QUICE REVIEW CENTER

6th floor room 608-610 Doňa Amparo Bldg.

G. Tolentino St., Sampaloc Manila

GENERAL INSTRUCTION: Please select the best answer and submit on time.

1. It is desired to filter a cell broth at a rate of 2000 L/h on a rotary vacuum filter at a vacuum pressure of 70 kPa. The cycle
time for the drum is 60 s, and the cake formation time is 15 s. The broth to be filtered has a viscosity of 2.0 cp and a cake
solid per volume of filtrate of 10 g/L. From laboratory tests, the specific cake resistance has been determined to be 9 
1010 cm/g. Determine the area of the filter that is required.
a. 3.09 m2 c. 1.22 m2
b. 5.99 m 2 d. 8.79 m2

2. How many poles exist in the following transfer function?

5(𝑠−1)𝑒 −3𝑠
(𝑠 2 +1)(𝑠+5)
a. 1 b. 2 c. 3 d. 4
3. In the vicinity of the triple point, the vapor pressures of liquid and solid ammonia are respectively given by:
ln p = 15.16 - 3063/T and ln p = 18.70 - 3754/T
where p is in atmospheres and T is in Kelvin. What is the temperature at the triple point? Also calculate the triple point
pressure.
a. Triple point temperature = 395.2 K, Triple point pressure = 0.588 atm
b. Triple point temperature = 195.2 K, Triple point pressure = 0.788 atm
c. Triple point temperature = 195.2 K, Triple point pressure = 0.588 atm
d. Triple point temperature = 295.2 K, Triple point pressure = 0.588 atm
4. A vertical cylinder with a freely floating piston contains 0.1 kg air at 1.2 bar and a small electric resistor. The resistor is
wired to an external 12 Volt battery. When a current of 1.5 Amps is passed through the resistor for 90 sec, the piston
sweeps a volume of 0.01 m3. Assume (i) piston and the cylinder are insulated and (ii) air behaves as an ideal gas with
Cv = 700 J/(kg.K). Find the rise in temperature of air.
a. 6 K. b. 12 K c. 23 K d. 112 K
5. A Brayton refrigeration cycle uses air as the working fluid and operates between a high pressure of 800kPa and a low
pressure of 120kPa. The compressor and turbine inlet temperature are 540 and 510K respectively. The turbine is
isentropic and the compressor ha s an isentropic efficiency of 88%. Calculate Wnet in kJ/kg, and the coefficient of
performance of the cycle.
a. Wnet = -119 kJ/kg , COP = 1.13 c. Wnet = -219 kJ/kg , COP = 3.13
b. Wnet = -19 kJ/kg , COP = 1.13 d. Wnet = -219 kJ/kg , COP = 1.13
6. An ideal air-standard Diesel cycle engine has a compression ratio of 18 and a cutoff ratio of 2. At the beginning of the
compression process, the working fluid is at 100 kPa, 27°C (300 K). Determine the thermal efficiency.
a. 58% b. 34% c. 82% d. 68%
7. A throttling valve is used to reduce the pressure in a steam line from 10MPa to 300kPa. If the steam enters the throttling
valve at 500°C, determine the steam temperature at the outlet of the throttling valve and the area ratio(A2/A1) required to
make the kinetic energy the same at the inlet and outlet.
a. 447°C; 33.7 b. 447°C; 33.7 c. 447°C; 33.7 d. 447°C; 33.7
8. Wet steam at 260 psia is expanded in a throttling calorimeter to a final pressure of 1 atm and the final temperature of 240
°F. What is the quality of the 260 psia steam?
a. 85.5% b. 95.5% c. 75.5% d. 98.5%
9. A closed vessel of 10ft3 capacity is filled with saturated steam at 250 psia. If subsequently 25% of the steam is
condensed, how much must be removed and what is the final pressure?
a. Q= -1052 BTU, P = 136 psia c. Q= -2052 BTU, P = 186 psia
b. Q= -1052 BTU, P = 392 psia d. Q= -1052 BTU, P = 186 psia
10. Determine the final equilibrium state when 2 lbm of saturated liquid mercury at 1 psia is mixed with 4 lbm of mercury
vapor at 1 psia and 1400oF. During the process the pressure in the cylinder is kept constant and no energy is lost
between the cylinder and mercury.
a. Mixture of saturated liquid and vapor at 3 psia and 0.89 quality
b. Mixture of saturated liquid and vapor at 1 psia and 0.19 quality
c. Mixture of saturated liquid and vapor at 1 psia and 0.79 quality
d. Mixture of saturated liquid and vapor at 2 psia and 0.79 quality

11. Steam at 3MPa, 300oC leaves the boiler and enters the high-pressure turbine (in a reheat cycle) and is expanded to 300
kPa. The steam is then reheated to 300oC and expanded in the second stage turbine to 10 kPa. What is the efficiency of
the cycle if it is assumed to be internally reversible?
a. η = 0.317 b. η = 0.817 c. η = 0.517 d. η = 0.717
12. A container which has a volume of 0.1 m3 is fitted with a plunger enclosing 0.5 kg of steam at 0.4 MPa. Calculate the
amount of heat transferred when the steam is heated to 300oC at constant pressure.
a. Q = 3 804.8 kJ b. Q = 4 804.8 kJ c. Q = 2 504.8 kJ d. Q = 2 804.8 kJ
13. A container which has a volume of 0.1 m3 is fitted with a plunger enclosing 0.5 kg of steam at 0.4 MPa. Calculate the
amount of work done when the steam is heated to 300oC at constant pressure.
a. W = 91.0 Kj b. W = 91.0 Kj c. W = 91.0 Kj d. W = 91.0 Kj
14. A central power plant, rated at 800 000 kW, generates steam at 585 K and discards heat to a river at 295 K. if the thermal
efficiency of the plant is 70% of the maximum possible value, how much heat is discarded to the river at rated power?
a. -1.505 X 106 Kw b. 2.505 X 106 kW c. -2.505 X 106 kW d.. 3.505 X 106 kW
For Problem 15 and 16
The following heat engines produce power of 95 000 kW. Determine in each case the rates at which heat is absorbed from the
hot reservoir and discarded to the cold reservoir.
15. A Carnot engine operates between heat reservoir at 750 K and 300 K
a. QC = - 3.33 X 104 kW and QH = 1.583 x 105 kW c. QC = - 5.33 X 104 kW and QH = 4.583 x 105 kW
b. QC = - 5.33 X 104 kW and QH = 1.583 x 105 kW d. QC = - 12.33 X 104 kW and QH = 1.583 x 105 wk
16. A practical engine operates between the same heat reservoirs but with a thermal efficiency of 0.35.
a. QC = - 4.76X 105 kW and QH = 2.71 x 105 Kw c. QC = - 1.76X 105 kW and QH = 2.71 x 105 Kw
b. QC = - 1.76X 10 kW and QH = 7.71 x 10 Kw
5 5 d. QC = - 1.76X 105 kW and QH = 5.11 x 105 Kw
17. Steam generated in a power plant at a pressure of 8000 kPa and a temperature of 500oC is fed to a turbine. Exhaust from
the turbine enters a condenser at 10 kPa, where it is condensed to a saturated liquid, which is then pumped to the boiler.
What is the thermal efficiency of a Rankine cycle operating at these conditions?
a. η = 0.394 b. η = 0.494 c. η = 0.894 d. η = 0.194
For Problem 18 and 19
Consider a steam power plant operating on the ideal regenerative Rankine cycle with one open feedwater heater. Steam
enters the turbine at 15 MPa and 600oC and is condensed in the condenser at a pressure of 10 kPa. Some steam leaves
the turbine at a pressure of 1.2 MPa and enters the open feedwater heater.
18. Determine the fraction of steam extracted from the turbine.
a. y = 0.4270 b. y = 0.2270 c. y = 0.2970 d. y = 0.3270
19. Determine the thermal efficiency.
a. η = 0.463 b. η = 0.463 c. η = 0.463 d. η = 0.463
20. A heat engine takes in 1000 J of energy at 1000 K and exhaust 700 J at 400 K. what is the actual efficiency of this heat
engine?
a. η = 0.20 b. η = 0.10 c. η = 0.30 d. η = 0.40

21. Air is bubbled through a drum of liquid hexane at a rate of 0.100 kmol/min. The gas stream leaving the drum contains
10.0 mole% hexane vapor. Air maybe considered insoluble in liquid hexane. Use an integral balance to estimate the time
required to vaporize 10.0 m3 of the liquid.
a. 2000 min b. 3498 min c. 5660 min d. 6880 min

For Problem 22, 23, and 24

In an absorption tower (or absorber), a gas is contacted with a liquid such that one or more components in the gas is
transferred in the liquid. A stripping tower (stripper) also involves a gas contacting a liquid but components are transferred
from the liquid into the gas. A process consisting of an absorber and a stripper is used to separate the components of a
gas containing 30.0 mole% CO2 and the balance CH4. This gas is fed to the absorber. A liquid containing 0.500 mole%
CO2 and the balanced methanol is recycled from the stripper and also fed to the absorber. The effluent gas leaving the
absorber contains 1.00 mole% CO2 and all the CH4 in the feed gas. The effluent solvent leaving the absorber is fed to the
stripper (the same stripper that supplies the recycled CO2-methanol liquid mixture) together with a stream of nitrogen gas.
Ninety percent of the CO2 in this effluent solvent is removed in the stripper and the nitrogen/CO2 stream leaving the
stripper passes out to the atmosphere. Methanol may be assumed to be nonvolatile and nitrogen may be assumed
insoluble in methanol. Taking 100 mol/h of the gas fed to the absorber, calculate the
22. Fractional CO2 removal in the absorber (moles CO2 absorbed/mole CO2 in gas feed).
a. 0.576 mol CO2 absorbed/mol fed c. 0.776 mol CO2 absorbed/mol fed
b. 0.976 mol CO2 absorbed/mol fed d. 0.476 mol CO2 absorbed/mol fed
23. Molar flow rate and composition of the liquid feed to the stripping tower.
a. 680 mol/h; 0.0478 mol CO2/mol c. 780 mol/h; 0.0478 mol CO2/mol
b. 620 mol/h; 0.0478 mol CO2/mol d. 680 mol/h; 0.0978 mol CO2/mol
(Ans. 680 mol/h; 0.0478 mol CO2/mol)
24. Molar feed rate of the gas to the absorber required to produce an absorber product gas flow rate of 1000 kg/h.
a. (Ans. 12.69 x 104 mol/h) c. (Ans.4.69 x 104 mol/h)
b. (Ans. 8.69 x 104 mol/h) d. (Ans.9.69 x 104 mol/h)
Problem 25 and 26
Fresh orange juice contains 12.0 wt% solids and the balance water, and the concentrated orange juice contains 42.0 wt%
solids. Initially a single evaporation process was used for the concentration, but volatile constituents of the juice escaped
with the water, leaving the concentrate with a flat taste. The current process overcomes this problem by bypassing the
evaporator with a fraction of the fresh juice. The juice is concentrated to 58 wt% solids, and the evaporator product
stream is mixed with the bypassed fresh juice to achieve the desired final concentration. Calculate the amount of product
(42% concentrate) produce per 100 kg fresh juice fed to the process and the fraction of the feed that bypasses the
evaporator.
25. Calculate the amount of product (42% concentrate) produce per 100 kg fresh juice fed to the process
a. 58.6 kg product per 100 kg feed c. 28.6 kg product per 100 kg feed
b. 78.6 kg product per 100 kg feed d. 18.6 kg product per 100 kg feed
 26. Calculate the fraction of the feed that bypasses the evaporator.
a. 0.112 b. 0.0234 c. 0.401 d. 0.095
27. A reactor is generally termed as an autoclave, when it is a
a. high pressure batch reactor. C high pressure tubular reactor.
b. atmospheric pressure tank reactor. D. atmospheric pressure CSTR.
28. Six kg of carbon is burnt with an amount of air containing 18 gm oxygen. The product contains 16.5 gms CO 2 and 2.8
gms CO besides other constituents. What is the degree of conversion on the basis of disappearance of limiting
reactant?
a. 50% b. 76% c. 85% d. 95%
29. A reversible liquid phase endothermic reaction is to be carried out in a plug flow reactor. For minimum reactor
volume, it should be operated such that the temperature along the length
a. Increases c. is at the highest allowable temperature throughout.
b. Decreases d. first increases and then decreases
30. Oil with a viscosity of 30 cp and a density of 60 lb/ft3 flows through a ½ inch inside diameter pipe. Determine the
velocity in ft/s below which flow will be laminar.
A. 87.20 b. 0.63 c. 13.10 d. 16.90
31. Water at 60 0F is flowing through a 3 in inside diameter smooth horizontal pipe. If the Reynolds number is 353,000 ,
calculate the ratio of maximum velocity to average velocity.
A. 1.89 b. 1.05 c. 1.22 D. 1.72
32. The pressure after the pump in a 6 inch diameter smooth pipe conducting water is 20 psia. The water is discharged
at an open tank 100 ft. from the pump. Calculate the ratio of discharge of water in ft3/s.
A. 21.0 b. 58.3 c. 0.6 d. 3.58
33. Check valve is used for ________flow.
A. Very precise control of b. Unidirectional c. Multidirectional d. None of these
34. For a given Reynolds number, in a hydraulically smooth pipe, further smoothening ____________ the friction factor.
A. Brings about no further reduction of c. Decreases
B. Increases d. None of these
35. Power number is the ratio of
A. Drag stress to inertial stress c. Inertial stress to gravitational stress
B. Inertial stress to drag stress d. Gravitational stress to drag stress
36. A thick walled cylinder has an inside radius of 1 cm and an outside radius of 1.8cm. the inner and outer surface
temperature are held at 3050C and 2950C, respectively. Assume k varies linearly with temperature, with ka = 371.9
W/m-k and b = -9.25 x 10 -5 K-1. Determine the heat loss per unit length.
A. 1 W b. 10 W c. 1 kW d. 40kW
37. A 6 in thick wall is 12 ft high and 1.6 ft long. One face is at 12000F and the other at 3000F. the total heat loss in
BTU/hr is (k = 0.15 BTU/hr-ft-0F).
A. 69,900 BTU/hr b. 69,120 BTU/hr c. 12,960 BTU/hr d. 91,260 BTU/hr
38. The view factor F21 of a sphere (1) of diameter D inside a cubical box (2) of length L =D is
A. 1 b. 3.14 c. 1.57 d. 0.524
39. Crystal size in a continuous crystallizer depends upon the
a. Rate of heat transfer c. Degree of supersaturation
b. Degree of turbulence d. All of these
For problems 40-41:
For a vessel containing 5000gal of liquid with specific gravity = 0.9 and viscosity of 100 cp,
40. Find the superficial linear velocity in fps
A. 0.68 b. 6.8 C. 8.3333 D. 0.8333
41. What is the blend time?
A. 96.79s b. 1.67 min C. 9.679 min D. 16.7s
42. The following are methods of mixing fluids EXCEPT
A. Mechanical mixing b. Hydraulic mixing c. Pipeline mixing d. None of these
43. The most frequently occurring combinations of phases are
A. Gases with gases c. Atomization
B. Gas dispersion d. All of these
44. The purpose of agitation is
A. The intensification of transport processes in agitated batch
B. Preparation of materials of required properties
C. Both (a) and (b)
D. None of these.
45. Assuming that the efficiency of mixing of a rotary drum mixer is dependent on the diameter of the drum, the speed of
rotation, the density and viscosity of the liquid, determine the speed of an actual mixer to mix SAE oil (density= 917
kg/m3, viscosity = 0.29kg/m-s) efficiently. A laboratory prototype one-fourth the size of the size actual mixer required
½ rpm to mix ethyl alcohol (density =789 kg/m3, viscosity = 1.2 x 10 -3 kg/m-s) efficiently.
A. 13 rpm C. 20 rpm
B. 6.5 rpm D. 1770 rpm
46. The brinkman number is often used in the analysis of organic liquid flows. This dimensionless number is proportional
to viscosity, µ . Derive the Brinkman number if it depends on the viscosity, velocity of flow, V , thermal conductivity, k,
and fluid temperature, T.
A. µk/VT C. kT/µV2
 B. µV2/kT D. TV2/µk

47. A pendulum bob of weight W is connected to a weightless string of length L. if the weight of the bob is doubled and
the length of the string is cut to one-half, the period or time of a complete swing becomes _____________________
the original period.
A. ½ C. 0.707 times
B. Twice D. 1.41 times
48. The Reynolds Number may be defined as the ratio of
A. Inertial forces to viscous forces C. gravity forces to inertial forces
B. Viscous forces to gravity forces D. none of these
49. It is a measure of inertial forces to gravitational forces
A. Froude Number C. Grashof Number
B. Reynolds number D. Prandtl Number
50. Which of the following is the dimensional formula for the volumetric quantity of water flowing in unit time?
A. Mt C. M3t-1
B. L3t D. L3t-1
51. Determine the capacity of a flight conveyor having a flight size and number of strands in mm of 15 x 7 (380 x 180 – 1
specification. See Table 21-10, Handbook.
A. 61 MT/h C. 71 MT/h
B. 113 MT/h D. 81 MT/h
52. The pipe size of a pneumatic conveyor to convey plastic pellets with bulk density of 30 lb/ft3 using blower with a
capacity of 600 ft3/ min is approximately ___ inches.
A. 2 C. 4
B. 6 D. 8
53. Determine the maximum horsepower requirement of a screw conveyor with a capacity of 30 tons/h and a speed of 55
rpm.
A. 14.3 hp C. 10 hp
B. 30.6 hp D. 5 hp
54. A solid handling equipment used to handle large volumes over long distance economically is a
A. Pneumatic Conveyor C. Bucket Conveyor
B. Belt Conveyor D. Screw Conveyor
55. A solid handling equipment used for moving powdered or granular materials to and from storage or between reaction
vessels as in moving bed catalytic.
A. Bucket Elevator C. Belt Conveyor
B. Screw Conveyor D. Pneumatic Conveyor
56. Which of the following conveyors for bulk materials is used for handling materials over a combination horizontal and
vertical path?
A. Continuous flow C. pivoted bucket
B. Gravity discharge bucket D. All of these
57. In the desorption of highly soluble gas from the liquid, the main resistance will be in the phase.
a. gas b. liquid c. both (a) & (b) d. neither (a) nor (b)

For numbers 58 to 59:

Carbon disulfide is to be absorbed from a dilute gas mixture of CS2 – N2 into a pure non-volatile oil at atmospheric
pressure in a counter current absorber. The mole fraction of CS2 in inlet gas stream is 0.05 and the flow rate of gas
stream, G is 1500 kmol/hr. The equilibrium relation is given by; y = 0.5x, Where x is the mole fraction of CS2 in liquid
stream. It is desired to reduce the mole fraction of CS2 in the gas stream is 0.005.
58. Calculate the minimum value of L/G, where L s the liquid flow rate in kmol/hr
a. 0.50 c. 0.18
b. 0.33 d. 0.45
59. Derive the equation for the operating line if L/G is equal to 1.5 times the minimum values.
a. y = 1.5x + 0.05 c. y = x + 0.005
b. y = 0.675x + 0.005 d. none of these
For numbers 60 to 61:
A counter current plate absorber is to be installed for scrubbing of an air mixture containing 5% ammonia by volume. The
scrubber is fed with water containing 0.002 mole NH3 per mole of water. The scrubbing water flows at a rate of 1.0 mole
water per mole air. It is necessary to absorb 85 percent of the ammonia present in the gas by operating the absorber at
200C. K = (0.80 mol NH3 / mol air) / (mol NH3 / mol H2O)
60. Calculate the concentration of NH3 in the outgoing liquid.
a. 0.0229 b. 0.0175 c. 0.0312 d. 0.0467
61. Estimate number of stages necessary for this operation.
a. 3 b. 2 c. 5 d. 4
62. Equilibrium relationship for the system heptane-oil-air is given by Y = 2X (Y and X are kg–heptane/kg-air and kg-
heptane/kg-oil respectively). Oil containing 0.005 kg-heptane/kg-oil is being used as solvent for reducing the heptane
content of air from 0.10 to 0.20 kg-heptane/kg-air in continuous counter-current pact bed absorber. What column
height is required to treat 1 400 kg/hr.m2 of empty tower cross section of pure air containing heptane if the overall
mass transfer coefficient is 320 kg/hr-m3 per unit gradient of Y? The oil rate employed is 5100 kg/hr-m2. Solve
analytically.
a. 8.65 m b. 7.06 m c. 9.10 m d. 6.72 m
63. H2S is being absorbed in a gas absorber unit. The height of the transfer unit based on the overall mass transfer
coefficient on the gas side is 0.4 m. The equilibrium data is given by, y = 1.5 x. The bulk concentration of H 2S has to
be reduced from 0.05 to 0.001 mole fraction in the gas side. The height of the tower in meters corresponding to an
operating line given by, y = 5x + 0.001 is
a. 2.0 b. 1.0 c. 1.56 d. 0.56
64. Acetone is to be removed from air in an isothermal dilute absorber using pure water as solvent. The incoming air
contains 5 mole% of acetone (yin = 0.05). The design equation to be used for obtaining the number of trays (N) of the
absorber is, N + 2 = 6 log (yin/yout).For 98% recovery of acetone, the number of trays required is/are
a. 6 b. 9 c. 8 d. 5
65. Heat transfer rate described by Fourier's law will decrease, if the __________ increases.
a. thermal conductivity b. thickness c. temperature difference d. heat transfer area
66. The capacity of double-effect evaporator is less than half of the capacity of two single effects, each of which is
operating over same terminal temperature difference, when the
a. solution has an elevation of boiling point.
b. evaporators operate under vacuum.
c. evaporators opreate at atmospheric pressure.
d. none of these.
67. Overall heat transfer co-efficient of a particular tube is U1. If the same tube with some dirt deposited on either side
has coefficient U2, then
a. U1 = U2 b. U2 > U1 c. U1 > U2 d. U1 = dirt factor - U2
68. Boiling point of a solution according to Duhring's rule is a linear function of the __________ of water.
a. boiling point (at the same pressure)
b. viscosity
c. density
d. thermal conductivity
69. At what value of Prandtl number, conduction is negligible in the turbulent core of a fluid flowing through a heated
pipe ?
a. 0.5 b. < 0.5 c. > 0.6 d. < 0.1
70. Walls of a cubical oven are of thickness l, and they are made of material of thermal conductivity k. The temperature
inside the oven is 100°C and the inside heat transfer co-efficient is 3k/l. If the wall temperature on the outside is held
at 25°C, what is the inside wall temperature in degree centigrade ?
a. 35.5 b. 43.75 c. 81.25 d. 48.25
71. If average heat transfer co-efficient is ha and the local coefficient at the end of the plate is hl then in case of heat
transfer to a fluid flowing over a flat plate, heated over its entire length
a. ha = hl b. ha = 2hl c. ha = 0.5 hl d. ha = 0.75 hl
72. The Fourier number (defined as a.t/L2) is used in the analysis of problem involving heat transfer by
a. forced convection c. transient conduction
b. natural convection d. steady state conduction
73. ‘Fouling factor' used in the design of a multipass shell and tube heat exchanger is a
a. non-dimensional factor.
b. factor of safety.
c. conversion factor for individual film heat transfer co-efficient to overall heat transfer co-efficient.
d. none of these.
74. Prandtl and Reynolds analogy are same, when Prandtl number is
a. 0.5 b. 1 c. > 2 d. 1.5
75. The ratio of kinematic viscosity to thermal diffusivity is called the __________ number.
a. Peclet b. Prandtl c. Stanton d. Nusselt
76. Routh test
a. criterion provides information about the actual location of roots.
b. cannot be used to test the stability of a control system containing transportation lag.
c. criterion is not applicable to systems with polynomial characteristic equation.
d. cannot determine as to how many roots of the characteristics equation have positive real roots.
77. Radiation thermometer cannot measure the temperature
a. inside a pressure vessel. C. of liquid oxygen.
b. of an object without coming in contact with it. D. of moving objects at high temperature.
78. Dilatometer is used to measure
a. Stress b. Deflection
b. Strain d. Contraction/expansion due to changes in temperature
79. Pick out the wrong statement.
a. There is no transfer lag for a single first order system.
b. Stirred tank with a water jacket exemplifies an interacting system.
c. Transfer lag is a characteristics of all higher order systems (other than first order systems).
d. Transfer lag decreases as the number of stages decreases.
80. Working principle of mercury in glass thermometer is
a. volumetric expansion. C. linear expansion.
b. pressure rise with temperature. D. none of these.
81. Which of the following can measure temperatures in the range of - 20 to 300°C ?
 a. Mercury in glass thermometer c. Resistance thermometer
b. Vapor pressure thermometer d. None of these.
82. A manometer measures the __________ pressure.
a. Atmospheric c. Gauge
b. Absolute d. None of these
83. Normal mercury thermometer can be used to measure a temperature of about 300°C. However, its maximum
temperature measurement range can be increased upto about 500°C by
a. filling nitrogen under pressure in the stem.
b. increasing the diameter of the tube.
c. using steel tube in place of glass tube.
d. accounting for the tube expansion.
84. Minute depression of freezing point of a liquid solvent on addition of a solid solute can be best measured by a
a. Beckman thermometer c. mercury thermometer
b. Dilatometer d. bimetallic thermometer

85. A system with transfer function is of __________ order.

a. Zero b. 1st c. 2nd d. 3rd
86. In Bode plot, Φ vs ω is plotted on a/an __________ graph paper.
a. log-log b. ordinary c. semi-log d. triangular
87. Plutonium
a. is recovered from spent fuel from thermal nuclear reactor.
b. has much lower melting point (640°C ) compared to thorium (1690°C).
c. both (a) and (b).
d. neither (a) nor (b).
88. Mass of a positron is same as that of a/an
a. Electron b. α-particle c. proton d. neutron
89. Biological shield is provided in a nuclear power reactor to protect the __________ from radiation damage.
a. fuel elements c. walls of the reactor
b. operating personnels d. none of these
90. Hydrogen differs from deuterium in __________ properties
a. Radioactive b. physical c. chemical d. all of these
91. A dry cleaning plant produces an air stream containing 2 mol% acetone. Regulations require that the concentration of
acetone be reduced below 0.1 mol% before this stream is released to the environment. This is to be done by
absorption with water in a counter-current packed column. The water enters the column already containing 0.5 mol%
acetone. The equilibrium relationship for acetone in air and water is given by y = 0.1246x where x and y are the mole
fractions of acetone in the aqueous and vapour phase respectively. Find the theoretical minimum liquid flowrate
required to achieve this separation
a. 12.55 b. 11.22 c. 10.94 d. 13.11
92. A water solution containing 0.005 mole fraction of benzoic acid is to be extracted by pure toluene as the solvent. If
the feed rate is 100 moles/h and the solvent rate is 100 moles/h, find the number of equilibrium stages required to
reduce the water concentration to 0.0001 mole fraction benzoic acid. Operation is isothermal and countercurrent. The
equilibrium represented by: mole fraction benzoic acid in water = 0.446 * mole fraction benzoic acid in toluene.
a. 3.11 b. 5.5 c. 4.9 d. 4.13
93. A commercial ion-exchange resin is made of 88 wt% styrene (MW = 0.104 kg/mol) and 12 wt% divinyl benzene (MW
= 0.1302 kg/mol). Estimate the maximum ion-exchange capacity in equivalents/kg resin when an sulfonic acid group
(MW = 0.0811 kg/mol) has been attached to each benzene ring
a. 1.22 b. 6.77 c. 5.33 d. 2.11
94. The concentration of a solute at both sides of a membrane with thickness 30μm is 0.030 kmol m-3 and 0.0050 kmol
m-3. The equilibrium constant K = 1.5 and DA = 7.0 10-11 m2 s-1 in the membrane. The mass transfer coefficients at
both liquid sides can be considered as infinite. Calculate the flux inside the membrane.
a. 8.75⋅10−8 kmol s−1 m−2
b. 12.75⋅10−8 kmol s−1 m−2
c. 2.75⋅10−8 kmol s−1 m−2
d. 12.75⋅10−10 kmol s−1 m−2
95. Copper sulfate is crystallized as CuSO4.5H2O by combined evaporative/cooling crystallization. 1000 kg/h of water is
mixed with 280 kg/h of anhydrous copper sulfate (MW = 0.160 kg/mol) at 40°C. The solution is cooled to 10°C and
38 kg/h of water is evaporated in the process. How many kg/h of crystals can be collected theoretically?
Temperature: 10°C 40°C
Solubility: 17.4 28.5 (g anhydrous salt/100 g water)
a. 195 kg/h b. 212 kg/h c. 144 kg/h d. 92 kg/h
96. A settling tank is used to separate ion exchange particles (ρS = 1200 kg/m3, dp = 1 mm) from an effluent stream (ρ =
1000 kg/m3, η = 0.001 Pa.s, Q = 0.3 m3/s). Calculate the required area of this settling tank operating under laminar
flow conditions.
a. 11.2 m2 b. 8.7 m2 c. 12.3 m2 d. 6.87 m2
97. A centrifuge basket 600 mm long and 100 mm internal diameter has a discharge weir 25 mm diameter. What is the
maximum volumetric flow of liquid through the centrifuge such that when the basket is rotated at 200 Hz all particles
 of diameter greater than 1 μm are retained on the centrifuge wall? Solid density ρS = 2600 kg/m3, liquid density ρL =
1000 kg/m3, liquid viscosity ηL = 0.01 poise.
a. 5.47⋅10−4m3/s c. 4.47⋅10−4m3/s
b. 12.47⋅10−4m /s 3 d. 14.47⋅10−4m3/s
98. A liquid benzene-toluene mixture with z = 0.40 should produce a liquid with x = 0.35 in a flash drum at 1.0 atm.
Calculate the required feed temperature
a. 100 deg C b. 96.8 deg C c. 112 deg C d. 89.2 deg C
99. 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/h. if the equilibrium relationships is Y = 2X, where Y = mass of C / mass of A and X = mass of C / mass of
B. the minimum flow rate of solvent B required (in kg/h) is
a. 1454 b. 1584 c. 1676 d. 1874
100. 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/h. if the equilibrium relationships is Y = 2X, where Y = mass of C / mass of A and X = mass of C / mass of
B. if the flow rate of B is 2400 kg/h, then the theoretical number of stages in the column, using Kremser’s equation
(adjusted to the next integer) is
a. 5 b. 9 c. 11 d. 13