chemical engineering Mcqs
1701. A good quality coal should have ______________________?
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A. High ash content

B. None of these

C. High sulphur content

D. Low fusion point of ash

1702. Hollander beater used during paper pulp manufacture does not facilitate the ______________ of fiber?
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A. Strengthening

B. Hydration

C. Cutting

D. Fibrillation

1703. The value of L/mG ratio for economical absorption operation ranges from _____________________?
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A. 0.5 to 0.8

B. 1.25 to 2.0

C. 0.8 to 1.2

D. 2.5 to 3.5

1704. Large scale usage of flash distillation is practised in __________________?
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A. Petroleum refining

B. Ammonia synthesis plant

C. Polymerisation industry

D. Soap manufacturing

1705. Leaching of coarse solid lumps is also termed as _____________________?
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A. Dissolution

B. Agitation and settling

C. Percolation

D. Decoction

1706. Which of the following processes is followed by unsaturated air (with dry bulb temperature 12C and relative humidity 47%) passing through water spray washer (temperature of water being constant at 40C ?
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A. Humidification only

B. Heating only

C. Both heating and humidification

D. Evaporative cooling

1707. Coke oven gas consists mainly of ____________________?
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A. CH4, & CO

B. CO, & CO2

C. H2, & CH4

D. H2, & CO

1708. Average sulphur content in Indian pyrites is about _________________ percent?
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A. 35

B. 55

C. 15

D. 70

1709. Gypsum is chemically __________________ ?
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A. Calcium chloride

B. Calcium sulphate

C. Potassium sulphate

D. Sodium sulphate

1710. Hollander beater machine used in the paper manufacturing plant does not accomplish the task of____________________?
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A. Cutting of fibres

B. Hydration of fibres

C. Final rolling out of paper

D. Fibrillation of fibre

1711. Main constituents of Portland cement are calcium aluminate and__________________?
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A. Silicates

B. Carbonates

C. Gypsum

D. Sodium silicate

1712. Flash distillation is _______________________?
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A. Same as simple distillation

B. Used for multi-component systems like crude refining

C. Most useful for handling binary systems

D. Same as differential distillation

1713. Operating velocity in a packed tower is usually __________________ the flooding velocity ?
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A. Twice

B. Half

C. More than

D. Equal to

1714. A solid is being dried in the linear drying rate regime from moisture content Xo to XF. The drying rate is zero at X = 0 and the critical moisture content is the same as the initial moisture Xo. The drying time for M = (Ls/ARc) is (where, L = total mass of dry solid, A = total surface area for drying Rc = Constant maximum drying rate per unit area X = moisture content (in mass of water/mass of dry solids)) ?
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A. M ln(Xo/XF)

B. M(Xo XF)

C. M(Xo/XF)

D. MXo ln(Xo/XF)
1715. The change in enthalpy, when a unit quantity of gas is absorbed by relatively large quantity of adsorbent (on which a definite concentration of the adsorbed gas already exists) is termed as the_________________?
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A. Integral heat of adsorption

B. None of these

C. Heat of wetting

D. Differential heat of adsorption
1716. Humidification involves mass transfer between a pure liquid phase and a fixed gas, which is___________________?
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A. Soluble in the liquid

B. Non-ideal in nature

C. Insoluble in the liquid

D. At a fixed temperature

1717. With increase in the liquid flow rate at a fixed gas velocity in a randomly packed counter current gas-liquid absorption column, the gas pressure drop___________________?
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A. Remains unchanged

B. Decreases exponentially

C. Decreases

D. Increases
1718. Measurement of the interfacial area of mass transfer is achieved easily & accurately in case of a _______________ column?
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A. Bubble cap plate

B. Packed

C. Wetted wall

D. Spray

1719. Freundlich equation applies to the adsorption of solute from___________________?
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A. Gaseous solutions at high pressure

B. Concentrated solutions

C. None of these

D. Dilute solutions, over a small concentration range
1720. Co-current absorbers are usually used when the gas to be dissolved in the liquid is ___________________?
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A. A pure substance

B. Highly soluble

C. A mixture

D. Sparingly soluble

1721. In case of cooling towers, the ratio of the rates of heat and mass transfer is indicated by the ______________ number ?
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A. None of these

B. Lewis

C. Grashoff

D. Sherwood

1722. For ethanol-water system, the lowering of distillate quality from 95% to 92% will cause ______________ plate requirement?
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A. None of these

B. Major decrease in the number of

C. No change in theoretical

D. Marginal decrease in the number of
1723. Plate efficiency in a distillation column is reduced due to the ______________ of liquid?
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A. Entrainment

B. Weeping & dumping

C. All A., B. & C.

D. Foaming

1724. The Reynolds number of the liquid was increased 100 fold for a laminar falling film used for gas-liquid contacting. Assuming penetrating theory is applicable, the fold increase in the mass transfer co-efficient (Kc) for the same system is_______________________?
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A. 5

B. 10

C. 100

D. 1

1725. The Knudsen diffusivity is proportional to (where, T = absolute temperature) ______________________?
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A. T2

B. T

C. ?T

D. T4

1726. Which of the following is a detergent ?
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A. Fatty acids

B. Methylene chloride

C. Alkyl benzene sulphonate (ABS)

D. Fatty alcohol

1727. Most commonly used rubber vulcanising agent is___________________?
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A. Alumina

B. Bromine

C. Platinum

D. Sulphur
1728. _____________ is used as a catalyst in fat splitting ?
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A. FeO

B. V2O5

C. ZnO

D. Ni

1729. Molality is defined as the number of gm moles of solute per _________________ of solvent ?
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A. Litre

B. gm

C. m3

D. Kg
1730. The velocity, concentration and temperature boundary, for the boundary layer development on a flat plate during connective mass transfer will be same, if___________________?
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A. NSc = NLe

B. NPr = NLe

C. NSc = 1

D. NSc = NPr = NLe
1731. Danckwerts developed the ____________________ theory?
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A. Film

B. Penetration

C. None of these

D. Surface renewal
1732. Lewis number (Le) is____________________?
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A. Sh Pr

B. Sc Pr

C. St Sh

D. Pr St

1733. With increase in the mass velocity of the gas, the rate of drying during the constant rate period ______________, if the conduction and radiation through the solid are negligible ?
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A. Increases linearly

B. Decreases

C. Increases

D. Remain same

1734. In gas-liquid contact operation, the number of ideal stages, N = (xa xb)/(xb x*b). This is true when the stripping factor S is ________________?
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A. S = ?

B. S > 1

C. S = 1

D. S < 1

1735. Yeast is used in the manufacture of ____________________?
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A. Penicillin

B. Wine

C. Antibiotics

D. Pasteurised milk

1736. Henrys law states that the ________________________?
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A. our

B. uid</strong>

C. Partial pressure of a component over a solution is proportional to its mole fraction in the

D. Partial pressure of a component over a solution is proportional to the mole fraction in the

E. Vapour pressure is equal to the product of the mole fraction and total pressure

F. Partial pressure is equal to the product of the mole fraction and total pressure

1737. Which of the following is used as a coagulant in treating turbid water ?
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A. Ferric sulphate

B. Activated carbon

C. Calcium sulphate

D. Chlorine

1738. Grignard reagent is chemically known as ____________________?
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A. Dichlorophenol

B. Methyl magnesium chloride

C. Monochloroacetic acid

D. Ethyl magnesium chloride
1739. Synthetic glycerine is produced from___________________?
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A. Propylene

B. Naphthalene

C. Toluene

D. Phenol

1740. A substance produced by a living organism and capable of anti-microbial activity is called a/an < ____________________?
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A. None of these

B. ong>A. Antibiotic</strong>

C. Antiseptic

D. Disinfectant

1741. Steam distillation is used to__________________?
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A. Avoid thermal decomposition of a component

B. Reduce the number of plates

C. Increase the total pressure of distillation

D. Increase the efficiency of separation

1742. Blowdown in a cooling tower__________________?
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A. Is undesirable

B. All A., B. & C.

C. Means discarding a small fraction of circulating water to prevent and limit the concentration

D. salt and impurities</strong>

E. Increases the scale forming tendencies of water

1743. Which of the following is not fixed by the process requirements, in the design of absorbers ?
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A. Terminal concentrations of gas stream

B. None of these

C. Flow rate of the entering gas

D. Composition of the entering liquid

1744. Lurgi coal gasifier is a pressurised _______________ bed reactor ?
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A. Fluidised

B. Entrained

C. Moving

D. Fixed

1745. Raschig ring made of porcelain cannot be used for treating concentrated___________________?
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A. Nitric acid

B. Alkalis

C. Hydrochloric acid

D. Sulphuric acid

1746. 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 ?
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A. 4

B. 10

C. 8

D. 9
1747. Absorption accompanied by heat evolution results in____________________?
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A. None of these

B. Increase in equilibrium solubility

C. Decrease in equilibrium solubility

D. Increased capacity of the absorber

1748. The binary diffusivity in gases and liquids vary respectively as_________________?
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A. T3/2 and ?T

B. ?T and T3/2

C. T3/2 and T

D. T and T3/2

1749. Azeotropism for ethyl alcohol-water system disappears by_____________________?
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A. Decreasing pressure

B. Increasing pressure

C. Increasing temperature

D. No means

1750. 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. 500

B. 900

C. 1200

D. 800