydrogen Cyanide HCN — 16.4 to 46.2 7.52823 1329.49 260.418 Methanol CH30H 14.9 to 83.7 8.08097 1582.271 239.726 Methanol* CH3OH —20 to 140 7.87863 1473.] 1 230.0 Methyl acetate C3H602 1.8 to 55.8 7.06524 1157.630 219.726 Methyl bromide CH3Br —70.0 to 36 7.09084 1046.066 244.914 Methyl chloride CH3C1 —75.0 to 5.0 7.09349 948.582 249.336 Methyl ethyl ketone C4I-130 42.8 to 88.4 7.06356 1261.339 221.969 Methyl isobutyl ketone CSHHO 21.7 to 116.2 6.67272 1168.408 191.944 Methyl methacrylate C5H302 39.2 to 89.2 8.40919 2050.467 274.369 Methylamine CH5N —83.1 to —6.2 7.33690 1011.532 233.286 Methylcyclohexane 0C7H14 25.6 to 101.8 6.82827 1273.673 221.723 Naphthalene CmHs 80.3 to 179.5 7.03358 1756.328 204.842 Nitrobenzene I C6H5N02 134.1 to 210.6 7.11562 1746.586 201.783 Nitromethane CH3N02 55.7 to 136.4 7.28166 1446.937 227.600 n-Nonane fl-CgHzo 70.3 to 151.8 6.93764 1430.459 201.808 1-Nonane C9ng 66.6 to 147.9 6.95777 1437.862 205.814 n—Octane n-Cngg 52.9 to 126.6 6.91874 1351.756 209.100 i—Octane i-C3H13 41.7 to 118.5 6.88814 1319.529 211.625 1-Octene Cnge 44.9 to 122.2 6.93637 1355.779 213.022 n—Pentane n-CsHu 13.3 to 36.8 6.84471 1060.793 231.541 i-Pentane i-C5H12 16.3 to 28.6 6.73457 992.019 229.564 1-Pentanol CSHHO 74.7 to 156.0 7.18246 1287.625 161.330 1-Pentene CsHm ' 12.8 to 30.7 6.84268 1043.206 233.344 Phenol C6HGO 107.2 to 181.8 7.13301 1516.790 174.954 1-‘Propanol C3H30 60.2 to 104.6 7.74416 1437.686 198.463 2-Propanol C3H80 52.3 to 8933 7.74021 1359.517 197.527 Propionic acid C3H502 72.4 to 128.3 7.71423 1733.418 217.724 Propylene oxide C3H50 -24.2 to 34.8 7.01443 1086.369 228.594 Pyridine C5H5N 67.3 to 152.9 7.04115 1373.799 214.979 Styrene CgHg 29.9 to 144.8 7.06623 1507.434 214.985 Toluene C7Hg 35.3 to 111.5 6.95805 1346.773 219.693 1,1,1-Trichloroethane C2H3C13 —5.4 to 16.9 8.64344 2136.621 302.769 1,1,2-Trichloroethane C2H3Cl3 50.0 to 113.7 6.95185 1314.410 209.197 Trichloroethylene CzHClg 17.8 to 86.5 6.51827 1018.603 192.731 Vinyl acetate C4H602 21.8 to 72.0 7.21010 1296.130 226.655 Water* H20 0 to 60 8.10765 1750.286 235.000 Water* H20 60 to 150 7.96681 1668.210 228.000 m-Xylene m-CgHw 59.2 to 140.0 7.00646 1460.183 214.827 o-Xylene 0-C3H10 63.5 to 145.4 7.00154 1476.393 213.872 p—Xylene p-C3H10 58.3 to 139.3 6.98820 1451.792 215.111 FACTORS FOR UNIT CONVERSIONS Equivalent Values 1kg = 1000 g = 0.001 metric ton = 2.20462 lbm = 35.27392 oz 11bm = 16 oz = 5 X 10"4 ton = 453.593 g = 0.453593 kg 1m = 1000m = 1000 mm = 106 microns (11m) = 1010 angstroms (A) = 39.37 in. = 3.2808 ft = 1.0936 yd = 0.0006214 mile 1 ft '= 12 in. = 1/3 yd = 0.3048m = 30.48 cm 1m3 = 1000L = 10661113 = 106mL 35.3145 ft3 = 220.83 imperial gallons = 264.17 gal = 1056.68 qt 1 03 = 1728 in.3 = 7.4805 gal = 0.028317 m3 = 28.317 L = 28,317 cm3 1 N = 1 kg-m/s2 = 105 dynes : 105 gem/s2 = 0.22481 lbf 1115f = 32.1741bm-ft/s2 = 4.4482N = 4.4482 x 105 dynes 1 atm = 1.01325 x 105 N/m2 (Pa) = 101.325 kPa = 1.01325 bar = 1.01325 x 106 dynes/cmz = 760 mm Hg at 0°C (torr) = 10.333 111 H20 at 4°C = 14.696 lbf/in.2 (psi) = 33.9 ftHZO at 4°C = 29.921 in. Hg at 0°C lN-m = 107 ergs = 107 dyne-cm 2.778 x 10‘7 kW-h = 0.23901 cal = 0.7376 ft-lbf = 9.486 x10"4 Btu 1 W = 1 J/s = 0.23901 cal/s = 0.7376 fi'lbf/S = 9.486 X 10'4 Btu/s 1.341 x 10‘3 hp Force Pressure lJ 2.20462 lbm 1000 g ‘ Example: The factor to convert grams to lbm is ( THE GAS CONSTANT ______________ 8.314 m3-Pa/(mol-K) 0.08314 L-bar/(mol-K) 0.08206 L-atrn/(mol-K) 62.36 L-mm Hg/(mol'K) 0.7302 ft3 ~atm/(lb-mole~°R) 10.73 ft3 ~psia/(lb—mole-°R) 8.314 J/(mol-K) 1.987 cal/(mol-K) 1.987 Btu/(lb-mole’R) / ...
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This note was uploaded on 02/22/2012 for the course CHBE 2100 taught by Professor Staff during the Summer '08 term at Georgia Tech.

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fall 2003 2 - DEC 1 4 2005 Midterm Exam#2 ChBE 2100 Fall...

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