Refresher Exam Questions Flashcards
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 wise in the water feed to the tubes is to be 20 deg K. Calculate the minimum number of tubes
A. 116 tubes
B. 130 tubes
C. 142 tubes
D. 85 tubes
A. 116 tubes
When a porous solid was dried under constant-drying conditions, 5 hours were required to reduce the moisture from 30 to 12 lb H2O.lb dry solid. Determine the time needed the time needed to dry the solid from 30 to 8 ln H2O/lb dry solid.
A. 3.34 hr
B. 7.74 hr
C. 1.25 hr
D. 2.88 hr
B. 7.74 hr
A rotary countercurrent dryer is fed with ammonium nitrate containing 5% moisture at the rate of 1.5 kg/s, and discharges the nitrate with 0.2% moisture. Calculate the mass of dry air passing through the dryer.
A. 1,6 kg/s
B. 2,4 kg/s
C. 3.8 kg/s
D. 6.1 kg/s
D. 6.1 kg/s
A rotary countercurrent dryer is fed with ammonium nitrate containing 5% moisture at the rate of 1.5 kg/s, and discharges the nitrate with 0.2% moisture. Calculate the humidity of the air leaving the dryer.
A. 0.0188 kg/kg
B. 0.0294 kg/kg
C. 0.08231 kg/kg
D. 0.0915
A. 0.0188 kg/kg
It is the angle at which a material will rest on pile
A. Angle of inclination
B. Angle of repose
C. Contact Angle
D. Banking Angle
B. Angle of Repose
It is partially decomposed plant matter that has accumulated underwater or in a water-saturated environment.
A. Oil shale
B. Tar Sands
C. Peat
D. Biomass
C. Peat
Which of the following is an ore of mercury
A. Bauxite
B. Galena
C. Spharelite
D. Cinnabar
D. Cinnabar
It is the most abundant metal of the earth’s crust.
A. Iron
B. Aluminum
C. Lithium
D. Sodium
B. Aluminum
Which of the following is a soft material
A. quartz
b. topaz
c. sapphire
d. gypsum
d. gypsum
When the temperature of the surrounding is higher than the blood temperature of a human body then the transfer of heat will between the body and the sorrounding
a. convection
b. radiation
c. cooling
d. evaporation
A. convection
It is frequently caused by crystallization of a material whose solubility at the wall temperature is lower than at the bulk liquid temperature
a. scaling
b. salting
c. fouling
a. scaling
It is a nonporous rock containing organic kerogen.
a. tar sands
b. natural gas
c. oil shale
c. oil shale
What is produced when calcium carbibe is mixed with water
acetylene
What is the chemical formula of alar
C6H12N2O3
How many liters is 27000 fluid barrels
3.22E6
How many liters is 27000 oil barrels
4.29E6
A cylindrical bucket 150 mm in diameter and 200 m high contains 150 mm of water. A boy swings the bucket on a vertical plane so that the bottom of the bucket describes
a. 24.22 rpm
b. 31.13 rpm
c. 38.88
b. 31.13
Calculate the volume of an octahedron whose length of sides are 2 m each.
a. 1.77 m3
b. 2.45 m3
c. 3.77 m3
c. 3.77 m3
Calculate the absolute entropy of solid NH3 at its melting point at 1 atm pressure, in Btu/lb-R. Boiling point = -33.4C melting point = -77.7C
A. 0.6066
B. 0.8244
C. 1.2288
0.6066
Calculate the change in entropy when 1 lb of NH3 at its melting point at 1 atm pressure, in Btu/lb-R. Boiling point = -33.4C melting point = -77.7C
A. -2.463
B. -1.655
C. 1.859
A. -2.463
Calculate the change in entropy when 1 lb of NH3 liquid will change to solid at its melting point at 1 atm pressure, in Btu/lb-R. Boiling point = -33.4C melting point = -77.7C
A. -0.407
B. -1.005
C. -1.776
A. -0.407
Establish the separation capability of a single-stage (differential) batch still processing a mixture of two compounds having a relative volatility.
A. 450 mol
B. 520 mol
C. 640 mol
D. 725 mol
D. 725 mol
From the data in #29, what is the mole fraction A in the distillate
A. 0.75
B. 0.70
C. 0.65
A. 0.75
If a right circular cone is cut parallel with the axis of symmetry, it will reveal a/an
Hyperbola
Location 1 is 3m away from location 2. A man walks 4 m and 40 degrees to location 3. How far is location 3 location 2.
A. 2.57 m
B. 3.42 m
C. 4.18 m
A. 2.57m
If the second derivative of the equation of a curve is equal to the negative of the equation of that same curve, the curve is
a. an exponential
b. a tangent
c. a sinusoid
c. a sinusoid
The highest ordinate on the stress-strain curve
A. ultimate strength
B. rupture point
Ultimate strength
Which does not belong to the group
A. microjoule
B. Watts
C. Kilowatt-hour
B. Watts
What is the molecular weight of sucrose
C12H22O11 - 342
Who coined the term serendipity
Horace Walpole
Who discovered radioactivity
Henri Becquerel
Which control system is used for multi-input, multi-output system?
model predictive control
A control structure with two feedback controller with the output of the primary controller changes the set point of the secondary controller whose output goes to the final controller
cascade control
In a process in which it is used as solvent, benzene is evaporated into dry nitrogen. at 297 K and 101.3 kPa, the resulting mixture has a percentage relative humidity of 60. it is required to recover 80 percent of the benzene present by cooling to 283 K and compressing to a suitable pressure. What should be this pressure be?
A. 120 kpa
b. 210 kpa
c. 392 kpa
C. 392 kpa
A boiler plant raises 5.2 kg/s of steam at 1825 kN/m2 pressure, using coal of calorific value 27.2 Mj/kg. if the boiler efficiency is 75%, how much coal is consumed per day? If the steam is used to generate electricity, what is the power generation in kilowatts assuming a 20% conversion efficiency of the turbines an generators
A. 0.713 kg/s; 3MW
B. 1.322 kg/s, 4.5 MW
C. 2.144 kg/s, 1.5 MW
A. 0.713; 3 MW
A benzene toluene feed (withh 40 mol % benzene and 60 mol % toluene) to a distillation column is at a temperature of 20C. The molar heat capacity of the feed is 159.2 kJ/kmol-K. Molar heat of vaporizations of benzene and toluene are 30.813 and 33.325 kJ/kmol. The slope of the feed line is closest to
A. 0
B. 1
C. 3.7
C. 3.7
A high speed diesel engine burns fuel to give an exhaust gas analyzing 7.14% CO2, 4.28% CO, 8.24% O2, and 80.34% N2. The cetane number of the fuel fired is
A. 44.56
B. 45.20
C. 52.38
A. 44.56
The amount of heat required to change the susbsance from solid to liquid state without change in temperature is known as the latent heat
a. evaporation
b. vaporization
c. fusion
fusion
An exclusive right granted by the government for the manufacture, use and sale of a specific product
a. copyright
b. trademark
c. patent
patent
What is the test for first order reaction?
a. log Ca vs t
b. Ca vs t
c. 1/Ca vs t
a. log Ca vs t
What is the unit of heat transfer coefficient?
a. W/m2-K
b. W/m-K
c. Btu/hr-ft-F
a. W/m2K
If the feed to the distillation column is a subcooled liquid feed, find the value of q.
a. q = 1
b. q = 0
c. q > 1
d. q < 1
c. q > 1
Buckingham pi theorem is applied to
A. pressure-velocity relationship in compressible fluid flow
b. heat transfer by natural convection
c. dimensional analysis of a physical system
c. dimensional analysis of a physical system
Which of the following set of reversible processes describes an ideal Otto cycle>
I. adiabatic compression, isometric heat addition, adiabatic expansion, isometric heat rejection
From which mineral is radium obtained
pitch blende
Entropy of vaporization for substances is determined to be constant, the value is __
a. 21 cal/mol K
b. 8 cal/mol-K
c. 18 cal/mol-k
a. 21 cal/mol-K
Magnesium is obtained from
Sea water
Dimensionless number defined as the ratio of inertial forces to viscous forces
Reynolds number
For the complete corrosion-resistant stainless steel, the minimum percentage chromium in the alloy is
a. 1.1%
b. 3.2%
c. 11%
c. 11%
Brix scale is the hydrometer scale for
sugar solution
Reactions which occur in a single step
elementary
The composition of the reaction component vary from position to position along a path of a/an
a. CSTR
b. adiabatic reactor
c. batch reactor
d. plug flow reactor
d. plug flow reactor
___ factor equals sinking fund factor plus interest rate.
a. single payment compound amount
b. uniform series present worth
c. capital recovery
c. capital recovery
Another name of specific gravity
a. specific weight
b. relative weight
c. relative density
c. relative density
Who is the Philippine president who signed RA 9297 also known as the New Chemical Engineering Law of the Philippines
Pres Gloria Macapagal Arroyo
Another name for moment
Torque
The locus of a point which moves so that it is always equidistant from a fixed point
a. circle
b. parabola
c. ellipse
a. circle
The curve represented by the equation r=6 is
circle
Electron affinity is
a. the change in energy when a gaseous atom in its ground state gains an electron
b. the pull an atom has on the electrons in a chemical bond
a. the change in energy when a gaseous atom in its ground state gains an electron
A triple bond consists of
1 sigma and 2 pi bonds
Deuterium is an isotope of
hydrogen
first ionization energy refers to
a. removal of an electron from a gas atom
b. energy to form the most probable ion
removal of an electron from a gas atom
A body of mass __ kg is rested on a frictionless horizontal plane. A horizontal force of P=30 N is applied. Find the distance and what is the velocity?
a. 1.2 m, 2.2 m/s
b. 2.1 m, 1.2 m/s
c. 6.0 m, 1.2 m/s
c. 6.0 m, 1.2 m/s
Compare the costs of electricity at P1.00 per kWh and gas at P15.00 per therm.
a. cost of electricity is P0.14 per MJ
b. cost of gas is P0.28 per MJ
c. cost of electricity is P0.14 per MJ more than cost of gas
c. cost of electricity is P0.14 per MJ more than cost of gas
A wooden spherical ball with specific gravity of 0.42 and a diameer of 300 mm is dropped from a height of 4.3 m above the surface of water in a pool of unknown depth. The ball barely touched the bottom of the pool before it begin to float.
a. 1.22m
b. 2.18 m
c. 3.11 m
c. 3.11m
Air at 1 bar and 25C enters a compressor at low velocity, discharges at 3 bar, and enters a nozzle in which it expands to a final velocity of 600 m/s at the initial conditions of pressure and temperature. if the work compression is 240 kJ per kilogram of air. how much heat must be removed during compression?
a. -60 kJ/kg
b. -30 kJ/kg
c. -45 kJ/kg
a. -60 kJ/kg
Humid air at temperature 600F and a total pressure of 1 atmosphere is passed through a dehumidifier at a rate of 1000 ft3/min. the partial pressure of water vapor in air is reduced from 45 mmhg to 10 mmhg. how many pounds of water is removed per hour?
a. 81.9
b. 45.4
c. 65.4
c. 65.4
A contact sulfuric acid plant produces 98.0% sulfuric acid, by absorbing SO3 into a 97.3% sulfuric acid solution. A gas containing 8.00 % SO3 (remainder inerts ) enters the SO3 absorption tower at the rate of 28 lb mol per hour. 98.5 % of the SO3 is absorbed in this tower. 97.3% sulfuric acid is introduced into the top of the tower and 95.9% sulfuric acid from another part of the process is used as a make-up acid. The flow sheet is given in the figure with all of the known data on it (Note of the flow diagram: Liquid solution leaving at the bottom of the tower is split into product and recycle stream which is mixed with the make-up acid and introduced as feed solution at the top of the tower). Calculate the:
a) Tons/day of 95.9% H2SO4 make-up acid solution required
b) Tons/day of 97.3% H2SO4 introduced into the top of the tower
c) Tons/day of 98% H2SO4 solution produced
a. 2060
b. 6470
c. 2240
What is the molecular weight of lindane?
C6H6Cl6 - 290.83 g/mol
1000 gal/min of water is cascading done a height of 100 ft from a reservoir. If half of the energy is converted to electrical energy, how many 105 watts bulb can be lighted in 30 seconds?
a. 84
b. 94
c. 90
c. 90
Situation - A liquid with no appreciable elevation of boiling point is concentrated in a multiple-effect evaporator. the temperature of the steam to the first effect is 395 K and vacuum is applied to the third effect so that the boiling point is 325 K.
What is the temperature in the first effect
In the second effect
In the third effect
381.5 K
363.2 K
325 K
What is the specific gravity of nitrogen at 80 F and 745 mmhg compared to air at 80F and 745 mmhg
a. 0.79
b. 0.85
c. 0.97
c. 0.97
The distance between plates is delta y = 0.5 cm, delta v = 10 cm/s and the fluid is ethyl alcohol at 273 K having viscosity of 1.77 cp. Calculate the shear stress in dyne per square centimeter
a. 0.210
b. 0.354
c. 0.540
b. 0.354
A right circular conical tank has radius of 6 inches across the top and a height of 2 ft and contains water with a height of 12 inches. If water flows out from the bottom of the tank at a constant rate 2 in3/min.
a) find the dh/dt in in/min at the instant that the height is 12 inches.
b) find the volume of water in the tank in in3 when the height of water is 12 inches
c) find the volume of water in the tank in in3 when the height of water is 6 inches
a) -2/9pi
b) 36pi
c) 9/2pi
It refers to waste or scrap glass, usually ground.
A. cullet
B. fluorospar
C. feldspar
D. glass float
A. cullet
Property of a fluid to form droplets and assume the shape of a sphere and rise in a capillary tube.
a. surface tension
b. condensate
c. abrasion
a. surface tension
Which plot is linear for a first order reaction?
log [A] vs t
Oxygen at pressures much greater than 1 atm is toxic to lung cells. Assume a deep-sea diver
breathes a mixture of oxygen and helium. By weight, what ratio of helium to oxygen must be
used if the diver is at an ocean depth of 50.0 m
less than 1
At which temperature the speed of sound in hydrogen will be same as that of speed of sound in
oxygen at 100C.
Sqrt of 3RT/M = 101C
How much is the amount of work done to move a 6.51 kg chair 7.841 m across the floor at
constant velocity if the coefficient of kinetic friction between the chair and the floor is 0.651 and
you are pushing at an angle at 15.41° relative to the floor?
354.2 J
Discovered Helium
Ramsay and Travers
