chemical engineering Mcqs
1651. Which of the following parameters remains constant during chemical dehumidification ?
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A. Dry bulb temperature

B. None of these

C. Wet bulb temperature

D. Partial pressure of vapour

1652. Coal tar is used as a___________________?
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A. Fuel in rotary kiln

B. All A , B. and C.

C. Binder in making carbon electrodes

D. Binding material for coal briquettes

1653. For the gas absorption, the height of a transfer unit, based on the gas phase is given by (G: superficial molar gas velocity, L: superficial molar liquid velocity, FG: mass transfer co-efficient, moles/m2, a: interfacial area per unit volume of tower) ?
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A. L/(FG . G)

B. (G . a)/FG

C. FG/(G . a)

D. G/(FG . a)
1654. The critical moisture content in case of drying indicates the ________________ rate period?
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A. End of falling

B. Beginning of falling

C. Beginning of constant

D. None of these

1655. Common salt is generally not produced commonly by ________________ method from brine ?
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A. Electrolytic

B. Freeze drying

C. Solar evaporation

D. Vacuum evaporation

1656. To remove all the moisture from a wet solid it requires exposure to _____________ air?
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A. High temperature

B. Perfectly dry

C. Highly humid

D. None of these

1657. Washing soda is chemically represented by _________________?
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A. Na2CO3.H2O

B. NaHCO3

C. Na2CO3.10H2O

D. Na2CO3

1658. Bakelite is _________________?
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A. An inorganic polymer

B. Not a polymer

C. Same as Polytetrafluoroethylene (PTFE)

D. Same as thermosetting phenol-formaldehyde
1659. pertaining to the analogy between equations of heat and mass transfer operations ?
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A. k out the wrong statement

1660. Phthalic anhydride is made by the ______________________?
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A. Dehydrogenation of ethyl benzene

B. None of these

C. Oxidation of naphthalene

D. Oxidation of benzene

1661. Flash point of most vegetable oils is about _______________ C ?
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A. 300

B. 100

C. 200

D. 50

1662. Presence of sodium tripolyphosphate (an additive) in synthetic detergent___________________?
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A. None of these

B. Does not allow redeposition of dirt on the cleaned surface

C. Facilitates its use even in hard water (by sequestering the water-hardening Ca & Mg ions)

D. Inhibits its corrosive effects

1663. Phenol formaldehyde resin is used as an adhesive in making__________________?
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A. Laminates

B. Books

C. Card boxes

D. Furniture

1664. The commonly used solvent in supercritical extraction is_____________________?
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A. Methyl ethyl ketone

B. Carbon dioxide

C. Carbon tetrachloride

D. Water

1665. Trinitrotoluene (TNT), an explosive, is made by the nitration of ____________________?
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A. Nitrobenzene

B. Nitrotoluene

C. Benzene

D. Toluene
1666. ______________ is produced using molasses as the starting raw material ?
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A. Dimethyl ether

B. Benzol

C. Methyl alcohol

D. Ethyl alcohol
1667. When the gas to be dissolved in liquid is a/an ___________________ then normally co-current adsorber are used?
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A. Sparingly soluble gas

B. Mixture of two gases

C. Pure gas

D. Ideal gas

1668. Coffee is prepared from coffee beans by leaching with____________________?
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A. Naphtha

B. Hot water

C. Dilute hot caustic solution

D. Cold water

1669. Which is not concerned directly with mass transfer ?
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A. Lewis relationship

B. Froude number

C. Sherwood number

D. Schmidt number

1670. Which of the following is not produced on commercial scale from sea water ?
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A. Potassium compounds

B. Magnesium compounds

C. Bromine

D. Sodium sulphate
1671. Sudden temperature fluctuation does not affect pyrex glass, because of its __________________?
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A. Low co-efficient of expansion

B. High co-efficient of expansion

C. High melting point

D. Both B. and (C)

1672. Sea weeds are an important source of_________________?
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A. Bromine

B. Iodine

C. Fluorine

D. Chlorine

1673. Drying of a wet solid under constant drying conditions means the exposure of the wet solid to the air of constant______________________?
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A. All A., B. & C.

B. Velocity

C. Humidity

D. Temperature

1674. Moisture in a solid exerting an equilibrium vapour pressure equal to that of the pure liquid at the same temperature is called the ___________________ moisture ?
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A. Bound

B. Critical

C. Free

D. Unbound
1675. Oils and fats are converted to soap in a process called _________________?
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A. Saponification

B. None of these

C. Esterification

D. Hydrogenation

1676. Free alkali in a toilet soap is _______________ that in a laundry shop ?
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A. Less than

B. Same

C. More than

D. None of these

1677. Rayleigh equation applies to _________________ distillation ?
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A. Molecular

B. Equilibrium

C. Differential

D. Flash

1678. The equation, NA = (DAB . Pt /RTZ) (y1 y2) is for _______________________?
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A. Steady state equimolar counter diffusion

B. Steady state diffusion for stagnant case

C. Ficks first law of diffusion

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

1679. With increase in temperature, the equilibrium constant at constant pressure (Kp) for oxidation of sulphur dioxide________________?
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A. Decreases

B. Increases linearly

C. Increases

D. Decreases linearly

1680. For water-ethanol system, the minimum reflux ratio_____________________?
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A. Is computed from the intercept of the operating line

B. Cannot be computed

C. Is computed from the slope of the upper operating line that is tangent to the equilibrium curve

D. Is the optimum reflux ratio

1681. Most important factor to be considered in the selection of packings for absorbers is the ______________ of packing?
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A. Cost

B. Durability

C. Size

D. Porosity
1682. Which of the following is used for the concentration of rubber latex ?
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A. Short tube evaporator

B. Calandria

C. Agitated film evaporator

D. Long tube vertical evaporator

1683. Use of water having dissolved oxygen in boilers promotes___________________?
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A. Scale formation

B. Sequestration

C. Corrosion

D. None of these

1684. Unsaturated air (with dry and wet bulb temperatures being 35 and 25C respectively) is passed through water spray chamber maintained at 35C. The air will be__________________?
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A. Cooled

B. Humidified

C. Both A. & B.

D. Dehumidified

1685. What is the degree of freedom of an absorption process in which only one component is transferred between phases ?
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A. 3

B. 2

C. 4

D. 1

1686. Hydrazine is largely used____________________?
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A. In photographic industry

B. As a starting material for hypo

C. As rocket fuel

D. In printing industry

1687. The wet and dry bulb temperature for a vapour-gas mixture are 25C and 30C respectively. If the mixture is heated to 45C at constant pressure, the wet bulb temperature will be ______________ C ?
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A. 25

B. > 25

C. 25

D. < 25

1688. _______________ equation applies to diffusivities in liquids?
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A. Gilliland

B. None of these

C. Hirschfelder

D. Wilke and Chang

1689. Gun powder uses_____________________?
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A. Charcoal

B. All A , B, & C.

C. Potassium nitrate

D. Sulphur

1690. Riboflavin is a/an____________________?
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A. Anaesthetics

B. Analgesic drug

C. Vitamin

D. Anti-malarial drug

1691. Raoults law does not apply, when the___________________?
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A. Size of component molecules are not equal

B. mation of solution

C. Component molecules are non-polar

D. Attractive forces between like and unlike molecules in the solution are approximately equal

E. Chemical combination or molecular association between unlike molecules takes place in the

1692. Absorption of SO3 in 97% H2SO4 is_______________?
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A. Not possible

B. None of these

C. Endothermic

D. Exothermic
1693. The dew point of an unsaturated gas-vapor mixture does not depend upon the _________________ of the mixture?
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A. Total pressure

B. Composition

C. Temperature

D. All A, B. and C.

1694. Mechanism of moisture removal in case of freeze drying of food stuff is by ___________________?
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A. Adsorption

B. Sublimation

C. Evaporation

D. Dehydration

1695. Which of the following increases during evaporative cooling process with recirculated water supply ?
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A. Wet bulb temperature

B. Relative humidity

C. Partial pressure of vapour

D. Both B. and C.
1696. Cumene is the starting material for the production of________________?
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A. Benzoic acid

B. Isoprene

C. Styrene

D. Phenol and acetone
1697. The relative volatility of a binary mixture at the Azeotropic composition is _______________________?
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A. 0

B. > 1

C. 1

D. ?

1698. For a binary mixture with low relative volatility___________________?
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A. Use steam distillation

B. Use high pressure distillation

C. An azeotrope may be formed during distillation

D. Use molecular distillation

1699. 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 H2S 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 ______________________?
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A. 2.0

B. 0.56

C. 1

D. 1.56

1700. In a single stage extraction process, 10 kg of pure solvent S (containing no solute A) is mixed with 30 kg of feed F containing A at a mass fraction xf = 0.2. The mixture splits into an extract phase E and a raffinate phase R containing A at xB = 0.5 and xR = 0.05 respectively. The total mass of the extract phase is (in Kg) ?
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A. 8.25

B. 8.89

C. 6.89

D. 10