Chemical-engineering-refresher-course.pdf

CHEMICAL ENGINEERING REFRESHER COURSE CHE CALCULATIONS AND ENVIRONMENTAL ENGINEERING 1. Which of the following banned POPs was the key ingredient in Scotchgard, which is a popular fabric protector made by the global manufacturing giant 3M? (A) Chlordane (B) PFOS (C) Lindane (D) DDT 2. How many of the following statements is/are true about PCBs? i. PCB stands for Polychlorinated Biphenols ii. The resistance of a specific PCB to degradation is directly proportional to the number of Chlorine atoms its molecule. iii. The maximum number of Chlorine atoms that can be found in a PCB molecule is 10 (A) (B) (C) (D)

0 1 2 3

3. It is the international statue that is currently the primary basis of the Philippines in its latest environmental dispute with Canada. (A) Kyoto Protocol (B) Copenhagen Talks (C) Basel Convention (D) None of the Above 4. What is the name of the report that formally defined and introduced the global concept of ‘Sustainable Development?’ (A) The Brundtland Report (B) The Gro Harlem Report (C) The World’s Future (D) None of the Above 5. Life Cycle Analysis (LCA) and Environmental Impact Assessments (EIA) are examples of tools demanded by which ISO series? (A) ISO 9000 (B) ISO 14000 (C) ISO 22000 (D) None of the Above 6. Which of the following refers to the Philippine Biofuels Act of 2006?

(A) (B) (C) (D)

RA 9763 RA 9736 RA 9637 9673

7. According to DENR’s administrative Order 34 on the Classification and Water Quality Criteria for bodies of water, fresh water that caters to non-contact recreational activity is classified as: (A) A (B) B (C) C (D) D 8. Which of the following acid combination is the dominant composition of acid rain? (A) Nitric acid and carbonic acid (B) Nitric acid and sulfuric acid (C) Carbonic acid and sulfuric acid (D) None of the above 9. All of the biogeochemical cycles involve the atmosphere as either sink or reservoir except for one. This exception cycle uses the _______ as its sink. (A) Lithosphere (B) Hydrosphere (C) Either (a) or (b) (D) Neither (a) nor (b) 10. In solid waste composting, a carbon content that is way higher than the optimum browns to green ratio will result to: (A) Low bacterial activity (B) Odorous composting products (C) Long composting time (D) None of the above 11. In the recycling of plastic, numbers indicate the type of plastic to ensure that recycling of similar materials are carried out. Which of the following is the correct pair of number and plastic material? (A) 5 - PP (B) 4 - HDPE (C) 3 - LDPE (D) 2 - PET 12. It is an odorless and colorless gas that is lethal to humans with exposure as short as a few minutes to concentration exceeding 5000 ppm. It reacts with hemoglobin in the blood and rendering the latter incapable of carrying oxygen to the body. (A) Carbon Monoxide (B) Nitrogen Dioxide (C) Sulfur Dioxide (D) Sulfur Trioxide

13. In the process of ozone depletion, the Chlorine gets recycle thus rendering its long lifetime in the atmosphere. The basic unit of measure of ozone layer thickness is named after: (A) Henri Buisson (B) Charles Fabry (C) Sydney Chapman (D) GM Dobson 14. It is the type of biological unit processes that remove biodegradable organic substances (whether colloidal or dissolved) in the wastewater in the presence or absence of oxygen. (A) Diaerobic (B) Aerobic (C) Anaerobic (D) None of the Above 15. Determine the BOD2 of a sample wastewater if its BOD5 is 135 mg/L with a rate constant of 0.23/day. (A) 197.55 mg/L (B) 72.84 mg/L (C) 40.6 mg/L (D) None of the Above 16. A specific town has a low-turbidity raw water and is designing its overflow weir at a loading rate of 150 m3/day-meter. If its plant flow rate is 0.5m3 per second, how many linear meters of weir are required? (A) 144 meters (B) 216 meters (C) 288 meters (D) 432 meters 17. An illegally buried drum of toluene gas begun to leak into an unconfined drinking water aquifer. A homeowner’s well is located 60 meters down from the leaking drum. If the soil has a retardation coefficient of 17 for toluene and the linear speed of the water in the aquifer is 4.7 × 106 m/s, how long will it take for the said contaminant to reach the well? (A) 10.3 months (B) 3.44 years (C) 6.88 years (D) 13.76 years 18. A sanitary landfill has available space of 16.2 ha at an average depth of 10m. 765 cubic meters per day of solid waste are dumped at the site 5 days per week. This waste is compacted to twice its delivered density. Estimate the expected life of the landfill in years. (A) 12 years (B) 18 years (C) 24 years (D) None of the Above

19. The following test results were obtained for a wastewater sample taken from a treatment plant. All of the tests were performed using a sample size of 50-mL. Determine the concentration of the total volatile solids in the wastewater. Tare Mass of Evaporating Dish Mass of Evaporating Dish plus residue after evaporation at 105˚C Mass of Evaporating Dish plus residue after ignition at 550˚C Tare Mass of whatman filter paper Residue on whatman filter paper after drying at 105 ˚C Residue on whatman filter paper after ignition at 550˚C (A) (B) (C) (D)

62.003 g 62.039 g 62.036 g 1.540 g 1.552 g 1.549 g

60 mg/L 240 mg/L 120 mg/L None of the Above

20. Using the same data in the previous number, what is the total dissolved solids of the sample? (A) 60 mg/L (B) 240 mg/ (C) 120 mg/L (D) None of the Above 21. How many name-derived units are there in the SI Unit of Measurement? (A) 15 (B) 19 (C) 22 (D) None of the Above 22. It is the number wherein the API scale will be equal to the Brix scale for specific gravity. (A) 0.9628 (B) 1.0389 (C) 1.9256 (D) 2.0774 23. Phenol (94) can be manufactured by reacting chlorobenzene (112.45) with sodium hydroxide (40). To produce 1000 kg of phenol, 1200 kg of sodium hydroxide and 1,320 chlorobenzene are used. What is the maximum conversion of the excess reactant? (A) 29.66% (B) 31.05% (C) 35.47% (D) 39.13% 24. Hydrogen chloride gas is produced along with carbon dioxide by burning chlorine in methane and air. A ceramic-lined burner is used for a feed charge consisting 70% chlorine and 20% methane together with 10% excess air at 30˚C and 29 in Hg. After

burning, the gases leaving shows 27.3% hydrogen chloride. What is the degree of completion of the reaction? (A) 0.80 (B) 0.75 (C) 0.65 (D) 0.50 25. Glucose is converted to fructose in catalytic reactor using a fresh feed containing 60% glucose and 40% inert. The single pass conversion of glucose in the reactor is 25%. If only the unreacted glucose from the reactor is recycled to join the fresh feed, calculate the amount of recycle stream in kg per 100 kg of fresh feed to the process. (A) 45 (B) 64 (C) 90 (D) 180 26. From sugar cane ethanol is commercially produced at a rate of 100,000 liters per day (99.5% v/v). From here, fermentation occurs at a rate of 0.511 kg ethanol per kg of fermentable sugar. If the syrup is 53% fermentable sugar and cane juice is 25% syrup with distillation and fermentation being 99% and 90% efficient respectively, what is the amount of cane juice feed in tons per day? (A) 1024 (B) 1303 (C) 1056 (D) 1408 27. Using the same data and cane juice feed from the previous problem, what percent of the ideal ethanol production amount is actually produced? (A) 89.1% (B) 96.4% (C) 98.5% (D) None of the Above 28. These are materials which directly participate in the actual process and come out as part of the final product. However, the final product may still be produced even without these materials. (A) Primary Materials (B) Premium Materials (C) Ancillary Materials (D) Auxiliary Materials 29. A solid material with 15% w/w water is dried to 7% under the following conditions. Fresh air is mixed with recycled air and it is blown over the solid. The fresh air contains 0.01 lb water/ lb dry air and the recycled air, which is part of the air leaving the dryer, contains 0.1 lb water/ lb dry air. The proportions of fresh and recycled air adjusted so that the mixture entering the dryer contains 0.03 lbs water/ lb dry air. How many pounds of dry air are in the fresh air feed per 100 lbs of wet material? (A) 8.60

(B) 27.34 (C) 95.60 (D) None of the Above 30. How many pounds of dry air are recycled per 100 lbs of wet material? (A) 8.60 (B) 27.34 (C) 95.60 (D) None of the Above 31. What is the density of the unknown gas if its specific gravity at STP is 1.83? (A) 1.83 g/mL (B) 1.83 g/L (C) 1.83 g/m3 (D) None of the Above 32. A distillation column separates 10,000 kg/hr of a 50-50 benzene toluene mixture. The product recovered from the condenser at the top of the column contains 95% benzene and the bottom contains 95% toluene. The vapor stream entering the condenser from the top of the column is 8000 kg/hr. A portion of the product from the condenser is returned to the column as reflux and the rest is withdrawn for other use. What is the flow rate at the top of the column? (A) 2950 kg/hr (B) 4950 kg/hr (C) 5050 kg/hr (D) 6450 kg/hr 33. What is the recycle ratio in the previous problem? (A) 46% (B) 58% (C) 60% (D) 78% 34. Assuming that air is dominantly composed of nitrogen and oxygen, what is the mass percentage of nitrogen in air? (A) 21 (B) 23 (C) 77 (D) 79 35. A furnace uses a coal whose ultimate analysis shows 57.22% C, 5.53% H, 1.41% N, 3.65% S and 14.65% ash. The combustible matter left in the ash from the furnace is negligible. On the assumption that this furnace secures complete combustion, 80% excess air and all of the sulfue in combustion gases appear as SO7, what is the percent nitrogen in the dry flue gas on an SO2 dry basis? (A) 71.3 (B) 60.1 (C) 75.7

(D) 80.6 36. A 95-octane gasoline is burned in a brand new engine. What is the percentage of carbon dioxide in the Orsat analysis assuming complete combustion and theoretical oxygen is supplied? (A) 11.38% (B) 12.61% (C) 14.67% (D) None of the Above 37. A furnace is fired with coal containing 6% moisture, 18% VCM, 67% FC and 9% ash. The refuse analysis shows 5% VCM, 23% FC and 62% ash. The higher heating value of the coal as fired is 14,300 Btu/lb. Calculate the percentage of the heating value of the coal that is lost in the refuse. Assume that the moisture in the refuse is due to the ‘wetting down’ to prevent dusting and not moisture from the original coal. (A) 4.68% (B) 7.02% (C) 9.36% (D) 15.0% 38. What is the volume percent of gasoline in E10? (A) 10% (B) 20% (C) 80% (D) 90% 39. Butane is burned with 50% excess air. The percent conversion is 90% and 25% of which reacts to form CO. What is the percentage carbon monoxide in the dry flue gas? (A) 0.2% (B) 2.% (C) 6% (D) 10% 40. What is the percentage flue gas in the previous problem? (A) 8.8% (B) 9.1% (C) 10% (D) None of the Above

CHEMICAL ENGINEERING REFRESHER COURSE CHE CALCULATIONS AND ENVIRONMENTAL ENGINEERING 1. Pick out the wrong statement. (A) The concentric atmosphere layer just above the troposphere is called stratosphere, which is rich in ozone. (B) Mesosphere is characterized by very low atmospheric pressure and low temperature. (C) Troposphere is a dusty, zone containing water vapor and clouds. (D) The radio waves used in the long distance radio communication are reflected back to earth by stratosphere. 2. Inhalation of lead compounds present in the automobile exhausts (using leaded petrol) causes (A) Blood poisoning (B) Anemia (C) Nervous system disorder (D) All (a), (b) and (c) 3. Pick out the wrong statement. (A) A slight haze at the top of chimney indicates good combustion in the furnace. (B) A bag filter incurs very small pressure drip and is very efficient for removal of sub-micronic dust particles from flue gases at very high temperature. (C) Electrostatic precipitator is the most efficient dust collection equipment for removal of sub-micronic dust particles present flue gas. (D) None of these. 4. The detrimental effect on organism and water quality with temperature rise of aquatic system is the reduction of ___________________ of water. (A) Dissolved oxygen content (B) Biological oxygen demand (C) Vapor pressure (D) All (a), (b) and (c) 5. Soluble silica present in boiler feed water can be removed by (A) Coagulation (B) Filtration (C) Anion exchanger (D) Preheating 6. Which of the following plastics may not be safe for food packaging (A) Polystyrene (B) Polyethylene terephthalate (C) High density polyethylene

(D) None of these 7. Presence of nitrogen in high concentration in contaminated air reduced partial pressure of oxygen in lungs, thereby causing asphyxia (suffocation) leading to death from oxygen deficiency. Concentration of N2 in contaminated air at which it acts as a natural asphyxant is ≥ ________ percent. (A) 80 (B) 84 (C) 88 (D) 90 8. The main pollutant in waste water discharged from a petroleum refinery oil (both in free and emulsified form). Free oil is removed by (A) Trickling filters (B) Aerated lagoons (C) Biological oxygen pond (D) Gravity separator having oil skimming devices 9. Automobile exhaust is passed through two compartment catalytic converter employing platinum as catalyst for (A) Conversion of CO into CO2 in the second compartment (B) Conversion of NOx into N2 and NH3 in the first compartment (C) Oxidation of unburnt hydrocarbon fuel in the second compartment (D) All (a), (b) and (c) 10. Presence of a certain minimum quantity of fluorine iss desirable in potable water to prevent (A) Dental cavities (B) Scale formation (C) Water-borne disease (D) Corrosion 11. In water treatment plant, zeolite process is used to remove the __________ of water. (A) Acidity (B) Alkalinity (C) Hardness (D) Iron & zinc 12. RA 6969 is known as the “Toxic Substances and Hazardous and Nuclear Wastes Control Act of 1990.” According to this republic act, its scope includes: (A) Manufacture of all unregulated chemical substances and mixtures in the Philippines (B) Use of all unregulated chemical substances and mixtures in the Philippines (C) Storage of hazardous and nuclear wastes in the Philippines (D) All of them are included

13. In a BOD test, 1.0mL of raw sewage was diluted to 100mL, maintained at 20˚C. The dissolved oxygen concentration of diluted sample at the beginning was 6 ppm and it was 4 ppm 5 days later. The BOD of raw sewage (in ppm) is (A) 100 (B) 200 (C) 300 (D) 400 14. In facultative stabilization pond, the sewage is treated by (A) Aerobic bacteria (B) Algae (C) Anaerobic bacteria (D) A and C 15. The main industrial source of emission of hydrogen sulfide air pollutant is (A) Petroleum refineries (B) Coal based thermal power plants (C) Pulp and paper plant (D) Metallurgical roasting & smelting plant 16. Philippine Clean Air Act of 1999 is also known as: (A) RA 6969 (B) RA 8749 (C) RA 9003 (D) RA 9275 17. Operating principle of cyclone separator is based on the action of ___________ dust particles, (A) Diffusion of (B) Centrifugal force on (C) Gravitational force on (D) Electrostatic force on 18. Iron & manganese present as pollutant in water cannot be removed by (A) Ion exchange process (B) Oxidation followed by settling & filtration (C) Lime soda process or manganese zeolite process (D) Chlorination 19. Pick out the wrong statement. (A) Inhalation of pollutant carbon monoxide results in death by asphyxiation. (B) Sulfur dioxide is the main pollutant emitted from the exhaust petrol driven automobiles. (C) Catalytic converters is fitted in automobiles to reduce carbon monoxide concentration in exhaust emissions. (D) Decomposition of plants containing chlorophyll is a natural source of carbon monoxide in atmosphere.

For numbers 20 and 21: A hydrocarbon is burnt with excess air. The Orsat analysis of the flue gas shows 10.81% CO2, 3.78% O2 and 85.40% N2. 20. Calculate the atomic ratio of C H in the hydrocarbon. (A) 1.2 (B) 1.4 (C) 1.3 (D) 3.8 21. % excess air. (A) 10 (B) 20 (C) 30 (D) 40 For numbers 22 and 23: The reaction A→2B + C takes place in a catalytic reactor. The reactor effluent is sent to a separator. The overall conversion of A is 95%. Leaving the separator is the product and recycle stream. The product stream from the separator consists of B, C and 0.5% of A entering the separator, while the recycle stream consists of the remainder of the unreacted A and 1% of B entering the separator. 22. Calculate the Single Pass Conversion of A (A) 9.97 (B) 7.99 (C) 6.88 (D) 8.68 23. Molar ratio of recycle to feed (A) 9.97 (B) 7.99 (C) 6.88 (D) 6.68 24. 30% oleum is equal to ____ H2SO4. (A) 102.25$ (B) 104.5% (C) 106.75% (D) 109% 25. In an Orsat analyzer, Carbon Monoxide is absorbed by (A) Pyrogallol (B) Cuprous chloride (C) Potassium hydroxide (D) None of these

For numbers 26 and 27 A solution of ethyl alcohol containing 8.6% alcohol by weight is fed at the rate of 5000 kg/hr to a continuous fractionating column operating at atmospheric pressure. The distillate which is the desired product contains 95.4% alcohol by weight and the residue from the bottom of the column contains 0.1% alcohol by weight. Calculate the following: 26. The mass flow rates of the distillate in kg/hr. (A) 433 (B) 446 (C) 4554 (D) 5445 27. The percentage loss of alcohol. (A) 6.01 (B) 1.06 (C) 0.16 (D) None of these 28. A solvent recovery system delivers a gas saturated with benzene (C6H6) vapor that analyzes on a benzene free basis as follows: CO2 – 15%, O2 – 4% and N2 – 81%. This gas is at 21˚C and 750 mm Hg pressure. It is compressed at 5 atmospheres and cooled to 21˚C after compression. How many kilograms of benzene are condensed by this process per 1000 m3 of the original mixture? Vapor pressure of benzene at 21˚C = 75 mm Hg. (A) 261.4 kg (B) 241.6 kg (C) 214.6 kg (D) 412.6 kg For numbers 29 and 30: Calcium hypochlorite is produced by absorbing chlorine in a milk of lime. A gas by the Deacon process is fed to an absorption column at a pressure of 100kPa at a temperature of 20˚C. The partial pressure of chlorine 8.266kPa, the remainder being inert gases. The gas leaves the column at a temperature 29.5V and a pressure of 99.3˚C with a chlorine partial pressure of 0.093kPa. 29. Calculate the volume (in m3) of gases leaving the absorption column per 100 m3 entering. (A) 27.35 (B) 23.75 (C) 59.51 (D) 95.15 30. Weight (in kg) of chlorine gas absorbed per 100m3 entering. (A) 27.35 (B) 23.75 (C) 69.51 (D) 95.15

31. A storage tank of Demineralized water has a holding capacity of 1500 m3 up to an overflow point. The DM water having silica as SIO2) content of 0.005 mg/L is flowing into a tank t a rate of 25 L/s. The outflow from a tank to the high pressure boilers is 25 L/s. With time, the quality of DM water deteriorates and the silica content rose up to 0.02 mg/L. Assuming that the inflow and outflow remain constant, determine the time required for the silica content in the storage tank to increase to 0.01 mg/L. (A) 76.6 hrs (B) 6.76 hrs (C) 10.5 hrs (D) 66.7 hrs For numbers 32. To 34: In manufacture of chlorine, feed containing hydrochloric acid gas and air are fed to an oxidizer. The product gases leaving the oxidizer are found to contain 13.2% O2, 42.9% N2, 30% Cl2, and 7.6% H2O (by weight). Calculate: 32. Percent excess air used. (A) 13.06 (B) 70.00 (C) 34.72 (D) 44.05 33. Percent wt. HCl feed gas (A) 13.06 (B) 70.00 (C) 34.72 (D) 44.05 34. Degree of completion (A) 13.06 (B) 70.00 (C) 34.72 (D) 44.05 35. One gram of a magnesium aluminum alloy was reacted with excess muriatic acid to form magnesium chloride, aluminum chloride and hydrogen gas. Hydrogen gas collected over mercury at 0˚C, occupied 1.2L at 93.26kPa. Find the % Mg in the alloy. (A) 47 (B) 53 (C) 57 (D) 43 For numbers 36 and 37: The fresh feed to the process was 0.5 kmol/hr of O2 and an excess methanol. All of the O2 reacts in the reactor. Formaldehyde and water are removed from the product stream first, after which H2 is removed from the recycled methanol. The recycle flow rate of methanol was 1 kmol/hr.The ration of methanol reacting by decomposition to that by oxidation was 3.

36. Calculate the per pass conversion (in %) of methanol in the reactor. (A) 60 (B) 70 (C) 80 (D) 90 37. Calculate the fresh fee rate (in kmol/hr) of methanol. (A) 3 (B) 3.5 (C) 4 (D) 4.5 For numbers 38 to 40: A gas stream containing 25% CO2 and 75% CH4 is treated in a gas containing plan. The stream is fed to an absorption lower at a rate of 100 kmol/hr and is contacted in the tower with a liquid solvent containing 0.5 mol% dissolved CO2 and the balance methanol. The gas leaving the absorber contains 1.0 mole% CO2 and essentially all of the methane fed to the unit. The CO2 rich solvent leaving the absorber goes to a stripping column in which a stream of nitrogen gas contacts the solvent, removing 90% of the dissolved CO2. The regenerated solvent is then recycled to the absorption column. Assume methanol to be non-volatile (i.e. none enters the vapor phase in the process unit). 38. Calculate the present CO2 absorbed from feed gas. (A) 80.3 (B) 75 (C) 97 (D) 33.4 39. Calculate the molal flow rate (kmol/hr) of the liquid feed to the absorber. (A) 563 (B) 539 (C) 1200 (D) 75 40. Molal flow rate (kmol/hr) of gas fed to the absorber required to produce 1000 kg/hr of absorber product gas. (A) 80.3 (B) 75 (C) 97 (D) 33.4

CHEMICAL ENGINEERING REFRESHER COURSE CHE CALCULATIONS AND ENVIRONMENTAL ENGINEERING 1. One hundred pounds of solution containing 80% wt Na2SO4 must obtained by evaporating a dilute solution using a double effect evaporator. If the evaporator from the 2nd effect is 60% of that coming from the first effect and the concentrate of the first effect contains 1 lb Na2SO4 per pound of water. Calculate for the composition of the feed. (A) 31% H2O, 69% Na2SO4 (B) 45% H2O, 54% Na2SO4 (C) 54% H2O, 45% Na2SO4 (D) 69% H2O, 31% Na2SO4 2. Process in which the solute components of a gas mixture are dissolved in a liquid. (A) Evaporation (B) Distillation (C) Gas absorption (D) Drying 3. If moist hydrogen containing 4% water by volume is burnt completely in a furnace with 25% excess air, calculate the percent moisture of the flue gas produced from the furnace. (A) 11.89% (B) 20.90% (C) 29.61% (D) 41.56% 4. A mixture of pure sulfur and pyrites analyzing 85% FeS2 and 15% gangue is burned in a standard pyrites burner. The burner gas contains 10% SO2, 7% O2, and 83% N2 on an SO3free basis and contains 1 mol SO3 per 100 mol SO3-free burner gas. The cinder contains 2% S as SO3. Calculate the percentage of FeS2 in the charge. (A) 54.89% (B) 73.35% (C) 80.0% (D) 91.23% 5. Which of the following solutions is used to absorb oxygen in an Orsat Analysis Apparatus? (A) Sulfuric acid (B) Cuprous chloride (C) KOH (D) Pyrogallol 6. Suppose that 0.600 kg of stibnite (Sb2S3) and 0.250 kg of iron turnings are heated together to give 0.20 kg of Sb metal. Calculate the degree of completion.

(A) (B) (C) (D)

0.35 0.45 0.55 0.65

7. Solid calcium fluoride reacts with sulfuric acid to form calcium and gaseous hydrofluoric acid. The HF is then dissolved in water to form hydrofluoric acid. The source of calcium fluoride is fluorite ore containing96.0% wt CaF2 and 4.0% SiO2. In a typical process, fluorite ore is reacted with 93% wt aqueous sulfuric acid, supplied wiwth15% excess of the stoichiometric amount. Ninety five percent of the ore dissolves in the acid. Some of the HF formed reacts with the dissolved silica according to the reaction: 6HF + SiO2 →H2SiF6 (aq) + 2H2O (l) The hydrogen fluoride exiting from the reactor is subsequently dissolved un enough water to produce 60% wt HF. Calculate the quantity of ore needed to produce one metric ton of the acid. (A) 1533 kg (B) 1633 kg (C) 1733 kg (D) 1833 kg 8. 250 pounds per hour of 98% H2SO4 enters an absorption tower of a contact sulfuric acid plant. If 20% oleum is produced per hour, how many pounds of SO3 are absorbed? (A) 70.0 lb/h (B) 80.0 lb/h (C) 90.0 lb/h (D) 100 lb/h 9. N-Hexane is burned with excess air. On a dry basis, the product gas contains 0.268% mol n-hexane, 7.6% mol O2, 9.1% mol CO2 and the balance N2. Determine the percent excess air fed to the reactor. (A) 30 (B) 32 (C) 35 (D) 65 10. Wet leather enters a continuous leather dryer with a moisture content of 61% and leaves with a moisture content of 6% at a rate of 485 lbs/hr. Dry air at 140˚F and 1 atm enters the ddryer, and air and evaporated water leave the dryer at 130˚F and 1 atm. Vapor pressure at 130˚F is 115mm Hg. Determine the volumetric flowrate of the inlet air in ft3/hr if the outlet air has a relative humidity of 50%. (A) 127,589 (B) 398,103 (C) 203,000 (D) 421,621 11. A fuel mixture contains 35% mol CH4, 20% mol C2H6 and 45% mol CO2. Calculate the average molecular weight of the mixture. (A) 31.40

(B) 30.00 (C) 28.76 (D) 22.13 12. Calculate the mass of 50˚ (62.18%) H2SO4 which may be made from one pound of sulfur. (A) 3.00 lb (B) 5.00 lb (C) 7.00 lb (D) 9.00 lb 13. Losses in calorific value of fuels may be due to the following: (A) Due to incomplete combustion (B) Due to sensible heat (C) Due to uncondensed water vapor (D) All of these 14. Ethylene oxide, C2H4O, is produced by the catalytic oxidation of ethylene. However, undesired reaction is the combustion of ethylene. The feed to the reactor contains 3 moles of ethylene per mole of oxygen. The single pass conversion of ethylene is 20% and for every 100 moles of ethylene consumed in the reactor, 90 moles of ethylene oxide in the reactor products. A multiple unit process is used to separate the products ethylene and oxygen are recycled to the reactor, ethylene oxide is sold as product and CO2 and H2O are discarded. What should be the molar flow rate of ethylene to produce 2000 lbs of ethylene oxide per hour? (A) 37.8 (B) 50.4 (C) 67.1 (D) 89.2 15. Which of the following statements are TRUE? (A) Theoretical oxygen depends on the amount of fuel burned. (B) Theoretical oxygen is calculated according to the oxygen required to from CO and CO2. (C) Free oxygen accounts only for oxygen required to burn combustibles in the flue gas. (D) None of these 16. An evaporator-crystallizer process is used to obtain solid K2SO4 from an aqueous solution of this salt. The fresh feed to the process contains 19.6% wt K2SO4.This fresh feed joins a recycle stream from the filtrate product of the crystallizer and enters the evaporator where 45% of the water fed is evaporated. The evaporator has a maximum capacity of 175 kg water evaporated per second. The concentrated solution then enters the crystallizer. The wet filter cake consists of solid K2SO4 crystals and a 40% wt K2SO4 solution in a ratio of 10 kg crystals/kg solution. The filtrate is recycled to join the fresh feed. Calculate the maximum recycle to fresh feed ratio. (A) 0.80 (B) 1.80 (C) 2.40

(D) 3.2 17. These are small amount of metallic sulfide and appreciable amounts of totally combustible materials. (A) Pyrites (B) Cinder (C) Ashes (D) Gangue 18. 100 kmol of a benzene-toluene mixture in equimolal amounts is distilled. 96% of the benzene is obtained in the distillate product while 90% of the toluene is in the bottoms. Which of the following is true in the product streams? (A) 4.26% benzene (B) 4.26% toluene (C) 95.74% benzene (D) Both (b) and (c) 19. Six hundred pound of wet material containing 20% moisture (dry basis) is fed to a dryer per hour. The product obtained was 515 lbs per hour. Find the composition of the product in % moisture (dry basis) (A) 2% (B) 4% (C) 7% (D) 3% 20. A certain brand of gasoline was burned with 10% excess air and was analyzed to have the following flue gas composition: 11.5% CO2, 3.8% CO, 3.9% O2 and the balance N2. Determine the cetane number of the fuel. C16H34 (𝜌 = 0.7751 g/mL) C11H10(𝜌 = 1.025 g/mL) (A) 12 (B) 25 (C) 50 (D) 75 21. A global treaty that aims to regulate emissions of greenhouse gases. (A) Stockholm Convention (B) Montreal Protocol (C) Kyoto Protocol (D) None of these 22. Color of wastewater which is partly due to suspended matters which can be filtered out. (A) Grayish (B) Apparent (C) Black (D) True 23. A code for plastics used for food wrapping, trash bags, grocery bags and baby diapers. (A) 2

(B) 3 (C) 4 (D) 5 24. It is called fog when its concentration is high enough to obscure visibility. (A) Mist (B) Fume (C) Smoke (D) Spray 25. Total uptake chemicals by an organism from food items as well as via mas transport of dissolved chemicals. (A) Bioaccumulation (B) Biomagnification (C) Bioconcentration (D) All of these 26. Which of the following is NOT used as a coagulant aid? (A) Activated silica (B) Clay (C) Polymer (D) Ferric chloride 27. The BOD5 of a domestic wastewater at 20˚C is 220 mg/L and its ultimate BOD is 320 mg/L. Calculate the rate constant at 15˚C. (A) 0.062/day (B) 0.124/day (C) 0.248/day (D) 0.496/day 28. In COD test, the acid solution used is ___________ (A) Sulfuric (B) Dichromate (C) Bromate (D) Perchlorate 29. Measure of the total organic and ammonia nitrogen in the wastewater. It also gives a measure of the availability of nitrogen for building cells. (A) TKN (B) COD (C) NBOD (D) None of these 30. Type of recycling where recycled materials are used to make new products with different characteristics than the originals is called (A) Primary (B) Close Loop (C) Secondary

(D) Tertiary 31. Recyclable material labeled as no. 1 (A) PET (B) PS (C) PVC (D) HDPE 32. A global treaty that aims to diminish and eventually phase out the chlorofluorocarbons. (A) Stockholm Convention (B) Montreal Protocol (C) Kyoto Protocol (D) None of these 33. The condition of the atmosphere if the following data were obtained is Elevation, m Temperature, ˚C 85 19 150 21 (A) Adiabatic (B) Superadiabatic (C) Subadiabatic (D) Inverted 34. It is the total uptake of an organism from food items as well as via mass transport of dissolved chemicals through the gills or epithelium (A) Biomagnification (B) Bioconcentration (C) Bioaccumulation (D) Biaoacceleration 35. It is a very unstable gas used for disinfection, a very powerful oxidant capable of oxidizing 200 to 300 times more than chlorine and can reduce complex taste, odor and color. (A) Hypochlorite (B) Hydrogen peroxide (C) Ozone (D) Fluorine 36. Collective term for the initial POPs identified by the Stockholm Convention (A) Dirty 12 (B) 12 Pops (C) Dirty dozen (D) EDCs 37. What volume of wastewater sample is required for a BOD and oxygen consumption of 25 mg/L and 2.46 mg/L, respectively? (A) 50 mL (B) 40mL

(C) 30mL (D) 20mL 38. Class of water intended for primary contact recreation such as bathing, swimming, skydiving, etc. (A) Class AA (B) Class A (C) Class B (D) Class C 39. Glutamic acid (C5H5O4N) is used as one of the reagents for a standard to check BOD test. Determine the theoretical oxygen demand if 150 ppm of glutamic acid using the following reactions: C5H5O4N + 4.5 O2→ 5CO2 + 3H2O + NH3 NH3 + 2O2→ NO3 + H + H2O (A) 125 ppm (B) 186 ppm (C) 212 ppm (D) 256 ppm 40. If the sampled water came from a certain sewage plant, what would the expected 12day demand be? (A) 200 mg/L (B) 230 mg/L (C) 274 mg/L (D) 360 mg/L

CHEMICAL ENGINEERING REFRESHER COURSE PHYSICAL CHEMISTRY AND THERMODYNAMICS

A (l)→ A (g) 74˚C 155˚C 75 1. Consider the process which is carried out at constant pressure. The total ∆S for this process is known to be 75.0 J K-1 mol-1 . For A (l) and A(g), the CP values are 75.0 J K-1 mol-1, respectively, and are not dependent on temperature, Calculate ∆Hvap for A(l) at 125˚C (its boiling point). (A) 2.50 x 104 J (B) 5.20 x 104 J (C) 2.50 x 10-4 J (D) 5.20 x 10-4 J 2. It is desired to supply steam in a sauna bath 20 meters above sea level initially at a temperature and pressure are 300˚C and 500 kPa. The outlet steam supplied to the bath house is at 200˚C and 100 kPa to compensate heat losses along the pipeline. As such, the outlet velocity of steam must be four times as fast as the inlet steam velocity to neglect heat losses along the pipeline. As available, calculate the mass flow rate of steam to be supplied from a 5 cm pipe diameter. 3. PROPERTIES OF STEAM T(˚C) P (kPa) H (kJ/kg) V (m3/kg) x 103 300 500 3064.2 522.6 200 100 2875.3 2172.0 (A) (B) (C) (D)

0.08 kg/sec 0.16 kg/sec 0.31 kg/sec 0.62 kg/sec

4. All of the following have standard enthalpy of formation values of zero at 25˚C EXCEPT (A) Cl2 (g) (B) O2 (g) (C) Na (g) (D) N2 (g) 5. A 50.00 mg sample of n-hexane was burned in a bomb calorimeter causing a temperature rise of 1.345˚C. The heat capacity of the calorimeter is 1.803 kJ/K. Calculate the molar heat of combustion of n-hexane at constant pressure if the mean temperature of the calorimeter is 25˚C. (A) 4179.74 kJ/mol (B) 4162.38 kJ/mol

(C) 4055.67 kJ/mol (D) 3989.08 kJ/mol 6. For the reaction CO (g) + 2H2 (g) →CH3OH (g) Calculate the heat of reaction using bond enthalpy data. BOND ENTHALPY (kcal/mol) H–H 104 C=C C–H 99 C–O (A) (B) (C) (D)

147 84

O-H C=C

111 194

C-C C=O

83 170

114 kcal 378 kcal 492 kcal 870 kcal

7. Heat required raising the temperature of one pound mass of a substance by one degree Fahrenheit. (A) Calorie (B) BTU (C) Specific heat (D) Heat Capacity 8. An ideal gas initially at 5L is compresses adiabatically against a variable opposing pressure given by P(atm) = 10/V. If the gas was observed to have an increase in internal energy of 80 cal, calculate its final volume. (A) 3.6 L (B) 3.8 L (C) 4.0 L (D) 4.2 L 9. For a particular chemical reaction, ∆H˚ is positive and ∆S˚ is negative. Which of the following statements about the spontaneity of the reaction under standard conditions is TRUE? (A) The reaction will be spontaneous only if the magnitude of ∆H˚ is large enough to cover the unfavorable entropy change. (B) The reaction will be spontaneous only if the magnitude of ∆S˚ is large enough to overcome the unfavorable enthalpy change. (C) The reaction will be spontaneous regardless of the magnitudes of ∆H˚ and ∆ S˚. (D) The reaction cannot be spontaneous. 10. A piece of chocolate cake contains about 400 calories. A nutritional Calorie is equal to 1000 calories (thermochemical calories). How many 8-inch high steps must a 180-lb man climb to expend the 400 Cal from the piece of cake? (A) 100 steps (B) 1,000 steps (C) 10,000 steps (D) 100,000 steps

11. Which of the following statements is CORRECT? (A) Work or mechanical energy can spontaneously be converted completely to heat or thermal energy. (B) Thermal energy with some effort can only be partially converted to mechanical energy. (C) For a closed system operating adiabatically, work is obtained from the direct conversion of internal energy of the fluid to work. (D) All of these 12. Liquid water at 25˚C is introduced into a evacuated, insulated vessel. All of the following statements are true EXCEPT (A) ∆H and∆H˚ (B) Sign for ∆G cannot be determined but the process is spontaneous. (C) The water will become cooler (D) ∆Suniv is negative 13. Which of the following reactions will have the same heat of reaction at constant pressure and volume? (A) H2 (g) + I2↔ 2HI(g) (B) N2(g) + 2H2↔ 2NH3 (g) (C) CH4 (g) + 2O2↔ CO2 (g) + 2H2O(l) 1

(D) Na(s) + 2 Cl2 (g) ↔ NaCl (s) 14. A sample of a monoatomic ideal gas at 1.00 atm and 25˚C expands adiabatically and reversibly from 5.00L to 12.5 L. Calculate the change in internal energy. (A) -346 J (B) -206 J (C) -149 J (D) -100 J 15. A refrigerator is maintained at -25˚ in a room temperature of 35˚C. The heat temperature into the refrigerator is estimated as 104 J/min. Assuming the unit is operating at 45% of its maximum thermodynamic efficiency, determine its power requirement in watts. (A) 40 W (B) 80 W (C) 120 W (D) 160 W 16. A process is said to be isentropic if and only if (A) The process is reversible (B) The process is adiabatic (C) The process is both adiabatic and reversible (D) The process is neither adiabatic nor reversible 17. At 25 ˚C, for the reaction 2NO2 (g)↔ N2O4 (g) the values of ∆H˚ and ∆S˚ are -58.03 kJ/mol and -176.6 J K-1 mol-1, respectively. Calculate the value of K at 25˚C.

(A) (B) (C) (D)

0.872 8.72 87.2 872

18. At 1000 K and 1 atm, CO2 is 60% dissociated to CO and O2. Its percentage dissociation when the pressure is decreased to 0.5 atm is (A) 57% (B) 67% (C) 77% (D) 87% 19. The ratio of coefficient of thermal expansion, 𝛼 and isothermal compressibility 𝜅𝜏 is equivalent to

(∂𝑉∂𝑇)𝑃 ∂𝑃 (B) (∂𝑉)𝑇 ∂𝑃 (C) (∂𝑇)𝑉 ∂𝑉 (D) (∂𝑃)𝑇 (A)

20. Which of the following statements is CORRECT? (A) The heat of formation of elements is positive (B) For reactions involving solids and liquid, FHHrxn is always greater than UUrxn (C) In the calculation of heat of reaction from bond enthalpies, compounds with ionic and covalent bonds are considered (D) None of these 21. Steam flows at steady state through a converging insulated nozzle, with an outlet diameter of 1 cm. At the nozzle entrance, the temperature and pressure are 300˚C and 500 kPa. At the nozzle exit, the steam temperature and pressure are 200˚C and 100 kPa and velocity is 610 m/s. Calculate the diameter at the nozzle entrance. Temperature (˚C) Pressure Specific Enthalpy Specific Volume (MPa) (kJ/kg) (m3/kg) 300 0.5 3064.2 0.5226 200 0.1 2875.3 2.1720 (A) 1.0 cm (B) 1.4 cm (C) 1.8 cm (D) 2.0 cm 22. At pH = 7 and pressure of 1 bar, the cell potential for the half reaction 2H+(aq) + 2e-→ H2 (g) is ___ (A) 0 V (B) -0.0414 V (C) -0.828 V

(D) -1.255 V 23. A sphere of radius 5 x 10-2 cm and density of 1.10 g/cc falls at constant velocity through a liquid of density 1.0 g/cc and viscosity of 1.00 poise. What is the velocity of the falling sphere? (A) 0.0545 cm/s (B) 0.00545 cm/s (C) 0.545 cm/s (D) 5.45 cm/s 24. A solution of benzene and toluene is distilled at a total reflux and the equilibrium liquid composition analyzes 45% mole toluene. Calculate the temperature at which this solution boils if the total pressure is 760 mm Hg. Assume ideal behavior for both phases existing at equilibrium. Antoine Constants [Form: log Psat (mmHg) = A – B* (t˚C + C) -1] COMPOUND Benzene Toluene (A) (B) (C) (D)

A 6.89272 6.95805

B 1203.531 1346.773

C 219.888 219.693

72.13˚C 85.55˚C 90.70˚C 96.53˚C

25. Which of the following affects the equilibrium constant? (A) Concentration of reagents (B) Temperature (C) Concentration of products (D) All of these 26. Ammonia decomposes isothermally in a rigid vessel according to the reaction: 2NH3 (g) → N2 (g) + 3H2 (g). Initially, the pressure of the vessel was noted to be 780 mm Hg. Calculate the fraction of ammonia dissociated if the pressure of the resulting mixture increased to 890 mm Hg and ammonia was the only gas present at the start of the reaction. (A) 7% (B) 14% (C) 21% (D) 28% 27. Generally, the viscosity of a gas _______ as temperature increases. (A) Increases (B) Decreases (C) Remains the same (D) None of these 28. A reaction has k = 1.77 x 10-6 M-1 s-1 at 25.0˚C and an activation energy of 20.0 kJ/mol. What is the value of rate constant at 100˚C? (A) 2.08 x 10-6 M-1 s-1

(B) 4. 16 x 10-6 M-1 s-1 (C) 8.32 x 10-6 M-1 s-1 (D) 16.64x 10-6 M-1 s-1 29. At what temperature will CO2 (g) move twice as fast as N2 (g) at 300K? (A) 471.43 ˚C (B) 513.25˚C (C) 669.71˚C (D) 942.86˚C 30. Based on kinetic theory of gases, the rate of diffusion of O2 at 0˚C would be _____ times that of CO2 at 50˚C. (A) 1.73 (B) 1.08 (C) 0.98 (D) 0.87 31. Which of the following cases might have been applied if the equilibrium position for the given reaction below shifted to the right? CO (g) + H2O (g) ↔H2 (g) + CO2 (g) (Exothermic) (A) The pressure was increase by adding helium gas (B) The temperature was increased (C) The pressure was increase by decreasing the volume of the container (D) Gaseous carbon dioxide was removed 32. A liquid with high boiling pint has _____ vapor pressure. (A) Low (B) High (C) Constant (D) Zero 33. An atmospheric chemist studying the reaction of the pollutant SO2 places a mixture of SO2 and O2 in a 3.57L container at 819 K and an initial pressure of 1.95 atm. When the reaction occurs, gaseous SO3 forms, and the pressure eventually falls to 1.65 atm. How many grams of SO3 form? (A) 1.28 g (B) 2.55 g (C) 3.97 g (D) None of these 34. How many grams of HgO (216.58) are needed to prepare 2.5L of O2gas that is collected over H2O at 25˚C and 740 torr? (A) 33.6 g (B) 38.4 g (C) 41.7 g (D) 45.6 g

35. What volume of F2 gas, at 25 ˚C and 1.00 atm, is produced when molten KF is electrolyzed by a current of 10.0 A for 2.00 h? (A) 5.12 L (B) 9.12 L (C) 12.12 L (D) 19.12 L 36. Determine the total equilibrium pressure of the vapor in equilibrium with a 1:1 molar ratio of hexane and cyclohexane, if the equilibrium vapor pressure of the two components are 151.4 and 97.6 torr, respectively. (A) 722.50 torr (B) 598.00 torr (C) 249.00 torr (D) 124.50 torr 37. In an Ostwald Viscometer, assume all other parameters are constant, the viscosity of an unknown fluid changes by a factor ______ is the radius if halved. (A) 1/8 (B) 1/16 (C) 8 (D) 16 38. Which of the following is NOT correct about ideal gas? (A) Intermolecular forces of attraction may be considered negligible (B) Collision of molecules accompanies conservation of kinetic energy and momentum. (C) Individual volume of molecules may be considered negligible compared to the total volume of the gas. (D) The product pressure and volume of an ideal gas is always constant. 39. Consider a sample of hydrocarbon at 0.959 atm and 298 K. Upon combusting the entire sample in oxygen, you collect a mixture of gaseous CO2 and H2O at 1.51 atm and 375K. This mixture has a density of 1.391 g/L and occupies a volume four times as large as that of the pure hydrocarbon. Determine the molecular formula of the hydrocarbon. (A) C2H6 (B) C3H8 (C) C2H2 (D) C4H10 40. A sample of dry nitrogen gas weighing 100.0 g is bubbled through liquid water at 25˚C. The gaseous mixture of nitrogen and water vapor escapes at a total pressure of 700 torr. What mass of water has vaporized? (P˚ H2O at 25˚C= 23.8 torr) (A) 1.00 g (B) 2.25 g (C) 5.00 g (D) 6.75 g

41. Before mixing 50 mL of 1.0 M HNO3 and 51mL of 1.0 M NaOH, the temperature of the reactant was 23.1˚C. After mixing, the temperature of the reaction was 29.4˚C. The specific heat of the reaction mixture is 3.89 J/g˚C and 1.04 g/mL, From this information, calculate the heat of neutralization of the reaction. (A) -5.3 x 10-4 J/mol (B) -2.6 x 10-3 J/mol (C) -2.5 x 104 J/mol (D) -6.2 x 103 J/mol

CHEMICAL ENGINEERING REFRESHER COURSE PHYSICAL CHEMISTRY AND THERMODYNAMICS 1. A mixture of 660 grams of camphor and 0.050 grams of an organic solute freezes at 157˚C. If the solute contains 10.5% H by weight, determine the molecular formula of the solute. The freezing point of the camphor is 178.4˚C and the value of its KI is 38. (A) C10H12 (B) C2H6 (C) C6H6 (D) C6H16 2. The equilibrium constant K for the dissociation N2O4 into nitrogen dioxide is 4.63x10-3 at 25˚C. What is the value of its Kp at this temperature? (A) 0.592 (B) 0.841 (C) 0.113 (D) 0.495 Naphthalene melts at80.2˚C. If the vapor pressure of the liquid is 10 torr at 85.8˚C and 40 torr at 119.3˚C, 3. Calculate the normal boiling point. (A) 453 K (B) 550 K (C) 467 K (D) 489K 4. Calculate the entropy of vaporization at the boiling point. (A) 99 J/mol-K (B) 99 kJ/mol-K (C) 9.9 J/mol-K (D) 9.9 kJ/mol-K The temperature dependence of the vapor pressure of solid and liquid SO2 can be approximated by the following relationships respectively: Log (P/Torr) = 10.5916 – 1871.2 / (T/K) Log (P/Torr) = 8.3186 – 1425.7 / (T/K) 5. Estimate the pressure of the triple point of SO2 (A) 111 Torr (B) 11.1 Torr (C) 1045 Torr (D) 1.045 Torr

6. If ethanol and methanol are mixed 50/50 by weight at 60˚C and the solution assumed to be ideal, what is the vapor above the solution? (A) 59% ethanol, 41% methanol (B) 41% ethanol, 59% methanol (C) 72% ethanol, 28% methanol (D) 28% ethanol, 72% methanol 7. If 10.0 A of current were passed through a lead storage cell for 1.5 hours during a charging process, how much PbSO4 would decompose? (A) 85 grams (B) 170 grams (C) 255 grams (D) None of the abovE 8. Which of the following is another name for a dry cell? (A) Galvanic Cell (B) Daniell cell (C) Leclanche cell (D) None of the above 9. Given ∆G298/kJ-mol-1 = 0 for Zn(s) and Cu(s), -147.06 for Zn2+(aq) and 65.49 for Cu2+ (aq), calculate the cell potential at the given condition. (A) 1.101 V (B) 1.011 V (C) 1.010 V (D) 1.110 V 10. What can be concluded about the previously described cell? (A) It is spontaneous at the given condition (B) It is non-spontaneous at the given condition (C) It may be both spontaneous and non-spontaneous at the given condition (D) Its spontaneity cannot be determined at the given condition 11. Polonium is an example of metal that follows which crystal structure? (A) Tetragonal (B) Hexagonal (C) Cubic (D) Rhombic 12. At the triple point of water, ice, liquid water and water vapor are in equilibrium pressure of 4.58 mmHg. At this temperature, the heat of fusion and vaporization of water is 1436 cal/mole and 10,767 cal/mole respectively. Find the heat of sublimation of ice. (A) 9331 cal/mole (B) 7895 cal/mole (C) 13,639 cal/mole (D) 12,203 cal/mole

13. From the previous problem, what is the corresponding entropy of sublimation per mole of the substance? (A) 44.7 eu/mole (B) 49.93 eu/mole (C) 28.90 eu/mole (D) 34.16 eu/mole 14. Calculate the change in the molar Gibbs free energy of hydrogen gas when it is compress isothermally from 1 atm to 100 atm at 298K. (A) 15 kJ/mole (B) 11 kJ/mole (C) -15 kJ/mole (D) -11 kJ/mole A sample of 3.0 moles of a perfect diatomic gas at 200K is compressed reversibly and adiabatically until its temperature reaches 250 K. Given that Cv = 27.5 J/mol-K, 15. Calculate the work associated with the process. (A) 0 J (B) -4.1 x 103 J (C) 4.1 x 103 J (D) 5.4 x 103 J 16. Calculate the change in the enthalpy of the system. (A) 0 J (B) -4.1 x 103 J (C) 4.1 x 103 J (D) 5.4 x 103 J 17. An Ostwald viscometer was calibrated using water at 25˚C (𝜂=8.9x10-4 Pa-s and density = 1.00 x 103 kg/m3). The same viscometer was used at 193˚C to determine the viscosity of liquid air (density = 0.92 x 103 kg/m3). Assuming that the time ratio of water to liquid air is 0.193 and neglecting volume changes, find the above mentioned quantity. (A) 4.30 x 103 Pa-s (B) 2.15 x 10-3 Pa-s (C) 1.6x10-7 Pa-s (D) None of the above 18. Calculate the ∆H˚r-298 for the hydrogen of benzene of cyclohexane given that the enthalpies of combustion at 20˚C are -3273, -286.1 and -3924 kJ/mol for benzene, hydrogen and cyclohexane respectively. (A) -311 kJ (B) -207 kJ (C) -104 kJ (D) None of the above

19. The latent heat of vaporization of water at atmospheric pressure is 970 BTU/lbm. During the vaporization process, the specific volume changes from 0.01672 ft3/lbm to 26.8 ft3/lbm. What is the change in integral energy? (A) -897 BTU/lbm (B) +897 BTU/lbm (C) -970 BTU/lbm (D) +970 BTU/lbm 20. What is the specific gas constant of dry air in J/kg per unit Kelvin? (A) 0.287 (B) 2.87 (C) 28.7 (D) 287 21. Ethane, when used as a refrigerant will be named as: (A) R-170 (B) R-161 (C) R-271 (D) None of the Above 22. A refrigerator has an input rating of about 500 kW and can absorb heat that is three times its power requirement. What is the coefficient of performance of this engine when operated as a heat pump? (A) 3 (B) 4 (C) 5 (D) None of the Above 23. Which of the following relationships is not true?

(∂𝐴∂𝑉)𝑇 = ‒ 𝑇 ∂𝐺 (F) (∂𝑇)𝑃 = ‒ 𝑆 ∂𝐻 (G) ( ∂𝑃 )𝑆 = 𝑉 ∂𝑈 (H) (∂𝑉)𝑆 = 𝑃 (E)

24. A supply line carries a two phase liquid vapor mixture of steam t 300 lb/in2. A small fraction of the flow in the line is diverted through a throttling calorimeter and exhausted to the atmosphere at 14.7 lb/in2 and a temperature of 250˚F. Determine the quality of the supply steam. (A) 0.74 (B) 0.86 (C) 0.91 (D) 0.96 25. Fifty five gallons of water passes through a heat exchanger and absorbs 28,000 BTU of heat. The exit temperature is 570 R. What is the inlet water temperature in ˚F? (A) 68

(B) 56 (C) 49 (D) 41 26. This kind of process does not involve any amount of heat transfer. (A) Isothermal (B) Reversible (C) Isentropic (D) None of the Above 27. A system consists of moist air and water inside a closed container. What is this system’s degree of freedom? (A) 0 (B) 1 (C) 2 (D) 3 28. Which of the following uses steam as a typical working fluid? (A) Stirling cycle (B) Ericsson cycle (C) Reheat cycle (D) Diffusing cycle 29. A cylinder fitter with a weightless, frictionless piston contains m pounds of air at T1, V1 and ambient pressure Pa. Heat is then added until the air in the cylinder is at T2, V2 and Pa. What is the expression for the heat transferred during the process? (A) mCv( T2 – T1) (B) mCv( T2 – T1) – Pa(V2 – V1) (C) mCv( T2 – T1) + Pa(V2 – V1) (D) mCp( T2 – T1) + Pa(V2 – V1) 30. A tank holds Nitrogen gas at 82˚C and 940 mmHg. After releasing 2 grams of the gas, the remaining contents inside the tank then exerts a pressure of 480 mmHg at 30˚C. How much nitrogen gas was originally in the tank? (A) 3.0 g (B) 5.0 g (C) 139.4 g (D) 154.3 G 31. A Carnot engine, operating between 70˚F and 2000 ˚F, is modified by raising the high temperature to 2150 ˚F and raising the low temperature to 100˚F. Which of the following statements is incorrect? (A) More heat is absorbed during vaporization (B) More work is done during the reversible adiabatic expansion (C) Net work is increased (D) Thermodynamic efficiency is decreased 32. The state of a thermodynamic system is always defined by its ___________.

(A) (B) (C) (D)

Absolute temperature Process Pressure Properties

33. If 6 L of a gas at a pressure of 100 kPa are compressed reversible according to PV2= C until the volume is a third of its original amount, how much work was used for the compression? (A) +600J (B) -600J (C) +1200J (D) -1200J 34. Which of the following processes is accompanied by an increase in entropy? (A) Condensation of water vapour (B) Formation of ice (C) Melting of ice (D) Isothermal compression of air 35. In a constant volume, non-flow process, this quantity may be considered zero. (A) Internal energy (B) Enthalpy (C) Heat (D) Work 36. What is the Carnot efficiency an ideal reversible heat engine operating between 1540˚F and 340˚F? (A) 22% (B) 40% (C) 60% (D) 78% Air will be compressed with the use of a compressor that has shaft work of 240 kJ/kg and will further releases using a nozzle. The initial velocity is zero with 1 bar as its initial pressure under 250˚C temperature. The pressure at the end of the compressor has been measured to be 3 bars. The velocity and pressure after the nozzle is said to be 600m/s and 1 bar respectively. The entire system works in an isothermal condition. 37. Calculate for the change in kinetic energy involved in the process. (A) 60 kJ/kg (B) -60 kJ/kg (C) 360 kJ/kg (D) 0 38. Calculate for the heat involved for the same process in the previous problem. (A) 60 kJ/kg (B) -60kJ/kg (C) 360 kJ/kg

(D) 0 39. Based on the limitations imposed by the 2nd Law, what is the maximum power output from a unit using 1 x 106 BTU/hr of fuel, operating between 1540˚F and 40˚F? (A) 98 hp (B) 295 hp (C) 1140 hp (D) 3820 hp 40. The fugacity coefficient of a certain gas at 200 K and 50 bar is 0.72. Calculate the difference if its chemical potential from that of a perfect gas in the same state. (A) -0.25 kJ/mole (B) 0.25 kJ/mole (C) -0.55 kJ/mole (D) 0.55 kJ/mole

CHEMICAL ENGINEERING REFRESHER COURSE

PHYSICAL CHEMISTRY AND THERMODYNAMICS 1. A brayton cycle compresses air to a pressure of 88.2 psia. Three moles of air are entering at 25°C with a Cp of (7/2)R. If the cycle receives heat at 560 Btu/mol, what is the maximum amount of work it produces? (A). 1680 Btu (B). 1008 Btu (C). 672 Btu (D). 224 Btu 2. What is the efficiency of a diesel cycle with air as working fluid (ϒ=1.4) and compresses air adiabatically to 1/6 of its original volume and adiabatically expands the air to three times the volume at constant pressure stage? (A). 0.5717 (B). 0.4283 (C). 0.8167 (D). 0.1833 3. Eight grams of oxygen gas at 27°C and 10 atm expands adiabatically and reversibly to a final pressure of 1.0 atm. The work done in the process is (A). 842 J (B). 445 J (C). 798 J (D). 752 J 4. A supply line carries a two phase liquid vapour mixture of steam at 300 lbf/in2. A small fraction of the flow in the line is diverted through a throttling calorimeter and exhausted to the atmosphere at 14.7 lbf/in2 and a temperature of 250°F. Determine the quality of the supply steam. (A). 0.74 (B). 0.86 (C). 0.91 (D). 0.96 5. An inventor claimed that he has devised an engine that absorbs 1000 kW of heat from the heat source and discards 700 kW of heat to the heat sink. If the engine operates between 500K and 200K, is the inventor's claim valid? (A). Yes (B). No (C). Maybe (D). Cannot be determined 6. Fifty five gallons of water passes through a heat exchanger and absorbs 28,000 BTU of heat. The exit temperature is 570R. What is the inlet water temperature in F? (A). 68 (B). 56

(C). 49 (D). 42 7. Which of the following processes do not involve any amount of heat transfer? (A). Isothermal (B). Isochoric (C). Isentropic (D). Isenthalpic 8. A system consists of moist air and water inside a closed container. What is this system's degree of freedom? (A). 0 (B). 1 (C). 2 (D). 3 9. The turbine in a hydroelectric plant is fed by water falling from a height of 30 m. Assuming 95% efficiency in converting potential energy to electrical energy and 10% loss of resulting power during transmission, how many metric tons of water per hour are needed to keep a 100W light bulb burning? (A). 1.43 (B). 1.29 (C). 1.63 (D). 1.75 10. A tank holds nitrogen gas at 82°C and 940 mmHg. After releasing 2 grams of the gas, the remaining contents inside the tank then exert a pressure of 480 mmHg at 30°C. How much nitrogen gas was originally in the tank? (A). 3.0 g (B). 5.0 g (C). 139.4 g (D). 154.3 g 11. A Carnot engine, operating between 70°F and 2000°F, is modified by raising the high temperature to 2150°F and raising the low temperature by 100°F. Which of the following statements is incorrect? (A). More heat is absorbed during vaporization (B). More work is done during the reversible adiabatic expansion (C). Net work is increased (D). Thermodynamic efficiency is increased 12. If 6 liters of a gas at a pressure of 100 kPa are compressed reversibly according to PV2 = C until the volume is a third of its original amount, how much work was used for the compression? (A). + 600 J (B). - 600 J (C). + 1200 J (D). - 1200 J

13. Which of the following processes is accompanied by an increase in entropy? (A). condensation of water vapour (B). formation of ice (C). melting of ice (D). isothermal compression air 14. For a closed system, which of the following statements is false? (A). An example of which is a gas in a fitted cylinder. (B). In an isobaric process, the hear involved is equal to the change in the enthalpy of the system. (C). In an adiabatic process, the work involved is equal to the change in the internal energy of the system. (D). In an isothermal process, the both the changes in internal energy and enthalpy are equal to zero. 15. A heat engine absorbs heat from the combustion of gasoline at 2200°C. The gasoline has a specific gravity of 0.8 and a heat of combustion of 11,200 cal/gram. The engine rejects heat at 1200°C. The maximum work in calories that can be obtained from 1 liter of gasoline is (A). 3.62 x 106 cal (B). 4.53 x 106 cal (C). 3.78 x 106 cal (D). 4.22 x 106 cal 16. The first law of Thermodynamics states that: (A). Heat energy cannot be completely transformed into work (B). Internal energy is due to molecular action (C). Heat can only be transferred from a bosy of higher temperature to one that is lower (D). Energy can neither be created nor destroyed Air will be compressed with the use of a compressor that has a shaft work of 240 kJ/kg and will be further released using a nozzle. The initial velocity is zero with 1 bar as its initial pressure under 250°C temperature. The pressure at the end of the compressor has been measured to be 3 bars. The velocity and pressure after the nozzle is said to be 600 m/s and 1 bar respectively. The entire system works in an isothermal condition. 17. Calculate the change in the system's kinetic energy. (A). 60 kJ/kg (B). -60 kJ/kg (C). 360 kJ/kg (D). 0 18. Calculate the heat involved in the system. (A). 60 kJ/kg (B). -60 kJ/kg (C). 360 kJ/kg

(D). 0 19. A newly designed air-conditioning unit has a capacity of 3140 watts and an input rating of 735 watts. If this machine is operated as a heat pump, its coefficient of performance is (A). 4.27 (B). 5.27 (C). 4.44 (D). 5.67 20. The latent heat of vaporization of water at atmospheric pressure is 970 BTU/lbm. During h vaporization process, the specific volume changes from 0.01672 ft3/lbm to 26.6 ft3/lbm. What is the change in the internal energy? (A). -897 BTU/lbm (B). +897 BTU/lbm (C). -970 BTU/lbm (D). +970 BTU/lbm 21. If ethanol and methanol are mixed 50/50 by weight at 60˚C and the solution assumed to be ideal, what is the composition of the vapor above the solution? (A). 59% ethanol, 41% methanol (B). 41% ethanol, 59% methanol (C). 72% ethanol, 28% methanol (D). 28% ethanol, 72% methanol Naphthalene melts at 80.2˚C. If the vapor pressure of the liquids is 10 torr at 85.8˚C and 40torr at 119.3˚C, 22. Calculate the normal boiling point: (A). 453 K (B). 550 K (C). 467 K (D). 489 K The temperature dependence of the vapor pressure of solid and liquid SO2 can be approximated by the following relationships respectively: Log (P/Torr) = 10.5916 – 1871.2 / (T/K) Log (P/Torr) = 8.3186 – 1425.7 / (T/K) 24. Estimate the temperature of the triple point of SO2. (A). 19.6 K (B). 196 K (C). 19.6 ˚C (D). 196 ˚C 25. Estimate the pressure of the triple point of SO2 (A) 111 Torr (B) 11.1 Torr (C) 1045 Torr

(D) 1.045 Torr 26. If 10.0 A of current were passed through a lead storage cell for 1.5 hours during a charging process, how much PbSO4 would decompose? (A) 85 grams (B) 170 grams (C) 255 grams (D) None of the above 27. Which of the following is another name for a dry cell? (A) Galvanic Cell (B) Daniell cell (C) Leclanche cell (D) None of the above 28. Given ∆G298/kJ-mol-1 = 0 for Zn(s) and Cu(s), -147.06 for Zn2+(aq) and 65.49 for Cu2+ (aq), calculate the cell potential at the given condition. (A) 1.101 V (B) 1.011 V (C) 1.010 V (D) 1.110 V 29. What can be concluded about the previously described cell? (A) It is spontaneous at the given condition (B) It is non-spontaneous at the given condition (C) It may be both spontaneous and non-spontaneous at the given condition (D) Its spontaneity cannot be determined at the given condition 30. At the triple point of water, ice, liquid water and water vapor are in equilibrium pressure of 4.58 mmHg. At this temperature, the heat of fusion and vaporization of water is 1436 cal/mole and 10,767 cal/mole respectively. Find the heat of sublimation of ice. (A) 9331 cal/mole (B) 7895 cal/mole (C) 13,639 cal/mole (D) 12,203 cal/mole 31. What is the corresponding entropy of sublimation per mole of the substance? (A) 44.7 eu/mole (B) 49.93 eu/mole (C) 28.90 eu/mole (D) 34.16 eu/mole 32. The evidence that the solute does not freeze with the solvent is that: (A) The first crystals formed are precipitates od the solute (B) The crystals formed could clearly be seen as that of the solution (C) The freezing point of the solution that remains liquid is getting lower and lower as freezing proceeds (D) The freezing point asymptotically approaches a constant value

33. All of the following increases the strength of Van der Waals forces between molecules except by an (A) Increase in the molecular weight of the molecules (B) Increase in the number of atoms in the molecules (C) Increase in the number of electrons in the molecules (D) Increase in the ionic strength of the molecules 34. Calculate the change in the molar Gibbs free energy of hydrogen gas when it is compress isothermally from 1 atm to 100 atm at 298K. (A) 15 kJ/mole (B) 11 kJ/mole (C) -15 kJ/mole (D) -11 kJ/mole A sample of 3.0 moles of a perfect diatomic gas at 200K is compressed reversibly and adiabatically until its temperature reaches 250 K. Given that Cv = 27.5 J/mol-K, 35. Calculate the work associated with the process. (A) 0 J (B) -4.1 x 103 J (C) 4.1 x 103 J (D) 5.4 x 103 J 36. Calculate the change in the enthalpy of the system. (A) 0 J (B) -4.1 x 103 J (C) 4.1 x 103 J (D) 5.4 x 103 J 37.Calculate the entropy suffered by the system. (A) 0 J (B) -4.1 x 103 J (C) 4.1 x 103 J (D) 5.4 x 103 J 38. An Ostwald viscometer was calibrated using water at 25˚C (𝜂=8.9x10-4 Pa-s and density = 1.00 x 103 kg/m3). The same viscometer was used at 193˚C to determine the viscosity of liquid air (density = 0.92 x 103 kg/m3). Assuming that the time ratio of water to liquid air is 0.193 and neglecting volume changes, find the above mentioned quantity. (A) 4.30 x 103 Pa-s (B) 2.15 x 10-3 Pa-s (C) 1.6x10-7 Pa-s (D) None of the above 39. Calculate the ∆H˚r-298 for the hydrogen of benzene of cyclohexane given that the enthalpies of combustion at 20˚C are -3273, -286.1 and -3924 kJ/mol for benzene, hydrogen and cyclohexane respectively. (A) -311 kJ (B) -207 kJ

(C) -104 kJ (D) None of the above 40. The fugacity coefficient of a certain gas at 200K and 50 bars is 0.72. Calculate the difference of its chemical potential from that of a perfect gas in the same state. (A) -0.25 kJ/mole (B) 0.25 kJ/mole (C) -0.55 kJ/mole (D) 0.55 kJ/mole

CHEMICAL ENGINEERING REFRESHER COURSE UNITS OPERATIONS 1 1. Which of the following statements is not true? (A.) Potential flow is the flow of incompressible fluids with no shear. (B.) For calculations involving fans, incompressible-flow theory is not adequate. (C.) In pumps and fans, the density of the fluid does not change appreciably. (D.) In blowers and compressors, the density increase of the fluid is very high and compressible-flow theory is required. 2. What is the viscosity of methane at 75°F (A.) 1.2x10-5 Pa-s (B.) 1.2x10-4 Pa-s (C.) 0.018 cp (D.) 0.009 cp 3. Determine the relative volatility of n-butane/n-pentane mixture at 30°C and 1 atm abs. (A.) 2.55 (B.) 3.04 (C.) 3.46 (D.) 4.28 For Numbers 4 and 5 Cooling water at 22°C flows through a 25mm inside diameter smooth tube of length 10m. If the pressure drop throughout the pipe is 20 kN/m2, 4. What is the velocity of water in the pipe? (A.) 2.24 m/s (B.) 3.11 m/s (C.) 3.41 m/s (D.) 4.68 m/s 5. What is the mass flow rate at the outlet of the pipe? (A.) 1.01 kg/s (B.) 1.12 kg/s (C.) 1.73 kg/s (D.) 2.14 kg/s For Numbers 6, and 7: Steam is flowing through an adiabatic throttling valve (no heat loss and no external work). Steam enters upstream of the valve at 689 kPa absolute and at 171.1°C. It leaves the valve at 330.2 kPa absolute. 6. Estimate the enthalpy of the inlet steam in kJ/kg. (A.) 2605 (B.) 2774 (C.) 2910

(D.) 2963 7. What will be its outlet temperature? (A.) 171.1 °C (B.) 161 °C (C.) 132 °C (D.) 120 °C 8. Calculate the equivalent diameter of a 200 mm by 300 mm rectangular duct through which air flows. (A.) 0.06 m (B.) 0.12 m (C.) 0.24 m (D.) 0.29 m For Problems 9, 10 and 11: 600 mL/s of water at 320 K is pumped in a 40 mm inside diameter pipe through a total length of 150 m in a horizontal direction and up through a vertical height of 10 m. In the pipe there is as control valve which may be taken as equivalent to 200 pipe diameters and there are other fittings equivalent to 60 pipe diameters. Also, in the line there is a heat exchanger across which there is a loss in head of 1.5 m of water. If the main pipe has a roughness of 0.0002 m and the overall pump efficiency is 60%. 9. How much is the head loss due to the valve and fittings? (A.) 1.1 j/kg (B.) 1.1x103 j/kg (C.) 9.1x106 j/kg (D.) 9.1x107 j/kg 10. What is the total dynamic head? (A.) 2.3x107 j/kg (B.) 2.2x106 j/kg (C.) 130 j/kg (D.) None of these 11. What is the power requirement of the pump? (A.) 130 W (B.) 1.3x102 j/kg (C.) 1.3x103 kW (D.) 1.3x102 kW 12. Water at 20°C flows at 3m3/hr through a sharp-edged 3 cm dia. orifice in a 6cm dia. pipe. Estimate the pressure drop across the orifice. (A.) 490 Pa (B.) 725 Pa (C.) 1358 Pa (D.) 1751 Pa

13. Water flows at 1200 gpm through an 8 inch inside dia. pipe. A pitot tube is inserted at the centerline of the pipe. If the differential head is 1.42 ft of water, what should be the velocity at the center of the pipe in ft/s? (A.) 9.6 (B.) 9.1 (C.) 8.4 (D.) 7.6 14. Methane is to be compressed from 40°F, 20 psia to 80 psia in an adiabatic single stage compressor. Estimate the power required to handle 100ft3/min (measured at 60°F and 1 atm). For methane, cp/cv=1.31. (A.) 6.6 kW (B.) 10.1 kW (C.) 10.1 hp (D.) 14.5 hp 15. Methane gas is being pumped through a 305 ms length of 52.5 mm i.d, steel pipe at the rate of 41 kg/(m2-s). If the inlet pressure is to be 345.1 kPa abs, what is the velocity of the gas at the outlet in m/s? Assume constant temperature of 288.8 K. (A.) 14.9 (B.) 20.6 (C.) 258.1 (D.) 387.4 16. A slurry of CaCO3 in water is filtered in a Plate and Frame filter press with a total area of 86.1 ft2, and operated at constant pressure drop of 2 atm. The mass of dry cake collected is 742 lbs and the volume collected is 68.1 ft3. The following data have been determined for the said slurry. Viscosity= 0.982 cp; specific resistance= 1.27x1011 ft/lb; resistance due to the filter medium= 1.55x1010/ft. Calculate the filtration time in minutes (A.) 28 (B.) 36 (C.) 42 (D.) 48 17. In the filtration of sludge, the initial period is effected at a constant rate with the feed pump at full capacity until the pressure differential reaches 400 kPa. The pressure is then maintained at this value for a remainder of the filtration. The constant rate operation requires 900 seconds and 1/3 of the total filtrate is obtained during this period. No washing of the cake is done. If the time for removing the cake and reassembling the press is 1200 seconds determine the total time per cycle. (A.) 5700 s (B.) 5100 s (C.) 4500 s

(D.) 4015 s 18. Ammonia gas is diffusing using through nitrogen under steady-state conditions with nitrogen non-diffusing since it is insoluble in one boundary. The total pressure is 1 atm and T= 25 °C. The partial pressure of ammonia at one point is 1.333x104 N/m2 and at the other point 20 mm away it is 6.666 kPa. The diffusivity for the mixture is 2.30x10-5 m2/s. How much ammonia is diffusing in kg-mols/(s-m2)? (A.) 2.74x10-6 (B.) 3.11x10-6 (C.) 3.44x10-6 (D.) 3.41x10-5 19. Determine the amount of ammonia diffusing in kg-mols/(s-m2) for Problem 18 for equimolal counterdiffusion. (A.) 2.74x10-6 (B.) 3.11x10-6 (C.) 3.44x10-6 (D.) 3.41x10-5 20. One hundred mols of 15% by mole n-butane/n-pentane mixture is distilled until the the residual liquid contains 45.5 mols. Using the value of the relative volatility obtained in Problem 3, find the average concentration of the distillate by mol % butane. (A.) 20.6 (B.) 24.7 (C.) 32.4 (D.) 48.5 21. An equimolal mixture of benzene and toluene is subjected to flash distillation at a separator pressure of 1 atm. If 40% of the charge is vaporized, at what temperature will the vapour and liquid separate? (A.) 76.5 °C (B.) 82.1 °C (C.) 95 °C (D.) 106 °C 22. Nitrobenzene is to be open-stream distilled at 125.8°C at a vacuum of 26 “ Hg. How many pounds of steam will be theoretically required to collect 2000 pounds of pure nitrobenzene? (A.) 93 (B.) 114 (C.) 193 (D.) 232 23. One hundred kgmols/hr of 40 mole % benzene- toluene mixture is fractionated in a plate column at 1 atm. The overhead product must contain 95 mole % benzene and the bottoms must contain 95 mole % toluene. The feed is saturated liquid. If the actual reflux ratio is to be twice the minimum, determine the kgmols per hour of the overhead vapor? (A.) 38.9

(B.) 43.7 (C.) 61. 5 (D.) 157.9 For Problems 24 and 25; Benzene in an air/benzene mixture is to be removed in a gas absorber using hydrocarbon oil (M=200). The absorber operates at constant temperature of 80°F and at a pressure of 1 atm. The mixture enters the bottom of the tower at a rate of 600 lbmoles/hr containing 5% benzene by volume. 24. Assuming Raoult’s law applies, determine the minimum liquid flow rate in lbs/hr to recover 90% of the entering benzene. Assume the vapour pressure of benzene at 80°F is 103 mmHg. (A.) 15725 (B.) 12450 (C.) 10879 (D.) 9285 25. If the actual oil rate used is 1.5 times the minimum, determine the number of theoretical stages. (A.) 5 (B.) 7 (C.) 8 (D.) 9 For Numbers 26 and 27: Air in the amount of 1000 cfm at 150°F, 20% RH is passed over refrigerated coil and thereby brought to 60°F, 90% RH with the condensed moisture withdrawn at 55°F. The air is then reheated by means of an electric heating coil to 150°F. 26. Estimate the amount of heat removed by the refrigerated coil in tons of refrigeration. (A.) 15 (B.) 22 (C.) 29 (D.) 37 27. How much heat in kW is to be supplied by the heating of coil? (A.) 25 (B.) 18 (C.) 12 (D.) 8 28. A wet solid is dried in a batch drier under constant drying conditions from 25 % db to 10 % db in 4.17 hours. The critical moisture content is 15 % db and the equilibrium moisture content is 5 % db. How long will it take to drythe solid from 30 % db to 8 % db under the same drying conditions? (A.) 6.66 hrs

(B.) 4.44 hrs (C.) 2.65 hrs (D.) 1.44 hrs For Numbers 29 and 30: Wet solid is fed to a drier with at the rate 0.3 kg/s and the moisture removed is 35% of the wet charge. The feed stock enters and leaves the drier at 324 K. Air enters the drier counter currently at a dry bulb temperature of 341 K and absolute humidity 0.01 kg H2O/kg d.a., and it leaves at a dry bulb temperature of 310 K and absolute humidity 0f 0.02 kg H2O/kg d.a.. 29. What is the volumetric flow rate of entering air assuming the total pressure is 1 atm? (A.) 523 m3/s (B.) 519 m3/min (C.) 1663.9 m3/hr (D.) 617 m3/min 30. Determine the amount of heat lost from the drier in kW. (A.) 135 (B.) 108 (C.) 89 (D.) 61

CHEMICAL ENGINEERING REFRESHER COURSE UNIT OPERATIONS II 1. A finely ground mixture of galena and limestone in the proportion of 1 to 4 by weight is subjected to elutriation by an upward current of water flowing at 5 mm/s. Assuming that the size distribution for each material is the same as shown by the table below: Diameter, microns Percentage by weight of undersize

20 30 40 50 60 70 80 15 28 48 54 64 72 78

100 88

Take the absolute value of water as 1 mN-s/m2, specific gravity of galena = 7.5, specific gravity of limestone = 2.7 and use Stokes’ equation. On the basis of 100 kg of feed, the percentages of galena in the material carried away in the material left behind are (A) (B) (C) (D)

87.28% & 64.59% 12.72% & 35.41% 12.72% & 87.28% 35.41% & 65.59%

2. A tower having a diameter of 0.1524 m is being fluidized with water at 20.2oC. Water at 20.2oC has a density = 997.5 kg/m3 and viscosity = 1 x 10-3Pa-s. The uniform spherical beads in the tower bed have a diameter of 4.42 mm and a density if 1603 kg/m3. The minimum fluidizing velocity is (A) (B) (C) (D)

0.53 m/s 0.026 m/s 0.312 m/s 0.082 m/s

3. Two identical aqueous solution containing a valuable solute are colored by small amounts of an impurity, to different extent. The dark solution has a color intensity of 50 units and the light solution has 20 color units, measured on the same arbitrary scale. It is desired o treat an equal amount of light and dark solutions to a color unit or 0.5. The equilibrium adsorption isotherm on activated carbon is given by the Freundlich equation Y = mXn where n = 1 and m = 0.005 with Y = color units/kg solution and X = color units adsorbed/kg carbon. The color scale is such that colors are additive, equal weights of solution of color 20 and 50 will give a solution of color (20 + 50)/2 = 35. In the single stage process which of the following is more economical of carbon: (A) (B) (C) (D)

To first blend the original solutions and to treat the blend To treat each other separately and blend later To blend the finished product Both a and b

4. A glass sphere in water at 68oF contains 1206 g of glass spheres in 1140 cm3 of total volume. The average diameter of the spheres, as determined from photomicrographs, was 0.0061 in. and the true density of the spheres was 154 lb/ft3. For water at 68oF, the density is 62.2 lb/ft3 and viscosity is 6.72 x 10-4 lb/ft-s. The terminal velocity in ft/s for the hindered settling is (A) (B) (C) (D)

0.341 4.3 x 10-4 3.41 x 10-3 1.43 x 10-2

5. A tube of 0.05 m2 cross sectional area is packed with spherical particles to a height of 0.325 m. The porosity of the bed is 0.35. It is desired to fluidize the particles with water (density = 1000 kg/m3, µ = 10-3 Pa-s). The minimum velocity of fluidization is given by the Ergun’s equation: ∆𝑷 𝑫𝑷 𝝐𝟑 𝟏𝟓𝟎𝝁(𝟏 ‒ 𝝐) = + 𝟏.𝟕𝟓 𝟐 𝑳 𝝆 𝒗 𝟏‒ 𝝐 𝑫 𝑷 𝝆𝒇 𝒗 𝒇

Data: Diameter of particles = 0.01 m Density of solid particles = 2600 kg/m3 The minimum velocity of fluidization in m/s is (A) 0.059 (B) 0.035 (C) 0.56 (D) 0.0035 Problems 6 and 7 are based on the following information: A bed of spherical particles (specific gravity is 2.65) of uniform size 1500 microns is 0.5 m in diameter and 0.5 m high. In the packed bed state, the porosity may be taken as 0.4. Ergun’s equation for the above particle fluid system (in SI units) is given below: ∆𝑷 𝑳

= 𝟑.𝟕𝟓 𝒙 𝟏𝟎𝟑𝑽𝑶𝑴 + 𝟏𝟎.𝟗𝟒 𝒙 𝟏𝟎𝟔𝑽𝑶𝑴𝟐

6. If water is to be used as the fluidizing medium, the minimum fluidization velocity, VOM in mm/s is (A) 12 (B) 16 (C) 24 (D) 28 7. In actual operation, the above bed has a height = 1m. What is the porosity of the fluidized bed? (A) 0.2 (B) 0.5 (C) 0.7 (D) 0.9 8. A short head cone crusher is available for crushing 2.0 tons of pyrites per hour. On similar materials, the overall efficiency has been found to be 3.15%. The raw feed is to

be crushed by a jaw crusher, whose product constitutes the feed to the cone crusher. The cone crusher operates in closed circuit with a 14-mesh screen. The surface ratio may be considered to be 6.5 above 3.0 mesh. The full load energy requirement for the short cone crusher is 5 Hp. The cone crusher product and recycle stream analyses are recycle ration (recycle stream per product stream) is 1.0 and specific surface of 57.6 cm2/g. If for pyrite the Rittinger’s number is 314 cm2 per ft-lb and density of 5.0 g/cc, the average diameter of feed to the cone crusher is (A) 3.68 cm (B) 2.2 cm (C) 5.3 cm (D) 12.2 cm 9. The data below were obtained on the operation of a 6-mesh (square) hummer screen ate the tipple of a coal mine. The screening was done to separate a very fine refuse from a fine coal stream so that it could be reprocessed. Feed to Screen, 131 tons per hour (Approximately 5% moisture) Size Sample weight + ¼ in 3825 grams ¼ x 6 mesh 1006 6 x 14 750 14 x 28 303 28 x 48 219 48 x 0 807

Overflow from Screen

Size + ¼ in ¼ x 6 mesh 6 x 14 14 x 28 28 x 48 48 x 0

Sample Weight 2905 grams 767 405 117 68 278

Undeflow

Size + ¼ in ¼ x 6 mesh 6 x 14 14 x 28 28 x 48 48 x 0

Sample, % 11.3 7.8 6.9 8.6 3.3 62.1

The screen effectiveness is (A) 34.14% (B) 54.6% (C) 44.13% (D) 76.3% 10. A simple vacuum crystallizer is to produce 10,000-lb copper crystals (FeSO4.7H20) per hour. The feed is a solution containing 38.9 parts FeSO4 per 100 parts total water, and it enters crystallizer at 158°F. the crystallizer vacuum is such as to produce a crystallizer temperature of 80°F. Saturated solution at 80°F contains 30.2 parts of FeSO4 per 100 parts total water. The enthalpies of saturated solution, the crystals leaving the crystallizer, the feed and vapor are: H = -2.4Btu/lb hc = -91Btu/lb hr = 46.8Btu/lb Hv = 1096Btu/lb The feed needed is (A) 37,450 lb/h (B) 8,070 lb/h (C) 50,520 lb/h

(D) 50,920 lb/h 11. In a single stage extraction, 10kg of pure solvent S (containing no solute A) is mixed with 30kg of feed F containing A at a mass fraction Xf = 0.2. The mixture splits into an extract phase E and a raffinate R, containing A at Xe = 0.5 and Xr = 0.05 respectively. The total mass of the extract phase is (A) 6.89kg (B) 8.89kg (C) 10kg (D) 8.25kg 12. An aqueous solution of acetic acid is to be extracted with isopropyl either, the solution contains 24.6kg acetic acid and 80kg of H2O. Water and isopropyl either may be considered completely immiscible under these conditions. At the temperature of extraction, the following equilibrium data apply: Kg acetic acid/kg isopropyl ether

0.03

0.046 0.063

0.07

0.078

0.086

Kg acetic acid/kg H2O

0.1

0.15

0.22

0.28

0.26

0.2

If 100kg of isopropyl either is added to the solution, the weight of acetic acid that will be extracted by isopropyl either if equilibrium conditions are attained is (A) 18kg (B) 15kg (C) 24.6kg (D) 7kg 13. An oil water separator for coconut oil mill is being designed by the plant’s chemical engineer to remove coconut oil from the mill’s effluent water. Experiments have shown that with the specific gravity differential between coconut oil and water the rising velocity of coconut oil globules in water is 0.0945 m/min. Practice has shown that for the separator to be effective the following parameters hold: Water velocity along the separator,Vh = 0.91m/min. Depth of water separator, D = 0.3B (where B is the width of the separator) If 230m3 of effluent water is to be handled per hour, the length of the separator in meters is (A) 11m (B) 15m (C) 9m (D) 1.125m 14. In a rotating centrifuge a liquid layer is thrown outward from the axis of rotation and is hold against the wall of the ball by centrifugal force. The pressure drop in a single liquid in centrifuge bowl assuming density is constant is strictly applies only when r1 and r2 are not greatly different may be evaluated using the equation below; P2 – P1 =

𝜔2𝜌(𝑟12 ‒ 𝑟22) 2

Where r1 = radiant distance from the axis of rotation to the free liquid surface r1 = radius of the centrifugal bowl A centrifuge bowl with 250mm ID ( internal diameter) is turning at 4000rev/min. It contains alayer of aniline 50mm thick. If the density of the aniline is 1002kg/m3 and the pressure at the liquid surface is atmospheric, the gauge pressure exerted on the wall of the centrifuge bowl is (A) 8.791bar (B) 2.241bar (C) 4.48bar (D) 17.56bar Problems 15 to 17 are based on the following information: A gas micture with a flow rate of 0.1m3/s contains 0.203kg/m3 of benzene. The temperature is 10°C and the pressure 1 atm (1.013 bar). Benzene needs to be separated to give a gas stream with a benzene concentration of less than 5mg/m3. It is proposed to achieve this by adsorption using activated carbon in a fixed bed. The activated carbon is to be regenerated using superheated steam. The experimental adsorption isotherms cannot be adequately represented by Freundich isotherms, and instead, can be correlated at 10°C by the empirical relationship: Ln V = -0.0113(lnP)2 + 0.2071 lnP – 3.0872 Where V = volume benzene adsorbed (m3/kg) P = partial pressure Pa It can be assumed that the gas mixture follows ideal gas behavior and that the kilogram molar mass of a gas occupies 22.4m3 at standard conditions of 0°C and 1 atm (1.013 bar) 15. The mass of benzene that can be a adsorbed per kg of activated carbon is (A) 0.41kg (B) 0.81kg (C) 1.14kg (D) 2.8kg 16. Assuming a cycle time of 2 hours and that the actual volume is three times the equilibrium volume and the bulk density of activated carbon is 450kg/m3, the volume of the activated carbon required is (A) 1.08m3 (B) 3.28m3 (C) 8.23m3 (D) 2.38m3 17. The concentration of benzene in the gas stream must be less than 5mg/m3 after the bed has been regenerated with steam at 200°C and brought back online at 10°C. The fraction of benzene that must be recovered from the bed by the regeneration to achieve this if the bed is assumed to be saturated before regeneration is (A) 0.52 (B) 0.75 (C) 0.95 (D) 0.0296

18. The “tripper” is the most positive means of unloading at intermediate points. The tripper runs on rails which are installed along each side of the belt. It is equipped with two pulleys over which the belt runs. It may be placed at any desired unloading point. The use of a tripper increases the power required to drive the conveyor. Power requirement for trippers may be computed as follows: Hp = YS + ZT S = belt speed in fpm T = peak capacity in tons per hour Y and Z = constants dependent on the width of the belt If the tripper is constructed so that it will move back and forth, the power required to convey a 4000kg per hour of a material using a 36 in belt width (constants Y = 0.006 and Z = 0.005) at a speed of 800 fpm is (A) 8.4Hp (B) 3.2Hp (C) 6.8Hp (D) 4.82Hp 19. A ball mill , operated in a closed circuit with a classifier, is used to grind calcite after it has had been preliminary crushing in jaw crushers. The screen analyses of the ball mill feed, recycler classifier sands and product classifier overflow obtained a fractional specific surface of 603 cm2/g. The ball mill feed (25 tons per hour) is estimated to have a specific surface of 292 cm2/g. When the ball mill is operated with a recycle of 75 tons per hour, 75kW are requires too the drive the ball. The efficiency of the ball if the Rittinger’s number of calcite is 1053 cm2 per ft – lbs. (A) 3.37% (B) 7.33% (C) 8.7% (D) 4.37% Problems 20 to 22 are based on the following information: The distribution equilibrium for A between extract solvent S and a raffinate solvent B is given by Y = 2X where Y = mass of A per unit mass of S, X =mass A per unit mass of B. The extract and raffinate solvents are immiscible with each other at all concentrations of A. From these data, calculate the amout extract solvent needed per 100kg solution containing 30% A in B if 95% of A is to be removed for each of the following arrangements: 20. Single stage contact (A) 665kg (B) 565kg (C) 180kg (D) 70kg 21. Three stage batch contact, one third of the solvent will be used in each contact (A) 60kg (B) 665kg (C) 210kg

(D) 180kg 22. Three stage countercurrent operation (A) 70kg (B) 79kg (C) 280kg (D) 250kg 23. Which of the following is not an ultrafine grinder (colloid mill)? (A) Micronizers (B) Agitated mills and fluid energy mills (C) Toothed roll crusher (D) Hammer mills with internal classification 24. (A) (B) (C) (D)

Centrifuge is normally used in sugar mills Tubular bowl Disc-bowl Suspended batch basket Perforated horizontal basket continuous

Problems 25 to 27 are based on the following information: A viscous solution containing particles with a density of 1461kg/m3 is to be clarified by centrifugation. The solution density is 801 kg/m3 and its viscosity is 100cp. The centrifuge has bowl with r2 = 0.02225m, r1 = 0.00716m and bowl height of 0.197m. The centrifuge rotates at 23,000 rev/min and the flow rate is 0.002832m3/h. 25. The critical particle diameter of the largest particle in the exit stream is (A) 0.747µm (B) 0.537µm (C) 0.868µm (D) 0.477µm 26. The physical characteristic of the centrifuge (area of the gravitational setter), 2 is (A) 169.1m2 (B) 196.1m2 (C) 296.1m2 (D) 259.1m2 27. A new centrifuge having the following dimensions is to be used r2 = 0.01432m, b = 0.394m and N = 26,000 rev/min. The new scale up flow rate using the same solution is (A) 5.08 X 104 m3/s (B) 8.77 X 105 m3/s (C) 8.05 X 103 m3/s (D) 8.05 X 102 m3/s 28. Solid particles separation based on the difference in their flow velocities through fluids is termed as the (A) Clarification

(B) Classification (C) Elutriation (D) Sedimentation 29. Ball mills and tube mills with flint or porcelain balls are use for size reduction of (A) Asbestos (B) Rubber (C) Non-metallic ores (D) Limestone 30. The power required to move an empty belt conveyor is 𝐿

P = C1VαS + 0.0295 (0.4 + 91.42)ω + 9.69 X 10-3∆Z ω Where P = total power requirement in kW C1 = constant for specific belt width and length VαS = speed of belt in m/s L = horizontal length of the conveyor in meters ω = mass flow rate of solid material in kg/s A cement clinker solid with a bulk density of 1600kg/m3 is to be transported a horizontal distance of 365m up an incline of 5°. The troughed belt conveyor has been selected to handle 101kg/s with this material with a running angle of repose of 19°. A 0.61m troughed belt conveyor with an indicated slope angle of 20° and operating at a normal speed of 1.52m/s has a capacity of 99.9kg/s. If C1 = 4.6kW-s/m, the power requirement in kW for this solids transport is (A) 45.3 (B) 51.3 (C) 61.4 (D) 38.3 31. A tube of 0.05 m2 cross sectional area is packed with spherical particles to a height of 0.325 m. The porosity of the bed is 0.35. It is desired to fluidize the particles with water (density = 1000 kg/m3, µ = 10-3 Pa-s). The minimum velocity of fluidization is given by the Ergun’s equation: ∆𝑷 𝑫𝑷 𝝐𝟑 𝟏𝟓𝟎𝝁(𝟏 ‒ 𝝐) = + 𝟏.𝟕𝟓 𝟐 𝑳 𝝆 𝒗 𝟏‒ 𝝐 𝑫 𝑷 𝝆𝒇 𝒗 𝒇

Data: Diameter of particles = 0.01 m Density of solid particles = 2600 kg/m3 The minimum velocity of fluidization in m/s is (E) 0.059 (F) 0.035 (G) 0.56 (H) 0.0035

32. If water is to be used as the fluidizing medium, the minimum fluidization velocity, VOM in mm/s is (A) 12 (B) 16 (C) 24 (D) 28 33. In actual operation, the above bed has a height = 1m. What is the porosity of the fluidized bed? (A) 0.2 (B) 0.5 (C) 0.7 (D) 0.9 34. At a given equilibrium pressure, with increase in temperature, the concentration of adsorbed gas on solid absorbent (A) Increase (B) Decrease (C) Remains unchanged (D) Increase exponentially 35. Which of the following adsorbent is used to decolorize yellow glycerine? (A) Slilica gel (B) Alumina (C) Fuller’s earth (D) Activated carbon 36. In which of the following unit operations, the selectivity is an important parameter? (A) Distillation (B) Solvent extraction (C) Absorption (D) Adsorption 37. The feed to a cooling crystallizer is 1000lb/h at 120°F. The solution is cooled to 70°F. It has a 3ft2 of cooling surface per foot of running length of crystallizer. The required rate of heat transfer is 44,900 BTU/h. Colling will be provided by a countercurrent flow of chilled water entering the cooling jacket at 60°F and leaving at 85°F. The overall heat transfer coefficient, U, is expected to be 20 BTU/h-ft2F. The length of the crystallizer is (A) 73ft (B) 37ft (C) 28ft (D) 23ft 38. A crushing mill reduces limestone from a mean particle size of 45mm to a product and in doing so requires 21KJ/kg of material crushed. The power required to crush the same material from a feed having a mean size of 25mm to a product with a mean size of 1.0mm assuming kick’s law applies is Size (mm) Percent

12.5 7.5 5.0 2.5 1.5 0.75 0.4 0.2 (A) (B) (C) (D)

0.5 7.5 45.0 19.0 16.0 8.0 3.0 1.0

56 kJ/kg 39 kJ/kg 12 kJ/kg 28 kJ/kg

39. The mass fraction of solute in the underflow is and R = 0.631 kg solution retained per kg inert solids 0.195 (A) 0.195 (B) 0.155 (C) 232 (D) 0.212

if X = 0.401kg solute/kg solution

40. The aperture (clear opening) of a Tyler standard screen for number 35 with a wire diameter of 0.0122 in is (A) 0.0195 in. (B) 0.0232 in. (C) 0.0138 in (D) 0.0164 in. 41. A treated ore containing inert solid gangue and copper sulfate is to be leached in a countercurrent multistage extractor using pure water to leach the CuSO4. The solid charge rate per hour consists of 10,000kg of inert gange,1200 kg of CuSO4 and 400kg of H2O. The exit wash solution is to contain 92 wt % water 8 wt % CuSO4. A total of 95% of the CuSO4 in the inert ore is to be recovered. The number of stages required if underflow is constant at 0.5kg inert gangue solid per kg aqueous solution is (A) 6 (B) 5 (C) 12 (D) 9 42. Two hundred cubic centimeters of an acetone-water mixture that contains 10 wt% acetone are mixed with 400 cm3 chloroform at 25°C, and the phases are allowed to settle. What percentage of acetone is transferred from the water to the chloroform? (A) 86% (B) 92% (C) 74% (D) 80%

43. The maximum speed of rotation of a phosphor bronze centrifuge basket, 0.3m diameter and 5mm thick, when it contains a liquid of density 1000kg/m3 forming a layer 75mm thick at the walls is (A) 65 Hz (B) 56 Hz (C) 34 Hz (D) 76 Hz 44. Solid spherical particles of coffee extract from a dryer having a diameter of 400µm are falling through air at a temperature of 422°K. The density of the particles are 1030kg/m3. The pressure is 101.32kPa. The distance of fall in 5sec. is (A) 4.75m (B) 7.45m (C) 5.47m (D) 9.49m 45. A thickener is to handle 20tons/hr of slurry, producing a clear overflow and an underflow on sludge containing 20% by weight solids. Assume that the constant rate of settling in the batch sedimentation is the rate of settling in the clarification zone of the continuous thickness. The average value of the rate of settling is 1.45cm/min and a 2.91% by weight of CaCO2 in pure water. The thickener area required is (A) 192ft2 (B) 180ft2 (C) 292ft2 (D) 102ft2

CHEMICAL ENGINEERING REFRESHER COURSE CHEMISTRY AND BIOCHEMICAL ENGINEERING 1. For a germanium atom, determine the total number of completely or partially filled porbitals in its ground state configuration. (A) 2 (B) 3 (C) 6 (D) 8 2. Which of the following is diamagnetic? (A) N (B) Ni (C) Te (D) Ba 3. Which of the following molecules has a distorted tetrahedron molecular geometry? (A) XeCl2 (B) Cl3 (C) PCl5 (D) TeF4 4. Which of the following is not soluble in water? (A) SO2 (B) NF3 (C) SeF4 (D) KrF2 5. Which of the following exhibits H-bonding? (A) HCl (B) HF (C) CH4 (D) CHCl3 6. A sample of solid ammonium chloride was placed in an evacuated container and then heated so that it decomposed to ammonia gas and hydrogen chloride gas. After heating, the total pressure in the container was found to be 4.4 atm. Calculate Kp at this temperature for this decomposition reaction. (A) 2.2 atm (B) 4.8 atm (C) 5.7 atm (D) 6.9 atm 7. An atom of a particular element is travelling at 1% of the speed of light. The wavelength is found to be 3.31 x 10-3 pm. The element is

(A) (B) (C) (D)

Be Mg Ca Sr

8. It takes 208.4 kJ of energy to remove one mole of electrons from the atoms on the surface of rubidium metal. If rubidium metal is irradiated with 254 nm light, what is the maximum kinetic energy the released electrons can have? (A) 3.02 x 10-19 J (B) 4.36 x 10-19 J (C) 5.89 x 10-19 J (D) 7.82 x 10-19 J 9. Which of the following nuclides is STABLE? (A) 45 19K (B) 56 26Fe (C) 20 11Na 194 (D) 81 Tl 10. The easiest fusion reaction to initiate is between the nuclei of deuterium and tritium to produce an alpha particle. How much energy is released for every formation of an alpha particle? (deuterium = 2.01410 amu, protium = 4.00460 amu). (A) -1.889 x 10-5 J (B) -1.698 x 10-10 J (C) -2.82 x 10-12 J (D) -4.56 x 10-14 J 11. Which of the following is the conjugate acid of hydrogen phosphate? (A) H2O (B) H2PO4 (C) OH (D) H3PO4 12. In an experiment, when 40 mL of 3.50 x 10-3 M potassium hydrogen is mixed with 69 mL of 6.68 x 10-4 M barium bromide, a hydroxide compound is formed (Ksp = 5.0 x 10-3). Which of the following correctly describes the resulting solution? (A) The product solution is unsaturated (B) The mixture product is saturated (C) The resulting solution is supersaturated (D) The solution is over supersaturated 13. What volumes of 0.50 M HNO2 (pK3 = 3.40) and 0.50 M NaNO2 must be mixed to prepare 1.00 L of a solution buffered at pH = 3.55? (A) 0.42 L HNO2 and 0.58 L NaNO2 (B) 0.58 L HNO2 and 0.42 L NaNO2 (C) 0.42 L HNO2 and 0.85 L NaNO2 (D) 0.58 L HNO2 and 0.27 L NaNO2

14. A 516.7 mg sample containing a mixture of K2SO4 and (NH4)2SO4 was dissolved in water to be treated with Ba Cl2, precipitating the SO42- as BaSO4. The resulting precipitate was isolated by filtration, rinsed free of impurities, and dried to a constant weight, yielding 863.5 mg of BaSO4. What is the %w/w K2SO4 in the sample? (A) 65.34% (B) 45.56% (C) 34.45% (D) 22.22% 15. A 0.9092 g sample of wheat flour was analyzed by the Kjeldahl procedure. The ammonia formed was distilled into 50.00 mL of 0.05063 M HCl; a 7.46 mL back titration with 0.04917 M NaOH was required. Calculate the percentage of protein in the flour. (A) 15.69% (B) 18.99% (C) 21.30% (D) 25.67% 16. A 50.00 mL aliquot of a solution containing iron(III) required 13.73 mL of 0.01200 M EDTA. The solution contains how much iron? (A) 134 ppm (B) 184 ppm (C) 213 ppm (D) 245 ppm 17. The KClO3 in a 0.1279 g sample of an explosive was determined by reaction with 50.00 mL of 0.08930 M Fe2+. ClO3 + 6Fe2+ + 6H+ → Cl + 3H2O + 6Fe3+ When the reaction was complete, the excess Fe2+ was back-titrated with 14.93 mL of 0.083610 M Ce2+. Calculate the percentage of KClO3 in the sample. (A) 31% (B) 41% (C) 51% (D) 61% 18. Calculate the percentage of MnO2 in a mineral specimen if the I2 liberated by a 0.1344 g sample in the net reaction MnO2(S) + 4H+ + 2I- → Mn2+ + I2 + 2H2O required 32. 30 mL of 0.077220 M sodium thiosulfate. (A) 65.45% (B) 70.13% (C) 75.43% (D) 80.06% 19. An unknown mixture of carbonates and hydroxides was analyzed using double indicator method. Using phenolphthalein as indicator, 25 mL of a mixture required 19.5 mL of 0.005 N HCl for the endpoint. When methyl orange was the indicator, 25 mL of the

solution required 25.9 mL of the same HCl for end point. Which of the following is TRUE? (A) 1 liter of solution contains 0.1357 g Na2CO3 (B) 1 liter of solution contains 0.1048 g NaOH (C) 1 liter of solution contains 0.1357 g NaHCO3 (D) 1 liter of solution contains 0. 8400 g Na2CO3 20. A 4.971 g sample containing the mineral tellurite was dissolved and then treated with 50.00 mL of 0.03114 M K2Cr2O2. 3TeO2 + Cr2O72- + 8H+ → 3H2TeO4 + 2Cr3+ + H2O When the reaction is complete, the excess Cr2O72- required a 10.05 mL back-titration with 0.1135 M Fe2+. Calculate the percentage of TeO2 in the sample. (A) 9.14% (B) 13.17% (C) 17.78% (D) 21.98% 21. A solution of 2.0 g of (+)-glyceraldehyde in 10.0 mL of water was placed in a 100 mm polarimeter tube. Using the sodium D line, a rotation of 1.74o was observed at 25oC. (+)glyceraldehyde was the mixed with some quantity of (-)-glyceraldehyde and the resulting mixture had a specific rotation of +6.9o. What percentage of the mixture was ()-glyceraldehyde? (A) 8.6% (B) 10.35% (C) 20.69% (D) 79.31% 22. Give the IUPAC name of the following compound.

(A) (B) (C) (D)

5-Cyclopropyl-2,3-dihydroxy-8-oxochloro-2-octenoale 8-Chlorocarbonyl-5-cyclopropyl-2,3-dihydroxy-2-octenoic acid 4-Cyclopropyl-6,7-dihydroxy-8-carboxyoctenoyl chloride 8-Chloro-5-cyclopropyl-1,8-dioxo-2-octene-1,2,3-triol

23. Which of the following compound is AROMATIC?

(A)

(C)

(B)

(D)

24. Which of the following organic compound has the highest boiling point? (A) Pentane (B) Diethyl ether (C) Butanal (D) Butanol 25. What is the main product when the compound below is reacted with propanoyl chloride?

(A)

(C)

(B)

(D)

26. When 1-Chloro-2-methylcyclobutane is reacted with potassium hydroxide, the product formed is (A) Methylcyclobutane (B) Methylcylobutanol (C) 1-Chloro-2-methylcyclobutanol (D) (B) and (C)

27. Give the IUPAC name of the product formed from the reaction between isopropyl alcohol and acetyl chloride. (A) Methylethoxyethane (B) Methylethylhanoate (C) Chloromethylbutanal (D) Chloromethyl-2-butanone 28. Which of the following pairs of products can be obtained when an alkene such as 3Hexane is reacted with peroxyacetic acid? (A) Alcohol and carboxylic acid (B) Epoxide and ester (C) Ether and ester (D) Epoxide and carboxylic acid 29. 3-Methyl-3-hexanol can be prepared by reacting propyl magnesium bromide with what? (A) Ester (B) Ether (C) Ketone (D) Carboxylic acid 30. What must be the starting material to produce an alcohol during hydroborationoxidation reaction? (A) Alkane (B) Carboxylic acid (C) Alkene (D) Ester 31. In humans, this chemical compound is released during hugging and touching in both genders. (A) Oxytocin (B) Adrenaline (C) G-proteins (D) Serotonin 32. When energy-depleted elements associated with a proton are accepted by an organic molecule, the process is called (A) Fermentation (B) Anaerobic (C) Aerobic (D) Catabolism 33. The average molar mass of one base pair of nucleotides in DNA is approximately 600 g/mol. The spacing between successive base pairs is about 0.34 nm, and a complete turn in the helical structure of DNA occurs every 3.4 nm. If a DNA molecule has a molar mass of 4.5 x 109 g/mol, approximately, how many complete turns in the DNA α-helix structure? (zumdahl, 104, p 1067) (A) 6 x 105 (B) 7 x 105

(C) 8 x 105 (D) 9 x 105 34. Part of a certain DNA sequence is GGTCTATAC. What is the complementary sequence? (A) CCAGATATG (B) TTGAGCGCA (C) AAGTGTTAC (D) CCGTGTCAG 35. Calculate the isoelectric point for the amino acid, arginine, (pKa1 = 1.82, pKa2 = 8.99, pKa3 = 12.48) (A) 5.41 (B) 7.76 (C) 10.74 (D) 7.15 36. In the “Methode Champenoise”, strawberry juice is fermented in a 825 mL wine bottle to produce sparkling wine. Fermentation of 719 mL aqueous strawberry juice is allowed to take place in the bottle until 12% by volume is ethyl alcohol. Calculate the pressure of CO2 inside the wine bottle at 29oC. (The density of ethanol is 0.79 g/cm3) (A) 150 atm (B) 250 atm (C) 350 atm (D) 450 atm 37. 1000 kg of raw materials for yogurt production were enzymatically hydrolyzed and the resulting hydrolyzate containe 40% lactose, 15% maltose, 12% sucrose, 15% oligosaccharides and the rest accounts for flavoring agents. Calculate the amount of alcohol that can be produced when the hydrolyzate is fermented by alcohol yeast. (A) 260.5 kg (B) 360.5 kg (C) 460.5 kg (D) 560.5 kg 38. Histidine, an essential α-amino acid present in our body can transform into histamine under enzymatic activity of histidine decarboxylase. When the reaction velocity is 2.6 mM/s, 1.67 mM of histamine is formed. Assuming 15 mM of the decarboxylase (K =30 s1) is used, determine the Michaelis-Menten constant K . M (A) 0.19 M (B) 0.29 M (C) 0.39 M (D) 0.49 M 39. Antihistamine, a histamine antagonist, is a pharmaceutical drug that inhibits competitively the action of histamine by blocking it from attaching to histamine receptors. If 3 mM of antihistamine is bound to the enzyme in the previous problem, what will be the reaction velocity of the enzyme if the dissociation constant of the enzyme-inhibitor complex is 1.5 mM?

(A) (B) (C) (D)

0.4762 mM/s 0.6589 mM/s 0.8621 mM/s 3.56 mM/s

40. A chemostat operating in steady-state at a dilution rate of 0.25 h-1 sets a limiting nutrient concentration of 0. 6 µmol/L. Determine the Monod constant if the maximum specific growth rate for the organism is 0.60 h-1. (A) 0.64 µmol/L (B) 0.74 µmol/L (C) 0.84 µmol/L (D) 0.94 µmol/L

CHEMICAL ENGINEERING REFRESHER COURSE OPTIMUM DESIGN, PROCESS EQUIPMENT DESIGN AND CHEMICAL PROCESS INDUSTRIES 1.

Lang Factor is defined as the ratio of the capital investment to the delivered cost of major equipment. The value of Lang factor for fixed capital investment of a fluid processing chemical plant is (A). 4.7 (B). 4.3 (C). 5.0 (D). 6.0

2.

A small evaporator system is used to concentrate a colloidal suspension. Steam costs P300 per million Btu and each pound of steam will evaporate 0.8N pound water with N being the number of effects. The total capital cost of each effect is P4,000,000 and has an estimated life of 10 years. The annual maintenance expense is 10% the capital cost. Labor and other expenses not mentioned maybe considered to be independent of the number of effects. The system will operate 300 days per year with 1 x 108 Btu per day evaporator duty. Depreciation of equipment is by 7-year straight line method and tax rate is 35%. The number of evaporator effects for minimum total annual operating expense is (A). 5.0 (B). 3.0 (C). 6.0 (D). 4.0

3.

In the manufacture of sulfuric acid by the contact process, the catalytic oxidation of SO2 is carried out in multiple stages mainly to (A). increase the reaction rate by providing inter-stage heating (B). increase overall conversion by providing inter-stage heating (C). increase overall conversion by providing inter-stage cooling (D). decrease the overall conversion by removing SO3 between stages

4.

Match the reactant-product combination in Group I with the unit process in Group II Group I Group II L. propylene – butanol 1. Pyrolysis M. cumene – phenol 2. Dehydrogenation J. butane – butadiene 3. Hydroformylation R. ethylene dichloride – vinyl chloride 4. Peroxidation (A). L-3; M-2; J-4; R-1 (B). L-2; M-4; J-3; R-1 (C). L-1; M-3; J-2; R-4 (D). L-3; M-4; J-2; R-1

5.

Total capital investment for a chemical process plant comprises of the fixed capital investment and the

(A). overhead costs (B). working capital (C). indirect production cost (D). direct production cost 6.

In an integrated steel plant, NH3 present in coke oven gas is normally recovered as (A). (NH4)2SO4 (B). NH4Cl (C). NH4NO3 (D). liquid NH3

7.

A certain pressure vessel manufacturer avoids during reinforcement calculations for openings by always providing a reinforcing pad extending up to double the diameter of the opening and of the same material and thickness as that of the shell wall. If area compensation is accepted as code guideline, the approach leads to safe design (A). only if the opening is on the spherical vessel (B). only if the opening is on a vertical cylindrical vessel (C). only if the opening is on a horizontal cylindrical vessel (D). irrespective of the shape of the vessel

8.

Match the process in Group I with the product in Group II. Group I Group II L. DCDA process 1. Sodium Hydroxide M. Mercury cells 2. Sulfuric acid 3. Sodium carbonate 4. Nitric acid (A). L-1; M-4 (B). L-1; M-3 (C). L-2; M-3 (D). L-2; M-1

9.

Starch has the formula (A). (C6H12O6)n (B). (CH2O)n (C). (C6H10O5)n (D). C12H22O11

10.

Match the process or technologies in Group 1 with the items in Group 2 Group 1 Group 2 L. Urea manufacture I. Microencapsulation M. Coal gasification II. Ultra-low sulfur diesel J. Controlled release of chemicals III. Shale oil R. Deep hydro-desulfurization IV. Prilling tower V. Gas hydrates VI. Gas-solid non-catalytic reaction (A). L – I, M – V, J – II, R – VI (B). L – IV, M – VI, J – I, R – II (C). L – IV, M – I, J – III, R –II

(D). L – V, M – VI, J – IV, R – II 11.

For a cylindrical internally pressurized vessel, which of the following closure types would withstand highest pressure if each closure is of the same material and thickness? (A). L – I, M – V, J – II, R – VI (B). L – IV, M – VI, J – I, R – II (C). L – IV, M – I, J – III, R –II (D). L – V, M – VI, J – IV, R – II

12.

Sucrose content in the raw juice extracted from sugar cane may be around (A). 1 – 2 % (B). 11 – 15 % (C). 50 – 60 % (D). 80 – 85 %

13.

A designer is concerned (A). to specify an economical system (B). with piece of equipment suitable for a specific chemical process (C). with process parameters (D). all of the above

14. Match the chemicals written on the left with the raw material required to produce them mentioned on the right. I. Single superphosphate (SSP) L. Rock phosphate + sulfuric acid + ammonia II. Triple superphosphate (TSP) M. Brine III. Diammonium phosphate (DAP) J. Rock phosphate + sulfuric acid IV. Caustic soda R. Rock phosphate + Phosphoric acid (A). I – M, II – J, III – R, IV – L (B). I – R, II – L, III – M, IV – J (C). I – J, II – R, III – L, IV – M (D). I – R, II – J, III – L, IV – M 15. A pressure vessel is said to be made of thick shell If the ratio of its diameter to wall thickness is (A). <10 (B). >10 (C). >20 (D). <20 16. In the production of (NH4)2SO4, ammonia was first formed from the nitrogen of the air. Assuming 80% efficiency of (NH4)2SO4 conversion, the kilograms of 78% sulfuric acid solution used to produce one metric ton (NH4)2SO4 is (A). 2380 kg (B). 1190 kg (C). 1109 kg (D). 1250 kg 17.

Apex angle of conical heads used in the bottom heads of chemical process equipment is

usually (A). 30° (B). 45° (C). 60° (D). 90° 18.

Identify which of the following statements are FALSE. L. Oils with an oleic radical (1 double bond) are more suitable than oils with a linolenic radical (3 double bonds) as film forming vehicles for paints. M. Production of synthesis gas from coal and steam is an endothermic process. J. Use of chlorine for bleaching of wood pulp results in the release of dioxins. R. In the manufacture of urea from ammonia, the main intermediate product formed is ammonium bicarbonate (A). L and M only (B). J and R only (C). M and J only (D). L and R only

19.

Catalytic cracking is (A). a hydrogen addition process (B). a carbon rejection process (C). an exothermic process (D). a coking process

20.

A sphere with a 30 ft inside diameter stores gas at a maximum pressure of 75 psi at 125°F. The sphere is made of a low-alloy steel plate, a double welded butt joints with full radiography are used, and the material has a code-allowable stress of 17,500 lbf/in2. The thickness of the spherical vessel with no corrosion allowance is (A). ½ in. (B). 1/8 in. (C). ¼ in. (D). ¾ in.

21.

Metals in heads of pressure vessel can be approximated by calculating the area of the blank (disk) used for forming the head. The required diameter of blank can be calculated by multiplying the head outside diameter by approximate factors. The blank diameter factor for a hemispherical head with ratio d/t (head diameter / nominal minimum head thickness) between 18 – 30 is (A). 1.15 (B). 1.65 (C). 1.09 (D). 1.24

22.

Wood is digested in the sulfite process in vessels constructed of (A). Brick lined steel (B). Stainless steel (C). Glass lined steel (D). Rubber coated steel

23.

Which ONE of the following statements is CORRECT? (A). The major components of biodiesel are triglycerides. (B). Biodiesel is essentially a mixture of ethyl esters. (C). Biodiesel is highly aromatic. (D). Biodiesel has a very low aniline point.

24.

For turbulent flow in steel pipes and Di ≥ 0.0254 m, the optimum inside pipe diameter is given by (A). Diopt = 0.363 qf0.46ρ0.13μc0.025 (B). Diopt = 0.363 qf0.45ρ0.13 (C). Diopt = 0.49 qf0.49ρ0.14μc0.027 (D). Diopt = 4.7 qf0.49μc0.18

25.

For high pressure process equipment/vessels, the connected nozzle should be (A). welded (B). screwed (C). flanged (D). brazed

26.

Match the raw materials of Groups I and II with the final products of Group III. Group I Group II Group III L1: Ethylene C1: Ammonia M1: Synthetic fiber L2: Propylene C2: 1-Butene M2: Nylon 66 L3: Adipic acid C3: Ethylene glycol M3: LLDPE L4: Terephthalic acidC4: Hexamethylene diamine M4: Acrylonitrile (A). L1 + C2 → M3, L2 + C1 → M4, L3 + C4 → M2, L4 + C3 → M1 (B). L1 + C1 → M3, L2 + C3 → M1, L3 + C4 → M4, L4 + C2 → M2 (C). L1 + C2 → M2, L2 + C3 → M1, L3 + C4 → M3, L4 + C1 → M4 (D). L1 + C1 → M4, L2 + C2 → M3, L3 + C4 → M2, L4 + C3 → M1

27.

The purpose of the market research group is for (A). product evaluation job (B). process design (C). cost estimation (D). equipment selection

28.

Of the following four methods, the one that will actually increase the galvanic corrosion of more active metal is (A). Using combination of two metals as close as possible in galvanic series (B). Coupling two widely separated metals in the galvanic series (C). Protective oxide films (D). Insulating the two metals from each other

29.

As a process engineer, which of the following materials of construction you would recommend for the hydrolyzer

(A). Brick lined vessel (B). Haveg (C). Hastelloy C (D). Rubber lined steel 30.

For viscous flow in steel pipes and Di ≥ 0.0254 m, the optimum inside pipe diameter is given by (A). Diopt = 3.6 qf0.45μc0.28 (B). Diopt = 3 qf0.36μc0.18 (C). Diopt = 0.863 qf0.36μc0.18 (D). Diopt = 1.33 qf0.4μc0.2 where:

qf = fluid volumetric flow rate, m3/s μc = fluid viscosity, Pa-s Diopt = optimum inside pipe diameter, meters

31.

Match the polymer mentioned on the left with the catalyst used for its manufacture given on the right. I. Low density polyethylene L. Ziegler-Natta catalyst II. High density polyethylene M. Traces of oxygen III. Polyethylene terephthalate J. Butyl Lithium IV. Polyvinyl chloride R. Antimony (A). I – M, I – J, III – R, IV – L (B). I – R, II – L, III – M, IV – J (C). I – M, II – L, III – R, IV – J (D). I – R, II – J, III – L, IV – M

32.

Optimum economic pipe diameter for fluid flow is determined by the (A). viscosity of the fluid (B). density of the fluid (C). total cost considerations (pumping cost plus fixed cost of the pipe) (D). viscosity and density of the fluid

33. Determine the allowable pressure for a vessel with the following original design details, but which now has a minimum thickness of 0.40 in. Corrosion allowance = 1/8 in. Carbon steel, allowable stress = 15,000 lb/in2 Nominal thickness = 0.688 in. Design pressure = 500 psi Outside diameter = 24 in. Longitudinal double welded butt joint will full radiography An ellipsoidal head attached to each end of the shell with a single welded butt joint with a backing strip, and only spotradiographed Use the formula below for a cylindrical shell to calculate for the longitudinal welded or seamless joints. 𝑆𝐸𝑡 𝑃= 𝑅 + 0.6𝑡 (A). 510 psi (B). 840 psi

(C). 610 psi (D). 490 psi 34.

Which of the following is not included in market analysis? (A). opportunities (B). competition (C). economics (D). distribution

35.

Match the product in Group I with the raw materials in Group II Group I Group II L. Urea I. Ammonia and carbon dioxide M. Polyester II. Dimethyl terephthalate and ethylene glycol III. Ammonia and carbon monoxide IV. Hexamethylene diamine and adipic acid (A). L – I, M – IV (B). L – III, M – II (C). L – IV, M – 3 (D). L – 1, M – II

36.

A tank contains 50,000 kg of 20% oleum. (a 20% oleum means that in 100 kg of material there is 20 kg of SO3 dissolved in 80 kg of pure H2SO4). The kilograms of water that must be added to the tank to give 93.2 weight percent sulfuric acid (commonly called oil of vitriol) is (A). 6560 kg (B). 7060 kg (C). 6000 kg (D). 6060 kg

37.

For thick spheres, a-y factor is used to determine thickness, t if P is known. The equations are: 1

2(𝑆𝐸 + 𝑃)

𝑡 = 𝑅(𝑦3 ‒ 1) 𝑦 = 2SE ‒ 𝑃 and where: t = minimum required thickness of sphere, in. R = inside radius of sphere, in. S = allowable stress, lbf/in2 E = joint efficiency, % P = allowable pressure Assuming S = 14,000 lbf/in2, P = 3000 psi and E = 100%, the thickness of a sphere with a 10 in. inside diameter to be used with a 3000 psi allowable pressure is (A). 5/16 in. (B). ¾ in. (C). 9/16 in (D). ½ in. 38.

The fundamental purpose of product design program is to sell more goods and gain greater profits by

(A). keeping the company products and product line in a strong competitive position (B). diversifying the product lines to serve the industries (C). improving or replacing products (D). all of the above 39.

Frasch process is for (A). making oxygen (B). producing helium (C). mining sulfur (D). making nitrogen

40.

Inversion of sucrose produces (A). d-fructose (B). d-glucose (C). both a and b (D). d-galactose

41.

Massecuite is a terminology used in (A). paint industry (B). oil hydrogenation industry (C). soap industry (D). sugar industry

42.

While making and estimate of the total product cost for a chemical plant, expenditure on research and development (R&D) is (A). overhead cost (B). fixed expense (C). general expense (D). direct production cost

43.

Optimum number of effects in a multiple effect evaporator is decided by the (A). cost benefit analysis (B). floor area availability (C). terminal parameters (D). evaporation capacity required

44.

Purchased cost of equipment for a chemical process plant ranges from _________ of the fixed capital investment. (A). 15% to 40% (B). 25% to 55% (C). 45% to 60% (D). 65% to 75%

45.

Hastelloy C is a good material of construction in chemical process industries since it is (A). highly corrosion resistant and is easily fabricated (B). relatively inexpensive although it can be fabricated with some difficulty (C). corrosion resistant to most alkalis because of its copper content

(D). light and resist attacks by acids

CHEMICAL ENGINEERING REFRESHER COURSE UNIT OPERATIONS II 1.

In the Tyler standard screen scale series, when the Mesh number increases from 3mesh to 10mesh (A). the clear opening decreases (B). the clear opening increases (C). the clear opening is unchanged (D). the wire diameter increases

2.

One hundred tons per hour of a rock feed, of which 80% passed through a mesh size of 2.54 mm, were reduced in size such that 80% of the crushed product passed through a mesh size of 1.27 mm. The power consumption was 100kW. If the 100 ton/h of the same material is similarly crushed from a mesh size of 5.08 mm to a mesh size of 2.54 mm, the power consumption in kW using Bond's law is (A). 58 kW (B). 65 kW (C). 89 kW (D). 71 kW

3.

In the elutriation leg of a commercial crystallizer containing a mixture of coarse and very fine particles of the same material, a liquid is pumped vertically upward. The liquid velocity is adjusted such that it is slightly lower than the terminal velocity of the coarse crystals only. Hence (A). the very fine and coarse crystals will both be carried upward by the liquid (B). the very fine and coarse crystals will both settle at the bottom of the tube (C). the very fine crystals will be carried upward and the coarse crystals will settle (D). the coarse crystals will be carried upward and the very fine crystals will settle

4.

Urea is to be crystallized from an aqueous solution that is 90% saturated at 100°C. If 90% of the urea is to be crystallized in the anhydrous form and the final solution temperature is to be 30°C, the fraction of the water that must be evaporated on the basis of 1000 kg of feed is (A). 0.215 (B). 0.512 (C). 0.676 (D). 0.812

5.

In order to produce fine solid particles between 5 and 10 microns, the appropriate size reduction equipment is (A). fluid energy mill (B). hammer mill

(C). jaw crusher (D). smooth roll mill 6.

The average pore diameter and surface area of polystyrene for the removal of organics and antibiotics recovery are (A). 0.3-0.6 and 0.5-20 (B). 10-25 and 0.15-0.4 (C). 2-4 and 0.9-1.2 (D). 4-20 and 0.3-0.7

7.

A 10,000 lb-batch of a 32.5% MgSO4 solution at 120°F is cooled without appreciable evaporation to 70°F. At 70°F the concentration of solids is 26.3 lb MgSO4 solution per 100 lb solution. Assuming that the mother liquor leaving is saturated, the mass of MgSO47H20 crystals that will be formed is (A). 4174 lb (B). 6655 lb (C). 2756 lb (D). 3345 lb

8.

In a dying process, air is circulated through a bed of peas that have a 3 mm diameter contained in a cylindrical column of 85 cm diameter. The bed has a void fraction equal to 0.40. Air circulates with a flow of 5000 m3/h measured at the entrance to the column (1.5 atm, 90°C) and a viscosity of 0.0135 mPa-s. The pressure drop per unit of bed length experienced by air when passing through the bed of peas is (A). 30.398 kPa/m (B). 47.818 kPa/m (C). 60.978 kPa/m (D). 50.979 kPa/m

9.

The solubility of dibasic potassium phosphate in water at 25°C is _____ parts per 100 parts water (A). 53 (B). 33 (C). 25 (D). 48

10.

The terminal settling velocity in water of 70°F of a particle with a specific gravity of 2.0 and diameter of 100 microns is _____ ft/s (A). 0.0135 (B). 0.000175 (C). 0.0081 (D). 0.018

11.

The distribution coefficient of solute A between solvents B and S is given by Y = 3X where Y and X are the mass ratios of A to solvents in extract and raffinate phase respectively. B and S are mutually insoluble with each other. One hundred kg of a 30% solution of A in B is to be successively treated in two batch contacts with 60 kg of solvent each time. The overall percent recovery of A is

(A). 89.9% (B). 92.16% (C). 96.5% (D). 78.9% 12.

A counter-current leaching equipment is to be used to extract NaOH from a feed consisting of 80 kg NaOH, 400 kg water and 100 kg CaCO3 using water as a solvent. The final extract solution will contain 10% NaOH with the recovery of 95% of the NaOH. Setting the underflow constant at 3.0 kg solution / kg CaCO3, the number of ideal stages required is (A). 4.0 (B). 2.0 (C). 7.0 (D). 5.0

13.

A centrifuge with a 20 in diameter bowl 14 in deep operates at 1200 rpm giving a 2.0 in thick liquid later when used with a sludge whose liquid has a specific gravity of 1.2 and viscosity of 2.5 cp. The solid component of the sludge has a specific gravity of 1.7. If the cut size of the particles is 35 microns, the capacity of the centrifuge in gallons per min is (A). 738 gal/min (B). 865 gal/min (C). 840 gal/min (D). 740 gal/min

14.

The viscosity of water is ___cp at 70°C (A). 0.24 (B). 0.42 (C). 0.56 (D). 0.35

15.

The composition of feed and underflow (percent solids) in the design of a typical thickener for the sugar beet carbonation process are (A). 2-5 and 15-20 (B). 0.01-0.05 and 2-8 (C). 10-30 and 25-65 (D). 1-5 and 6-25

Problems 16 and 17 are based on the following information One hundred kg of a solid containing 40% solute A and 60% inert Bis treated with solvent C in a single stage single contact extraction. The extracted solids are then screw pressed. The pressed solids contain 1.2 kg solution per kg of inert. Entrainment of solids in the extract may be neglected. 16.

The mass fraction of the solute in the extract if 90% of the solute in the feed is to be recovered in a single stage single contact is (A). 0.556 (B). 0.0556

(C). 0.665 (D). 0.665 17.

The percent recovery of the solute if the extraction is carried out in two crosscurrent stages if 50% of the solvent amount in problem no. 20 used in each stage is (A). 90% (B). 15.7% (C). 81.1% (D). 96.7%

18.

A suspension of glass beads in ethylene glycol has a hindered settling velocity of 1.7 mm/s while the terminal settling velocity in a single glass bead in ethylene glycol is 17 mm/s. If the Richardson and Zaki hindered settling index is 4.5, the void fraction of solids in the suspension is (A). 0.1 (B). 0.4 (C). 0.6 (D). 0.9

19.

The terminal velocity of spherical air bubbles with an average diameter of 1 mm rising in pure water is ____ cm/s (A). 0.1 (B). 0.4 (C). 0.6 (D). 0.9

20.

The surface area and sorptive capacity of silica gel adsorbent are between _____ km2/kg dry solid between _____kg/kg dry solids respectively (A). 0.3 to 0.5 and 0.2 to 0.33 (B). 0.15 to 0.25 and 0.08 to 0.18 (C). 0.6 to 0.8 and 0.35 to 0.5 (D). 0.82 to 0.95 and 0.55 to 0.7

21.

A certain circular plate of diameter, D and thickness, t has a sphericity of 0.594. The ratio of t to D is (A). 0.333 (B). 0.166 (C). 1.333 (D). 0.666

Problems 22 and 23 are based on the following information It is desired to recover lead from an ore containing 10% lead sulfide (PbS) and the balanve assumed to be silica, 500 tons of ore being treated per 24 hr-day. It is assumed that the concentrate from a single cell is of acceptable purity but the tailings are to be retreated in scavenger cells with return of scavenger concentrate to the rougher. Laboratory findings indicate that if the water to solids ratio L/S = 2.0 and the contact time is 8 min in the rougher and L/S = 4.0 for 15 min in scavenger with mechanically agitated machines of the

Denver type. The following compositions will be found for the various products. PbS SiO2 Feed

10%

90%

Final Concentrate

80%

20%

Rougher Tailings

2%

98%

Scavenger Concentrate

11%

89%

Final Tailings

0.5%

99.5%

The densities of PbS and SiO2 are 7.5 and 2.65 g/cc respectively. 22.

The volume needed in the rougher is (A). 420 ft3 (B). 650 ft3 (C). 240 ft3 (D). 350 ft3

23.

The volume needed in the scavenger is (A). 750 ft3 (B). 570 ft3 (C). 680 ft3 (D). 840 ft3

Problems 24 to 27 are based on the following conditions: To clean a sand bed filter, it is fluidized at minimum conditions using water at 24°C. The density and viscosity for water at 24°C are 997.31 kg/m3 and 0.9142 x 10-3 Pa-s respectively. The round sand particles have a density of 2550 kg/m3 and an average diameter of 0.4 mm. For round sand, at minimum fluidizing conditions are as follows: void fraction, εmf = 0.42 and shape factor, Φs = 0.86. 24.

The diameter of the bed is 0.4 m and the desired height of the bed at these minimum fluidizing conditions is 1.75 m. The amount of solids needed is (A). 235.52 kg (B). 352.33 kg (C). 523.35 kg (D). 325.25 kg

25.

The pressure drop at these conditions is (A). 14.5 kPa (B). 13.4 kPa (C). 15.46 kPa (D). 17.3 kPa

26.

The minimum velocity for fluidization is (A). 6.75 m/h

(B). 7.65 m/h (C). 5.76 m/h (D). 7.57 m/h 27.

Using 4 times the minimum velocity, the porosity of the expanded bed is (A). 0.334 (B). 0.421 (C). 0.593 (D). 0.683

28.

A dispersion of oil in water is to be separated using a centrifuge. Assume that the oil is dispersed in the form of spherical globules 5.1 x 10-5 m diameter and that its density is 894 kg-m-3. If the centrifuge rotates at 1500 rev/min and the effective radius at which the separation occurs is 3.8 cm, calculate the velocity of the oil through the water. Take the density of water to be 1000 kg-m-3 and its viscosity to be 0.7 x 10-3 N-s-m-2. (A). 0.083 m/s (B). 0.0205 m/s (C). 0.0502 m/s (D). 0.215 m/s

29.

The figure below shows a tubular-bowl centrifuge for separating two liquid phases. The distances shown are as follows: r1 is the radius to surface of light liquid layer, r2 is the radius to liquid-liquid interface, and r4 is the radius to surface of heavy liquid downstream. A cream separator centrifuge has an outlet discharge of 50.8mm and outlet radius of 76.2 mm. The density of skim milk is 1032 kg/m3 and that of cream is 865 kg/m3. The radius of the interface neutral zone is (A). 51 mm (B). 205 mm (C). 180 mm (D). 150 mm

30. Glass spheres having a diameter of 1.554 x 10-4 m are settling in water at 293.2K. The density and viscosity of water at 293.2K are 998 kg/m3 and 1.005 x 10-3 Pa-s respectively. The slurry contains 60 wt% solids and the density of glass spheres is 2467 kg/m3. The hindered settling velocity of glass sphere is (A). 1.525 x 10-3 m/s (B). 0.01525 m/s (C). 0.521 m/s (D). 5.251 x 10-3 m/s 31.

From measurements on a uniformly sized material from a dryer, it is inferred that the surface area of the material is 1200 m2. If the density of the material is 1450 kg/m3 and the total weight is 360 kg, calculate the equivalent diameter of the particles if their value of λ is 1.75.

(A). 1272 microns (B). 2295 microns (C). 2172 microns (D). 3127 microns 32.

It is desired to extract phenol from water using methylnaphthalene as extraction solvent at 25°C. The partition ratio is (A). 39.8 (B). 7.06 (C). 2.13 (D). 3.44

33.

A 35 weight % Na2SO4 solution in water initially at 50°C is fed to a crystallizer at 20°C. The product stream contains hydrated crystals Na2SO410H2O in equilibrium with a 20 weight% Na2SO4 solution. The molecular weights of Na2SO4 and Na2SO410H2O are 142 and 322 respectively. The feed rate of 35% solution required to produce 500 kg/h of hydrated crystals is (A). 403 kg/h (B). 603 kg/h (C). 803 kg/h (D). 1103 kg/h

34.

A mixture of particles in packed bed contains the following volume percent of particles and sizes: 15%, 10 mm; 25%, 20mm; 40%, 40 mm and 20%.70 mm. The effective mean diameter, Dpm if the shape factor is 0.74 is (A). 23.43 mm (B). 16.81 mm (C). 12.38 mm (D). 18.34 mm

35. Air at 101.3 kPa absolute at 25°C is flowing at a velocity of 10 m/s in a wind tunnel. A long cylinder having a diameter of 90 mm is placed in the tunnel and the axis of the cylinder is held perpendicular to air flow. For air at 25°C and 101.3 kPa. ρ = 1.187 kg/m3& μ = 1.845 x 10-5 kg/m-s. The force on the cylinder per meter length is (A). 6.94 N (B). 4.69 N (C). 9.46 N (D). 5.49 N

CHEMICAL ENGINEERING REFRESHER COURSE CHEMISTRY AND BIOCHEMICAL ENGINEERING 1. How many liters of hydrogen gas are collected over water at 22 °C and 758.22 mmHg when 0.84 g of lithium reacts with 4.00 mL of water? Aqueous lithium hydroxide also forms. (Vapor pressure of H2O is 19.8 mmHg at 22 °C). (A.) 1.00L (B.) 1.50 L (C.) 2.32 L (D.) 2.77 L 2.The decomposition of a certain reactant is first order. A sample of the reactant is injected into a reaction vessel at 306 °C. The reactant has a half-life of 100 seconds. It takes 60 seconds for its initial concentration to have a decrease of 0.0111 mol/L. Find the initial pressure. (A). 35 in. Hg (B). 140 kPa (C). 1180 mm Hg (D). none of these 3. Calculate the energy released by fission of 235U (235.0439 amu) to form 142Ba (141.9164 amu) and 91Kr (90. 9234 amu). (A). -741 MeV (B). -417 MeV (C). -271 MeV (D). -174 MeV 4. Radon-222 has a half-life of 3.82 days. How many alpha emissions are produced when a 10 g sample of radon-222 decays over 19.1 days? (A). 4.18 x 1022 emissions (B). 6.22 x 1022 emissions (C). 1.84 x 1022 emissions (D). 2.62 x 1022 emissions 5. Caffeine has the following percent composition; carbon 49.48%, hydrogen 5.19%, oxygen 16.48% and nitrogen 28.85%. Its molecular weight is 194.19 g/mol. What is its molecular formula? (A). C10H8N2O4 (B). C4H10N2O8 (C). C8H10N2O4 (D). C8H10N4O2 6. 1M NaOH is added to the following solutions (each is 1M) which will precipitate first? (A). Mn(OH)2 (ksp = 2 x 10^-13) (B). Al(OH)3 (ksp = 3.7 x 10^ -15) (C). Mg(OH)2 (ksp = 1.2 x 10^-11)

(D). AgOH( ksp= 1.5 x 10^-8) 7. The molecular geometry of XeF4O. (A). Tetrahedral (B). Trigonal Bipyramidal (C). Square Pyramid (D). Octahedral 8. What are the coefficients in front of NO3(aq) and Cu(s) when the following redox equation is balanced in an acidic solution: NO3-(aq) + Cu(s)NO(g) + Cu2+(aq) (A). 2, 3 (B). 2, 6 (C). 3, 4 (D). 3, 6 9. A 0.8715 g sample of sorbic acid, a compound first obtained from the berries of a certain ash tree, is burned completely in oxygen to give 2.053 g of carbon dioxide and 0.5601 g of water. The empirical formula of sorbic acid is (A).CH2O (B). C3H4O (C). CH4O3 (D).C3H4O2 10. An aqueous fructose solution having a density of 1.049 g/cm3 is found to have an osmotic pressure of 17.0 atm at 25 °C. find the temperature at which this solution freezes. (A). -1.52 °C (B). -1.41 °C (C). -1.57 °C (D). -1.69 °C 11. How many grams of solid KF( molar mass= 58.1 g/mol0 should be added to 1.00 L of 0.250 M HF to make a buffer of pH= 3.143? (Ka for HF = 7.20 x 10-4) (A). 14.5 g (B). 15.4 g (C). 6.95g (D). 10.2g 12. a 1.000 L solution is prepared in which Au+, Ag+ and Cu+ ions are present in solution as nitrates, all at a concentration of 0.0010 M. A solution of sodium chloride is slowly added. Which compound will begin to precipitate first? The Ksp of AuCl = 2.0 x 10-13, AgCl =1.8 x 10-10, CuCl= 1.9 x 10-7. (A). NaCl (B). CuCl (C). AgCl (D).AuCl

13. Calculate the approximate pOH in a solution that is 0.200 M in NaF Ka for HF IS 6.7x10 -4. (A). 8.5 (B). 5.8 (C). 9.6 (D).6.9 14. Determine the pH range of an indicator given is Ka= 5x 10-8. (A).6.6-8.0 (B). 3.5-4.5 (C). 9.7-11.1 (D).12.0-13.0 15. a 2.500-gram sample of pure HgO (FW= 216.59) was dissolved in sufficient water and treated with excess KI liberating hydroxide according to the reaction HgO +4I- +H2O HgI4- 2 + 2H2O The liberated hydroxide was filtrated with 0.1350 HCl. Determine the volume of HCl that will react completely with the HgO sample. (A).85.50 ml (B). 171.00 ml (C). 342.00 ml (D).none of these 16. Phosphate in a 0.2711 g sample was precipitated giving 1.1682 g of (NH4)2PO4. 12 MoO3 (FW=1876.5). Find the percentage of P2O5 in the sample (P= 30.97). (A). 25.3% (B). 16.3% (C). 40.3% (D). 65.3% 17. A sample of meat scrap weighing 2.000 g is digested with concentrated H2SO4 plus a catalyst until the N in the material is converted to NH4HSO4, NaOH liberates NH3 which is absorbed in 50.00 ml of dilute H2SO4, and the excess acid then requires 22.14 mL of 0.6190 N NaOH. A separate 50.00 mL portion of the H2SO4 is neutralized by 40.23 mL of the NaOH titrating solution. Calculate the percentage of protein in the sample. (A). 53.05% (B). 49.02% (C). 33.34% (D). 24.51% 18. a sample that may contain NaOH, Na2CO3, NaHCO3, and inert matter alone or in compatible combination is titrated with 0.1000 N HCl with phenolphthalein as the indicator andthe solution became colorless after the addition of 48.8 ml. Methyl orange is then added and 14.55 ml more of the acid are needed for the color change. If the sample weighs 2.345 grams, it contains (A). 5.842% NaHCO3 and 6.570% Na2CO3 (B). 65.70% Na2CO3 and 5.842%NaHCO3 (C). 6.570%Na2CO3 and 58.42% NaOH (D).65.70% Na2CO3 and 5.842% NaOH

19.A 0.12 g sample of calcite (CaCO3) is treated with 36.82 mL of 0.08132 N HCl and the excess is found to require 6.2 mL of 0.09677 N NaOH for back titration. Calculate the % purity of calcite. (A). 99.8 (B). 98.3 (C).89.3 (D).39.8 20. How long (in hours) must a current 5.0 amperes be maintained to electroplate 60 g of calcium from molten CaCl2? (A).27 hours (B). 8.3 hours (C). 11 hours (D).16 hours 21. When C5H12 is reacted with Cl2 (g), in the presence of ultraviolet light, four different monochlorination products form. What is the IUPAC name of the correct structure of C5H12 in this reaction? (A). pentane (B). 2-Methylbutane (C). 2,2-Dimethylpropane (D).Pentene 22. The reaction of propene with HBr in the presence of ROOR proceeds through which of the following products? (A).Propane (B). 1-Bromopropane (C). 2-Bromopropane (D).reaction not possible 23. Acid catalyzed dehydration of alcohols a low temperature produces (A).alcohols (B). ethers (C). aldehydes (D).ketones 24. What carboxylic acid must be used in a Fischer esterification reaction in order to prepare phenyl propionate? (A).CH3COOH (B). CH3CH2CH2COOH (C). C6H5COOH (D).CH3CH2COOH 25. What compound can be converted to 3-ethyl-3-pentanol by reaction with Grignard reagent? (A).3-pentanone (B). Butanone (C).A and B (D).none of these

26. Which of the following molecules has the highest boiling point? (A). methyl ethyl ether (B). dimethylbutylamine (C). butane (D).butanol 27.Which series of reactions would give 1-phenylbutane as the major product? (A).1-chlorobutane + benzene+ AlCl3 (B). 1) butanoyl chloride + benzene 2) Zn + HCl (C). 1) butanoyl chloride+ benzene + AlCl3 2) Zn + HCl (D).butanoyl chloride + benzene + AlCl3 28. Which of the following intermediates is pyramidal in shape? (A).H3C(+) (B). H2C (C). H3C(-) (D).HC=C(-) 29. Which sequence of the reactions would be best for preparing meta-propylaniline from benzene? (A) (i) HNO3&H2SO4& heat (ii) C3H7COCl + AlCl3 (iii) 5 H2& Pt or Ni catalyst (B). (i) C3H7COCl + AlCl3 (ii) HNO3& H2SO4& heat (iii) 5 H2& Pt or Ni catalyst (C) (i) C3H7COCl + AlCl3 (ii) 2 H2& Pt or Ni catalyst (iii) HNO3& H2SO4& heat (iv) 3 H2& Pt or Ni catalyst (D). (i). HNO3& H2SO4& heat (ii) 3 H2& Pt or Ni catalyst (iii) C3H7COCl (iv) 2 H2& Pt or Ni catalyst 30. If the rate of reaction of [0.1 M] sodium cyanide with [0.1 M] 1-bromoethane is 1.4 x 10 -4, what effect will an increase in NaCN concentration to [0.3] alkyl bromide concentration to [0.2] have on the overall reaction rate? (A). increase by 2 times (B). increase by 3 times (C).increase by 6 times (D).increase by 1.5 times 31. Ingested glucose is phosphorylated in the liver by both hexokinase and glucokinase. Hexokinase has a Km for glucose of about 1 x 10-5 M and glucokinase has a Km for glucose about 1.5 x 10 -2 M. the glucose concentration available to liver cells is approximately equal to the concentration in the blood, and this value is about 0.75 x 10-2 M. Assuming that the ATP concentration and other factors are optimal, the velocity of the glucokinase reaction will be about? (A). 0.75 Vmax (B). 0.66 Vmax (C). 0.25 Vmax (D). 0.33 Vmax

32. It is the first vitamin to be discovered and synthesized in the laboratory? (A). Vitamin B (B). Vitamin C (C). Vitamin D (D). Vitamin K 33. What mRNA would result from the following template strand of DNA?5+ - ACCTAGTCA 3+ (A). 5+ - ACCUAGUCA-3+ (B). 5+ - ACCTAGTCA-3+ (C).5+ - TGACTAGGT- 3+ (D).5+ - UGACUAGGU- 3+ 34. Which statement describes the streochemical relationship between D-mannose and Dglucose? (A).They are C-1 epimers (B). They are C-2 epimers (C). They are C-3 epimers (D).They are C-4 epimers 35. Which of the following tripeptides will be cleaved by trypsin? (A).val-ser-lys (b). asp-pro-gly (c).lys-gly-ala (d).glu-phe-arg 36. One of the enzymes involved in glycolysis, aldolase, requires Zn2+ for catalysis. Under conditions of zinc deficiency, when the enzyme may lack zinc, it would be referred to as the: (A).Apoenzyme (B). Holoenzyme (C).Prosthetic Group (D).Coenzyme 37. Lactic acid is produced by human muscles during strenuous exercise because of lack of (A).Glucose (B). NAD(C).Oxygen (D).ATP 38. What is the dominant form of aspartic acid @ pH = 5. (pka1 =1.99, pka2=3.9, pka3=10) (A).Zwitterion (B). H2A (C).HA2(D).H3A 39. Birds dispose nitrogenous wastes in the form of (A). Urea (B). Uric Acid (C).Ammonia

(D).Nitrogen Gas 40. In cells having organelles, the steps of the Krebs cycle and the electron transport system occur in the (A). Cell Membrane (B). Nucleus (C).Endoplasmic Reticulum (D).Mitochondria

CHEMICAL ENGINEERING REFRESHER COURSE CHEMISTRY AND BIOCHEMICAL ENGINEERING 1. For a germanium atom, determine the total number of completely or partially filled porbitals in its ground state configuration. (A.) 2 (B.) 3 (C.) 6 (D.) 8 2. Which of the following is diamagnetic? (A.) N (B.) Ni (C.) Te (D.) Ba 3. Which of the following molecules has a distorted tetrahedron molecular geometry? (A.) XeCl2 (B.) ICl3 (C.) PCl5 (D.) TeF4 4. Which of the following is not soluble in water? (A.) SO2 (B.) NF3 (C.) SeF4 (D.) KrF2 5. Which of the following exhibits H-bonding? (A.) HCl (B.) HF (C.) CH4 (D.) CHCl3 6. A gas sample of solid ammonium chloride was placed in an evacuated container and then heated so that it decomposed to ammonia gas and hydrogen chloride gas. After heating, the total pressure in the container was found to be 4.4 atm. Calculate Kp at this temperature for this decomposition reaction. (A.) 2.2 atm (B.) 4.8 atm (C.) 5.7 atm (D.) 6.9 atm 7. Eugenol C10H12O2, is a pale yellow liquid that dissolves in ethanol. When a certain amount of eugenol is dissolved in 50.0 g ethanol at 20°C, the vapor pressure lowers by

2.03 mmHg. Calculate the boiling point of the resulting solution if pure ethanol boils at 78.4°C (For ethanol Kb=1.20°C/m; P° at 20°C=44.6 mmHg) (A.) 78.0 °C (B.) 78.4 °C (C.) 78.0 °C (D.) 79.6 °C 8. An atom of a particular element is travelling at 1% of the speed of light. The wavelength is found to be 3.31x10-3 pm. The element is (A.) Be (B.) Mg (C.) Ca (D.) Sr 9. It takes 208.4 kJ of energy to remove one mole of electrons from the atoms on the surface of rubidium metal. If rubidium metal is irradiated with 254-nm light, what is the maximum kinetic energy the released electrons can have? (A.) 3.02x10-19 J (B.) 4.36x10-19 J (C.) 5.89x10-19 J (D.) 7.82x10-19 J 10. Which of the following nuclides is STABLE? (A) 45 19K (B) 56 26Fe (C) 20 11Na 194 (D) 81 Tl 11. The easiest fusion to initiable is between the nuclei of deuterium and tritium to produce an alpha particle. How much energy is released for every formation of an alpha particle? (deuterium= 2.01410 amu, protium= 3.01605 amu, alpha particle= 4.00260 amu). (A.) -1.889x10-5 J (B.) -1.698x10-10J (C.) -2.82x10-12 J (D.) -4.56x10-14 J 12. Which of the following is the conjugate acid of hydrogen phosphate? (A.) H2O (B.) H2PO4(C.) OH(D.) H3PO4 13. What is the pH of gram of an aqueous solution (density=1.054 g/mL) containing 0.69 ng of HCl? (A.) 5.45 (B.) 6.00

(C.) 6.96 (D.) 7.70 14. What is pH of a 0.200 M solution of ammonium cyanate? (Ka= 2x10-4). (A.) 9.50 (B.) 7.50 (C.) 6.50 (D.) 4.50 15. What is molar solubility of beryllium of beryllium (II) hydroxide in a solution that is 1.50 M in NH3 and 0.25 M in NH4Cl? The molar solubility of beryllium (II) hydroxide is 8.6x10-7 M in pure water. (A.) 1.8x10-5 M (B.) 8.6x10-7 M (C.) 2.1x10-10 M (D.) 2.5x10-18 M 16. A 0.6407-g sample containing chloride and iodide ions gave a silver halide precipitate weighing 0.4430 g. This precipitate was then strongly heated in a stream of Cl2 gas to convert the AgI to AgCl; on the completion of this treatment, the precipitate weighed 0.3181 g. Sample contains (A.) 4.72% Cl(B.) 4.72% I(C.) 27.05% I(D.) (a) and (c) 17. The iodine produced when an excess of KI was added to a solution containing 0.1259 g K2Cr2Orequired a 41.26-mL titration with sodium thiosulfate. Calculate the molar concentration of thiosulfate solution. (A.) 0.01037 M (B.) 0.02073 M (C.) 0.03110 M (D.) 0.0622 M 18. Aqueous solutions containing approximately 3% w/w H2O2 are sold in drug stores as disinfectants (agua oxigenada, density= 1.00 g/mL). Under acidic medium, the exact amount of H2O2 can be determined by titration with KMnO4 is required for titration, calculate the volume of agua oxigenada sample being analyzed. 33.31 mL of the permanganate solution was required for standardization against 0.1278 g Na2C2O4. (A.) 895 mL (B.) 1135 mL (C.) 1395 mL (D.) 500 mL 19. A 0.0193-g sample of impure Na2CO3 was analyzed by the Volhard method. After adding 50.00 mL of 0.06911 M AgNO3, the sample was back titrated with 0.05781 M KSCN, requiring 27.36 mL to reach the end point. Report the purity of the Na2CO3 sample. (A.) 71%

(B.) 81% (C.) 91% (D.) 99% 20. A 0.5000-g sample of ore containing 10.00% Ni is decomposed; and the ammoniacal solution is treated with 60.00 mL of 0.08333 M KCN. A little KI is added, and the solution is then titrated to a faint turbidity with 0.06667 M AgNO3. What volume of AgNO3 solution is required? (A.) 23.85 mL (B.) 15.53 mL (C.) 11.90 mL (D.) 8.71 mL 21. A sample that may contain NaOH, Na2CO3, NaHCO3 and inert matter alone or in compatible combination is titrated with 0.100 M HCl using phenolphthalein as the indicator and the solution become colorless after addition 0f 48.8 mL. Methyl orange is then added and 14.55 mL more of the acid are needed for the color change. If the sample weighs 2.345 g, what is the composition of the mixture? (A.) 5.84% NaOH, 6.58% Na2CO33 (B.) 5.84% Na2CO33, 6.58% NaOH (C.) 7.06% NaHCO3, 6.58% Na2CO33 (D.) 5.84% NaOH, 7.06% NaHCO3 22. The Merck Index indicates that 10 mg of guanidine, CH5N3, may be administered for each kilogram of body weight in the treatment of myasthenia gravis. The nitrogen in a 4tablet sample that weighed a total of 7.50 g was converted to ammonia by Kjeldahl digestion, followed by distillation into 100.0 mL of 0.1750 M HCl. The Analysis was completed by titrating the excess acid with 11.37 mL of 0.1080 M NaOH. How many of these tablets represent a proper dose for patients who weigh 150 lb. (A.) 4.5 (B.) 6.5 (C.) 8.5 (D.) 10 23. A sample of synthetic cholesterol was prepared consisting entirely of (+)-cholesterol. This synthetic (+)-cholesterol was mixed with some natural (-)-cholesterol. The mixture at 20°C had specific rotation of -13°. What is the percentage of the mixture was (+)cholesterol? The observed rotation of a 0.3-g sample of cholesterol (isolated from natural resources) in 15 mL of chloroform contained in a 10-cm polarimeter tube is 0.78°. (A.) 25% (B.) 66.67% (C.) 50% (D.) 33.33%

24. Which of the following compounds is AROMATIC?

(C)

(C)

(D)

(D)

25. What is the main product when the compound below is reacted with propanoyl chloride?

(A)

(C)

(B)

(D)

26. In general, which of the following will best undergo an addition reaction with 3-Methyl3-heptene? (A.) HF (B.) HCl

(C.) HBr (D.) HI 27. If the reaction (using the best reagent) in question 26 is carried out under the presence of an organic peroxide, the product is (A.) 3-Fluoro-3-methyheptane (B.) 3-Chloro-3-methyheptane (C.) 3-Bromo-3-methyheptane (D.) 4-Iodo-3-methyheptane 28. What will be the product when the alkene in question 26 undergoes hydroborationoxidation reaction? (A.) 3-Methy-3-heptanol (B.) 3-Methy-4-heltanone (C.) 3-Methy-4-heptoxide (D.) 3-Methy-4-heptanol 29. When the product obtained in question 28 is treated with HCl, what will likely be the mechanisms of the reaction? (A.) SN1 (B.) SN2 (C.) (a) or (b) (D.) E2 30. If the product in question 28 is oxidized, one will likely get a/an (A.) Aldehyde (B.) Carboxylic acid (C.) Ketone (D.) Ether 31. What will be the product if the answer to question 30 is reacted to a Grignard reagent? (A.) Ester (B.) Alcohol (C.) Alkyl halide (D.) Alkane 32. What could have been reacted with the product in question 28 if the resulting product is an ester? (A.) Acid anhydride (B.) Ether (C.) Ketone (D.) Carboxylic acid 33. The ester in question 32 is treated with basic NaOH solution forming a salt, which is then further reacted with Ethanoyl chloride. What is the product? (A.) Acid halide (B.) Alkyl halide (C.) Acid anhydride

(D.) Epoxide 34. Part of a certain DNA sequence is GGTCTATAC. What is the corresponding RNA sequence? (A.) CCAGATATG (B.) TTGAGCGCA (C.) AAGTGTTAC (D.) CCGTGTCAG 35. Calculate the isoelectric point for the amino acid, arginine (pKa1=1.82, pKa2=8.99, pKa3=12.48). (A.) 5.41 (B.) 7.76 (C.) 10.74 (D.) 7.15 36. In the “Methode Champenoise,” strawberry juice is fermented in a 825-mL wine bottle to produce sparkling wine. Fermentation of 719 mL aqueous strawberry juice is allowed to take in the bottle until 12% by volume is ethyl alcohol. Calculate the pressure of CO2 inside the wine bottle at 29°C? (The density of ethanol is 0.79 g/cm3.) (A.) 150 atm (B.) 250 atm (C.) 350 atm (D.) 450 atm 37. 1000 kg of raw materials for yogurt production were enzymatically hydrolyzed and the resulting hydrolyzate contains 40% lactose, 15% maltose, 12% sucrose, 15% oligosaccharides and the rest accounts for flavoring agents. Calculate the amount of alcohol that can be produced when hydrolyzate is fermented by alcohol yeast? (A.) 260.5 kg (B.) 360.5 kg (C.) 460.5 kg (D.) 560.5 kg 38. Histidine, an essential α-amino acid present in our body can transform into histamine under enzymatic activity of histidine decarboxylase. When the reaction velocity is 2.6 mM/s, 1.67 mM of histamine is formed. Assuming 15 mM of the decarboxylase (Kcal= 30 s-1) is used, determine the Michaelis-Menten constant KM. (A.) 0.19 M (B.) 0.29 M (C.) 0.39 M (D.) 0.49 M 39. Antihistamine, a histamine antagonist, is a pharmaceutical drug inhibits competitively the action of histamine by blocking it from attaching to histamine receptors. If 3 mM of antihistamine is bound to be enzyme in the previous problem, what will be the reaction velocity of the enzyme if the disassociation constant of the enzyme-inhibitor complex is 1.5 mM?

(A.) (B.) (C.) (D.)

0.4762 mM/s 0.6589 mM/s 0.8621 mM/s 3.56 mM/s

40. A chemostat operating in steady-state at a dilution rate of 0.25 h-1 sets a limiting nutrient concentration of 0.6 µmol/L. Determine the Monod constant if the maximum specific growth rate for the organism is 0.60 h-1. (A.) 0.64 µmol/L (B.) 0.74 µmol/L (C.) 0.84 µmol/L (D.) 0.94 µmol/L

CHEMICAL ENGINEERING REFRESHER COURSE CHEMISTRY AND BIOCHEMICAL ENGINEERING 1. For these quantum numbers; n=4, m = 0; determine the possible number of electrons (A.) 4 (B.) 8 (C.) 16 (D.) 32 2. Which of the following is soluble in water? (A.) CCl4 (B.) NF3 (C.) KrF2 (D.) BeH2 3. At 75ºC and 2.50 atm pressure, uranium metal reacts with ClFn to form 3.53 g of uranium hexafluoride and 343 mL of gaseous chlorine monofluoride. Determine the molecular geometry of ClFn (A.) Distorted tetrahedron (B.) T-shaped (C.) Trigonal pyramidal (D.) Trigonal planar 4. At 25ºC, gaseous carbon dioxide and ammonia are formed when solid ammonium carbamate, N2H6CO2, sublimes. Calculate Kcif the total pressure of the gases in the equilibrium with the solid is 0.250 atm. (A.) 1.6 x 10-3 (B.) 1.6 x 10-5 (C.) 1.6 x 10-7 (D.) 1.6 x 10-9 5. All of the following exhibit high vapor pressure except (A.) BCl3 (B.) SeF4 (C.) NF3 (D.) NH3 6. With regard to the colligative properties of solutions, which of the following statements is not true? (A.) Cooking with hot water is faster in a pressure cooker than in an open pan (B.) Salt is used and spread on icy roads (C.) Melted sea ice from the Arctic Ocean forms fresh water (D.) Dry ice has a normal boiling point under normal atmospheric conditions

7. A certain particle, of a wavelength of 1.5 fm, is travelling at 90% of the speed of light. What could this particle be? (A.) Electron (B.) Neutron (C.) Alpha particle (D.) Dirt particle 8. Rb can be irradiated, such that, at 254-nm wavelength light, it takes 208.4 kJ of energy to remove 1 mol of electrons from the atoms of Rb metal surface. Calculate the maximum kinetic energy that these electrons can have? (A.) 7.80 x 10-19 J (B.) 3.40 x 10-19 J (C.) 3.40 x 10-22 J (D.) 4.30 x 10-19 J 9. Which of the following nuclides is STABLE? (A.) 4519K (B.) 5326Fe (C.) 2011Na (D.) 19481Tl 10. Calculate the amount of energy evolved when protons and neutrons collide to form 1 mol of an alpha paticle. (A.) -6.60 x 10-11 kJ/mol (B.) -4.60 x 10-10 kJ/mol (C.) -2.60 x 10-9 kJ/mol (D.) -1.00 x 10-7 kJ/mol 11. H3N is the conjugate acid of? (A.) H2O (B.) N3(C.) HN2(D.) H2N 12. An aqueous solution, with a specific gravity of 1.054, contains 690 pm. Calculate the pH of 1 g of this solution. (A.) 7.70 (B.) 6.96 (C.) 6.00 (D.) 5.45 13. A 50 mL of 4.0 x 10-3 M Na OH is mixed with a 150-mL solution of 2.4 x 10-7 M MgCl2. The Ksp involved is 1.8 x 10-11. The resulting solution is (A.) Unsaturated (B.) Saturated (C.) Supersaturated (D.) Super-duper saturated

14. Determine the volumes of the same concentration of sodium nitrite and nitrous acid (Ka = 3.98 x 10-4) that must be mixed to prepare a 1-L of pH = 3.55 solution (A.) 300 mL, 500 mL (B.) 250 mL, 600 mL (C.) 580 mL, 420 mL (D.) 455 mL, 657 mL 15. The iron in a 900-mg of an ore sample was reduced to its ferrous form upon dissolution in an acid solution. How much iron is originally present if the resulting solution is titrated with 30 mL of 0.150 N KMnO4 (A.) 5.6% (B.) 14.0% (C.) 28.0% (D.) 39.5% 16. In an experiment, an excess amount of KI was added to a solution containing 0.550 g potassium dichromate. Calculate the concentration of a 50-mL thiosulfate solution needed to treat the iodine liberated in this experiment. (A.) 0.142 M (B.) 0.224 M (C.) 0.324 M (D.) 0.424 M 17. A 10-% Ni ore weighing 500 mg is made ammoniacal and then treated with 0.060 L of 0.08333 M potassium cyanide. The solution s further titrated with 0.09445 M silver nitrate to permanent faint turbidity. Calculate the volume of the silver nitrate used in this titration (A.) 3.42 mL (B.) 5.42 mL (C.) 8.42 mL (D.) 10.42 mL 18. A 500-mg of soda ash sample was analyzed by the Volhard method. The sample was back-titrated with 27.36 mL of 0.05781 M potassium thiocyanate after the addition of 0.0500 L of 0.06911 M silver nitrate. How pure is the soda ash sample? (A.) 10% (B.) 20% (C.) 30% (D.) 40% 19. In the treatment of myasthenia gravis, the Merick index prescribes that 10 mg of guanidine, CH5N3, may be administered for each kilogram of body weight. A 7.5-g sample consisting of 4 tablets is analyzed by the Kjeidahl method, such that, the nitrogen in the sample is converted to ammonia which in turn treated with 100-mL 0.175 M HCl solution. The analysis is completed by titrating the excess acid with 11.37 mL of 0.1080 M NaOH. Determine the number of tablets that would represent the proper dose for patients weighing 159 lb (A.) 7

(B.) 8 (C.) 9 (D.) 10 20. An unknown mixture of bicarbonates, hydroxides, or possible compatible combination of these was analyzed via the double indicator method; it took 18.9 mL of 0.1 M HCl to reach the first stoichiometric point and further26.7 mL to reach the second. The mixture contains (A.) 57% NaHCO3 (B.) 43% NaOH (C.) 57% Na2CO3 (D.) 43% Na2CO3 21. A slightly turbid solution absorbs approximately 20% of the light passing through it. What percentage of light would be transmitted if the concentration of this solution is tripled? (A.) 6.67% (B.) 20.01% (C.) 51.20% (D.) 60.00% 22. A sample of sucrose hydrolyzes to a mixture of dextrose and levulose upon treatment with a strong acid or an appropriate enzyme. A solution of 2.0 g of dextrose in 10 mL water is placed in a 100-mm polarimeter tube and a rotation of 10.5º is observed. If a mixture of dextrose and levulose had an optical rotation of -31.5º, how much of the levulose was present? (A.) 20% (B.) 40% (C.) 60% (D.) 80% 23. Which of the following compounds would you expect to be the least soluble in water? (A.) CH3CH2CH2CH2CH2CH2CH2CH2CH2CH3 (B.) CH3CH2CH2CH2OH (C.) CH3CH2CH2CH2CH2CH2CH2OH (D.) CH3CH2CH2-O-CH2CH2CH3 24. All of the following are aromatic except

(A.)

(B.)

(D.)

25. Which of the following pairs of reagent will suitably undergo an addition reaction with 3-methyl-3heptene? (A.) HCl and HI (B.) HF and HI (C.) HBr and HF (D.) HCl and HBr 26. What would the product be if the addition reaction in #25 utilizing the best reagent, is performed under the presence of organic peroxide? (A.) 4-Bromo-3-methylheptane (B.) 3-Fluoro-3-methylheptane (C.) 4-Chloro-3-methylheptane (D.) 3-Iodo-4-methylheptane 27. The alkene in #25 is converted to alcohol via the following reactions except (A.) Hydrocarboration-oxidation (B.) Oxymercuration-demercuration (C.) Acid-catalyzed hydration (D.) Ozonolysis For numbers 28 to 30: Given that the alcohol in #27 is produced under the influence of AntiMarkovnikov 28. What will likely be the mechanism of the reaction if its treated with HCl? (A.) E1 or E2 (B.) SN1 (C.) SN2 (D.) SN1 or SN2 29. What would the product be if it undergoes an oxidation reaction? (A.) Ether

(B.) Carboxylic acid (C.) Aldehyde (D.) Ketone 30. What could have been reacted with the alcohol if the reaction resulted to the production of ester? (A.) Ether (B.) Ketone (C.) Carboxylic acid (D.) Acid anhydride 31. Determine the product when a carboxylate is reacted with an alkanoyl halide? (A.) Epoxide (B.) Acid anhydride (C.) Acid halide (D.) Alkyl halide 32. The reaction of methylamine with butanoic acid results to the formation of (A.) Primary amide (B.) Secondary amide (C.) Tertiary amide (D.) No reaction 33. What would the major product be if p-Methylbenzoic acid undergoes nitration under the presence of H2SO4? (A.) 4-Methyl-3-nitrobenzoic acid (B.) 4-Methyl-2-nitrobenzoic acid (C.) 4-Methyl-3-sulfobenzoic acid (D.) 4-Methyl-2-sulfobenzoic acid 34. For a particular amino acid with the following pKa values (pKa1 = 1.55, pKa2 = 4.23, pKa3 = 10.45), calculate the isoelectric point. (A.) 2.89 (B.) 5.41 (C.) 6.00 (D.) 7.34 35. Which of the following is not a “happy” chemical compound? (A.) Serotonin (B.) Oxytocin (C.) Dopamine (D.) Secretin 36. Via the base pairing method, what is the complementary sequence of the following DNA sequence; GGCTTATCG (A.) AATCCGCAT (B.) CCGAATAGC (C.) TTAGGCGAT

(D.) GGTCCTCGC 37. 1.575 MT of raw materials is being processed for the production of an oatmeal product. Upon hydrolysis, the following components are obtained: 10% cellobiose, 30% oligosaccharides, 20% glucose, 15% maltose, 15% lactose, and the rest impurities. Fermentation of the resulting hydrolyzate led to the production of alcohol in which all the mono- and the disaccharides are fermented. Calculate the amount of alcohol produced in this fermentation process. (A.) 250 kg (B.) 500 kg (C.) 750 kg (D.) 1000 kg

For numbers 38 and 39: Histamine, an organic nitrogenous compound which can use cause allergic rhinitis, can be produced in our body through the decarboxylation of the amino acid histidine. Given that 15 mM of the decarboxylase is used and 2 mM of histamine forms 38. Calculate the Michaelis-Menten constant KM, if the reaction velocity and the TON are 3 mM/s and 40 s-1, respectively. (A.) 0.198 M (B.) 0.298 M (C.) 0.398 M (D.) 0.498 M 39. If 4 mM of an anti-histamine competitively inhibits the formation of histamine, what will be the reaction velocity of the enzyme given that the dissociation of the enzymeinhibitor complex is 2.5 mM? (A.) 2.55 mM/x (B.) 1.16 mM/s (C.) 0.87 mM/s (D.) 0.16 mM/s 40. In a small biochemical plant, a 600-L capacity steady state chemostat is being used to control the growth of microorganisms by adjusting the dilution rate. The Monod constant and the maximum specific growth rate are 0.70 µmol/L and 0.90 h-1, respectively. Given a limiting exit concentration of 0.90 µmol/L, calculate the daily amount of the substance that the bioreactor is able to process. (A.) 5290 L/d (B.) 6290 L/d (C.) 7290 L/d (D.) 8290 L/d