chemical engineering Mcqs
1501. Paper grade bamboo contains about _______________ percent cellulose ?
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A. 40

B. 60

C. 20

D. 5
1502. Alcohol percentage in molasses may be around _____________________?
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A. 40

B. 10

C. 85

D. 70

1503. Which of the following is a constituent of coffee ?
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A. Nicotine

B. Lignin

C. Caffeine

D. Calgon

1504. Pick out the wrong statement ?
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A. Absorption factor is constant, when the equilibrium and operating lines are straight

B. In case of a stripper, the equilibrium curve is always below the operating line

C. In the absorption of low solubility gases, the liquid film is the controlling resistance

D. In case of an absorber, the operating line is always above the equilibrium curve

1505. The equation, NA = (DAB . Pt /RTZ . PBM) (PA1 PA2) is for_______________________?
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A. None of these

B. Steady state diffusion for stagnant case

C. Ficks second law of diffusion

D. Liquid M.T.C. by Higbie penetration theory

1506. Experiments were conducted to determine the flux of a species A in a stagnant medium across a gas-liquid interface. The overall mass transfer co-efficient based on the liquid side for dilute systems for the above was estimated to be 4 10-3 kg mole/m2.s. The equilibrium data for the system is given as y = 2x. The flux across the interface (in kg mole/m2 .s) for bulk concentrations of A in gas phase and liquid phase as y = 0.4 and x = 0.01 respectively is _________________________?
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A. 5.6 10-3

B. 5.6 10-4

C. 8.5 10-3

D. 8.5 10-4
1507. The cooling effect in a cooling tower can be speeded up by _______________________?
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A. Reducing the barometric pressure

B. Reducing the humidity of the air

C. Increasing the air velocity and area of exposed wet surface

D. All A., B. and C.
1508. The drying time between fixed moisture content within diffusion controlled falling rate period is proportional to (assuming that drying occurs from all surfaces of the solid) (where, T = thickness of the solid) ?
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A. T

B. ?T

C. T3

D. T2
1509. Dried finished product sampled from various parts of a ________________ dryer exhibits nonuniformity in the moisture content?
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A. None of these

B. Tray

C. Rotary

D. Freeze

1510. At the boiling point of the liquid at the prevailing pressure, the saturated absolute humidity becomes_____________________?
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A. ?

B. 0

C. None of these

D. 1

1511. Liquefaction of gases cannot be done by___________________?
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A. Adiabatic expansion through a throttle valve (Joule-Thomson expansion)

B. Adiabatic expansion against a piston or in a turbine

C. Merely compressing it beyond critical pressure

D. Exchange of heat with colder stream

1512. Paper industry employs _____________ driers ?
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A. Spray

B. Rotary

C. Fluidised bed

D. Cylinder
1513. Water entrained by circulating air in cooling towers is termed as________________?
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A. Vapor load

B. None of these

C. Blow down

D. Drift
1514. With increase in temperature, the leaching rate increases due to__________________?
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A. Decreased liquid viscosity

B. Increased diffusivity

C. Both A. and B.

D. Neither A. nor B.

1515. When acetone is added in a two layer mixture of methyl isobutyl ketone and water at 30C, the acetone distributes between the two layers and the composition of the layer follows two solubility curves. For this system ?
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A. As the acetone concentration increases, the solubility curves approach each other

B. Both the phases become identical at a particular common point on both the solubility curves

C. led the plait point

D. The distribution curve which is a plot between x (acetone concentration in one phase) and y

E. etone concentration in other phase) is analogous to x-y curve used in distillation and

F. orption terminates on the x = y diagonal at the concentration of the plait point

1516. In case of physical adsorption, the difference between heat of adsorption and heat of normal condensation is_________________?
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A. Called integral heat of adsorption

B. Equal to the heat of wetting

C. Equal to the heat of formation of surface compound

D. Zero

1517. In a vapor-liquid contacting equipment, the overall gas phase mass transfer co-efficient (M.T.C), KG is related to individual co-efficients (KG and KL) as ___________________ ?
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A. 1/KG = 1/KL + m/KG

B. 1/KG = 1/KG + m/KL

C. KG = 1/KL + m/KG

D. KG = 1/KG + m/KL

1518. Systemic insecticides________________?
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A. Kill insects following external bodily contact

B. Emit poisonous vapour

C. Are stomach poisons

D. Are absorbed throughout the plant
1519. For the same system, if the same liquid used in an absorber is decreased, the tower height will__________________?
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A. Decrease

B. Decrease or increase; depends on the type of liquid

C. Increase

D. Remain unaffected

1520. Which of the following is directly concerned with Psychrometry ?
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A. Weber number

B. Galileo number

C. Dean number

D. Lewis relationship
1521. Molecular sieves are regenerated by heating to ______________ C?
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A. 200-330

B. > 500

C. < 150

D. > 1000

1522. In most of the mechanically agitated liquid-liquid extractors, baffles or horizontal compartmental plates are provided, which helps in_________________?
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A. Reducing the axial mixing

B. Maintaining the concentration difference between the two phases

C. All A , B & C.

D. Increasing the rate of extraction

1523. To get high tray efficiency___________________?
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A. Interfacial surface between liquid and gas phase should be large

B. Gas velocity should be very low

C. Time of contact between the two phases should be less

D. Liquid entrainment should be severe

1524. Dehydrogenation of Isopropanol produces ____________________?
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A. Formaldehyde

B. Acetone

C. Propyl alcohol

D. Trichloroethylene

1525. Silicon carbide is a/an_______________?
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A. Brittle material

B. Type of glass

C. Abrasive

D. Adhesive

1526. Relative volatility varies with the concentration of component for an ideal solution. The relative volatility of a binary mixture may be defined as the ratio of vapor pressure of component A to that of component B, when_________________?
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A. Only liquid phase obeys Daltons law

B. Vapor phase obeys Daltons law and liquid phase obeys Raoults law

C. Only vapor phase follows Raoults law

D. Liquid phase obeys Daltons law and vapor phase obeys Raoults law

1527. Trinitro-toluene (TNT) is _________________ ?
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A. Used in glycerine manufacture

B. None of these

C. An explosive

D. Used in dye manufacture

1528. Sucrose content in cane sugar may be around ______________________ percent ?
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A. 95

B. 80

C. 70

D. 50

1529. For gas absorption, low viscosity solvents are preferred, because of their ____________________?
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A. Rapid absorption rates

B. Low pumping pressure drop

C. Better flow characteristics

D. All A., B. and C.
1530. Which of the following is a disaccharide ?
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A. Starch

B. Glucose

C. Sucrose

D. Maltose

1531. Alcohol is dehydrated using ______________ distillation?
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A. Molecular

B. Steam

C. Extractive

D. Azeotropic
1532. The product obtained on mixing calcium oxide with water is called __________________?
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A. Milk of lime

B. Slaked lime

C. None of these

D. Quicklime

1533. For a binary mixture distillation process, the degree of freedom is 2. However, if the pressure is fixed in this process, the number of independent variables in this process will be ___________________?
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A. 2

B. 0

C. 3

D. 1
1534. The process used for the manufacture of ethyl alcohol from molasses is_________________?
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A. None of these

B. Dehydrogenation

C. Distillation

D. Dehydration

1535. The slope of 9-line is determined by the__________________?
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A. Relative volatility

B. Plate efficiency to be achieved

C. Thermal condition of the feed

D. Reflux ratio

1536. Powdery materials can be guarded against caking tendency on storage by___________________?
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A. Providing irregular grain size

B. Providing minimum percentage of voids

C. None of these

D. Having maximum possible points of contact

1537. In industrial nomenclature, alcohol means_________________?
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A. Butyl alcohol

B. Ethanol

C. Propyl alcohol

D. Methyl alcohol

1538. Solvay process is not used for the manufacture of potassium carbonate, because of the reason that potassium bicarbonate ?
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A. All A , B. and C.

B. Has high water solubility and is unstable

C. Is soluble in ammonium chloride and potassium chloride solution

D. Is prone to thermal decomposition

1539. Humidity chart is useful for the solution of problems concerning condensation, vaporisation and air conditioning. At a given dry bulb temperature, value of humidity obtained from the humidity chart directly, is in terms of _______________ humidity?
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A. Relative

B. Percentage

C. Molal

D. None of these

1540. Rayleighs equation applies to ________________ distillation?
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A. Flash

B. Differential

C. Steam

D. Continuous

1541. Commercial scale production of hydrogen from iron-steam reaction represented by, 3Fe + 3H2O = Fe3O4 + 4H2, is not practised, as it is __________________?
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A. A discontinuous reaction (requiring regeneration of iron by water gas intermittently)

B. Still in development stage (by employing fluidised bed technique)

C. All A , B. and C

D. A slow reaction

1542. Out of the following processes of paper pulp manufacture, the maximum corrosion problem in digestion & handling equipments is encountered in the _____________ process?
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A. Mechanical

B. Sulphate/Kraft

C. Neutral sulphite semi-chemical

D. Sulphite

1543. For the flow of gases through a capillary, with increase in temperature, the permeability __________________ as per Knudsen law?
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A. Increases

B. Decreases

C. Either A. or B.; depends on the gas

D. Remain same

1544. The slope of the operating line for a single component co-current absorber when plotted in terms of mole ratio units is_____________________?
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A. -ve

B. #NAME?

C. 0

D. ?

1545. Moisture content of a substance when at equilibrium with a given partial pressure of the vapour is called the _______________ moisture?
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A. Bound

B. Equilibrium

C. Free

D. Unbound

1546. Which of the following can be calculated theoretically using steam table and Daltons law of partial pressure; if the relative humidity and dry bulb temperature of moist air is known ?
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A. Wet bulb temperature

B. Dew point

C. Humidity ratio

D. None of these

1547. Pick out the wrong statement. Generally for physical adsorption, a gas of________________?
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A. High critical temperature is adsorbed in preference to a gas of low critical temperature

B. None of these

C. Higher molecular weight is adsorbed in preference to a gas of low molecular weight

D. Low volatility is adsorbed in preference to a gas of high volatility

1548. Pick out the wrong statement pertaining to solvent extraction of oil. Rate of extraction__________________?
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A. Increases with the increasing flake size keeping the flake thickness constant

B. Decreases with decrease of thickness of the flakes

C. Increases considerably with the rise of temperature

D. Decreases as the moisture content of flakes increases
1549. Vulcanisation of rubber____________________?
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A. Increases its oil & solvent resistance

B. Decreases its tensile strength

C. Increases its ozone & oxygen reactivity

D. Converts its plasticity into elasticity
1550. During the constant rate period of drying of a solid ?
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A. Increasing the air temperature decreases the drying rate

B. Surface evaporation of unbound moisture occurs

C. Increased air humidity decreases the rate of drying

D. None of these