chemical engineering mcqs to prepare for nts, kppsc, fpsc, ppsc and more

chemical engineering Mcqs

1601. Mass transfer co-efficient is defined as__________________?
0

A. Flux=concentration difference/coefficient

B. Flux = Co-efficient/concentration difference

C. Co-efficient = Flux/concentration difference

D. None of these

1602. A 25 cm 25 cm 1 cm flat sheet weighing 1.2 kg initially was dried from both sides under constant drying rate conditions. It took 1500 seconds for the weight of the sheet to reduce to 1.05 kg. Another 1m 1m 1cm flat sheet of the same material is to be dried from one side only. Under the same constant drying rate conditions, the time required for drying (in seconds) from its initial weight of 19.2 kg to 17.6 kg is ____________________?
0

A. 2500

B. 1000

C. 2000

D. 1500

1603. Ammonia present in the coke oven gas is removed by washing with___________________?
0

A. Dilute HCl

B. Ethanolamine

C. Caustic solution

D. Dilute ammoniacal liquor

1604. In an absorption column, the flooding velocity for random packing is ___________________ that for stacked/regular packing?
0

A. Greater than

B. Either A., or B.; depends on the type of packing

C. Equal to

D. Smaller than

1605. Large scale drying of wheat is done in a ________________ dryer?
0

A. Fluidised bed

B. Spouted bed

C. Vacuum rotary

D. Tray

1606. Bromine content in sea water may be around _________________ ppm?
0

A. 640

B. 1875

C. 70

D. 2500

1607. Use of packed towers for distillation is generally limited to the__________________?
0

A. High pressure operation

B. Small sizes

C. Vacuum distillation

D. Multi-component distillation

1608. Carbon content of pitch (residue of coal tar distillation) is around ________________ percent?
0

A. 70

B. 55

C. 94

D. 80

1609. During sensible cooling process ______________________?
0

A. Relative humidity decreases

B. Relative humidity increases

C. Wet bulb temperature decreases

D. Both B. and C.

1610. Raw materials required for the manufacture of __________________ is acetylene and hydrochloric acid?
0

A. Phthalic anhydride

B. Maleic anhydride

C. Dacron

D. Vinyl chloride

1611. Glycerine can be obtained from ________________ ?
0

A. Fat

B. Cumene

C. Naphthalene

D. Sucrose

1612. How much temperature is maintained during quicklime manufacture in the calcination zone of the vertical shaft kiln ?
0

A. 750C

B. 1500C

C. 1000C

D. 500C

1613. For absorbing a sparingly soluble gas in a liquid, the_____________________?
0

A. Gas side co-efficient should be decreased

B. Liquid side co-efficient should be decreased

C. Gas side co-efficient should be increased

D. Liquid side coefficient should be increased

1614. In case of absorption & stripping, the interface of the liquid & gas phases are present in equilibrium, when the diffusional resistance of _______________ is zero?
0

A. Liquid phase

B. All A , B. & C.

C. Gas phase

D. Interface

1615. The relative volatility of a binary mixture at constant temperature _________________ the total pressure?
0

A. Increases with increase in

B. None of these

C. Decreases with increase in

D. Is independent of

1616. Le-Blanc process is a primitive process for the manufacture of___________________?
0

A. Soda ash

B. Caustic soda

C. Hydrochloric acid

D. Bromine from sea water

1617. Swenson-Walker crystalliser is a __________________ unit ?
0

A. Batch

B. Semi-batch

C. Cooling (adiabatic)-cum-evaporation

D. Continuous

1618. Massecuite is ___________________?
0

A. Used as a cattle feed

B. Highly acidic in nature

C. Used for paper making

D. None of these

1619. Cox chart, which is useful in the design of distillation column particularly for petroleum hydrocarbons, is a plot of (where, P = vapor pressure, T = temperature) ?
0

A. T vs. P

B. log P vs. T

C. P vs. log T

D. log P vs. log T

1620. Heating of _______________ to 120C, produces plaster of paris ?
0

A. Calcium sulphate

B. Blue vitriol

C. Gypsum

D. Calcium silicate

1621. A bio-catalyst produced by living cells which acts independent of the cell is called a/an_______________?
0

A. Substrate

B. None of these

C. Enzyme

D. Nutrient

1622. Potassium is kept & transported under ___________________ ?
0

A. Liquid ammonia

B. Water

C. Alcohol

D. Kerosene oil

1623. In the layout plan for a vacuum distillation unit, operating at 60 mm Hg, supported by a barometric condenser, the appropriate place for the location of vacuum drum for collecting the distillate will be___________________?
0

A. 2 metres above the ground

B. At ground level

C. 5 metres above ground

D. 10 metres above ground

1624. When an unsaturated air-water mixture is heated at constant pressure, then ____________________ ?
0

A. The relative humidity increases

B. The relative humidity decreases

C. The partial pressure of water vapour increases

D. The specific humidity decreases

1625. Parathion and Malathion are _____________________?
0

A. Pain-relieving drugs (analgesic)

B. Plasticisers for unsaturated polyesters

C. Tranquilisers

D. Pesticides

1626. Pressure drop through plate tower as compared to that through packed tower, for the same duty will be___________________?
0

A. Either A. or B.; depends on the packing height

B. Less

C. More

D. Equal

1627. Electric bulbs are made of _______________ glass ?
0

A. Jena

B. Crookes

C. Pyrex

D. Flint

1628. Pore size of the molecular sieve 5A is ____________________ mm ?
0

A. 50

B. 0.05

C. 5

D. 0.5

1629. Drying of a solid involves _________________ transfer ?
0

A. Only heat

B. Only mass

C. Both heat and mass

D. None of these

1630. Hydrogenation of vegetable oils is a/an _______________ reaction ?
0

A. Autocatalytic

B. Homogenous

C. Endothermic

D. Exothermic

1631. For stripping of a gas in a counter current stripper, the operating line _____________________?
0

A. Lies above the equilibrium curve

B. Can lie above or below the equilibrium curve

C. Lies below the equilibrium curve

D. Is always parallel to the equilibrium curve

1632. Use of hydrated lime in water treatment_________________?
0

A. Before filtration, reduces the bacterial load on filters

B. After filtration, combats the corrosiveness of water due to the presence of O2 & CO2

C. All A , B. and C.

D. Is to adjust the pH value

1633. In extraction, as the temperature increases, the area of heterogeneity (area covered by binodal curve)____________________?
0

A. None of these

B. Decreases

C. Increases

D. Remains unchanged

1634. Sulphuric acid is mainly used in the _______________ industry ?
0

A. Fertiliser

B. Steel

C. Paint

D. Paper

1635. Reboiler is considered as one theoretical plate, because_____________________?
0

A. Vapour is recycled to the column

B. Reboiler itself contains one plate

C. Of the assumption that vapour and liquid leaving the reboiler are in equilibrium

D. None of these

1636. In distillation where q is defined as the moles of liquid flow in the stripping section per mole of feed introduced, for saturated liquid feed____________________?
0

A. q = 1

B. q > 1

C. q = 0

D. q < 1

1637. Laboratory determination of the diffusivity of vapor is done by ______________ method?
0

A. Wikes

B. Gillilands

C. Wetted wall column

D. Winkelmanns

1638. Large quantity of silica gel is normally dried in a _________________ dryer?
0

A. Rotary vacuum

B. Through circulation

C. Freeze

D. Tray

1639. The minimum liquid rate to be used in an absorber corresponds to an operating line__________________?
0

A. Of slope = 1

B. Tangential to the equilibrium curve

C. Of slope = 0.1

D. None of these

1640. The individual mass transfer co-efficients (moles/m2s) for absorption of a solute from a gas mixture into a liquid solvent are, KL = 4.5 and KG = 1.5. The slope of the equilibrium line is 3. Which of the following resistance (s) is (are) controlling ?
0

A. Liquid side

B. Gas side

C. Interfacial

D. Both liquid and gas side

1641. Which of the following provides maximum contact surface for a liquid-vapour system ?
0

A. Wetted wall column

B. Packed tower

C. Bubble-cap plate column

D. Sieve-plate column

1642. Plaster of Paris is __________________?
0

A. CaSO4.H2O

B. Used for setting of broken bones

C. Both A. and B.

D. Same as gypsum

1643. In liquid extraction, if the selectivity is unity, then__________________?
0

A. Amount of solvent required will be minimum

B. No separation will occur

C. Solvent flow rate should be very low

D. Separation of the constituents is the most effective

1644. When the mixture to be distilled has a very high boiling point and the product material is heat sensitive, the separation technique to be used is _______________ distillation?
0

A. Continuous

B. None of these

C. Steam

D. Azeotropic

1645. An alkali metal salt of Palmitic acid is known as _____________________?
0

A. Soap

B. Detergent

C. Metallic soap

D. Alkaloid

1646. Percentage of uranium in Carnotite ore found in Jadugoda (Jharkhand) is about ___________________?
0

A. 5 to 10

B. 1 to 5

C. 15 to 25

D. 0.1 to 0.5

1647. Penetration theory relates the average mass transfer co-efficient (K) with diffusivity D. as____________________?
0

A. K ?D

B. K ??D

C. K ?D1.5

D. K ?D2

1648. The boiling points of pure components of a binary system ________________ with increase in total pressure of the system ?
0

A. Increases

B. Remains unchanged

C. Decreases

D. May increase or decrease, depends on the system

1649. Which of the following processes is not an example of adsorption applied to gaseous separations ?
0

A. Dehumidification of air and gas

B. Decolouration of yellow glycerine

C. Removal of objectionable odour and impurities from industrial gases

D. Recovery of valuable solvent vapors from dilute mixture with air and other gases

1650. Zeolite used in water softening process (cation exchange) is regenerated by washing with___________________?
0

A. Liquid chlorines

B. Chloramines

C. Brine

D. Sodium bisulphite

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