FECE Flashcards by ayel cross

Which of the following is true for water at a reference temperature where enthalpy is
zero?
a. Internal energy is negative
b. Entropy is nonzero
c. specific volume is zero
d. Vapor pressure is zero

a. Internal energy is negative

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Heat to the hydrolyzer is to be supplied by an immersion heater of suitable material of
construction. The heater uses steam at 75psig. The suitable material of construction is
a. stainless steel 316
b. Teflon
c. Karbate
d. Hastelloy B

c. Karbate

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What type of power cycle does the diagram illustrate?
a. a carnot cycle
b. an idealized rankine cycle
c. an idealized diesel cycle
d. an idealized stirling cycle

b. an idealized rankine cycle

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Shear stress in a fluid flowing in a round pipe
a. is zero at the center and varies linearly with the radius
b. varies parabolically across the cross section
c. is zero at the wall and increases linearly to the center
d. remains constant over the cross section

a. is zero at the center and varies linearly with the radius

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A steam turbine operates adiabatically at a power level of 3500 kW. Steam enters the
turbine at 2400 kPa and 500C and exhausts from the turbine at 20 kPa. What is the turbine efficiency?

82%

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A ten minute run shows that 75% of liquid reactant is converted to product by a half
order rate. What would be the amount converted in a half hour run?

100%

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At 378.5C the half life for the first order decomposition of ethylene oxide is 363 minutes, and E=52000 cal/mole. If the temperature is increased to 450C, find the time for ethylene oxide to be 75% decomposed.

13.8 min

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At 500 K, the rate of a biomolecular reaction is ten times the rate of 400K. Activation energy of this reaction is 9.15 kcal/mol. How much faster is the reaction at 450 K?

3.6 times at 450K

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The off gas from a boiling water nuclear power reactor contains a whole variety of radioactive trash, one of the most troublesome being Xe-133 (half-life 5.2 days). This off
gas flows continuously through a large holdup tank in which it mean residence time is 30
days, and where we can assume that the contents are well mixed. Find the reaction of
activity removed in the tank.

98%

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Liquid A decomposes by second-order kinetics, and in a batch reactor 50% of A is
converted in a 5-minute run. How much longer would it take to reach 75% conversion?

10 more minutes

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The analysis of a flue gas from a fuel gas containing no nitrogen is 4.62% CO2. 3.08% CO. 8.91% O2, and 83.39% N2. Moles of water (H2O) formed is:

67%

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The analysis of a flue gas from a fuel gas containing no nitrogen is 4.62% CO2. 3.08% CO. 8.91% O2, and 83.39% N2. Moles of air supplied per 100 moles of dry flue gas

14.08 moles

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A certain substance A is mixed with equal amount of B and C. After 10 minutes, half of A has reacted. What will be the conversion after 20 minutes if the reaction is second order with respect to A?

1.055

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The ratio of moles of a reactant converted into the desired product to that converted
into unwanted product is called
a. operational yield
b. selectivity
c. relative yield
d. none of the above

c. relative yield

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The moisture content of a solid is given as 50 % wet basis. What is the moisture
content, dry basis?
a. 0.5
b. 1
c. 2
d. 50

b. 1

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The term “ adiabatic” comes from the greek word “adiabastos” which means
a. No transformation
b. No transfer
c. Not to be passed
d. No heat

c. Not to be passed

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A fumace is fired with coal containing 6% moisture,18% VCM, 67% FC and 9% ash.
The refuse analysis shows 5% VCM, 23%FC and 62% ash. The higher heating value of
the coal as fired is 14,300 Btu/lb. Calculate the percentage of the heating value of the coal
that is lost in the refuse. Assume that the moisture in the refuse is due to the “wetting
down” to prevent dusting and not moisture from the original coal.

4.68%

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What is the theoretical oxygen demand of 100 grams of glucose?

107 grams

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A utility runs a Rankine cycle with a water boiler at 3.5 MPa and the cycle has the
highest and lowest temperature of 450C and 45C respectively. What is the cycle efficiency?

0.36

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The cycle has the following process:
1. The process from 1 to 2 is adiabatic, isentropic compression
2. The process from 2 to 3 is asobaric, heat addition
3. The process from 3 to 4 is adiabatic, isentropic expansion
4. The process from 4 to 1 is constant volume heat rejection

What is the name of this cycle?
a. carnot
b. diesel
c. otto
d. Rankine

b. diesel

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The compression ratio of an ideal Otto cycle is 6:1. P1 is 101.35 kPa, and T1 is 20
degC. What is the temperature at state 2 at the diagram shown?

600K

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An engine burns a liter of fuel each 12 minutes. The fuel has a specific gravity of 0.8 and a heating value of 45 MJ/kg. The engine has a efficiciency of 25%. What is most nearly the brake horsepower of the engine?

16.8 hp

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The COP of a Carnot refrigeration cycle operating at 100 deg F and 900 deg F is

5.875

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Maximum work that could be secured by expanding the gas over a given pressure
range is the ______________ work.
a. isothermal
b. adiabatic
c. isentropic
d. none of these

a. isothermal

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1 lbm of nitrogen is compressed at a constant temp of 70 deg F from 10 ft3 to 5 ft3. If the process is non-flow and if no work is done on the gas except by a moving piston, how much heat is added to or removed from the gas during the process? a. 30.27 BTU b. -30.27 BTU c. 28.54 BTU d. -26.07 BTU

d. -26.07 BTU

An engineer devises a scheme for extracting some power from waste process steam. The engineer claims that the steam enters the device at 700.5 kPa and a quality 75%, and the steam exits at 101.35 kPa and 65% quality. Which of the following statements is/are true? I. The device produces 216 kJ/kg of work II. The device violates the first law of thermodynamics III. The device violates the second law of thermodynamics a. I only b. II only c. III only d. I and II

c. III only

A chemical reaction involves the interaction collision of two molecules of A and B goes through the following energy profile. The energy,E, shown on the diagram represents which of the following? a. entropy of reaction b. enthalpy of reaction c. forward activation energy d. reverse activation energy

d. reverse activation energy

If 15 kJ of work is done by the surroundings on the system and the system loses 10 kJ heat to the surroundings then the total energy change is a. 25 kJ b. 10 kJ c. -5 kJ d. 5 kJ

What refers to the amount of removed from the colled space in BTS’s for 1 watt-hour of electricity consumed? a. coefficient of performance b. energy efficiency rating c. cost of performance d. cost efficiency rating

b. energy efficiency rating

Carnot cycle is the best known reversible cycle which was proposed in what year? a. 1824 b. 1832 c. 1834 d. 1842

a. 1824

Who coined the word “ energy” in 1807? a. Lord Kelvin b. Thomas Young c. Rudolph Clausius d. William Rankine

b. Thomas Young

Who formulated the zeroth law of thermodynamics? a. A. Celcius b. A. Einstein c. R.H. Fowler d. G. Fahrenheit

a. A. Celcius

A device that violates the second law of thermodynamics is called a ______. a. universal machine of the second kind b. ambiguous machine of the second kind c. unique machine of the second kind d. Perpetual-motion machine of the second kind

d. Perpetual-motion machine of the second kind

Which of the following denotes the effect of compressibility in fluid flow? a. weber number b. Euler number c. Reynolds number d. Mach number

d. Mach number

In the process of radiation, energy is carried by electromagnetic waves. What is the speed of electromagnetic waves? a. 188 000 miles/sec b. 186 000 miles/sec c. 184 000 miles/sec d. 182 000 miles/sec

b. 186 000 miles/sec

Determine the state of water according to the following condition at 440 deg F density of 842.3679 kg/m3 a. saturated liquid b. saturated vapor c. sub-saturated d. superheated

c. sub-saturated

Air enters a dryer at 70 degF and 20% humidity and leaves at 180 degF and 50% RH. If the dryer operates at atmospheric pressure of 14.3 psia, how many cubic feets of entering air would be needed when 12.0 lb/hr of water is evaporated from the wet material in the dryer? a. 6.78 cu ft/min b. 7.86 cu ft/min c. 8.67 cu ft/min d. 13.8 cu ft/min

c. 8.67 cu ft/min

A solution composed 50% ethanol and 40% water is fed at the rate of 100 kg/hr into a separator that produces one stream at the rate of 60 kg/hr with the composition of 80% ethanol, 15% methanol and 5% water, and a second stream of unknown composition. The mass flow rate of the second unknown stream in kg/hr is a. 60 b. 50 c. 40 d. 20

c. 40

A solution composed 50% ethanol and 40% water is fed at the rate of 100 kg/hr into a separator that produces one stream at the rate of 60 kg/hr with the composition of 80% ethanol, 15% methanol and 5% water, and a second stream of unknown composition. The mass fraction of ethanol in the unknown stream is a. 0.025 b. 0.05

b. 0.05

“Perspex” or “Plexiglass” is basically a. Poly (vinyl chloride) b. Poly (acrylonitrile) c. Poly (isobutylene) d. Poly (methyl methacrylate)

d. Poly (methyl methacrylate)

In a reciprocating pump, the ration of the quantity of liquid actually pumped to that which corresponds to the piston displacement is called a. Hydraulic efficiency b. Mechanical efficiency c. Volumetric efficiency d. Suction

c. Volumetric efficiency

Cold air at 10 degF is forced to flow over a flat plate maintained at 40 defC. The mean heat transfer coeeficient is 30 W/m2-K. Find the heat flow rate from the plate to the air through a plate area of 2m2. Assume radiation is negligible. a. 1.8 kW b. 2.0 kW c. 2.2 kW d. 2.4 kW

a. 1.8 kW

The function of manholes provided in the shell of a distillation column is to a. Keep check on the liquid gradient over the plate by direct visual observation b. Give access to the individual trays for cleaning, maintenance and installation c. Guard against foaming & entrainment by dumping antifoaming agent through it d. All a, b and c

b. Give access to the individual trays for cleaning, maintenance and installation

The lowest cost plastic commercially available a. Chlorinated polyether b. Polyethylene c. Polypropylene d. Cellulose acetate butyrate

b. Polyethylene

Scaling can be best handled by a. Increasing velocity b. Decreasing velocity c. Decreasing Viscosity d. Increasing viscosity

a. Increasing velocity

Solubility of a substance which dissolves with an increase in volume and liberation of heat will be favored by the a. low pressure and high temperature. b. low pressure and low temperature. c. high pressure and low temperature d. high pressure and high temperature

b. low pressure and low temperature.

You are asked what size of containers to use 1,000lbs of cotton seed oil (SG = 0.926). What would be the minimum size of drum expressed in gallons? a. 129.5 b. 254.2 c. 103.9 d. 85.6

a. 129.5

A pure formic acid at 30°C flowing at 0.015 m/s is pumped Through a 75 mm horizontal pipe 38 m long. The roughness of the pipe is 6x10-5 m. What will be be the pressure drop in the pipe? a. 71 kPa b. 35 kPa c. 21 kPa d. 42 kPa

a. 71 kPa

Of the pressure vessels, with same thickness but different diameters, which one withstands higher pressure? a. Larger dia vessel b. Smaller dia vessel. c. Larger dia long vessel d. Strength of the vessel is same irrespective of the diameter.

b. Smaller dia vessel.

In a laminar fluid flow, the average velocity is ____________ of the maximum velocity. a. one-half b. one-fourth c. twice d. four times

a. one-half

Design a multiple-contact extraction system to treat 1.25 tones (2500 lb) per hour of dry black ash, containing 40% Na2CO3 and 60% insoluble matter with 30 gpm of water. If 5% of the Na1CO3 remains unextracted, calculate the number of ideal stages by_the absorption factor method. Note: The mass ratio of insoluble matter to solvent in the underflow from stage is 1:2.

A 1-2 shell and tube exchanger heats 68 kg/min of water in a shell from 35°C to 75°C by an oil (Cp= 1.9 kJ/kg-°C). The oil enters the tube at 110°C and leaves at 75°C. The LMTD correction factor is: a. 0.81 b. 0.86 c. 0.91 d. 0.96

0.81

A large container 360 m long, 70 m wide and 25 m deep is being dragged in sea at a constant speed of 10 m/s. Calculate power required to drag such container. The temperature of sea water is 10oC. a. 21.6 MW b. 26.1 MW c. 62.1 MW d. 16.2 MW

a. 21.6 MW

An adiabatic compressor operating under steady-state conditions receives air (ideal gas) at 0.1 MPa and 300 K and discharges at 1 MPa. If the flow rate of air through the compressor is 2 mol/s, determine the power consumption of the compressor. Constant pressure, specific heat for air = 1kJ/kg a. 16.25 kW b. 25.16 kW c. 61.52 kW d. 52.61 k

a. 16.25 kW

What does the term 'uniform' implies? a. No change with location b. No change with volume c. No change with time d. No change with mass

a. No change with location

An insulated piston-cylinder system has air at 400kPa & 600K. Through an inlet pipe to the cylinder air at certain temperature T(K) and ressure P (kPa) is supplied reversibly into the cylinder till the volume of the air in the cylinder is 4 times the initial volume. The expansion occurs isobarically at 400kPa. At The end of the process the air temperature inside the cylinder is 450K Assume ideal gas behavior, compute the temperature of the air supplied through the inlet pipe. a. 380K b. 480 K c. 580 K d. 680 K

b. 480 K

0.6 m3/s of gas is to be dried from a dew point of 294 K to a dew point of 277.5 K. How much water must be removed and what will be the volume of the gas after drying? Vapour pressure of water at 294K = 2.5 kN/m2. Vapour pressure of water at 277.5K = 0.85 kN/m2 a. 0.6 m3/s at STP b. 1.2 m3/s at STP c. 1.8 rn3/s at STP d. 2.4 m3/s at STP

a. 0.6 m3/s at STP

A hydrogen stream at 300 K and atmospheric pressure has a dewpoint of 275K. It is to be further humidified by adding to it (through a nozzle) saturated steam at 240 kN/m2 at the rate of 1 kg steam: 30kg of hydrogen feed. What will be the humidity of the resultant stream? a. 0.1 kg/kg b. 0.2 kg/kg c. 0.3 kg/kg d. 0.4 kg/kg

a. 0.1 kg/kg

A cyclone separator, 0.3 m in diameter and 1.2 m long, has a circular inlet 75 mm in diameter and an outlet of the same size. If the gas enters at a velocity of 1.5 m/s, at what particle size will the theoretical cut occur? The viscosity of air is 0.018 mN s/m2, the density of air is 1.3 kg/m3 and the density of the particles is 2700 kg/m3 a. 1.17 x 10-6 m b. 2.17 x 10-6 m c. 3.17x10-6 m d. 4.17 x10-6 m

b. 2.17 x 10-6 m

In order to heat 0.5 kg/s of a heavy oil from 311 K to 327 K, it is passed through tubes of inside diameter 19 mm and length 1.5 m forming a bank, on the outside of which steam is condensing at 373 K. How many tubes will be needed? a. 11 b. 12 c. 13 d. 14

d. 14

Solute gas is diffusing into a stationary liquid, virtually free of solvent, and of sufficient depth for it to be regarded as semi-infinite in extent. In what depth of fluid below the surface will 90% of the material which has been transferred across the interface have accumulated in the first minute? Diffusivity of gas in liquid = 10-9 m2/s. a. 0.38 mm b. 0.48 mm c. 0.58 mm d. 0.68 mm

b. 0.48 mm

The wire diameter of a 14 mesh screen (Tyler standard) is a. 0.0235 in b. 0.025 in c. 0.028 in d. 0.03 in

b. 0.025 in

A heat exchanger is to consist of a number of tubes each 25 mm diameter and 5 m long arranged in parallel. The exchanger is to be used as a cooler with a rating of 4 MW and the temperature rise in the water feed to the tubes is to be 20 K. If the pressure drop over the tubes is not to exceed 2 kN/m2, calculate the minimum number of tubes that are required. Assume that the tube wails are smooth and that entrance and exit effects can be neglected. Viscosity of water = 1 mNs/m2. a. 106 tubes b. 116 tubes c. 126 tubes d. 136 tubes

b. 116 tubes

A liquid is pumped in streamline tow through a pipe of diameter d. At what distance born the center of the pipe will the fluid be flowing at the average velocity? a. 0.15d b. 0.35d c. 0.55d d. 0.75d

c. 0.55d

Oil of viscosity 10 mNs/m2 and specific gravity 0.90, flows through 60 m of 100 mm diameter pipe and the pressure drop is 13.8 kN/m2. What will be the pressure drop for a second oil of viscosity 30 mNs/m2 and specific gravity 0.95 flowing at the same rate through the pipe? Assume the pipe wall to be smooth. a. 14.9 kN/m2 b. 19.4 kN/m2 c. 23.6 kN/m2 d. 26.3 kN/m2

b. 19.4 kN/m2

Over a 30 m length of 150 mm vacuum line carrying air at 293 K, the pressure falls from 1 kN/m2 to 0.1 kN/m2. If the relative roughness e/d is 0.002, what is approximate flowrate? a. 0.022 kg/s b. 0.044 kg/s c. 0.066 kg/s d. 0.088 kg/s

a. 0.022 kg/s

A counter - current extraction column is designed to remove 99% of solute C from a solution of solvent A and solute C using pure solvent B. The initial concentration of solute in the solution of A + C is 20 wt%, and the total flow of solution is 1000 kg/hr. If the equilibrium relationship is Y=2X, where Y = mass of C/mass of A & X= mass of C/mass of B. The minimum flow rate of solvent B required in kg/hr is: a. 1454 b. 1584 c. 1676 d. 1874

b. 1584

The radiation received by the earth's surface on a clear day with the sun overhead is 1 kW/m2 and an additional 0.3 kW/m2 is absorbed by the earth's atmosphere. Calculate approximately the temperature of the sun, assuming its radius to be 700,000 km and the distance between the sun and the earth to be 150,000,000 km. The sun may be assumed to behave as a black body. a. 5170 K b. 5710 K c. 5071 K d. 5107 K

b. 5710 K

A device that violates the first law of thermodynamics is called a ______ a. Universal machine of the first kind b. Ambiguous machine of the first kind c. Unique machine of the first kind d. Perpetual-motion machine of the first kind

d. Perpetual-motion machine of the first kind

A rotary drum filter with 30% submergence is used to filter concentrated aqueous slurry of calcium carbonate containing 15 lbs of solids per cubic foot of water. The pressure-drop is 20' Hg If the filter cake contains 50% mixture (wet basis), calculate the filter area required to filter 10 gal/min of slurry. The filter cycle time is 5 min. The specific cake resistance depends on the pressure-drop as: Viscosity of the filtrate = 6.72 x 10-41bift-s. Density of calcium carbonate = 168.8 lb/ft, Neglect fitter medium resistance. a. 72 ft, b. 82 ft c. 92 ft d. 102 ft

b. 82 ft

With the following characteristics: length L = 30.48 m; inside diameter d = 0.0526 m; pipe roughness e = 0.000045m frictional pressure drop dP = 15720 N/m2; liquid dynamic viscosity = 0.01 Pa-s; liquid density p = 1200 kg/m3. Calculate the Reynolds number. a. 7138 b. 15000 c. 8273 d. 9569

a. 7138

With the following characteristics: length L = 30.48 m; inside diameter d = 0.0526 m; pipe roughness e = 0.000045m frictional pressure drop dP = 15720 N/m2; liquid dynamic viscosity = 0.01 Pa-s; liquid density p = 1200 kg/m3. The fanning friction factor f a. 0.00884 b. 0.00727 c. 0.00990 d. 0.00698

a. 0.00884

With the following characteristics: length L = 30.48 m; inside diameter d = 0.0526 m; pipe roughness e = 0.000045m frictional pressure drop dP = 15720 N/m2; liquid dynamic viscosity = 0.01 Pa-s; liquid density p = 1200 kg/m3. The steady mean velocity v (m/s). a. 1.13 b. 2.38 c. 1.25 d. 1.30

a. 1.13

Which of the following is not a valid assumption in continuous binary distillation for calculating the number of equilibrium stages by McCabe-Thiele's method? a. Reflux is not a saturated liquid b. Heat of mixing of normal liquid is assumed to be zero c. Sensible heat changes for vapor & liquid are negligibly small d. Molar latent heat of the two components are equal

a. Reflux is not a saturated liquid

In case of a supercooled solution, which is on the verge of crystallization, the free energy of the solution as compared to that of the solid is a. More b. Less c. Same d. More or less; depends on the nature of solution

a. More

All of the following biogeochemical cycles involve the atmosphere as either sink or reservoir except a. Water b. Carbon c. Nitrogen d. Phosporus

d. Phosporus

Correct use of 'factor of safety' is very important in equipment design. It is defined as the ratio of the a. ultimate stress to working stress b. working stress to ultimate stress c. ultimate stress to breaking stress d. working stress to breaking stress

a. ultimate stress to working stress

Pick out the wrong statement pertaining to of the bubble cap tray of a distillation column to give stable operation and even vapor distribution a. The dimensionless ratio of liquid gradient to pressure drop head caused by the bubble cap assembly should be less than 0.4 b. The pressure drop due to the caps & slots and the static submergence should be as high as practicable for reasonable operation c. Tendency towards stable operation is increased by increasing the skirt clearance of the caps, lowering the rate of liquid flow per unit plate width or increasing the spacing between the caps d. None of these

d. None of these

Graphically, gage pressure becomes negative under which scenario. a. The absolute pressure falls below the atmospheric pressure b. The atmospheric pressure falls below the absolute pressure c. The absolute pressure falls below the vacuum pressure. d. The atmospheric pressure falls below the absolute zero

The absolute pressure falls below the atmospheric pressure

In a gas-liquid absorption column, for obtaining the maximum absorption efficiency a. a. by passing should be completely avoided b. both gas as well as quid streams should be distributed uniformly c. gas stream should be distributed uniformly d. liquid stream should be distributed uniformly

b. both gas as well as quid streams should be distributed uniformly

FECE Flashcards

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