NO QUESTION A 1 gate valve 2 0.052 3 smooth pipes 4 5 6 evaporation 7 8 9 large effect 10 11 12 Crystallization occurs in a solution that is concentrated 13 14 A valve that controls flow by means of a disk or wedge-shaped dam sliding at right angles to the direction of flow and seating tightly in the valve The friction factor for flow through a pipe with relative roughness of 0.004 at a Reynold's No. of 80,000 is approximately equal to The equation that relates friction factor and Reynold's No., f=64/Reynold's No. holds for Oil flows under laminar conditions inside a steam heated copper pipe. The overall heat transfer coefficient is approximately equal to the heat transfer coefficient of the oil In multi-stage liquid-liquid extraction with partially miscible solvents the extraction must be done to form co- currently in order to minimize the The enrichment of the vapor steam as it passes through the column in contact with the reflux during The maximum number of plates for a given distillation system is obtained at variable reflux The correct unit for the specific rate constant for the reaction A--->B determined to be first order is square liter/square mol/min On one side of a heat exchanger where either a condensing vapor or a boiling liquid is present, the temperature may be assumed to be constant. In determining the logarithmic mean temperature For a cylinder where steady-state radial heat transfer takes place the heat flux is constant A plate holding a pool of liquid from which rises a vapor whose average composition is in equilibrium with a liquid whose composition is the average of that of the liquid leaving the plate is called separation plate Mass transfer in a flowing fluid may be correlated by Sherwood, Nusselt and Reynold's No The ratio of the average diameter of the feed to the average diameter of the product is the settling ratio
Transcript
NO QUESTION A B
1 gate valve butterfly valve
2 0.052 0.025
3 smooth pipes
4
5
6 evaporation stripping
7 variable reflux maximum reflux
8
9 large effect little effect
10 For a cylinder where steady-state radial heat transfer takes place
11 theoretical plate
12 Crystallization occurs in a solution that is concentrated unsaturated13 Mass transfer in a flowing fluid may be correlated by
14 settling ratio discharge ratio
A valve that controls flow by means of a disk or wedge-shaped dam sliding at right angles to the direction of flow and seating tightly in the valve body is a
The friction factor for flow through a pipe with relative roughness of 0.004 at a Reynold's No. of 80,000 is approximately equal to
The equation that relates friction factor and Reynold's No., f=64/Reynold's No. holds for
laminar and turbulent flow
Oil flows under laminar conditions inside a steam heated copper pipe. The overall heat transfer coefficient is approximately
equal to the heat transfer coefficient of the oil
the average between the heat transfer coefficient of the steam and that of oil
In multi-stage liquid-liquid extraction with partially miscible solvents
the extraction must be done to form co-currently in order to minimize the extraction.
the minimum number of stages occur when the operating lines are parallel.
The enrichment of the vapor steam as it passes through the column in contact with the reflux during distillation is called
The maximum number of plates for a given distillation system is obtained at
The correct unit for the specific rate constant for the reaction A--->B determined to be first order is
square liter/square mol/min
square liter/square mol/square min
On one side of a heat exchanger where either a condensing vapor or a boiling liquid is present, the temperature may be assumed to be constant. In determining the logarithmic mean temperature difference the direction of flow will have
the heat flux is constant
maximum heat transfer rate occurs at the surface
A plate holding a pool of liquid from which rises a vapor whose average composition is in equilibrium with a liquid whose composition is the average of that of the liquid leaving the plate is called
separation plate
Sherwood, Nusselt and Reynold's No
Peclet, Reynold's and Schimdt No
The ratio of the average diameter of the feed to the average diameter of the product is the
15
16 A device for increasing the velocity of a fluid in steady flow is a nozzle vent
17 In steady-state backmix flow reactor, composition is
18 net value salvage value
19 In fractionation, an increase in reflux ratio
20
21
22
23 switching bank vent
24
25
26
27 window glass wood
28 evaporation dehumidification
The rate of formation of C for the reaction 2A + B ---> C is found to be rate=k(A)(B)
the rate of formation of C is equal to the rate of disappearance of B
the order of reactio is zero
not constant throughout the reactor
constant throughout the reactor
The amount of money obtainable from the sale of used property over and above any changers involved in removal and sale is called
increases the number of theoretical plates
decreases the reboiler duty
In mass transfer where the solute in the gas phase is very soluble in the liquid phase
the ratio of liquid phase resistance to the overall resistance is close to unity
the gas phase resistance is approximately equal to the total resistance
Heat transfer in turbulent flow may be described through an empirical equation correlating
Nusselt, Stanton and Reynold's Nos
Nusselt, Prandtl and Reynold's Nos
Which of the following fittings exhibits the highest pressure drop for the same flow conditions?
90-degree long radius elbow
90-degree standard elbow
A chamber into which steam from a high pressure line can be bled during periods of low steam demand from the power plant is called
Which one of the following pipes has the highest relative roughness?
2" diameter Wrought iron pipe
4" dia Wrought iron pipe
In steady-state heat transfer through a series of materials with varying resistances, the heat transfer rate
decreases towards the direction of heat transfer
varies with the thermal conductivity of each material
Reactions whereby reactants proceed along several paths and give different products are
polymeric reactions
reversible reactions
Which one among the following materials has the best insulating property?
An operation where warm vapor mixture is cooled such as by contact with a liquid resulting in condensation and decreased humidity is
29 gauge pressure
30 For mass transfer to take place, there must be a phase change
31 212 deg F 80 deg F
32 The diffusity of water in air at 100 deg F in sq.cm./sec is 0.256 0.27833 5.9 2.5
34 66.6 58.1
35 16 kg 64 kg
36 32.2 31.4
37 4 2.18
38
39 0.0378 0.0504
40 4440000 5130000
41 dew point
42 74.3 75
The pressure exerted on a plane parallel to the direction of flow of a moving fluid is called
velocity pressure
reaction component
Water vapor condenses at 1 atm on a tube whose surface tmeperature is at 80 deg F. in analyzing the heat transfer through the condensate film, it is best to evaluate the liquid properties at
A fluid flowing at a rate of 25 cubic meters per hour inside a 60 mm I.D. pipe has an average velocity in meter per sec equal to
An equimolar mixture of benzene and toluene is subjected to a single batch distillation. Distillation is discontinued when 60% of the benzene in the feed is distilled. At this instance the bottom product when analyzed shows benzene to be 36.4 mole%. In the distillate, the mole% of benzene is
When 32 kg of methane is burned completely the theoretical oxygen required is
The standard heat of reaction for the production of water gas, in kcal/gmole, as given by the equation: C(s) + H2O(g) = CO(g) + H2(g) is
A rectangular duct 4 ft x 1.5 ft in cross section carries conditioned air. In determining the pressure drop through the duct the equivalent diameter in ft may be used which in this case is
A gas decomposition reaction has an activation energy of 245 kJ/mol. The rate of reaction can be accelerated by using a platinum catalyst where the activation energy for the resulting catalyzed reactions is lower at 136 kJ/mol. Using Arrhenius' law and assuming the frequency factor remains the same the catalyzed reaction is faster than the original reaction by a factor of
over 100,000 but less than a million
over 100 but less than 200
Water at 100 deg F is flowing through a straight 4-in Sch 40 pipe at a rate of 1.0 gal/min. The length of the pipe is 10 ft. The velocity at the center of the pipe in ft per sec is
A metallic rod 2 cm in diameter is used as a heating element. The thermal conductivity is 370 J/sec.sq.m.degC. The surface temperature is maintained at 200 deg C. For the center of the rod not to exceed 500 deg C, the maximum volumetric heat generation rate within the metallic rod in J/sec cu.m. must be
This is a steady state temperature reached by a small amount of liquid evaporating into a large amount of unsaturated vapor-gas mixture.
wet-bulb temperature
Air, supplied at the rate of 1200 cfm to a refrigerated coil, has a relative humidity of 20% and dry bulb temperature of 150 deg F. The mass flow of dry air entering per minute is
43
44 0.1 0.05
45 free moisture
46 rotary drier flash drier
47 In the constant-rate period, the rate of drying is established by
48 desorption surface tension
49 0.542 hrs 1.846 hrs
50 0.12 0.034
51
52
53 0.3 0.8
In adiabatic humidification, it is possible to maintain the temperature of water constant since
according to the phase rule, the degrees of freedom is 3
the system can be well insulated from the surroundings
An air-carbon tetrachloride vapor mixture at 100 deg F dry bulb and 60 deg F wet bulb is heated until the temperature reaches 180 deg F. the final percent relative humidity is about
The portion of water in the wet solid that cannot be removed by the air in its contact is called
final moisture content
This type of drier is used for drying pasty materials such as wet filter cakes and lumpy solids
a balance of the heat requirements for evaporation and the rate at which heat reaches the surface
the internal movement of moisture beneath the surface of the solid
Unbound moisture in granular and porous solid moves through the intertices of the solid by a mechanism involving
Wet solid is to be dried from 40% to 10% in 5 hours under constant drying conditions. The critical moisture content is 20% and the equilibrium moisture content is 7%. All moisture contents are on dry basis. The time needed to dry from 15% to 5% free moisture under the same drying conditions is
If the rate of drying under constant drying conditions with air at 140 deg F and absolute humidity of 0.03 lb water per lb dry air of unknown mass of solid is given by R=0.5-exp(-60X) [in lb water/hr-sqft], then the equilibrium moisture content (db) of the material is
In drying at the falling rate period, the rate at which moisture is removed from the solid material
remains constant
increases with time
The major problem in diffusion is to promote diffusion of the solute out of the solid and into the liquid. The most effective way of doing this is
to reduce the solid to the smallest size feasible
to use counter current operation
A slurry flaked soybeans weighing 100 kg contains 75 kg inert solids and 25 kg of solution 10 weight % oil and 90% wt solvent hexane. This slurry is contacted with 100 kg pure hexane in a single stage so that the value of retention for the outlet underflow is 1.5 kg of insoluble solid per kg solvent in the adhering solution. The composition of underflow leaving the extraction stage in %wt oil is
54 3 4
55 convection conduction
56 convection conduction
57
58 Film and drop are terms associated with boiling condensation
59 99.95 415.7
60 97 242
61 185.5 m 11.02 m
62 4301 kg 1500 kg
Tung meal containing 55% oil is to be extracted at the rate of 4000 lb per hour using n-hexane containing 5% oil as solvent. A countercurrent mulitple stage extraction system is to be used. The meal retains 2 lb of solvent per pound of oil free meal while the residual charge contain 0.11 lb oil per lb oil free meal while the product is conposed of 15% oil. The theoretical number of ideal stages is
The movement of molecules over a substantial distance is associated with the transfer of heat by
The mode of heat transfer that can take place in a vacuum is known as
The overall conductance for a composite material in series is equal to the
sum of the individual conductances
sum of the individual conductivities
A 6-in Sch 80 steel pipe is carrying glycerin at an average temperature of 100 deg F. The pipe is uninsulated, and the outside temperature is 30 deg F. The inside film conductance is 1000 Btu/h-ft-degF while the outside film conductance is 3.0 Btu/h-sq.ft.-degF. Determine the heat lost [Btu] per minute from a 75-ft length of the pipe. Glycerine is flowing at 800 gpm.
An oak (k=0.096 Btu/h-ft-degF) door, 30 in wide, 78 in high, and 2 in thick, has 9 glass (k=0.45 Btu/h-ft-degF) windows, each 6 in by 8 in by 1/4 in thick. Determine the amount of heat lost [Btu] each day with a surface-to-surface temperature difference of 80 deg F.
Determine the length needed for a simple concentric-tube, parallel flow heat exchanger to transfer heat from hot water to cold water at a rate of 900 W. The heat exchanger consists of two Type K copper (k=386 W/m-degC) tubes. The smaller tube has an inside diameter of 49.8 mm and an outside diameter of 54.0 mm. Assume that both film coefficients are equal to 100 W/sq.m.-degC. The hot water enters at 90 degC and leaves at 50 degC, and the cold water enters at 10 degC and leaves at 40 degC.
A saturated solution containing 1500 kg of potassium chloride at 360 K is cooled in an open tank to 290K. If the specific gravity of the solution is 1.2, the solubility of potassium chloride per 100 parts of water is 53.55 at 360K and 34.5 at 290K, calculate the amount of crystals obtained assuming that loss of water by evaporation is negligible.
63 55.8 sq.m. 58.5 sq.m.
64 115 kPa 101.3 kPa
65 10.92 9.12
66 37 38
67 10 9
68 72.2 28.7
An evaporator, working at atmospheric pressure, is to concentrate a solution from 5% to 20% solids at the rate of 1.25 kg/s. The solution which has a specific heat of 4.18 kJ/kg-K is fed to the evpaorator at 295K and boils at 380K. Dry saturated steam at 240 kPa is fed to the calandria and the condensate leaves at the temperature of the condensing steam. If the heat transfer coefficient is 2.3 kW/sq.m-K, what is the required area of heat transfer surface. The latent heat of vaporization maybe taken as the same as that of water.
2.5 kg/s of a solution at 288K containing 10% dissolved solids is fed to a forward-feed double effect evaporator operating at a pressure of 14 kPa in the last effect. If the product is to consist of a liquid containing 50% by weight of dissolved solids and dry saturated steam is fed to the steam coils, what should be the pressure of the steam? The surface in each effect is 50 sq.m. and the coefficients for heat transfer in the first and second effects are 2.8 and 1.7 kW/sq.m.-K respectively. Assume that the concentrated solution exhibits a boiling point rise of 5 degK, that the latent heat has a constant value of 2260 kJ/kg and that the specific heat of the liquid stream is constant at 3.75 kJ/kgK.
An acetone-air mixture containing 0.015 mol fraction of acetone has the mol fraction reduced to 1% of this value by countercurrent absorption with water in a packed tower. The gas flow-rate G is 1 kg/sq.m-s of air and the water entering is 1.6 kg/sq.m-s. For this system, Henry's law holds and Ye=1.75x, where Ye is the mol fraction of acetone in the vapour in equilibrium with a mol fraction x in the liquid. How many overall transfer units are required?
A still has a liquor composition of ortho-xylen 10%, meta-xylene 65%, para-xylene 17%, benzene 4%, and ethylbenzene 4%. How many plates at total reflux are required to give a product of 80% meta-xylene and 14% para-xylene? The data are given as mole percent.
A mixture of alcohol and water with 0.45 mol fraction of alcohol is to be continuously distilled in a column so as to give a top product of 0.825 mol fraction alcohol and a liquor at the bottom with 0.05 mol fraction alcohol. How many theoretical plates are required if the reflux ratio used is 3?
Prepared cottonseed meats containing 35% extractable oil are fed to a continuous countercurrent extractor of the intermittent drainage type using hexane as solvent. The extractor consists of ten sections, the section efficiency being 50%. The entrainment, assumed constant, is 1 kg solution/kg solids. What will be the oil concentration in the outflowing solvent if the extractable oil content in the meats is to be reduced to 0.5% by weight?
69 0.492 0.429
70 2173 696
71 12.54 12.68
72 64.5 54.6
73 77.2 150
74 3537 8457
75 10500 35000
76 38.1 18.3
77 2951 1644
0.4 kg/s of dry seashore sand, containing 1% by weight of salt, is to be washed with 0.4 kg/s of fresh water running countercurrent to the sand through two classifiers in series. Assume that perfect mixing of the sand and water occurs in each classifier and that the sand discharged from each classifier contains one part of water for every two of sand (by weight). If the washed sand is dried in a kiln drier, what percent of salt will it retain?
Forty-five pounds per minute of water is heated from 60 to 180 deg F in a 5/8 in., 16 BWG heat exchanger tube. If the steam condensing at 260 deg F, on the outside of the tube gives an hо of 1000 Btu/hr-sq.ft.-degF, calculate the inside heat transfer coefficient [Btu/hr-cu.ft-degF].
How many cu.ft. per minute of entering air is needed to evaporate 10 lb of water per hour from a rayon, if the air enters at 80 deg F and 25% humidity and leaves at 170 deg F and 55% relative humidity. The operating pressure is 14.3 psia.
Nicotine is to be extracted from water using kerosene. If 100 lb of a 2% nicotene solution is extracted once with 200 lb of kerosene, what percent of the nicotene is extracted? {Equilibrium data: Y[lb nicotene/lb kerosene] = 0.90X [lb nicotene/lb water]}
We must cool 2500 gpm of water from 120 to 80 deg F. A cooling tower, at 70 deg F and 1 atm, is to be designed to operate with entering air of 40% relative humidity. How many gpm of makeup water must be supplied if windage loss is 95% of the amount lost by evaporation.
We wish to build an economical cold room 20 ft square and 10 ft high. The outside temperature is 80 deg F and te room is to be maintained at 0 deg F. The boss has suggested parallel wooden outer and inner walls separated by a 6-in air space. What will be the heat loss [Btu/hr] through each wall?
A colloidal solution is to be concentrated from 15 to 65% solids. The specific heat of the feed, entering at 50 deg F is 0.93. The pressure of the saturated steam to the evaporator is 10 psia; the condenser pressure is 5-in. Hg abs. The steam chest has an overall heat transfer coefficient of 200 Btu/hr-sq.ft.-degF. Water must be evaporated at the rate of 35,000 lb/hr. Neglecting boiling point elevation, what is the steam consumption [lb/hr]?
What is the settling time [sec] for galena particles to settle under free settling conditions through 5 ft of water at 50 deg F. Galena is spherical in shape, with specific gravity and 0.01 inch in diameter.
A 10-ft diameter tank with a quick-opening value to a sump has a 10-ft depth of liquid. How long [t in sec] does it take to drain the tank if the valve is assumed to be equivalent to a 4-in diameter orifice? The liquid density is 60 lb/cu.ft.
78 2.21 1.35
79 63 84
80 34.2 27.7
81 11.61 14.24
82 113 227
83 0.15 0.5
84
85 75.2 55.2
86 13 272
What size sharp-edged orifice [inches] was in use if a flow of 120 gpm produced a 4-in Hg differential in a 4-in Schedule 40 pipe. The fluid, measured at 60 degF, had a viscosity of 1 cSt and a specific gravity of 1.
Seven hundred gallons per minute of water are being discharged by a centrifugal pump 5 ft above the pump inlet. The inlet pressure is 4-in Hg above atmospheric and the discharge pressure is 29 psia. If the pump has an 8-inch diameter inlet and a 4-inch diameter discharge, calculate the pump efficiency.
Determine the net positive suction head available to a centrifugal pump when the level of water is just at the suction point. The pumped fluid is water at 140 deg F and it is pumped from an atmospheric tank at 250 gpm. The tank suction point is 7 ft above the pump. The piping is 5-in Schedule 40, 10-ft long with two short radius 90 deg elbows. [Use density=61.38 lb/cuft, Pv=2.89 psi, viscosity=0.47 cP]
Water at 60 deg F flows through a 3-inch Schedule 40 pipe. A pitot tube in the pipe shows a 3-inch Hg differential. If the pitot tube is located at the center of the pipe, what is the mass flow rate of the water [lb/s]?
The gas phase irreversible reaction A+B---->C is elementary. The entering flow rate of A is 10 mol/min and is equal molar in A and B. The entering concentration of A is 0.4 mol/L. What CSTR volume [L] is necessary to achieve 90% conversion?
The irreversible zero order gas phase dimerization 2A ----->A2 is carried out in a packed bed reactor with 5 kg of catalyst. The entering pressure is 10 atm and the exit pressure is 1 atm. Pure A enters at a flow rate of 10 mol/min. The reaction is zero order in A. What is the exit conversion?
The gas phase reaction 2A+B----->C is carried out in a PFR. The feed is equal molar in A and B and the entering temperature is 500K and the entering pressure is 16.4 atm. If the exit conversion is x, then the exit concentration of B is
[B]=0.4(1-x)/(1-0.5x)
[B]=0.4(1-x)/(1-1.5x)
Heat is generated in a 2.5 cm square copper rod at the rate of 35.3e6 W/cu.m. The rod is exposed to a convection environment at 20 deg C where the convection heat transfer coefficient is 4 kW/sq.m.-degC. Determine the surface temperature [deg C] of the rod.
A 5cm diameter cylinder is maintained at a constant temperature of 200 deg C and it is "completely enclosed" by a wind tunnel test chamber, walls of which are at 10 deg C. Air at 350K is forced across the cylinder at a velocity of 50 m/s (h=180 W/m-degC). If the surface emissivity of the cylinder is 0.7, determine the total (i.e., convective and radiative) heat transfer from the cylinder [W per meter length].
87 0.028 0.119
88 325 300
89 1500 W 4392 W
90 1 18
91 170 100
92 A B
93 is doubled.
94 increases. decreases.
95 In all naturally occurring processes, the entropy of the universe increases. decreases.
A building wall consists of a 6-in of concrete (kc= 0.7 Btu/hr-ft-degF), 2 in of fiber insulating board, and 3/8 in of gypsum board (kg=0.03 Btu/hr-ft-degF). The inside and outside heat transfer coefficients are 2 and 7 Btu/hr-sqft-degF, respectively. The inside temperature is 72 degF and the outside temperature is 20 degF. Determine the overall heat transfer coefficient for this wall [Btu/hr-sqft-degF].
Current is passed through a cylindrical laboratory heater, which has a 3 cm diameter, generating heat at the rate of 20 MW/cu.m. The heater is exposed to a convection environment at 25 degC where the convection heat transfer coefficient is 0.5 kW/sq.m.-degC. Determine its surface temperature [degC].
A straight rectangular fin has a length of 3.5 cm, a thickness of 1.5 mm, and is made of a material characterized by thermal conductivity of 255 W/m-degC. The fin is exposed to a convection environment at 20 degC and h=1.5 kW/sq.m.-degC. Determine the maximum possible heat transfer from this fin for the base temperature of 150 degC.
A gaseous fuel is composed of 20% methane( CH4), 40% ethane (C2H6) and 40% propane (C3H8), where all percentages are by volume. The volumetric analysis of the dry products of combustion (ie. everything except the water) for this fuel gives 10.6% carbon dioxide (CO2), 3% oxygen (O2), 1% carbon monoxide (CO) and 85.4% nitrogen (N2). Determine the air fuel ratio on a mass basis for this reaction.
Dodecane (C12H26) gas at 25 degC is burned in a steady flow combustion chamber with 20% excess air that enters at -23.15 degC. The products leave the combustion chamber at 500K. Assuming steady operating conditions and complete combustion, determine the required mass flow rate of the dodecane to supply heat at a rate of 1.5 kW [kg/s].
Two rooms A and B of identical volume are connected by an open doorway. The thermostat in the rooms are set so that Ta<Tb. Which room contains more air molecules?
If the absolute temperature of a gas is doubled, the mean speed of the gas molecules
increases 4 times
When ice cubes melt in a glass of water, the temperature of the resulting mixture of water and ice
96
97 doubles. quadruples.
98 2.5 e8 2.2 e8
99 The material which remains unchanged in a process is limiting reactant tie substance
100 recycle ratio
101
102 cooked coal ash
103
104 An Orsat analysis of the flue gas when pyrite is roasted is on a SO2-free basis SO3-free basis
105
106 The equivalent of 45degTw in the Baume scale is 26.63 28.32107 1.2 1.53
108 Which has the lowest water content? 70% RH
An inventor seeking a patent claims that a building may be comfortably heated in winter by a device that draws heat into the building from the earth, even though the temperature of the earth is lower than the desired temperature inside the building. He further claims that the quantity of heat supplied to the building in a given time period can significantly exceed the work done by the device during the same period. If you were a patent clerk (like the young Albert Einstein), what should be your recommendation about the application?
The application should be rejected because it violates the first law of Thermodynamics.
The application should be rejected because it violates the second law of Thermodynamics.
A fixture containing an ordinary incandescent light bulb is connected to a dimmer switch. The dimmer is adjusted so that the temperature of the tungsten filament inside the bulb increases from 1300K to 2600K. The total power radiated by the bulb
A 30 MW geothermal electric power plant uses hot steam from the earth at 157 deg C to heat and vaporize isobutane, which turns a turbine that is connected to a generator. The isobutane is subsequently cooled to 27 degC using fans and condensed back to a liquid. The overall efficiency of the plant is 40% of the ideal (Carnot) efficiency. How many joules of heat must be released to the atmosphere per second?
The ratio of the total quantity of a reactant present in the reactor feed of a recycling operation to the quantity of the same reactant entering the operation as fresh feed is the
combined feed ratio
The heating value measured when water formed from combustion is in the liquid state.
Gross Calorific Value
Heat of combustion
In the combustion of solid fuels, the tie element between the feed and the refuse is the
The coal analysis which is based upon the volatilization characteristics of the fuel is
Proximate analysis
Modified analysis
The empirical relation which allows one to compute for the net hydrogen in a given solid fuel is the
Calderwood equation
Theoretical Oxygen Equation
A furnace completely burns coal containing 70%C. Analysis of the flue gas shows 15% CO2, 4% O2, 81% N2, and no CO. What is the % of the net hydrogen in the coal?
dew point at 20degC
109 PhP 405 PhP 424.26
110 0.01 0.02
111 2250 3750
112 4.22 8
113 0.8 0.85
114 63.25 57.24
115 3.52 6.53
116 The unit of k for a 1st order elementary reaction is 1/time conc/time117 4 3
118 The E of a reaction may be lowered by
119 The mechanism of a reaction can sometimes be deduced from
120
A contract was made between a buyer and a paper manufacturer for paper containing 5% moisture at PhP450/tonne FOB on specifications that price adjustment will be made if the quality is different. How much should the buyer pay for 1 tonne of paper with 8% moisture content? Freiht cost is PhP45/tonne.
One drier will dry a material from 45% moisture (wb) to 20% moisture (db). From here the material enters another drier where the water content is further reduced to give a final product weighing 1000 kg. If the total evporation from both driers is 800 kg, the moisture of the final product is
An experimental oil is used to distill 6000 kg.hr of Athabasta tar sand which analyzes 30% 'heavy oil', 'light oil', and non-volatile matter. If the distillate contains 12 % heavy oil and this constitutes 25% recovery of the component, the weight in kg of the distillate obtained is
Coal fired in a furnace has a heating value of 13800 Btu/lb and contains 78.05%C and 1.2%S. The proximate analysis shows 4%M, 24%FC, 8%A and the analysis of the refuse shows 8%VCM, 25%FC and 32% ash. Calculate the % of C lost in the refuse.
Ninety grams of ethane and 384 grams of oxygen are fed continuously to a laboratory furnace. The total combustion products collected was 16.2 gmole with no carbon dioxide. However, not all of the ethane was burned due to faulty combustion. The fraction of ethane that was burned is equal to
The furnace at the Bataan refinery is using a fuel gas which contains methane, ethane and 20% nitrogen. The orsat analysis of the combustion products showed 7.8% CO2, 7.4% O2, and 84.8% N2. The gas is burned with excess air. The % methane in the fuel gas is
Pyrite containing 78% FeS2 and 22% gangue is burned with excess air to produce a stack gas with the following analysis: 7.29% SO2, 8.92%O2, 82.44%N2 and 1.35%SO3. If the cinder was found to have a partial analysis of 62.10% Fe2O3, the % of FeS2 lost in the pyrite is
If the temperature of a chemical reaction is raised by 10 degC, the rate of reaction is increased by a factor of
increasing temperature
decreasing temperature
the activation energy
the temperature dependency of the rate
The equilibrium constant in a reversible chemical reaction at a given temperature
depends on the initial conc of the reactants
depends on the conc of one of the products at equilibrium
121 2 4
122 The rate of reaction is not influenced by
123 The net rate of reaction of an intermediate is 0 2124 log Ca vs time Ca vs time
125 Ca^2 vs time 1/Ca vs time
126 -ra = k Ca Cb^2
127 Hess' Law
128 The half life of a material undergoing second order decay is
129 66.8 74.7
130 0.0021 s 100 s
131 45.1 min 19.6 min
132 3.83 7.43
133 25.36 m 32.5 m
134 0.1697 0.183
If the volume of a reaction vessel is suddenly reduced to one half its original volume the rate will increase by a factor of
conc of the reactants
molecularity of the reaction
A reaction is known to be first order in A. A straight line will be obtained by plotting
If the reaction 2A ---> B+C is second order, which of the following plots will give a straight line?
For the reaction A+B ---> 2C, when Ca is doubled the rate doubles, when Cb is doubled the rate increases fourfold. The rate law is
-ra = k Ca^2 Cb^4
It states that the rate of a chemical reaction is proportional to the activity of the reactants.
Le Chatelier's principle
proportional to the square of the initial conc
independent of initial conc
A fluid flows through 2 CSTR in series. Each reactor has a capacity of 400,000 L and the fluid enters at 100 L per hr. The fluid undergoes a first order decay with a half life of 24 hours. Find the conversion of the fluid.
A first order reaction has a specific rate constant of 3e-3 per sec. The half life is
A certain reaction is 1st order in A. In 30 min, the concentration of A decreases from 0.55 to 0.15 mol/L. The time it will take for A to decrease from 0.35 to 0.15 mol/L is
A gas decomposes at 900 degC according to 2A--->2R+S with a rate constant of 1000 cc/gmol-s using pure A. The time it will take to react 80% of A in a batch reactor at 900 degC and 1 atm in min is
Calculate the length of a chlorinating pipe line with diameter of 0.6 m required to kill 95% of the bacteria in waste water flowing at 0.05 cu.m/s. Test shows that 95.33% kill is obtained in 5 minutes when treated with 5 mg/L of chlorine. Chlorine disinfection kinetics is given by the equation: dC/dt = k Ct^1.5 where C = number of bacteria. Assume that the same concentration of chlorine is used in actual treatment operation.
The set of data given below is for the parallel reaction: a---k1-->2R, a---k2-->S. At t=0, Ca=15 moles/cuft, Cr = 1 mole/cuft, Cs=1 mole/cuft; At t=1 hr, Cro = 9 moles/cuft, Cs = 3 moles/cuft. The value of K2 per hour is
135 257 275
136 0.732 0.427
137 10.3 11.4
138 8150 9150
139 Cao/2m Cao/(2m-1)
140 43.1 41.3
141 1/8 1/16
142 1/2 1
143 1/2 1
A batch reaction 2D+E----->F has a conversion factor expressed by the equation r =0.24 t^0.5 where r = conversion factor based on the reactant E; t = time in hours which ranges from 0.5 to 16 hours per batch depending upon the process variables. The average molecular weight of the feed is 60 and a density of 1.4 g/cc. The feed consists of 2 kgmole of D and 1 kgmole of E. The charging, cleaning and discharging time per batch is 2.5 hrs and the volume of the reactor is twice the volume of the feed. Assume 300 days per year and 12 hours operation/day. The volume of the reactor in liters is
A container holds 100 gal of salt solution containing 50 lb of dissolved salt. The bottom of the container is covered with a layer of rock salt. The bottom of the container is covered with a layer of rock salt whose surface is practically constant. The salt dissolved into the solution according to r = k(C-3) where C is the concentration of the brine expressed in lb/gal. If the water in the tank were fresh, the rate of solution would be 1.0 lb/min. Fresh water enters at 3 gpm and brine overflows at the same rate. Assume constant volume at any brine concentration, the concentration of brine in container after 1 hour in lb/gal of salt is
An aqueous solution of ethyl acetate is to be saponified with NaOH. The initial concentration of the ethyl acetate is 5 g/L and that of the caustic soda is 0.10M. Values of the second order rate constant in L/gmole-min are k = 23.5 at 0 degC; k = 92.4 at 20 degC. The reaction is essentially irreversible. The time required to saponify 95% of the water at 40 deg C is
At 500K the rate of bimolecular reaction is 10 times the rate at 400K. Find E in cal, the activation energy for this reaction from Arrhenius Law.
The reaction A+2B--->R is 1st order with respect to each reactant. If equimolar amounts of A and B are introduced into a constant-volume reactor and (1/m) th of A remains after t1, how much will remain after t2=2t1?
When the 1st order homogeneous reaction (gas-phase) A--->2.5R is carried out in an isothermal batch reactor at 2 atm with 20% inerts present, the volume increases by 60% in 20 min. When the reaction is carried out in a constant volume reactor, the time required for the pressure to reach 8 atm if the initial pressure is 5 atm, 2 atm of which consist of inerts in min is
When the ID of the pipe through which a fluid flows is doubled, the pressure loss due to friction per unit length of pipe and for the same volumetric flow rate is changed by approximately a factor of
When two centrifugal pumps are connected in series, the discharge changes by a factor of
When two reciprocating pumps are connected in parallel, the volumetric capacity of the system changes by a factor of
144 1/2 1
145 Cavitation occurs in a centrifugal pump when
146 0.63 13.1
147 1.05 1.22
148 0.6 3.58
149 PhP 3300 PhP 5000
150 1/2 1
151 potential head pressure head
152 viscosity friction factor
153 20 36
154 3x2x8.5E 4x3x8.5E
155 95 134
156 2 4
157 32 55
158 15 20
The pressure drop in a pipeline changes by a factor of _____ when the velocity of the flowing fluid is doubled.
the discharge pressure becomes too high
the discharge valve is closed
Oil with a viscosity of 30 cP and a density of 60 lb/cu.ft. flows through a 1/2-inch inside diameter pipe. Determine the velocity in fps below which flow will be laminar.
Water at 60 deg F flows through a 3-inch inside diameter smooth horizontal pipe. If the Reynold's number is 353000, calculate the ratio of maximum velocity to average velocity.
The pressure after the pump in a 6-inch inside diameter smooth pipe conducting water is 20 psia. The water is discharged at an open tank 100 ft from the pump. Calculate the rate of discharge of water in cu.ft/s.
A water storage tank assumes the supply of water into a factory. Water is supplied to the tank through a booster pump installed in the water line. The theoretical pump horsepower required is 3.25 hp. What is the monthly operating cost of the pump if electric power cost on the average is PhP 3.73/kWh. The pump is 65% efficient and operates for 12 hr a day.
When the impeller speed of an ideal centrifugal pump is doubled, the vol. flow rate of discharge is increased by a factor of
The differential height between two points which a fluid has to be transferred is the
The resistance of a layer of fluid to flow over the next layer is measured by
An axial flow pump operating at a speed of 880 rpm can supply water at a rate of 3000 gpm. The maximum head that this pump can deliver in ft. of water is
Specify the type of open impeller pump to use if the capacity is 400 gpm at a head of 200 ft of water.
What will be the rated capacity [gpm] of a 4-1/2 inch impeller centrifugal pump operating at a speed of 3450 rpm capable of generating a head of 40 ft of water.
If the speed of a centrifugal pump is doubled, the energy requirement becomes approximately ___ times the original energy requirement.
A cylindrical tank 1 ft in diameter discharges through a nozzle connected to the base. Find the time needed for the water level in the tank to drop from 4 ft to 2 ft above the nozzle. The diameter of the nozzle is 1 inch and its discharge coefficient maybe taken as unity.
The NPSH of a single suction centrifugal hot water pump at a speed of 3550 rpm operating at a pressure of 600 psi and a capacity of 450 gpm is ___ ft.
159
160 capacity economy
161 double-pipe plate
162 0.82 0.863
163
164 285.3 249.3
165 An insulator should have
166 Fouling factor
167 Natural convection is characterized by
168 The Graetz number is concerned with
169 Dropwise condensation occurs on
170 for liquid metals
The rate of evaporation at a given operating temperature in a n evaporator is more when
when the operating pressure is high
the operating pressure is low
An optimim number of the effects for a given application is a function of the
A popular type of heat exchanger for cooling large quantities of fluid is the
An evaporator is used to concentrate 10,000 lb/hr of a 20% solution of NaOH in water at 140oF using saturated steam at 25 psia at a rate of 7,000 lb/hr. The OHTC is 275 BTU/hr-ft2-oF when the pressure in the vapor is 1.7 psia. The steam economy, SE, is
A cross flow heat exchanger uses mixed air at 4 kg/s that enters at 15oC and leaves at 45oC. The air cools unmixed water, which enters at 95oC and 0.70 kg/s. The OHTC equals 150 W/m2-oC. After several months of operation, a scale resistance of 0.002 m2-oC/W developed. 16. The heat transfer area required to accomplish the change is
22.2 m2 25 m2
As solution of 28% wt Na2SO4 is to be crystallized to yield Glauber salt in a four section (one section is 10 ft in length) Swenson Walker Crystallizer. It is fed to the unit at 120oF and cooled to 60oF using cooling water which enters at 50oF and leaves at 70oF. The crystallizer has a cooling surface of 3 ft2 per foot of length. The feed rate is 500 lb/hr and the crystallizer is seeded with 50 lb/hr of 65 mesh crystals. 19. The amount of the crystalline crop (C) produced in lb per hour is
low thermal conductivity
high thermal conductivity
is a dimensionless quantity
does not provide a safety factor for design
Reynolds number
Grashhoff number
mass transfer between a gas and a liquid
absorption with chemical reaction
clean and dirt free surfaces
smooth clean surfaces
Dietus-Boelter equation for determination of heat transfer co-efficient is valid
for fluid in laminar flow
171 fluidizing pressure
172 0.98 0.89
173 305 mm 610 mm
174 settling ratio screen-mesh no
175 The sphericity of cubical particles is 1 0.87176 thickening classification
177 temperature pressure
178 Ordinary diffusion takes place because of ___ driving force. temperature pressure179 What are the two limiting cases of steady-state diffusion? UMD and EMD
180
181 Knudsen region turbulent region
182
183 Sc Sh
184 the liquid phase the gas phase
185 In two-phase mass transfer, equilibrium may exist at the interface in the gas phase
186 cooling of air air conditioning
187 Air conditioning in tropical countries involves
188
A type of pneumatic conveyor system characterized by a material moving in an air stream or pressure less than ambient.
If the total percentage of particles larger than the screen opening in the feed, oversize, undersize are 36%, 89% and 3%, respectively, the effectiveness of the screen if the undersize is the product is
The estimated width of an apron conveyor having a capacity of 75 tons/hr at a speed of 50 ft/min is
It is defined as the ratio of the average diameter of the feed to the average diameter of the product.
The separation of a dilute slurry or suspension by gravity settling into a clear fluid and a slurry or suspension by gravity settling into a clear fluid and a slurry of higher solids content is called
An ultracentrifuge is used to separate high-molecular weight fractions in polymeric or biological systems. What is the gradient for mass transfer in the separation using this mass transfer device?
ordinary and Knudsen
Which of the following is not true in (binary) equimolar counter-diffusion?
DAB = DBA c = cA + cB
A fluid is flowing on a surface, which contains a component that leaches out to the fluid. Assuming that all the 3 regions of mass transfer are present, in which of these regions is diffusion controlling?
In unsteady-state mass transfer, the quantity (DABt/rm^2) is
referred to asunaccomplished change
relative resistance
What is the equivalent of Prandtl number in convective mass transfer?
If kx > ky, then the controlling phase is
Which of the following processes may always be regarded as a constant- humidity process?
humidification by a process similar to that in a cooling tower
humidification by a process similar to air-water vapor saturator
What do you call the steady-state non-equilibrium temperature reached when a small amount of water is contacted under adiabatic conditions by a continuous stream of gas?
dry-bulb temperature
wet-bulb temperature
189 0.5 1
190 The moisture that can be removed by drying is called bound moisture
191 Falling-period in drying terminates at the
192 Which is not true at the interphase of a gas scrubbing operation?
193
194 5280 8490
195 1 hr 1.6 hr
196 The unit of volumetric diffusivity is cm/sec
197 0.5 2
198 packed lower
199 decreases increases
200 The suitable evaporator for concentration of foaming liquids is
201
202 For a packed column the main purpose of packing is to
203 the NTU is zero
The moisture content of a solid is given as 50% wet basis. What is the moisture content, dry basis?
equilibrium moisture
end of constant-rate period
origin of R vs X plot
the solute concentration of the gas is less than that of the bulk
the solute concentration of the liquid is less than that of the bulk
He and N2 gas are contained in a conduit 5 mm in diameter and a 0.1 m long at 298 K and a uniform pressure of He at one end of the tube is 0.6 atm and 0.02 atm at the other end. Assuming equimolar countercurrent diffusion, the flux in kmol/s-m2 is
2.35 exp -5 2.44exp -5
100 m3/hr of air at 60°C and 20% RH is needed for a chemical reactor. This will be obtained from process air at 60°C and 10% RH by humidifying adiabatically the process air followed by heating to its original temperature. The wattage of the heater at 80% efficiency is
Wet solid is to be dried from 36% to 8% moisture in 5 hr under constant drying condition. Critical and equilibrium moisture contents are 14 and 4% respectively. Calculate how much longer will it take to dry the same material from 8% to 5.5% moisture under constant drying condition. All moisture contents are on a dry basis.
cm^2/sec
If reflux to a distillation column is 100 moles/hr, when the overhead product rate is 50 moles/hr. the reflux ratio is
Which of the following provides maximum contact surface for a liquid-vapour system?
bubble-cup plate column
In extraction, as the temperature increases, the area of heterogeneity (area covered by bimodal curve)
long tube evaporator
short tube evaporator
Macroscopic transfer of mass between moving fluid and surface which is of different concentration is called
molecular diffusion
unsteady-state diffusion
strengthen the column
increase the surface area
In a gas absorption operation, when the operating line crosses the equilibrium curve
the liquid flow rate is maximum
204 0.15 0.31
205 0.92 0.86
206 14.7 18.5
207 0.54 min 0.85 min
208 For Newtonian fluids, the shear stress is constant.
209 An ideal fluid is one that is compressible
210 10.58 5.29
211 stream tube velocity profile
212 350 155
213 A simple pitot tube measures
214 pitot tube orifice
215 In the flow meter equation, Y, indicates the mass flow rate
216 The loss due to sudden contraction is proportional to velocity turbulence217 Stoke’s law is valid when the particle Reynolds number is < 1 > 1218 Priming needed in a Gear pump
219 40 ft 37 ft
220 butterfly globe
Methanol diffuses in 0.15 cm stagnant film of 1:1 mole mixture of hydrogen and CO2 at 100oC and 2 atm. The partial pressures of methanol on both sides are 0.6 and 0.2 atm. The average diffusivity of methanol in the hydrogen and CO2 at 0 oC and 1 atm in cm2/s is
Gaseous reactant A decomposes according to the reaction A --> 3R (-rA = 0.5 CA mole/L-min). The feed, which consists of 70% A and 30% inert, enters a 1.5-m3 CSTR at a flow rate of 150 L/min. 4. If CA0 = 0.30 mole/L, what is the conversion, XA?
Between 0 degC and 50 degC, the average activation energy of a certain reaction is 80 kJ/mol. How many times faster will the reaction occur at 300 K than at 275 K?
Consider a gas-phase reaction 2A ---> R + 2S with unknown kinetics. A space velocity of 0.8/min is needed for 95% conversion of A in a PFR. Find the mean residence time or holding time of the fluid in the PFR.
inversely proportional to rate of deformation.
incompressible & viscous
Water flows through an 8-in (ID=7.981 in) steel pipe at an average velocity of 6 ft/s. Downstream the pipe splits into an 8-in main and a 2 in (ID=2.067 in) bypass pipes. If the velocity in the bypass is twice the velocity of the main pipe, the volumetric flow rate [ft3/s] in the main pipe is
An imaginary line within a fluid flow such that a tangent at any point indicates the direction of flow at that point.
Air at 250C [viscosity=0.018 cP] enters a section of 2-in schedule 40 commercial steel pipe at a gauge pressure of 310 kPa and a flow rate of 1200 kg/h. Assuming isothermal flow, what is the pressure drop [kPa] in 60 m of pipe?
acoustical velocity
superficial velocity
Which of the following meters will have the highest permanent pressure loss?
compressibility factor
Reciprocating pump
Maximum theoretical suction lift for water at 60˚F by a centrifugal pump is 34 ft. The same for water at 200˚F will be
The most economical valve for use with large diameter pipes.
221 Multistage compressors are used in industry because, they
222 For ideally incompressible fluid, the mach number will be 0 1223 vacuum pumps blowers
224 pressure
225 0.007 kg 0.106 kg
226 The overhead product composition decreases with time in
227 low reflux ratio
228 Chemisorption is
229 The stage efficiency in leaching depends on the
230 Weeping in distillation or absorption column
231 What are the two contacting phase in leaching?
232 Distillation Leaching
233 caproic acid chloroform
234 Professional Regulations Commission was created under P.D. No. 223 P.D. No. 233235 1 0
236 18 19
237 inventive step novelty
reduce the cost of compressor
reduce the size requirement
of the following produces maximum pressure difference for transportation of gases?
The fluid property which matters for falling rain drops to acquire spherical shape is its
height of descend
A wastewater solution having a volume of 1000 L contains 0.21 kg phenol/m3 of solution. A total of 1.40 kg fresh granular activated carbon is added to the solution, which is then mixed thoroughly to reach equilibrium. What is the amount of phenol absorbed per kg carbon at equilibrium?
batch distillation with reflux
continuous distillation with reflux
For a binary mixture with low relativity, continuous rectification to get pure products will require
small cross-section
the same as van der Waals
characterized by adsorption of heat
time of contact between the solid and the solution
rate of diffusion of the solute through the solid and into the liquid
increases tray efficiency
provides larger surface for mass transfer
extract phase and raffinate phase
solvent phase and solute phase
Hydrogen sulfide is removed from water by contacting the solution with warm air. The operation is
Disregarding the cost, which is the best solvent for the extraction of acetic acid from an aqueous solution at 25deg C?
A chemical engineer who designed and built a new type pf reactor and for three years, sold many units to the public can still patent his reactor.
A person who has passed the Chemical Licensure Examination can take his/her oath as a chemical engineer if his/her age is not less than _______ years.
Which of the following is not a requirement for utility model registration?
238 disclosure abstract
239
240 paper cement
241 Sulfur is undesirable in petroleum because
242 fillers brighteners
243 Polyethylene is an example of _____________ polymerization condensation addition
244 condensation hydration
245 Carbon black is added to rubber compounding as activator curing agent246 The binder for all the powder materials of paint pigment vehicle247 bagasse pulp
248 Molasses is a by product of raw sugar from the ______ process milling extraction
249 Kraft process is a common name for sulfate pulping sulfite pulping250 Water insoluble cell binders of wood pulp cellulose251 DDT means
252 Rancidity of oil can be reduced by decoloration hydrogenation253 Varnish does not contain pigment dryer
254 Plasticisers are added to paints to
255 Silicone is thermoplastic a monomer
256 extrusion mastication
257 Alkyl benzene sulfonate (ABS) is a detergent rubber258 Neoprene is a monomer synthetic rubber
259 0.2348 0.3216
260 Work is a path function
A section of the patent application containing detailed descriptions of the benefits obtained from using the invention is called the
A document issued by the DENR secretary indicating that the proposed project will cause significant negative environmental impact.
Environmental Impact Statement
Environmental Compliance Certificate
In the Philippines, sulfur for sulfuric acid manufacturing is sourced from _______ industry.
it causes engine knocking
it increases the boiling pt of fuel
Materials added to detergent formulation to enhance cleaning performance by exhibiting synergistic cleaning effect with surfactant.
Principal chemical conversion in the production of resin from monomer.
A fibrous material left after cane sugar has been milled is commonly called as
Diphenyldichlorotriphenylethane
dichlorodiphenyldichloroethane
make it corrosion resistant
make glossy surface
The process involved in converting rubber into a thin sheet or coating it on fabric is called
Steam enters an adiabatic turbine at 10 MPa and 500 degC at a rate of 3 kg/s and leaves at 0.1 MPa. If the power output of the turbine is 2 MW, determine the turbine efficiency.
property of the system
261 Throttling process is
262 0 +1.13 kJ
263 isothermal adiabatic
264 Entropy
265 According to the first law of thermodynamics
266
267
268 isobaric isenthalpic
269 For an isolated system, maximum entropy will occur at half-life critical condition
270 A carnot cycle consists of
271 sphericity porosity
272 Froude number
273 3 2
a reversible and isothermal process
an irreversible and constant entropy
A sample consisting of 1.00 mole of Argon gas is expanded isothermally and reversibly at 0°C from 22.4L to 44.8L. The heat absorbed by the system is
Maximum work can be obtained from a system when the change taking place in it is
The ratio of work performed by a system and the heat it absorbed from a reservoir is referred to
Gibb’s free energy
Energy is neither lost nor gained in any energy transformation.
Perpetual motion is possible.
In a 3-stage compressor system whose isentropic efficiencies are reported to be 0.75, 0.85 and 0.84, respectively, steam initially at 10 kPa is compressed to a final pressure of 500 kPa. The overall efficiency of the system is
greater than 0.85
in between 0.75 and 0.85
In choosing the refrigerant, the fluid must have the following characteristics, except
environmentally benign
has a vapor pressure less than atmospheric
Coolers and boilers are ordinarily operated at ________ condition.
two isothermal and two adiabatic process
two isochoric and two adiabatic process
This is also known as the volume fraction of the voids in packed beds.
A measure of the ratio of the drag force acting on a unit area of the impeller & the inertial stress.
Reynold’s number
Sulfuric acid is pumped at 3 kg/s through a 60-m length of smooth 25 mm pipe. If the pressure drop falls by one-half, what will be the new flow rate [kg/s]? Assume the following properties of sulfuric acid: SG = 1.84, viscosity = 25 cP.
274
275 set point controller output
276 current temperature
277 Dead time is a function of distance and momentum acceleration278 2.83kPa/K 0.35kPa/K
279 Time constant
280 11.61 ft/s 37.1 kg/s
281 9365 9461
282 pi/4 inch 1 inch
283 20.2 41.4
284 73 degF 173 degF
The equation del(P) = -(rho)(g) del(z) is known as the hydrostatic vertical law for which all the following assumptions are applied, except
shear forces are not involved
fluid is incompressible
Which of the following can be adjusted by human operator in a closed feedback control loop?
The thermocouple is based on the Seebeck effect which states that a/an _____ is generated when opposite junction of certain dissimilar pairs of wires are exposed to different temperatures.
A pneumatic controller is used to control temperature within the range 280K to 310K. The controller is adjusted so that the output pressure goes from 20kPa (valve fully open) to 105 Kpa (valve fully closed) as the measured temperature goes from 295K to 300K with the sent point held constant. What is the proportional gain?
The parameter which completely describes the behavior of the response to a disturbance of a second order system is the
damping coefficient
Water is flowing through a 3-inch schedule 40 pipe at 60 deg F. A pitot tube is inserted at the centerline of the pipe and registers a 3-inch Hg differential. What is the mass flow rate of the water?
An oil well is 1200 ft below ground level. Oil at 500 psig at the bottom flows to ground level through a 12-inch schedule 80 commercial steel pipe. The oil has a SG of 0.86 and viscosity of 8 cP. The vol flow rate of oil in barrels per hour is
The equivalent diameter of a concentric annular space where 1-inch OD pipe is located inside a 2-inch ID pipe is
Based on Bond's crushing law, the power required to crush a certain material will change by _____% if the diameter of the product is made smaller by 50%.
The BPR of a 50% NaOH solution at an evaporator pressure of 4.7 psia is
C D ANSWER SCORE
globe valve orificea 1
0.03 0.038o 0
d 1
o 0
b 1
rectification fractionation c 1
minimum reflux optimum reflux c 1
mol/liter/min liter/mol/mino 0
no effect
o 0
c 1
transition plate bubble plate
d 1
supersaturated saturated c 1
o 0
reduction ratio c 1
turbulent flow only
laminar flow only
equal to the heat transfer coefficient equivalent to the resistance offerred by the pipe
equal to the heat transfer coefficient of the steam
the minimum number of stages occur when the tie line coincides with an operating line.
the amount of solvent used must be enough to form 2 phases.
significant effect
the heat transfer is constant
the temperature is uniform throughout the cylinder
Sherwood, Reynold's and Schimdt No
Prandtl, Schimdt and Reynold's No
classification ratio
c 1
orifice venturi a 1
b 1
book value market valueb 1
o 0
o 0
o 0
d 1
compressor accumulatorb 1
d 1
d 1
c 1
air concret b 1
humidification extractionb 1
the value of k is independent of the initial concentrations of A and B
the reaction cannot proceed
a function of time
not uniform throughout the reactor and varies from time to time
increases the amount of distillate
increases the condenser duty
the gas phase resistance is negligible
the ratio of gas phase resistance to liquid resistance is approximately zero
Peclet, Stanton and Prandtl Nos
Schimdt, Peclet and Friction Nos
45-degree standard elbow
square-corner elbow
1" dia Drawn tubing
4" dia Riveted steel pipe
through each material is inversely proportional to the thickness of the material
is constant throughout the series of materials
parallel reactions
consecutive reactions
static pressure o 0
c 1
113 deg F 146 deg F
0
1.484 0.581 01.5 0.6
0
33.4 54.4
0
128 kg 32 kg 0
26.4 57.80
1.5 2.75
0
over 20 million
0
0.0454 0.02520
6930000 2040000
0
a 1
75.26 78.50
tangential pressure
concentration gradient
momentum gradient
over 2 but less than 3
saturation temperature
dry-bulb temperature
b 1
0.02 0.01
0
c 1
tray drier freeze drier c 1
a 1
surface renewal d 1
2.129 hrs 3.42 hrs
0
0.01155 0.00116
0
c 1
a 1
1.5 2.3
0
the temperature of the air can also be maintained constant
increase in the humidity of the air is insignificant
equilibrium moisture content
critical moisture content
air flow perpendicular to the surface of the solid
air flow parallel to the solid surface
moisture diffusivity
decreases with time
no drying takes place
to use cross flow evaporation
to use spray percolators
5 6
0
radiation a 1
radiation c 1
c 1
evaporation b 1
451.7 475.1
0
5800 139200
0
5.51 m 4.14 m
0
966 kg 534 kg
0
all of A, B and C
all of A, B and C
inverse of the total resistance
sum of the individual resistances
all of A, B and C
85.8 sq.m. 88.5 sq.m.
0
14 kPa zero gauge
0
4.72 3.03
0
39 40
0
8 7
0
27.8 22.7
0
0.294 0.249
0
577 241
0
13.76 16.28
0
46.5 45.6
0
227.2 300
0
11994 20451
0
40130 45500
0
13.8 5
0
1163 19.4
0
4.67 2
0
95 100
0
7 0.52
0
31.7 37.1
0
851 900
0
0.75 1
0
[B]=0.2
0
25.2 20
0
3478 3750
0
[B]=0.4(1-0.5x)/(1-x)
0.714 6.01
0
100 25
0
13943 W 19343 W
0
23 33
0
38 0.038
0
a 1
decreases. 0
stays constant. c 1
stays the same. a 1
both contain the same no of air molecules
increases by about 40%
may increase or decrease.
0
increases 8x. increases 16x.
0
3 e7 5.2 e8
0
excess reactant product yield b 1
reactant ratiob 1
a 1
moistureb 1
a 1
O2-free basis N2-free basis b 1
c 1
32.48 42.56 a 12.38 6.13
0
60% saturationa 1
The application should be rejected because it violates both 1st and 2nd laws of Thermo.
The application should be given full consideration because it does not violate any laws of Thermodynamics.
fresh-feed conversion
Latent Heat of Condensation
Net Calorific Value
volatile combustible matters
Ultimate analysis
Elemental analysis
Dulong's formula
Oxygen unaccounted for equation
absolute humidity of 0.05
PhP 434.16 PhP 450
0
0.03 0.05
0
4350 6000
0
9.5 17
0
0.9 0.92
0
51.2 22.76
0
7.86 23.1
0
1/conc 1/conc-time 02 1.5 0
c 1
the rate law.d 1
c 1
adding a catalyst
removing the products of the reaction
the net equation
does not depend on the initial concentrations
is not a characteristic of the reaction
8 16 0
temperature c 1
> 0 <0 a 11/Ca vs time a 1
lof Ca vs time Ca vs time b 1
-ra = k Ca -ra = k Cb^2b 1
c 1
0
85.3 99.1
0
231 s 768 s 0
19.1 min 10.4 min0
8.33 9.33
0
52.63 m 56.23 m
0
0.3394 0.6197
0
nature of reactants
log Ca vs reciprocal time
Law of Mass Action
Second Law of Thermo
proportional to initial conc
inversely proportional to initial conc
300 527
0
0.327 0.237
0
12.7 20.7
0
9550 101500
Cao/(1-2m) Cao/2
0
37.1 31.8
0
1/32 1/64
0
2 4 0
2 4 0
2 4 0
suction is lost
c 1
16.9 87.20
1.72 1.890
21 58.3
0
PhP 7000 PhP 12000
0
2 2exp20
velocity head dynamic head a 1
surface tension drag coefficient a 1
63 850
4x3x6 3x2x13 0
248 3200
8 100
77 94
0
25 300
the suction pressure is too high
0
efficiency 0
shell and tube c 1
0.89 0.92
0
0
255.65 214.65
0
a 1
none of these
c 1
Peclet number Prandlt number 0
0
c 1
0
there is a vacuum
when the liquid level is high
none of the given choices
extended surfaces
17 m2 20 m2
less resistance to heat flow
a porous structure
accounts for additional resistance to heat flow
heat transfer in turbulent flow
heat transfer in laminar flow
contaminated cooling surfaces
polished surfaces
for fluids in turbulent flow
when Grashhoff number is very important
vacuumd 1
0.76 0.65
0
1220 mm 2400 mm 0
reduction ratio0
0.7 0.6 0sorting centrifugation
a 1
concentration electric field
b 1
concentration electric field b 1
0
0
buffer region
0
relative time0
Bi Pe 0
the interface b 1
in either film 0
heating of aird 1
c 1
a 0
pressure-vacuum
average particle diameter
thermal and ordinary
thermal and Knudsen
JA = JB NA = -cDAB dxA/dz
viscous sub-layer
relative position
either of the bulk phases
in the liquid phase
water-cooling in a cooling tower
dehumidification and removal of sensible heat
dehumidification by condensing water vapor in a refrigerator
adiabatic saturation temperature
dew point temperature
2 50 0
free moisture c 1
d 1
0
0
10050 11570
0
2.3 hr 2.9 hr
0
0
50 150 0
0
0
0
all of these 0
0
0
unbound moisture
critical free moisture content
equilibrium moisture content
the solute concentration of the liquid and gas phase are equal
the solute concentration of the gas is greater than the liquid
1.77exp -6 1.22 exp -6
cm^3/sec cm^2/sec^2
sieve-plate column
wetted wall column
remains unchanged
vacuum evaporator
falling film evaporator
convective mass transfer
increase the pressure drop in the tower
reduce the flow rate across the column
the gas flow rate is maximum
the number of stages is infinite
0.51 0.68
0
0.71 0.65
0
20.9 22.40
0.87 min 1.18 min
0
0
incompressible 0
1.84 0.25
0
streamline none of these 0
101.3 61
0
local velocity 0
venturi rotameter 0
0
velocity head static head 0< 5 0 0
0
34 ft 8 ft 0
needle gate 0
equal to shear rate of deformation.
a linear function of the shear rate of deformation.
incompressible & inviscid
mean linear velocity
coefficient of discharge
cross-sectional area
Centrifugal pump
Diaphragm pump
0
1.5 5 0fans compressors 0
viscosity surface tension 0
0.189 kg 0.198 kg
0
0
high reflux ratio 0
0
both A and B
0
0
0
Absorption Stripping 0
3-heptanol toluene0
P.D. No. 232 P.D. No. 826 0it depends
0
21 230
0
resemble closely to isothermal compression
are easy to control
continuous distillation without reflux
distillation operating at total reflux
less number of trays
an irreversible phenomenon
always in equilibrium
either A or B because these two mean the same thing
Energy is conserved in quality but not in quantity.
Energy is being created as time passes. We have more energy in the universe now than when time began.
in between 0.84 and 0.90
must be economically viable
exist at a high pressure at the condensation temperature
start of the process
one isochoric, one isobaric, and two adiabatic process
one isothermal, one isochoric and two adiabatic process
superficial velocity
0
load variable a 1
emf resistance
0
time velocity d 117kPa/K 0.06kPa/K
0
Rise time overshoot0
37.1 lb/s 317 lb/s
0
52581 393308
d 0
1.5 inch 2 inches 0
50.5 58.60
233 degF 297 degF 0
z axis is defined vertical & downward in direction
normal surface forces & gravity are the only forces involved
process variable
NO QUESTION A
1 gate valve
2 0.052
3 smooth pipes
4
5 In multi-stage liquid-liquid extraction with partially miscible solvents
6 evaporation
7 variable reflux
8
9 large effect
10 For a cylinder where steady-state radial heat transfer takes place
11 separation plate
12 Crystallization occurs in a solution that is concentrated13 Mass transfer in a flowing fluid may be correlated by
14 settling ratio
15
16 A device for increasing the velocity of a fluid in steady flow is a nozzle
A valve that controls flow by means of a disk or wedge-shaped dam sliding at right angles to the direction of flow and seating tightly in the valve body is a
The friction factor for flow through a pipe with relative roughness of 0.004 at a Reynold's No. of 80,000 is approximately equal to
The equation that relates friction factor and Reynold's No., f=64/Reynold's No. holds for
Oil flows under laminar conditions inside a steam heated copper pipe. The overall heat transfer coefficient is approximately
equal to the heat transfer coefficient of the oil
the extraction must be done to form co-currently in order to minimize the extraction.
The enrichment of the vapor steam as it passes through the column in contact with the reflux during distillation is called
The maximum number of plates for a given distillation system is obtained at
The correct unit for the specific rate constant for the reaction A--->B determined to be first order is
square liter/square mol/min
On one side of a heat exchanger where either a condensing vapor or a boiling liquid is present, the temperature may be assumed to be constant. In determining the logarithmic mean temperature difference the direction of flow will have
the heat flux is constant
A plate holding a pool of liquid from which rises a vapor whose average composition is in equilibrium with a liquid whose composition is the average of that of the liquid leaving the plate is called
Sherwood, Nusselt and Reynold's No
The ratio of the average diameter of the feed to the average diameter of the product is the
The rate of formation of C for the reaction 2A + B ---> C is found to be rate=k(A)(B)
the rate of formation of C is equal to the rate of disappearance of B
17 In steady-state backmix flow reactor, composition is
18 net value
19 In fractionation, an increase in reflux ratio
20
21
22
23 switching bank
24
25
26
27 window glass
28 evaporation
29 gauge pressure
30 For mass transfer to take place, there must be a phase change
31 212 deg F
32 The diffusity of water in air at 100 deg F in sq.cm./sec is 0.25633 5.9
not constant throughout the reactor
The amount of money obtainable from the sale of used property over and above any changers involved in removal and sale is called
increases the number of theoretical plates
In mass transfer where the solute in the gas phase is very soluble in the liquid phase
the ratio of liquid phase resistance to the overall resistance is close to unity
Heat transfer in turbulent flow may be described through an empirical equation correlating
Nusselt, Stanton and Reynold's Nos
Which of the following fittings exhibits the highest pressure drop for the same flow conditions?
90-degree long radius elbow
A chamber into which steam from a high pressure line can be bled during periods of low steam demand from the power plant is called
Which one of the following pipes has the highest relative roughness?
2" diameter Wrought iron pipe
In steady-state heat transfer through a series of materials with varying resistances, the heat transfer rate
decreases towards the direction of heat transfer
Reactions whereby reactants proceed along several paths and give different products are
polymeric reactions
Which one among the following materials has the best insulating property?
An operation where warm vapor mixture is cooled such as by contact with a liquid resulting in condensation and decreased humidity is
The pressure exerted on a plane parallel to the direction of flow of a moving fluid is called
Water vapor condenses at 1 atm on a tube whose surface tmeperature is at 80 deg F. in analyzing the heat transfer through the condensate film, it is best to evaluate the liquid properties at
A fluid flowing at a rate of 25 cubic meters per hour inside a 60 mm I.D. pipe has an average velocity in meter per sec equal to
34 66.6
35 16 kg
36 32.2
37 4
38
39 0.0378
40 4440000
41
42 74.3
43
44 0.1
45 free moisture
46 rotary drier
An equimolar mixture of benzene and toluene is subjected to a single batch distillation. Distillation is discontinued when 60% of the benzene in the feed is distilled. At this instance the bottom product when analyzed shows benzene to be 36.4 mole%. In the distillate, the mole% of benzene is
When 32 kg of methane is burned completely the theoretical oxygen required is
The standard heat of reaction for the production of water gas, in kcal/gmole, as given by the equation: C(s) + H2O(g) = CO(g) + H2(g) is
A rectangular duct 4 ft x 1.5 ft in cross section carries conditioned air. In determining the pressure drop through the duct the equivalent diameter in ft may be used which in this case is
A gas decomposition reaction has an activation energy of 245 kJ/mol. The rate of reaction can be accelerated by using a platinum catalyst where the activation energy for the resulting catalyzed reactions is lower at 136 kJ/mol. Using Arrhenius' law and assuming the frequency factor remains the same the catalyzed reaction is faster than the original reaction by a factor of
over 100,000 but less than a million
Water at 100 deg F is flowing through a straight 4-in Sch 40 pipe at a rate of 1.0 gal/min. The length of the pipe is 10 ft. The velocity at the center of the pipe in ft per sec is
A metallic rod 2 cm in diameter is used as a heating element. The thermal conductivity is 370 J/sec.sq.m.degC. The surface temperature is maintained at 200 deg C. For the center of the rod not to exceed 500 deg C, the maximum volumetric heat generation rate within the metallic rod in J/sec cu.m. must be
This is a steady state temperature reached by a small amount of liquid evaporating into a large amount of unsaturated vapor-gas mixture.
wet-bulb temperature
Air, supplied at the rate of 1200 cfm to a refrigerated coil, has a relative humidity of 20% and dry bulb temperature of 150 deg F. The mass flow of dry air entering per minute is
In adiabatic humidification, it is possible to maintain the temperature of water constant since
according to the phase rule, the degrees of freedom is 3
An air-carbon tetrachloride vapor mixture at 100 deg F dry bulb and 60 deg F wet bulb is heated until the temperature reaches 180 deg F. the final percent relative humidity is about
The portion of water in the wet solid that cannot be removed by the air in its contact is called
This type of drier is used for drying pasty materials such as wet filter cakes and lumpy solids
47 In the constant-rate period, the rate of drying is established by
48 desorption
49 0.542 hrs
50 0.12
51 remains constant
52
53 0.3
54 3
55 convection
56 convection
57
58 Film and drop are terms associated with boiling59 99.95
a balance of the heat requirements for evaporation and the rate at which heat reaches the surface
Unbound moisture in granular and porous solid moves through the intertices of the solid by a mechanism involving
Wet solid is to be dried from 40% to 10% in 5 hours under constant drying conditions. The critical moisture content is 20% and the equilibrium moisture content is 7%. All moisture contents are on dry basis. The time needed to dry from 15% to 5% free moisture under the same drying conditions is
If the rate of drying under constant drying conditions with air at 140 deg F and absolute humidity of 0.03 lb water per lb dry air of unknown mass of solid is given by R=0.5-exp(-60X) [in lb water/hr-sqft], then the equilibrium moisture content (db) of the material is
In drying at the falling rate period, the rate at which moisture is removed from the solid material
The major problem in diffusion is to promote diffusion of the solute out of the solid and into the liquid. The most effective way of doing this is
to reduce the solid to the smallest size feasible
A slurry flaked soybeans weighing 100 kg contains 75 kg inert solids and 25 kg of solution 10 weight % oil and 90% wt solvent hexane. This slurry is contacted with 100 kg pure hexane in a single stage so that the value of retention for the outlet underflow is 1.5 kg of insoluble solid per kg solvent in the adhering solution. The composition of underflow leaving the extraction stage in %wt oil is
Tung meal containing 55% oil is to be extracted at the rate of 4000 lb per hour using n-hexane containing 5% oil as solvent. A countercurrent mulitple stage extraction system is to be used. The meal retains 2 lb of solvent per pound of oil free meal while the residual charge contain 0.11 lb oil per lb oil free meal while the product is conposed of 15% oil. The theoretical number of ideal stages is
The movement of molecules over a substantial distance is associated with the transfer of heat by
The mode of heat transfer that can take place in a vacuum is known as
The overall conductance for a composite material in series is equal to the
sum of the individual conductances
A 6-in Sch 80 steel pipe is carrying glycerin at an average temperature of 100 deg F. The pipe is uninsulated, and the outside temperature is 30 deg F. The inside film conductance is 1000 Btu/h-ft-degF while the outside film conductance is 3.0 Btu/h-sq.ft.-degF. Determine the heat lost [Btu] per minute from a 75-ft length of the pipe. Glycerine is flowing at 800 gpm.
60 97
61 185.5 m
62 4301 kg
63 55.8 sq.m.
64 115 kPa
65 10.92
66 37
An oak (k=0.096 Btu/h-ft-degF) door, 30 in wide, 78 in high, and 2 in thick, has 9 glass (k=0.45 Btu/h-ft-degF) windows, each 6 in by 8 in by 1/4 in thick. Determine the amount of heat lost [Btu] each day with a surface-to-surface temperature difference of 80 deg F.
Determine the length needed for a simple concentric-tube, parallel flow heat exchanger to transfer heat from hot water to cold water at a rate of 900 W. The heat exchanger consists of two Type K copper (k=386 W/m-degC) tubes. The smaller tube has an inside diameter of 49.8 mm and an outside diameter of 54.0 mm. Assume that both film coefficients are equal to 100 W/sq.m.-degC. The hot water enters at 90 degC and leaves at 50 degC, and the cold water enters at 10 degC and leaves at 40 degC.
A saturated solution containing 1500 kg of potassium chloride at 360 K is cooled in an open tank to 290K. If the specific gravity of the solution is 1.2, the solubility of potassium chloride per 100 parts of water is 53.55 at 360K and 34.5 at 290K, calculate the amount of crystals obtained assuming that loss of water by evaporation is negligible.
An evaporator, working at atmospheric pressure, is to concentrate a solution from 5% to 20% solids at the rate of 1.25 kg/s. The solution which has a specific heat of 4.18 kJ/kg-K is fed to the evpaorator at 295K and boils at 380K. Dry saturated steam at 240 kPa is fed to the calandria and the condensate leaves at the temperature of the condensing steam. If the heat transfer coefficient is 2.3 kW/sq.m-K, what is the required area of heat transfer surface. The latent heat of vaporization maybe taken as the same as that of water.
2.5 kg/s of a solution at 288K containing 10% dissolved solids is fed to a forward-feed double effect evaporator operating at a pressure of 14 kPa in the last effect. If the product is to consist of a liquid containing 50% by weight of dissolved solids and dry saturated steam is fed to the steam coils, what should be the pressure of the steam? The surface in each effect is 50 sq.m. and the coefficients for heat transfer in the first and second effects are 2.8 and 1.7 kW/sq.m.-K respectively. Assume that the concentrated solution exhibits a boiling point rise of 5 degK, that the latent heat has a constant value of 2260 kJ/kg and that the specific heat of the liquid stream is constant at 3.75 kJ/kgK.
An acetone-air mixture containing 0.015 mol fraction of acetone has the mol fraction reduced to 1% of this value by countercurrent absorption with water in a packed tower. The gas flow-rate G is 1 kg/sq.m-s of air and the water entering is 1.6 kg/sq.m-s. For this system, Henry's law holds and Ye=1.75x, where Ye is the mol fraction of acetone in the vapour in equilibrium with a mol fraction x in the liquid. How many overall transfer units are required?
A still has a liquor composition of ortho-xylen 10%, meta-xylene 65%, para-xylene 17%, benzene 4%, and ethylbenzene 4%. How many plates at total reflux are required to give a product of 80% meta-xylene and 14% para-xylene? The data are given as mole percent.
67 10
68 72.2
69 0.492
70 2173
71 12.54
72 64.5
73 77.2
74 3537
75 10500
A mixture of alcohol and water with 0.45 mol fraction of alcohol is to be continuously distilled in a column so as to give a top product of 0.825 mol fraction alcohol and a liquor at the bottom with 0.05 mol fraction alcohol. How many theoretical plates are required if the reflux ratio used is 3?
Prepared cottonseed meats containing 35% extractable oil are fed to a continuous countercurrent extractor of the intermittent drainage type using hexane as solvent. The extractor consists of ten sections, the section efficiency being 50%. The entrainment, assumed constant, is 1 kg solution/kg solids. What will be the oil concentration in the outflowing solvent if the extractable oil content in the meats is to be reduced to 0.5% by weight?
0.4 kg/s of dry seashore sand, containing 1% by weight of salt, is to be washed with 0.4 kg/s of fresh water running countercurrent to the sand through two classifiers in series. Assume that perfect mixing of the sand and water occurs in each classifier and that the sand discharged from each classifier contains one part of water for every two of sand (by weight). If the washed sand is dried in a kiln drier, what percent of salt will it retain?
Forty-five pounds per minute of water is heated from 60 to 180 deg F in a 5/8 in., 16 BWG heat exchanger tube. If the steam condensing at 260 deg F, on the outside of the tube gives an hо of 1000 Btu/hr-sq.ft.-degF, calculate the inside heat transfer coefficient [Btu/hr-cu.ft-degF].
How many cu.ft. per minute of entering air is needed to evaporate 10 lb of water per hour from a rayon, if the air enters at 80 deg F and 25% humidity and leaves at 170 deg F and 55% relative humidity. The operating pressure is 14.3 psia.
Nicotine is to be extracted from water using kerosene. If 100 lb of a 2% nicotene solution is extracted once with 200 lb of kerosene, what percent of the nicotene is extracted? {Equilibrium data: Y[lb nicotene/lb kerosene] = 0.90X [lb nicotene/lb water]}
We must cool 2500 gpm of water from 120 to 80 deg F. A cooling tower, at 70 deg F and 1 atm, is to be designed to operate with entering air of 40% relative humidity. How many gpm of makeup water must be supplied if windage loss is 95% of the amount lost by evaporation.
We wish to build an economical cold room 20 ft square and 10 ft high. The outside temperature is 80 deg F and te room is to be maintained at 0 deg F. The boss has suggested parallel wooden outer and inner walls separated by a 6-in air space. What will be the heat loss [Btu/hr] through each wall?
A colloidal solution is to be concentrated from 15 to 65% solids. The specific heat of the feed, entering at 50 deg F is 0.93. The pressure of the saturated steam to the evaporator is 10 psia; the condenser pressure is 5-in. Hg abs. The steam chest has an overall heat transfer coefficient of 200 Btu/hr-sq.ft.-degF. Water must be evaporated at the rate of 35,000 lb/hr. Neglecting boiling point elevation, what is the steam consumption [lb/hr]?
76 38.1
77 2951
78 2.21
79 63
80 34.2
81 11.61
82 113
83 0.15
84
85 75.2
86 13
What is the settling time [sec] for galena particles to settle under free settling conditions through 5 ft of water at 50 deg F. Galena is spherical in shape, with specific gravity and 0.01 inch in diameter.
A 10-ft diameter tank with a quick-opening value to a sump has a 10-ft depth of liquid. How long [t in sec] does it take to drain the tank if the valve is assumed to be equivalent to a 4-in diameter orifice? The liquid density is 60 lb/cu.ft.
What size sharp-edged orifice [inches] was in use if a flow of 120 gpm produced a 4-in Hg differential in a 4-in Schedule 40 pipe. The fluid, measured at 60 degF, had a viscosity of 1 cSt and a specific gravity of 1.
Seven hundred gallons per minute of water are being discharged by a centrifugal pump 5 ft above the pump inlet. The inlet pressure is 4-in Hg above atmospheric and the discharge pressure is 29 psia. If the pump has an 8-inch diameter inlet and a 4-inch diameter discharge, calculate the pump efficiency.
Determine the net positive suction head available to a centrifugal pump when the level of water is just at the suction point. The pumped fluid is water at 140 deg F and it is pumped from an atmospheric tank at 250 gpm. The tank suction point is 7 ft above the pump. The piping is 5-in Schedule 40, 10-ft long with two short radius 90 deg elbows. [Use density=61.38 lb/cuft, Pv=2.89 psi, viscosity=0.47 cP]
Water at 60 deg F flows through a 3-inch Schedule 40 pipe. A pitot tube in the pipe shows a 3-inch Hg differential. If the pitot tube is located at the center of the pipe, what is the mass flow rate of the water [lb/s]?
The gas phase irreversible reaction A+B---->C is elementary. The entering flow rate of A is 10 mol/min and is equal molar in A and B. The entering concentration of A is 0.4 mol/L. What CSTR volume [L] is necessary to achieve 90% conversion?
The irreversible zero order gas phase dimerization 2A ----->A2 is carried out in a packed bed reactor with 5 kg of catalyst. The entering pressure is 10 atm and the exit pressure is 1 atm. Pure A enters at a flow rate of 10 mol/min. The reaction is zero order in A. What is the exit conversion?
The gas phase reaction 2A+B----->C is carried out in a PFR. The feed is equal molar in A and B and the entering temperature is 500K and the entering pressure is 16.4 atm. If the exit conversion is x, then the exit concentration of B is
[B]=0.4(1-x)/(1-0.5x)
Heat is generated in a 2.5 cm square copper rod at the rate of 35.3e6 W/cu.m. The rod is exposed to a convection environment at 20 deg C where the convection heat transfer coefficient is 4 kW/sq.m.-degC. Determine the surface temperature [deg C] of the rod.
A 5cm diameter cylinder is maintained at a constant temperature of 200 deg C and it is "completely enclosed" by a wind tunnel test chamber, walls of which are at 10 deg C. Air at 350K is forced across the cylinder at a velocity of 50 m/s (h=180 W/m-degC). If the surface emissivity of the cylinder is 0.7, determine the total (i.e., convective and radiative) heat transfer from the cylinder [W per meter length].
87 0.028
88 325
89 1500 W
90 1
91 170
92 A
93 is doubled.
94 increases.
95 In all naturally occurring processes, the entropy of the universe increases.
96
97 doubles.
A building wall consists of a 6-in of concrete (kc= 0.7 Btu/hr-ft-degF), 2 in of fiber insulating board, and 3/8 in of gypsum board (kg=0.03 Btu/hr-ft-degF). The inside and outside heat transfer coefficients are 2 and 7 Btu/hr-sqft-degF, respectively. The inside temperature is 72 degF and the outside temperature is 20 degF. Determine the overall heat transfer coefficient for this wall [Btu/hr-sqft-degF].
Current is passed through a cylindrical laboratory heater, which has a 3 cm diameter, generating heat at the rate of 20 MW/cu.m. The heater is exposed to a convection environment at 25 degC where the convection heat transfer coefficient is 0.5 kW/sq.m.-degC. Determine its surface temperature [degC].
A straight rectangular fin has a length of 3.5 cm, a thickness of 1.5 mm, and is made of a material characterized by thermal conductivity of 255 W/m-degC. The fin is exposed to a convection environment at 20 degC and h=1.5 kW/sq.m.-degC. Determine the maximum possible heat transfer from this fin for the base temperature of 150 degC.
A gaseous fuel is composed of 20% methane( CH4), 40% ethane (C2H6) and 40% propane (C3H8), where all percentages are by volume. The volumetric analysis of the dry products of combustion (ie. everything except the water) for this fuel gives 10.6% carbon dioxide (CO2), 3% oxygen (O2), 1% carbon monoxide (CO) and 85.4% nitrogen (N2). Determine the air fuel ratio on a mass basis for this reaction.
Dodecane (C12H26) gas at 25 degC is burned in a steady flow combustion chamber with 20% excess air that enters at -23.15 degC. The products leave the combustion chamber at 500K. Assuming steady operating conditions and complete combustion, determine the required mass flow rate of the dodecane to supply heat at a rate of 1.5 kW [kg/s].
Two rooms A and B of identical volume are connected by an open doorway. The thermostat in the rooms are set so that Ta<Tb. Which room contains more air molecules?
If the absolute temperature of a gas is doubled, the mean speed of the gas molecules
When ice cubes melt in a glass of water, the temperature of the resulting mixture of water and ice
An inventor seeking a patent claims that a building may be comfortably heated in winter by a device that draws heat into the building from the earth, even though the temperature of the earth is lower than the desired temperature inside the building. He further claims that the quantity of heat supplied to the building in a given time period can significantly exceed the work done by the device during the same period. If you were a patent clerk (like the young Albert Einstein), what should be your recommendation about the application?
The application should be rejected because it violates the first law of Thermodynamics.
A fixture containing an ordinary incandescent light bulb is connected to a dimmer switch. The dimmer is adjusted so that the temperature of the tungsten filament inside the bulb increases from 1300K to 2600K. The total power radiated by the bulb
98 2.5 e8
99 The material which remains unchanged in a process is limiting reactant100 recycle ratio
101
102 cooked coal
103
104 An Orsat analysis of the flue gas when pyrite is roasted is on a SO2-free basis105
106 The equivalent of 45degTw in the Baume scale is 26.63107 1.2
108 Which has the lowest water content?
109 PhP 405
110 0.01
111 2250
112 4.22
113 0.8
A 30 MW geothermal electric power plant uses hot steam from the earth at 157 deg C to heat and vaporize isobutane, which turns a turbine that is connected to a generator. The isobutane is subsequently cooled to 27 degC using fans and condensed back to a liquid. The overall efficiency of the plant is 40% of the ideal (Carnot) efficiency. How many joules of heat must be released to the atmosphere per second?
The ratio of the total quantity of a reactant present in the reactor feed of a recycling operation to the quantity of the same reactant entering the operation as fresh feed is the
The heating value measured when water formed from combustion is in the liquid state.
Gross Calorific Value
In the combustion of solid fuels, the tie element between the feed and the refuse is the
The coal analysis which is based upon the volatilization characteristics of the fuel is
Proximate analysis
The empirical relation which allows one to compute for the net hydrogen in a given solid fuel is the
Calderwood equation
A furnace completely burns coal containing 70%C. Analysis of the flue gas shows 15% CO2, 4% O2, 81% N2, and no CO. What is the % of the net hydrogen in the coal?
dew point at 20degC
A contract was made between a buyer and a paper manufacturer for paper containing 5% moisture at PhP450/tonne FOB on specifications that price adjustment will be made if the quality is different. How much should the buyer pay for 1 tonne of paper with 8% moisture content? Freiht cost is PhP45/tonne.
One drier will dry a material from 45% moisture (wb) to 20% moisture (db). From here the material enters another drier where the water content is further reduced to give a final product weighing 1000 kg. If the total evporation from both driers is 800 kg, the moisture of the final product is
An experimental oil is used to distill 6000 kg.hr of Athabasta tar sand which analyzes 30% 'heavy oil', 'light oil', and non-volatile matter. If the distillate contains 12 % heavy oil and this constitutes 25% recovery of the component, the weight in kg of the distillate obtained is
Coal fired in a furnace has a heating value of 13800 Btu/lb and contains 78.05%C and 1.2%S. The proximate analysis shows 4%M, 24%FC, 8%A and the analysis of the refuse shows 8%VCM, 25%FC and 32% ash. Calculate the % of C lost in the refuse.
Ninety grams of ethane and 384 grams of oxygen are fed continuously to a laboratory furnace. The total combustion products collected was 16.2 gmole with no carbon dioxide. However, not all of the ethane was burned due to faulty combustion. The fraction of ethane that was burned is equal to
114 63.25
115 3.52
116 The unit of k for a 1st order elementary reaction is 1/time117 4
118 The E of a reaction may be lowered by
119 The mechanism of a reaction can sometimes be deduced from
120
121 2
122 The rate of reaction is not influenced by
123 The net rate of reaction of an intermediate is 0124 log Ca vs time
125 Ca^2 vs time
126 -ra = k Ca^2 Cb^4
127
128 The half life of a material undergoing second order decay is
129 66.8
130 0.0021 s
131 45.1 min
132 3.83
The furnace at the Bataan refinery is using a fuel gas which contains methane, ethane and 20% nitrogen. The orsat analysis of the combustion products showed 7.8% CO2, 7.4% O2, and 84.8% N2. The gas is burned with excess air. The % methane in the fuel gas is
Pyrite containing 78% FeS2 and 22% gangue is burned with excess air to produce a stack gas with the following analysis: 7.29% SO2, 8.92%O2, 82.44%N2 and 1.35%SO3. If the cinder was found to have a partial analysis of 62.10% Fe2O3, the % of FeS2 lost in the pyrite is
If the temperature of a chemical reaction is raised by 10 degC, the rate of reaction is increased by a factor of
increasing temperature
the activation energy
The equilibrium constant in a reversible chemical reaction at a given temperature
depends on the initial conc of the reactants
If the volume of a reaction vessel is suddenly reduced to one half its original volume the rate will increase by a factor of
conc of the reactants
A reaction is known to be first order in A. A straight line will be obtained by plotting
If the reaction 2A ---> B+C is second order, which of the following plots will give a straight line?
For the reaction A+B ---> 2C, when Ca is doubled the rate doubles, when Cb is doubled the rate increases fourfold. The rate law is
It states that the rate of a chemical reaction is proportional to the activity of the reactants.
Le Chatelier's principle
proportional to the square of the initial conc
A fluid flows through 2 CSTR in series. Each reactor has a capacity of 400,000 L and the fluid enters at 100 L per hr. The fluid undergoes a first order decay with a half life of 24 hours. Find the conversion of the fluid.
A first order reaction has a specific rate constant of 3e-3 per sec. The half life is
A certain reaction is 1st order in A. In 30 min, the concentration of A decreases from 0.55 to 0.15 mol/L. The time it will take for A to decrease from 0.35 to 0.15 mol/L is
A gas decomposes at 900 degC according to 2A--->2R+S with a rate constant of 1000 cc/gmol-s using pure A. The time it will take to react 80% of A in a batch reactor at 900 degC and 1 atm in min is
133 25.36 m
134 0.1697
135 257
136 0.732
137 10.3
138 8150
139 Cao/2m
140 43.1
141 1/8
Calculate the length of a chlorinating pipe line with diameter of 0.6 m required to kill 95% of the bacteria in waste water flowing at 0.05 cu.m/s. Test shows that 95.33% kill is obtained in 5 minutes when treated with 5 mg/L of chlorine. Chlorine disinfection kinetics is given by the equation: dC/dt = k Ct^1.5 where C = number of bacteria. Assume that the same concentration of chlorine is used in actual treatment operation.
The set of data given below is for the parallel reaction: a---k1-->2R, a---k2-->S. At t=0, Ca=15 moles/cuft, Cr = 1 mole/cuft, Cs=1 mole/cuft; At t=1 hr, Cro = 9 moles/cuft, Cs = 3 moles/cuft. The value of K2 per hour is
A batch reaction 2D+E----->F has a conversion factor expressed by the equation r =0.24 t^0.5 where r = conversion factor based on the reactant E; t = time in hours which ranges from 0.5 to 16 hours per batch depending upon the process variables. The average molecular weight of the feed is 60 and a density of 1.4 g/cc. The feed consists of 2 kgmole of D and 1 kgmole of E. The charging, cleaning and discharging time per batch is 2.5 hrs and the volume of the reactor is twice the volume of the feed. Assume 300 days per year and 12 hours operation/day. The volume of the reactor in liters is
A container holds 100 gal of salt solution containing 50 lb of dissolved salt. The bottom of the container is covered with a layer of rock salt. The bottom of the container is covered with a layer of rock salt whose surface is practically constant. The salt dissolved into the solution according to r = k(C-3) where C is the concentration of the brine expressed in lb/gal. If the water in the tank were fresh, the rate of solution would be 1.0 lb/min. Fresh water enters at 3 gpm and brine overflows at the same rate. Assume constant volume at any brine concentration, the concentration of brine in container after 1 hour in lb/gal of salt is
An aqueous solution of ethyl acetate is to be saponified with NaOH. The initial concentration of the ethyl acetate is 5 g/L and that of the caustic soda is 0.10M. Values of the second order rate constant in L/gmole-min are k = 23.5 at 0 degC; k = 92.4 at 20 degC. The reaction is essentially irreversible. The time required to saponify 95% of the water at 40 deg C is
At 500K the rate of bimolecular reaction is 10 times the rate at 400K. Find E in cal, the activation energy for this reaction from Arrhenius Law.
The reaction A+2B--->R is 1st order with respect to each reactant. If equimolar amounts of A and B are introduced into a constant-volume reactor and (1/m) th of A remains after t1, how much will remain after t2=2t1?
When the 1st order homogeneous reaction (gas-phase) A--->2.5R is carried out in an isothermal batch reactor at 2 atm with 20% inerts present, the volume increases by 60% in 20 min. When the reaction is carried out in a constant volume reactor, the time required for the pressure to reach 8 atm if the initial pressure is 5 atm, 2 atm of which consist of inerts in min is
When the ID of the pipe through which a fluid flows is doubled, the pressure loss due to friction per unit length of pipe and for the same volumetric flow rate is changed by approximately a factor of
142 1/2
143 1/2
144 1/2
145 Cavitation occurs in a centrifugal pump when
146 0.63
147 1.05
148 0.6
149 PhP 3300
150 1/2
151 potential head
152 viscosity
153 20
154 3x2x8.5E
155 95
156 2
157 32
158 15
When two centrifugal pumps are connected in series, the discharge changes by a factor of
When two reciprocating pumps are connected in parallel, the volumetric capacity of the system changes by a factor of
The pressure drop in a pipeline changes by a factor of _____ when the velocity of the flowing fluid is doubled.
the discharge pressure becomes too high
Oil with a viscosity of 30 cP and a density of 60 lb/cu.ft. flows through a 1/2-inch inside diameter pipe. Determine the velocity in fps below which flow will be laminar.
Water at 60 deg F flows through a 3-inch inside diameter smooth horizontal pipe. If the Reynold's number is 353000, calculate the ratio of maximum velocity to average velocity.
The pressure after the pump in a 6-inch inside diameter smooth pipe conducting water is 20 psia. The water is discharged at an open tank 100 ft from the pump. Calculate the rate of discharge of water in cu.ft/s.
A water storage tank assumes the supply of water into a factory. Water is supplied to the tank through a booster pump installed in the water line. The theoretical pump horsepower required is 3.25 hp. What is the monthly operating cost of the pump if electric power cost on the average is PhP 3.73/kWh. The pump is 65% efficient and operates for 12 hr a day.
When the impeller speed of an ideal centrifugal pump is doubled, the vol. flow rate of discharge is increased by a factor of
The differential height between two points which a fluid has to be transferred is the
The resistance of a layer of fluid to flow over the next layer is measured by
An axial flow pump operating at a speed of 880 rpm can supply water at a rate of 3000 gpm. The maximum head that this pump can deliver in ft. of water is
Specify the type of open impeller pump to use if the capacity is 400 gpm at a head of 200 ft of water.
What will be the rated capacity [gpm] of a 4-1/2 inch impeller centrifugal pump operating at a speed of 3450 rpm capable of generating a head of 40 ft of water.
If the speed of a centrifugal pump is doubled, the energy requirement becomes approximately ___ times the original energy requirement.
A cylindrical tank 1 ft in diameter discharges through a nozzle connected to the base. Find the time needed for the water level in the tank to drop from 4 ft to 2 ft above the nozzle. The diameter of the nozzle is 1 inch and its discharge coefficient maybe taken as unity.
The NPSH of a single suction centrifugal hot water pump at a speed of 3550 rpm operating at a pressure of 600 psi and a capacity of 450 gpm is ___ ft.
159
160 capacity
161 double-pipe
162 0.82
163
164 285.3
165 An insulator should have
166 Fouling factor
167 Natural convection is characterized by Reynolds number
168 The Graetz number is concerned with
169 Dropwise condensation occurs on
170 for liquid metals
171 fluidizing
172 0.98
173 305 mm
174 settling ratio
175 The sphericity of cubical particles is 1
The rate of evaporation at a given operating temperature in a n evaporator is more when
when the operating pressure is high
An optimim number of the effects for a given application is a function of the
A popular type of heat exchanger for cooling large quantities of fluid is the
An evaporator is used to concentrate 10,000 lb/hr of a 20% solution of NaOH in water at 140oF using saturated steam at 25 psia at a rate of 7,000 lb/hr. The OHTC is 275 BTU/hr-ft2-oF when the pressure in the vapor is 1.7 psia. The steam economy, SE, is
A cross flow heat exchanger uses mixed air at 4 kg/s that enters at 15oC and leaves at 45oC. The air cools unmixed water, which enters at 95oC and 0.70 kg/s. The OHTC equals 150 W/m2-oC. After several months of operation, a scale resistance of 0.002 m2-oC/W developed. 16. The heat transfer area required to accomplish the change is
22.2 m2
As solution of 28% wt Na2SO4 is to be crystallized to yield Glauber salt in a four section (one section is 10 ft in length) Swenson Walker Crystallizer. It is fed to the unit at 120oF and cooled to 60oF using cooling water which enters at 50oF and leaves at 70oF. The crystallizer has a cooling surface of 3 ft2 per foot of length. The feed rate is 500 lb/hr and the crystallizer is seeded with 50 lb/hr of 65 mesh crystals. 19. The amount of the crystalline crop (C) produced in lb per hour is
low thermal conductivity
is a dimensionless quantity
mass transfer between a gas and a liquid
clean and dirt free surfaces
Dietus-Boelter equation for determination of heat transfer co-efficient is valid
A type of pneumatic conveyor system characterized by a material moving in an air stream or pressure less than ambient.
If the total percentage of particles larger than the screen opening in the feed, oversize, undersize are 36%, 89% and 3%, respectively, the effectiveness of the screen if the undersize is the product is
The estimated width of an apron conveyor having a capacity of 75 tons/hr at a speed of 50 ft/min is
It is defined as the ratio of the average diameter of the feed to the average diameter of the product.
176 thickening
177 temperature
178 Ordinary diffusion takes place because of ___ driving force. temperature179 What are the two limiting cases of steady-state diffusion? UMD and EMD
180
181 Knudsen region
182
183 Sc
184 the liquid phase
185 In two-phase mass transfer, equilibrium may exist at the interface
186 cooling of air
187 Air conditioning in tropical countries involves
188
189 0.5
190 The moisture that can be removed by drying is called
191 Falling-period in drying terminates at the
192 Which is not true at the interphase of a gas scrubbing operation?
193
The separation of a dilute slurry or suspension by gravity settling into a clear fluid and a slurry or suspension by gravity settling into a clear fluid and a slurry of higher solids content is called
An ultracentrifuge is used to separate high-molecular weight fractions in polymeric or biological systems. What is the gradient for mass transfer in the separation using this mass transfer device?
Which of the following is not true in (binary) equimolar counter-diffusion?
DAB = DBA
A fluid is flowing on a surface, which contains a component that leaches out to the fluid. Assuming that all the 3 regions of mass transfer are present, in which of these regions is diffusion controlling?
In unsteady-state mass transfer, the quantity (DABt/rm^2) is referred to
asunaccomplished change
What is the equivalent of Prandtl number in convective mass transfer?
If kx > ky, then the controlling phase is
Which of the following processes may always be regarded as a constant- humidity process?
humidification by a process similar to that in a cooling tower
What do you call the steady-state non-equilibrium temperature reached when a small amount of water is contacted under adiabatic conditions by a continuous stream of gas?
dry-bulb temperature
The moisture content of a solid is given as 50% wet basis. What is the moisture content, dry basis?
equilibrium moisture
end of constant-rate period
the solute concentration of the gas is less than that of the bulk
He and N2 gas are contained in a conduit 5 mm in diameter and a 0.1 m long at 298 K and a uniform pressure of He at one end of the tube is 0.6 atm and 0.02 atm at the other end. Assuming equimolar countercurrent diffusion, the flux in kmol/s-m2 is
2.35 exp -5
194 5280
195 1 hr
196 The unit of volumetric diffusivity is
197 0.5
198 packed lower
199 decreases
200 The suitable evaporator for concentration of foaming liquids is
201
202 For a packed column the main purpose of packing is to
203 the NTU is zero
204 0.15
205 0.92
206 14.7
207 0.54 min
208 For Newtonian fluids, the shear stress is constant.
209 An ideal fluid is one that is compressible
100 m3/hr of air at 60°C and 20% RH is needed for a chemical reactor. This will be obtained from process air at 60°C and 10% RH by humidifying adiabatically the process air followed by heating to its original temperature. The wattage of the heater at 80% efficiency is
Wet solid is to be dried from 36% to 8% moisture in 5 hr under constant drying condition. Critical and equilibrium moisture contents are 14 and 4% respectively. Calculate how much longer will it take to dry the same material from 8% to 5.5% moisture under constant drying condition. All moisture contents are on a dry basis.
cm^2/sec
If reflux to a distillation column is 100 moles/hr, when the overhead product rate is 50 moles/hr. the reflux ratio is
Which of the following provides maximum contact surface for a liquid-vapour system?
In extraction, as the temperature increases, the area of heterogeneity (area covered by bimodal curve)
long tube evaporator
Macroscopic transfer of mass between moving fluid and surface which is of different concentration is called
molecular diffusion
strengthen the column
In a gas absorption operation, when the operating line crosses the equilibrium curve
Methanol diffuses in 0.15 cm stagnant film of 1:1 mole mixture of hydrogen and CO2 at 100oC and 2 atm. The partial pressures of methanol on both sides are 0.6 and 0.2 atm. The average diffusivity of methanol in the hydrogen and CO2 at 0 oC and 1 atm in cm2/s is
Gaseous reactant A decomposes according to the reaction A --> 3R (-rA = 0.5 CA mole/L-min). The feed, which consists of 70% A and 30% inert, enters a 1.5-m3 CSTR at a flow rate of 150 L/min. 4. If CA0 = 0.30 mole/L, what is the conversion, XA?
Between 0 degC and 50 degC, the average activation energy of a certain reaction is 80 kJ/mol. How many times faster will the reaction occur at 300 K than at 275 K?
Consider a gas-phase reaction 2A ---> R + 2S with unknown kinetics. A space velocity of 0.8/min is needed for 95% conversion of A in a PFR. Find the mean residence time or holding time of the fluid in the PFR.
210 10.58
211 stream tube
212 350
213 A simple pitot tube measures acoustical velocity
214 pitot tube
215 In the flow meter equation, Y, indicates the mass flow rate
216 The loss due to sudden contraction is proportional to velocity217 Stoke’s law is valid when the particle Reynolds number is < 1218 Priming needed in a
219 40 ft
220 butterfly221 Multistage compressors are used in industry because, they
222 For ideally incompressible fluid, the mach number will be 0223 vacuum pumps
224 pressure
225 0.007 kg
226 The overhead product composition decreases with time in
227 low reflux ratio
228 Chemisorption is
229 The stage efficiency in leaching depends on the
230 Weeping in distillation or absorption column
Water flows through an 8-in (ID=7.981 in) steel pipe at an average velocity of 6 ft/s. Downstream the pipe splits into an 8-in main and a 2 in (ID=2.067 in) bypass pipes. If the velocity in the bypass is twice the velocity of the main pipe, the volumetric flow rate [ft3/s] in the main pipe is
An imaginary line within a fluid flow such that a tangent at any point indicates the direction of flow at that point.
Air at 250C [viscosity=0.018 cP] enters a section of 2-in schedule 40 commercial steel pipe at a gauge pressure of 310 kPa and a flow rate of 1200 kg/h. Assuming isothermal flow, what is the pressure drop [kPa] in 60 m of pipe?
Which of the following meters will have the highest permanent pressure loss?
Reciprocating pump
Maximum theoretical suction lift for water at 60˚F by a centrifugal pump is 34 ft. The same for water at 200˚F will be
The most economical valve for use with large diameter pipes. reduce the cost of compressor
of the following produces maximum pressure difference for transportation of gases?
The fluid property which matters for falling rain drops to acquire spherical shape is its
A wastewater solution having a volume of 1000 L contains 0.21 kg phenol/m3 of solution. A total of 1.40 kg fresh granular activated carbon is added to the solution, which is then mixed thoroughly to reach equilibrium. What is the amount of phenol absorbed per kg carbon at equilibrium?
batch distillation with reflux
For a binary mixture with low relativity, continuous rectification to get pure products will require
the same as van der Waals
time of contact between the solid and the solution
increases tray efficiency
231 What are the two contacting phase in leaching?
232 Distillation
233 caproic acid
234 Professional Regulations Commission was created under P.D. No. 223235 1
236 18
237 inventive step
238 disclosure
239
240 paper
241 Sulfur is undesirable in petroleum because
242 fillers
243 Polyethylene is an example of _____________ polymerization condensation
244 condensation
245 Carbon black is added to rubber compounding as activator246 The binder for all the powder materials of paint pigment247 bagasse
248 Molasses is a by product of raw sugar from the ______ process milling249 Kraft process is a common name for sulfate pulping250 Water insoluble cell binders of wood pulp251 DDT means
252 Rancidity of oil can be reduced by decoloration253 Varnish does not contain pigment254 Plasticisers are added to paints to
255 Silicone is thermoplastic
256 extrusion
257 Alkyl benzene sulfonate (ABS) is a detergent258 Neoprene is a monomer
extract phase and raffinate phase
Hydrogen sulfide is removed from water by contacting the solution with warm air. The operation is
Disregarding the cost, which is the best solvent for the extraction of acetic acid from an aqueous solution at 25deg C?
A chemical engineer who designed and built a new type pf reactor and for three years, sold many units to the public can still patent his reactor.
A person who has passed the Chemical Licensure Examination can take his/her oath as a chemical engineer if his/her age is not less than _______ years.
Which of the following is not a requirement for utility model registration?
A section of the patent application containing detailed descriptions of the benefits obtained from using the invention is called the
A document issued by the DENR secretary indicating that the proposed project will cause significant negative environmental impact.
Environmental Impact Statement
In the Philippines, sulfur for sulfuric acid manufacturing is sourced from _______ industry.
it causes engine knocking
Materials added to detergent formulation to enhance cleaning performance by exhibiting synergistic cleaning effect with surfactant.
Principal chemical conversion in the production of resin from monomer.
A fibrous material left after cane sugar has been milled is commonly called as
Diphenyldichlorotriphenylethane
make it corrosion resistant
The process involved in converting rubber into a thin sheet or coating it on fabric is called
259 0.2348
260 Work is a
261 Throttling process is
262 0
263 isothermal
264 Entropy
265 According to the first law of thermodynamics
266 greater than 0.85
267
268 Coolers and boilers are ordinarily operated at ________ condition. isobaric
269 For an isolated system, maximum entropy will occur at half-life270 A carnot cycle consists of
271 sphericity
272 Froude number
273 3
274
275 set point
276 current
Steam enters an adiabatic turbine at 10 MPa and 500 degC at a rate of 3 kg/s and leaves at 0.1 MPa. If the power output of the turbine is 2 MW, determine the turbine efficiency.
property of the system
a reversible and isothermal process
A sample consisting of 1.00 mole of Argon gas is expanded isothermally and reversibly at 0°C from 22.4L to 44.8L. The heat absorbed by the system is
Maximum work can be obtained from a system when the change taking place in it is
The ratio of work performed by a system and the heat it absorbed from a reservoir is referred to
Energy is neither lost nor gained in any energy transformation.
In a 3-stage compressor system whose isentropic efficiencies are reported to be 0.75, 0.85 and 0.84, respectively, steam initially at 10 kPa is compressed to a final pressure of 500 kPa. The overall efficiency of the system is
In choosing the refrigerant, the fluid must have the following characteristics, except
environmentally benign
two isothermal and two adiabatic process
This is also known as the volume fraction of the voids in packed beds.
A measure of the ratio of the drag force acting on a unit area of the impeller & the inertial stress.
Sulfuric acid is pumped at 3 kg/s through a 60-m length of smooth 25 mm pipe. If the pressure drop falls by one-half, what will be the new flow rate [kg/s]? Assume the following properties of sulfuric acid: SG = 1.84, viscosity = 25 cP.
The equation del(P) = -(rho)(g) del(z) is known as the hydrostatic vertical law for which all the following assumptions are applied, except
shear forces are not involved
Which of the following can be adjusted by human operator in a closed feedback control loop?
The thermocouple is based on the Seebeck effect which states that a/an _____ is generated when opposite junction of certain dissimilar pairs of wires are exposed to different temperatures.
277 Dead time is a function of distance and momentum278 2.83kPa/K
279 Time constant
A pneumatic controller is used to control temperature within the range 280K to 310K. The controller is adjusted so that the output pressure goes from 20kPa (valve fully open) to 105 Kpa (valve fully closed) as the measured temperature goes from 295K to 300K with the sent point held constant. What is the proportional gain?
The parameter which completely describes the behavior of the response to a disturbance of a second order system is the
B C D ANSWER SCORE
butterfly valve globe valve orificea 1
0.025 0.03 0.038 c 1
laminar flow only d 1
d 1
b 1
stripping rectification fractionation c 1
maximum reflux minimum reflux optimum reflux c 1
mol/liter/min liter/mol/minc 1
little effect no effect significant effect
d 1
c 1
theoretical plate transition plate bubble plate
d 1
unsaturated supersaturated saturated c 1
c 1
discharge ratio reduction ratio classification ratio c 1
c 1
vent orifice venturi a 1
laminar and turbulent flow
turbulent flow only
the average between the heat transfer coefficient of the steam and that of oil
equal to the heat transfer coefficient equivalent to the resistance offerred by the pipe
equal to the heat transfer coefficient of the steam
the minimum number of stages occur when the operating lines are parallel.
the minimum number of stages occur when the tie line coincides with an operating line.
the amount of solvent used must be enough to form 2 phases.
square liter/square mol/square min
maximum heat transfer rate occurs at the surface
the heat transfer is constant
the temperature is uniform throughout the cylinder
Peclet, Reynold's and Schimdt No
Sherwood, Reynold's and Schimdt No
Prandtl, Schimdt and Reynold's No
the order of reactio is zero
the value of k is independent of the initial concentrations of A and B
the reaction cannot proceed
a function of time
b 1
salvage value book value market valueb 1
d 1
b 1
c 1
square-corner elbow d 1
vent compressor accumulatorb 1
d 1
d 1
parallel reactions c 1
wood air concret b 1
dehumidification humidification extractionb 1
velocity pressure static pressure b 1
momentum gradient c 1
80 deg F 113 deg F 146 deg F
c 1
0.278 1.484 0.581 b 1
2.5 1.5 0.6 b 1
constant throughout the reactor
not uniform throughout the reactor and varies from time to time
decreases the reboiler duty
increases the amount of distillate
increases the condenser duty
the gas phase resistance is approximately equal to the total resistance
the gas phase resistance is negligible
the ratio of gas phase resistance to liquid resistance is approximately zero
Nusselt, Prandtl and Reynold's Nos
Peclet, Stanton and Prandtl Nos
Schimdt, Peclet and Friction Nos
90-degree standard elbow
45-degree standard elbow
4" dia Wrought iron pipe
1" dia Drawn tubing
4" dia Riveted steel pipe
varies with the thermal conductivity of each material
through each material is inversely proportional to the thickness of the material
is constant throughout the series of materials
reversible reactions
consecutive reactions
tangential pressure
reaction component
concentration gradient
58.1 33.4 54.4
a 1
64 kg 128 kg 32 kg c 1
31.4 26.4 57.8b 1
2.18 1.5 2.75
b 1
over 20 million
c 1
0.0504 0.0454 0.0252b 1
5130000 6930000 2040000
a 1
dew point dry-bulb temperaturea 1
75 75.26 78.5a 1
b 1
0.05 0.02 0.01b 1
c 1
flash drier tray drier freeze drier c 1
over 100 but less than 200
over 2 but less than 3
saturation temperature
the system can be well insulated from the surroundings
the temperature of the air can also be maintained constant
increase in the humidity of the air is insignificant
final moisture content
equilibrium moisture content
critical moisture content
a 1
surface tension surface renewal moisture diffusivity d 1
1.846 hrs 2.129 hrs 3.42 hrs
b 1
0.034 0.01155 0.00116
c 1
no drying takes place c 1
a 1
0.8 1.5 2.3
b 1
4 5 6
b 1
conduction radiation all of A, B and C a 1
conduction radiation all of A, B and C c 1
c 1
condensation evaporation all of A, B and C b 1
415.7 451.7 475.1
c 1
the internal movement of moisture beneath the surface of the solid
air flow perpendicular to the surface of the solid
air flow parallel to the solid surface
increases with time
decreases with time
to use counter current operation
to use cross flow evaporation
to use spray percolators
sum of the individual conductivities
inverse of the total resistance
sum of the individual resistances
242 5800 139200
d 1
11.02 m 5.51 m 4.14 m
c 1
1500 kg 966 kg 534 kg
d 1
58.5 sq.m. 85.8 sq.m. 88.5 sq.m.
b 1
101.3 kPa 14 kPa zero gauge
a 1
9.12 4.72 3.03
a 1
38 39 40
c 1
9 8 7
a 1
28.7 27.8 22.7
c 1
0.429 0.294 0.249
d 1
696 577 241
a 1
12.68 13.76 16.28
b 1
54.6 46.5 45.6
a 0
150 227.2 300
c 0
8457 11994 20451
d 1
35000 40130 45500
c 1
18.3 13.8 5
b 1
1644 1163 19.4
c 1
1.35 4.67 2
a 1
84 95 100
b 1
27.7 7 0.52
a 1
14.24 31.7 37.1
d 1
227 851 900
c 1
0.5 0.75 1
c 1
[B]=0.2
d 1
55.2 25.2 20
a 1
272 3478 3750
d 1
[B]=0.4(1-x)/(1-1.5x)
[B]=0.4(1-0.5x)/(1-x)
0.119 0.714 6.01
b 1
300 100 25
a 1
4392 W 13943 W 19343 W
c 1
18 23 33
b 1
100 38 0.038
d 1
Ba 1
increases 4 times decreases. c 1
decreases. stays constant. c 1
decreases. stays the same. a 1
d 1
quadruples. increases 8x. increases 16x.
d 1
both contain the same no of air molecules
increases by about 40%
may increase or decrease.
The application should be rejected because it violates the second law of Thermodynamics.
The application should be rejected because it violates both 1st and 2nd laws of Thermo.
The application should be given full consideration because it does not violate any laws of Thermodynamics.
2.2 e8 3 e7 5.2 e8
b 1
tie substance excess reactant product yield b 1reactant ratio
b 1
Net Calorific Value a 1
ash moisture b 1
Modified analysis Ultimate analysis Elemental analysis a 1
SO3-free basis O2-free basis N2-free basis b 1
Dulong's formulac 1
28.32 32.48 42.56 c 1
1.53 2.38 6.13c 1
70% RH 60% saturation a 1
PhP 424.26 PhP 434.16 PhP 450
c 1
0.02 0.03 0.05
a 1
3750 4350 6000
b 1
8 9.5 17
c 1
0.85 0.9 0.92
a 1
combined feed ratio
fresh-feed conversion
Heat of combustion
Latent Heat of Condensation
volatile combustible matters
Theoretical Oxygen Equation
Oxygen unaccounted for equation
absolute humidity of 0.05
57.24 51.2 22.76
b 1
6.53 7.86 23.1
b 1
conc/time 1/conc 1/conc-time a 1
3 2 1.5 c 1
adding a catalystc 1
the net equation the rate law.d 1
c 1
4 8 16 d 1
temperature c 1
2 > 0 <0 a 1Ca vs time 1/Ca vs time a 1
1/Ca vs time lof Ca vs time Ca vs time b 1
-ra = k Ca Cb^2 -ra = k Ca -ra = k Cb^2b 1
Hess' Law c 1
d 1
74.7 85.3 99.1
d 1
100 s 231 s 768 s c 1
19.6 min 19.1 min 10.4 minb 1
7.43 8.33 9.33
c 1
decreasing temperature
removing the products of the reaction
the temperature dependency of the rate
depends on the conc of one of the products at equilibrium
does not depend on the initial concentrations
is not a characteristic of the reaction
molecularity of the reaction
nature of reactants
log Ca vs reciprocal time
Law of Mass Action
Second Law of Thermo
independent of initial conc
proportional to initial conc
inversely proportional to initial conc
32.5 m 52.63 m 56.23 m
c 1
0.183 0.3394 0.6197
a 1
275 300 527
a 1
0.427 0.327 0.237
c 1
11.4 12.7 20.7
a 1
9150 9550 10150b 1
Cao/(2m-1) Cao/(1-2m) Cao/2
b 1
41.3 37.1 31.8
d 1
1/16 1/32 1/64
c 1
1 2 4 c 1
1 2 4 b 1
1 2 4 d 1
suction is lost
c 1
13.1 16.9 87.2c 1
1.22 1.72 1.89b 1
3.58 21 58.3
b 1
PhP 5000 PhP 7000 PhP 12000
b 1
1 2 2exp2c 1
pressure head velocity head dynamic head a 1
friction factor surface tension drag coefficient a 1
36 63 85b 1
4x3x8.5E 4x3x6 3x2x13 a 1
134 248 320c 1
4 8 10c 1
55 77 94
c 1
20 25 30b 1
the discharge valve is closed
the suction pressure is too high
b 1
economy efficiency b 1
plate shell and tube extended surfaces c 1
0.863 0.89 0.92
b 1
d 1
249.3 255.65 214.65
b 1
a porous structure a 1
none of these
c 1
Grashhoff number Peclet number Prandlt number b 1
d 1
polished surfaces c 1
c 1
pressure pressure-vacuum vacuum d 1
0.89 0.76 0.65
b 1
610 mm 1220 mm 2400 mm c 1
screen-mesh no reduction ratio c 1
0.87 0.7 0.6 a 1
the operating pressure is low
there is a vacuum
when the liquid level is high
none of the given choices
25 m2 17 m2 20 m2
high thermal conductivity
less resistance to heat flow
does not provide a safety factor for design
accounts for additional resistance to heat flow
absorption with chemical reaction
heat transfer in turbulent flow
heat transfer in laminar flow
smooth clean surfaces
contaminated cooling surfaces
for fluid in laminar flow
for fluids in turbulent flow
when Grashhoff number is very important
average particle diameter
classification sorting centrifugationa 1
pressure concentration electric field
b 1
pressure concentration electric field b 1
thermal and Knudsen a 1
c 1
turbulent region buffer region viscous sub-layer
d 1
relative resistance relative time relative positionc 1
Sh Bi Pe a 1
the gas phase the interface b 1
in the gas phase in either film a 1
air conditioning heating of air d 1
c 1
b 1
1 2 50 b 1
bound moisture free moisture unbound moisture c 1
d 1
a 1
a 1
ordinary and Knudsen
thermal and ordinary
c = cA + cB JA = JB NA = -cDAB dxA/dz
either of the bulk phases
in the liquid phase
water-cooling in a cooling tower
humidification by a process similar to air-water vapor saturator
dehumidification and removal of sensible heat
dehumidification by condensing water vapor in a refrigerator
wet-bulb temperature
adiabatic saturation temperature
dew point temperature
origin of R vs X plot
critical free moisture content
equilibrium moisture content
the solute concentration of the liquid is less than that of the bulk
the solute concentration of the liquid and gas phase are equal
the solute concentration of the gas is greater than the liquid
2.44exp -5 1.77exp -6 1.22 exp -6
8490 10050 11570
d 1
1.6 hr 2.3 hr 2.9 hr
b 1
cm/sec c 1
2 50 150 b 1
wetted wall column a 1
increases a 1
falling film evaporator a 1
all of these c 1
b 1
d 1
0.31 0.51 0.68
c 1
0.86 0.71 0.65
c 1
18.5 20.9 22.4b 1
0.85 min 0.87 min 1.18 min
b 1
d 1
incompressible d 1
cm^3/sec cm^2/sec^2
bubble-cup plate column
sieve-plate column
remains unchanged
short tube evaporator
vacuum evaporator
unsteady-state diffusion
convective mass transfer
increase the surface area
increase the pressure drop in the tower
reduce the flow rate across the column
the liquid flow rate is maximum
the gas flow rate is maximum
the number of stages is infinite
inversely proportional to rate of deformation.
equal to shear rate of deformation.
a linear function of the shear rate of deformation.
incompressible & viscous
incompressible & inviscid
5.29 1.84 0.25
c 1
velocity profile streamline none of these c 1
155 101.3 61
d 1
superficial velocity local velocity d 1
orifice venturi rotameter b 1
cross-sectional area b 1
turbulence velocity head static head c 1
> 1 < 5 0 a 1Gear pump Centrifugal pump Diaphragm pump c 1
37 ft 34 ft 8 ft b 1
globe needle gate a 1
are easy to control
c 1
1 1.5 5 b 1
blowers fans compressors d 1
height of descend viscosity surface tension d 1
0.106 kg 0.189 kg 0.198 kg
b 1
a 1
high reflux ratio d 1
always in equilibriumc 1
both A and B
c 1
is due to bubble cupsc 1
mean linear velocity
compressibility factor
coefficient of discharge
reduce the size requirement
resemble closely to isothermal compression
continuous distillation with reflux
continuous distillation without reflux
distillation operating at total reflux
small cross-section
less number of trays
characterized by adsorption of heat
an irreversible phenomenon
rate of diffusion of the solute through the solid and into the liquid
either A or B because these two mean the same thing
provides larger surface for mass transfer
results due to low gas velocity
d 1
Leaching Absorption Stripping d 1
chloroform 3-heptanol toluene c 1
P.D. No. 233 P.D. No. 232 P.D. No. 826 a 1
0 it depends not governed by lawa 1
19 21 23c 1
novelty a 1
abstract request claimsd 1
b 1
cement petroleum detergents a 1
a 1
brighteners builders perfumec 1
addition copolymerization natural b 1
hydration polymerization alkylation d 1
curing agent retarders fillers a 1vehicle opacifier filler a 1
pulp cellulose waste c 1
extraction evaporation crystallization c 1
sulfite pulping bleaching calendering b 1cellulose xylem lignin d 1
c 1
hydrogenation oxidation purification b 1
dryer thinner anti-skinning agent a 1
d 1
a monomer thermosetting plastic c 1
mastication vulcanization calendering d 1
rubber pesticide polyester a 1synthetic rubber polyester pigment b 1
solvent phase and solute phase
feed phase and solvent phase
overflow and underflow
industrial applicability
a technical solution to problem
Environmental Compliance Certificate
Environmental Impact Assessment
Environmental Critical Project
it increases the boiling pt of fuel
it poisons the catalyst in the refining process
all that are mentioned
dichlorodiphenyldichloroethane
Dichlorodiphenyldichlorobutane
diphenyldichlorotriphenylbutane
make glossy surface
increase atmospheric oxidation
give elasticity and prevent cracking of the film
an inorganic polymer
0.3216 0.6784 0.7652c 1
path function state function b 1
d 1
+1.13 kJ +1.57 kJ +2.27 kJc 1
adiabatic reversible irreversible c 1
Gibb’s free energy carnot efficiency c 1
a 1
less than 0.75
b 1
d 1
isenthalpic isothermal isentropic a 1
critical condition equilibrium start of the process c 1
a 1
porosity specific volume b 1
Reynold’s number Mach number Power number d 1
2 0.2 0.124
b 1
c 1
controller output process variable load variable a 1
temperature emf resistancec 1
state description of a system
an irreversible and constant entropy
a reversible and constant entropy process
constant enthalpy process
Helmholtz free energy
Perpetual motion is possible.
Energy is conserved in quality but not in quantity.
Energy is being created as time passes. We have more energy in the universe now than when time began.
in between 0.75 and 0.85
in between 0.84 and 0.90
has a vapor pressure less than atmospheric
must be economically viable
exist at a high pressure at the condensation temperature
two isochoric and two adiabatic process
one isochoric, one isobaric, and two adiabatic process
one isothermal, one isochoric and two adiabatic process
superficial velocity
fluid is incompressible
z axis is defined vertical & downward in direction
normal surface forces & gravity are the only forces involved
acceleration time velocity d 10.35kPa/K 17kPa/K 0.06kPa/K
