chemical engineering Mcqs
1551. With increase in temperature, the leaching rate increases because of the _____________________?
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A. Increased diffusivity

B. Decreased viscosity of liquid

C. Both A. and B.

D. Neither A. nor B.

1552. Margarine is a/an____________________?
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A. Rocket propellant

B. Fat

C. Explosive

D. Plasticiser

1553. Dacron (or Terylene) fibres as compared to nylon fibres have__________________?
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A. Better heat & acid resistant properties

B. Poorer dyeability

C. All A , B. and C.

D. Poorer resistance to alkalis

1554. Calculation of mass transfer co-efficient is mostly/normally done using ______________ theory?
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A. Film

B. Surface renewal

C. None of these

D. Penetration

1555. Which one of the following devices is not used for both the absorption as well as the liquidliquid extraction processes ?
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A. Packed towers

B. Wetted wall columns

C. Plate towers

D. Spray towers

1556. Permanent hardness of water is due to the presence of calcium & magnesium __________________?
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A. Carbonate

B. Sulphates & chlorides

C. Bi-carbonates

D. None of these

1557. The major constituent of black liquor generated during paper manufacture is sodium___________________?
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A. Sulphate

B. Bi-carbonate

C. Carbonate

D. Hydroxide

1558. Phthalic anhydride is produced by the oxidation of _________________?
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A. Aniline

B. Benzene

C. Naphthalene

D. Toluene

1559. Most widely and commonly used coagulant for the removal of suspended impurities in water is __________________?
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A. Copper sulphate

B. Slaked lime

C. Alum

D. Bleaching powder

1560. Glaubers salt is chemically represented by____________________?
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A. CaCl(OCl)

B. Na2SO4.10H2O

C. CaSO4.H2O

D. (NH4)2SO4

1561. In steam distillation, the _____________________?
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A. Temperature is 100C

B. Temperature is higher than the boiling point of either component

C. Temperature is more than 100 C

D. Product must be immiscible with water
1562. Chemical name of Grignard reagent is__________________?
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A. Sodium bicarbonate

B. Sodium thiosulphate

C. Sodium sulphite

D. Ethyl magnesium chloride
1563. Poly Tetrafluoroethylene (P.T.F.E.) is known as___________________?
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A. Dacron

B. Bakelite

C. Teflon

D. Celluloid

1564. The Hatta number is important in_________________?
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A. Gas absorption without chemical reaction

B. Multi-component distillation

C. Gas absorption with chemical reaction

D. Binary distillation

1565. Leaching of uranium ore and gold ore is done in_____________________?
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A. Pachuca tanks

B. Centrifugal extractor

C. None of these

D. Bollman extractor

1566. Oil produced by solvent extraction________________?
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A. Has low free fatty acid content

B. Is odourless

C. Both A. & B.

D. Neither A. nor B.
1567. Triple superphosphate is manufactured by reacting ____________________?
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A. Phosphate rock with nitric acid

B. Phosphate rock with sulphuric acid

C. Ammonium phosphate with phosphoric acid

D. Phosphate rock with phosphoric acid
1568. In a gas-liquid absorption column, for obtaining the maximum absorption efficiency___________________?
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A. Liquid stream should be distributed uniformly

B. Gas stream should be distributed uniformly

C. Both gas as well as liquid streams should be distributed uniformly

D. By passing should be completely avoided

1569. In triangular co-ordinates, the ternary composition point falls ___________________ of the triangle?
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A. In the corners

B. None of these

C. On the sides

D. Inside
1570. Ultimate analysis of coal determines its _______________________ content?
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A. Carbon, sulphur, volatile matter & ash

B. Carbon, volatile matter, ash & moisture

C. Carbon, ash, sulphur & nitrogen

D. Carbon, hydrogen, nitrogen & sulphur

1571. In case of unsaturated air_________________?
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A. Dew point < wet bulb temperature

B. Wet bulb temperature < dry bulb temperature

C. Both A. and B.

D. Neither A. not B.

1572. Penetration theory states that the mass transfer co-coefficient is equal to (where, De is diffusivity and t is time) ?
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A. (4De/?t)1/2

B. (4De/t)

C. (De.t)1/2

D. (De/t)1/2

1573. Though, theoretically the adsorption & desorption isotherms is expected to coincide but sometimes at least a part of the isotherms does not coincide and this phenomenon is known as adsorption hysteresis. In such cases, the desorption equilibrium pressure is ______________ that obtained for adsorption?
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A. Same as

B. Higher than

C. Lower than

D. Either same or higher than

1574. Perforated plate towers are unique for solvent extraction because, they provide_____________________?
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A. None of these

B. Repeated coalescence & redispersion of the drop phase

C. Higher contact area

D. Better contact of the phase

1575. Design calculation for multiple component distillation is done by_________________?
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A. McCabe-Thiele method

B. Tray to tray calculations

C. Ponchon-Savarit method

D. Enthalpy concentration method

1576. For a ternary mixture, in which equilateral triangular co-ordinate is used in leaching and extraction, a ____________ of the equilateral triangular co-ordinates?
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A. Pure component is represented by the apex

B. Ternary mixture is represented by the sides

C. Binary mixture is represented by the apex

D. Binary mixture is represented by any point inside

1577. Which of the following is a constituent of vinegar ?
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A. Around 10% alcohol

B. Around 1% acetic acid

C. Both A. and B.

D. Neither A. nor B.

1578. High pressure at the bottom of a distillation tower handling heat sensitive materials results in____________________?
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A. Thermal decomposition of bottoms

B. Very efficient operation

C. Increased relative volatility

D. Erosion of the tower

1579. As the reflux ratio, in a continuous counter-current extraction is increased, the number of stages_______________________?
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A. Decrease
B.

C. Remain unchanged

D. Can either increase or decrease, depends on the system

1580. The purpose of adding Na2CO3 to water of low alkalinity is to__________________?
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A. Permit the use of alum as a coagulant

B. Facilitate easy regeneration of zeolite

C. All A , B. and C.

D. Increase the softening capacity of zeolite

1581. According to the Fenske equation, what will be the minimum number of plates required in a distillation column to separate an equimolar binary mixture of components A and B into an overhead fraction containing 99 mol% A and a bottom fraction containing 98 mol% B ? Assume that relative volatility (?AB = 2) does not change appreciably in the column ?
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A. 9

B. 28

C. 5

D. 12

1582. Adipic acid is an intermediate in the manufacture of________________?
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A. Polystyrene

B. Bakelite

C. Nylon-66

D. Perspex

1583. The interfacial area per unit volume of dispersion, in a gas-liquid contactor, for fractional hold up of gas = 0.1 and gas bubble diameter = 0.5 mm is given by (in m2/m3)_________________?
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A. 900

B. 800

C. 500

D. 1200

1584. A natural draft cooling tower is filled with wooden grids, which covers about _________________ percent of the tower height?
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A. 10-15

B. 70-80

C. 90-100

D. 30-40

1585. Polar organic compounds are normally used as separating agents for the azeotropic and extractive distillation. Which of the following is the most important factor to be considered for the choice of the separating agent for extractive distillation ?
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A. Availability

B. Selectivity

C. Cost

D. Toxicity

1586. During the manufacture of sulphuric acid, the temperature of molten sulphur is not increased beyond 160C, as_______________________?
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A. It is very corrosive at elevated temperature

B. None of these

C. It decomposes on further increasing the temperature

D. ther reduced)</strong>

E. Its viscosity is not reduced on further heating (hence pressure drop on pumping it, cannot be
1587. Electro deposition of metals i.e. electroplating is never done on_____________________?
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A. Metals

B. Alloys

C. Refractories

D. Non-metals

1588. Deaeration of water in its treatment is necessary, as it___________________?
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A. None of these

B. Minimises its turbidity

C. Helps in controlling its taste and odour

D. Minimises its corrosiveness
1589. Acetone is produced by catalytic dehydrogenation of_________________?
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A. Ethyl benzene

B. Naphthalene

C. Isopropanol

D. Phenol

1590. A slurry is to be dried to produce flaky solid. Which dryer would you recommend ?
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A. Spray dryer

B. Dielectric dryer

C. Rotary dryer

D. Drum dryer

1591. The mass transfer co-efficient for a solid sphere of radius a dissolving in a large volume of quiescent liquid, in which D is the diffusivity of solute, is _____________________?
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A. Dependent on the Reynolds number

B. Proportional to ?D

C. D/2a

D. D/a

1592. Minimum reflux ratio in a distillation column results in_____________________?
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A. Maximum condenser size

B. Optimum number of trays

C. Minimum number of trays

D. Minimum reboiler size

1593. In the production of soda ash by Solvay process, the by-product is____________________?
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A. NH3

B. NaOH

C. CaCl2

D. NH4Cl

1594. Desulphurisation of petrol is done in a _____________________?
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A. Packed extraction column

B. Plate type extraction column

C. Rotating disc extractor

D. Bollman extractor

1595. Cement setting under water employs a/an _______________ process ?
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A. Reduction

B. Hydration

C. Decomposition

D. Oxidation

1596. Sodium salt of higher molecular weight fatty acid is termed as the ______________________ soap?
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A. Lubricating

B. Metallic

C. Soft

D. Hard

1597. Reaction of ethylene glycol and dimethyl terephthalate (DMT) produces ________________?
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A. PVC

B. Dacron

C. Polyester

D. Nylon-6

1598. At 750K and 1 atm, the approximate value of Schmidt number for air is_________________?
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A. 0.1

B. 0.01

C. 1

D. 10

1599. Which of the following is used as a binding material in soap to improve soap texture ?
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A. Sodium carbonate

B. Benzyl acetate

C. Borax

D. Rosin

1600. Experimental determination of ________________ is done by wetted wall column method?
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A. None of these

B. Diffusion co-efficient

C. NTU

D. Mass transfer co-efficient