MCQOPTIONS
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MCQOPTIONS
This section includes 590 Mcqs, each offering curated multiple-choice questions to sharpen your Chemical Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 551. |
An air-water vapour mixture has a dry bulb temperature of 60°C and a dew point temperature of 40°C. The total pressure is 101.3 kPa and the vapour pressure of water at 40°C and 60°C are 7.30 kPa and 19.91 kPa respectively. The humidity of air sample expressed as kg of water vapour/kg of dry air is__________________? |
| A. | 0.048 |
| B. | 0.079 |
| C. | 0.122 |
| D. | 0.152 |
| Answer» E. | |
| 552. |
Ammonia present in the coke oven gas is removed by washing with___________________? |
| A. | Caustic solution |
| B. | Dilute ammoniacal liquor |
| C. | Dilute HCl |
| D. | Ethanolamine |
| Answer» C. Dilute HCl | |
| 553. |
All moisture in a non-hygroscopic material is the ________________ moisture? |
| A. | Free |
| B. | Equilibrium |
| C. | Unbound |
| D. | Bound |
| Answer» D. Bound | |
| 554. |
Alcohol is dehydrated using _______________________ distillation? |
| A. | Extractive |
| B. | Azeotropic |
| C. | Steam |
| D. | Molecular |
| Answer» C. Steam | |
| 555. |
Alcohol is dehydrated using ______________ distillation? |
| A. | Extractive |
| B. | Azeotropic |
| C. | Steam |
| D. | Molecular |
| Answer» C. Steam | |
| 556. |
Air initially at 101. 3 kPa and 40°C and with a relative humidity of 50%, is cooled at constant pressure to 30°C. The cooled air has a____________________? |
| A. | Higher dew point |
| B. | Higher absolute (specific) humidity |
| C. | Higher relative humidity |
| D. | Higher wet bulb temperature |
| Answer» D. Higher wet bulb temperature | |
| 557. |
Air at a particular humidity is heated in a furnace. The new dew point_____________________? |
| A. | Decreases |
| B. | Increases |
| C. | Depends on the extent of heating |
| D. | Remain unchanged |
| Answer» C. Depends on the extent of heating | |
| 558. |
Agitator is provided in a crystalliser for____________________? |
| A. | Avoiding deposition on cooler surfaces |
| B. | Formation of nuclei |
| C. | Crystal growth |
| D. | All A., B. and C. |
| Answer» E. | |
| 559. |
Advantage of continuous drying over batch drying is that the_____________________? |
| A. | Drying cost per unit weight of dried product is less |
| B. | Product with more uniform moisture content is produced |
| C. | Equipment size required is smaller |
| D. | All A , B. & C. |
| Answer» E. | |
| 560. |
Adsorption is a unit operation which generally involves _______________ systems? |
| A. | Liquid-solid |
| B. | Gas-solid |
| C. | Fluid-solid |
| D. | Solid-solid |
| Answer» D. Solid-solid | |
| 561. |
‘ADDUCTS’ and ‘CLATHRATES’ are used in case of_____________________? |
| A. | Extractive distillation |
| B. | Crystallisation |
| C. | Absorption |
| D. | None of these |
| Answer» C. Absorption | |
| 562. |
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 ? |
| A. | 4 |
| B. | 8 |
| C. | 9 |
| D. | 10 |
| Answer» D. 10 | |
| 563. |
Acetic acid will be most economically separated from a dilute solution of acetic acid in water by____________________? |
| A. | Solvent extraction |
| B. | Continuous distillation |
| C. | Evaporation |
| D. | Absorption |
| Answer» B. Continuous distillation | |
| 564. |
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 (αAB = 2) does not change appreciably in the column ? |
| A. | 5 |
| B. | 9 |
| C. | 12 |
| D. | 28 |
| Answer» D. 28 | |
| 565. |
According to the film theory of mass transfer, the mass transfer co-efficient is proportional to (where, D = molecular diffusivity) ? |
| A. | D |
| B. | D2 |
| C. | D0.5 |
| D. | 1/D |
| Answer» B. D2 | |
| 566. |
According to Poiseuille’s law, the permeability for gas flow through a capillary is proportional to (where, μ = gas viscosity)___________________? |
| A. | μ |
| B. | 1/μ |
| C. | √μ |
| D. | μ2 |
| Answer» C. √μ | |
| 567. |
According to Chilton-Colburn analogy for mass transfer, NSt.NSc 2/3 is equal to_________________? |
| A. | f |
| B. | f/2 |
| C. | 2f |
| D. | 1/f |
| Answer» C. 2f | |
| 568. |
‘Absorption with chemical reaction’ is involved in the removal of__________________? |
| A. | Carbon dioxide from gaseous stream using alkaline solution |
| B. | Benzol from coke oven gas using solar oil/wash oil |
| C. | Ammonia from coke oven gas using refrigerated water |
| D. | Tar from coke oven gas in primary gas coolers using chilled water |
| Answer» B. Benzol from coke oven gas using solar oil/wash oil | |
| 569. |
Absorption (liquid-gas system) with evolution of heat as compared to isothermal absorption results in_________________? |
| A. | Decreased solute solubility |
| B. | Large minimum liquid to gas (L/G) ratio |
| C. | Large number of trays |
| D. | All A., B. and C. |
| Answer» E. | |
| 570. |
Absorption factor method is used to calculate the number of ideal stages, when_______________________? |
| A. | Operating line lies above the equilibrium line |
| B. | Operating line lies below the equilibrium line |
| C. | Both operating and equilibrium lines are parallel |
| D. | Pressure drop in the column is very high |
| Answer» D. Pressure drop in the column is very high | |
| 571. |
Absorption factor is defined as (where, S1 = slope of the operating line S2 = slope of the equilibrium curve) ____________________? |
| A. | S2/S1 |
| B. | S1/S2 |
| C. | S1 – S2 |
| D. | S1 × S2 |
| Answer» C. S1 – S2 | |
| 572. |
Absorption factor, for a fixed degree of absorption from a fixed amount of gas should be_________________? |
| A. | 1 |
| B. | > 1 |
| C. | < 1 |
| D. | ≤ 1 |
| Answer» C. < 1 | |
| 573. |
Absorption accompanied by heat evolution results in____________________? |
| A. | Increased capacity of the absorber |
| B. | Increase in equilibrium solubility |
| C. | Decrease in equilibrium solubility |
| D. | None of these |
| Answer» D. None of these | |
| 574. |
Absorption accompanied with chemical reaction is exemplified by the absorption of___________________? |
| A. | Ammonia in water |
| B. | Benzol present in coke oven gas by wash oil |
| C. | SO2 in alkaline solution |
| D. | All A., B. and C. |
| Answer» D. All A., B. and C. | |
| 575. |
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))_____________? |
| A. | M(Xo – XF) |
| B. | M(Xo/XF) |
| C. | M ln(Xo/XF) |
| D. | MXo ln(Xo/XF) |
| Answer» E. | |
| 576. |
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)) ? |
| A. | M(Xo – XF) |
| B. | M(Xo/XF) |
| C. | M ln(Xo/XF) |
| D. | MXo ln(Xo/XF) |
| Answer» E. | |
| 577. |
A pure drug is administered as a sphere and as a cube. The amount of drug is the same in the two tablets. Assuming that the shape and size do not influence the mass transfer, the ratio of rate of dissolution in water at t = 0 for the cubic to spherical tablet is___________________? |
| A. | 0.54 |
| B. | 1.04 |
| C. | 1.24 |
| D. | 1.94 |
| Answer» D. 1.94 | |
| 578. |
A plait point is the point on the solubility curve, where the tie line reduces to a point. What is the number of plait point for a ternary system containing two pairs of partially miscible liquids ? |
| A. | 0 |
| B. | 1 |
| C. | 2 |
| D. | 3 |
| Answer» B. 1 | |
| 579. |
A packed tower compared to a plate tower for a particular mass transfer operation__________________? |
| A. | Incurs smaller pressure drop |
| B. | Allows installation of cooling coils |
| C. | Is less costly when built in large sizes/diameters |
| D. | Is more suitable, if suspended solids are present in fluid streams |
| Answer» B. Allows installation of cooling coils | |
| 580. |
A natural draft cooling tower is filled with wooden grids, which covers about _________________ percent of the tower height? |
| A. | 10-15 |
| B. | 30-40 |
| C. | 70-80 |
| D. | 90-10 |
| Answer» B. 30-40 | |
| 581. |
A mixture of 10% C6H6 vapour in air at 25°C and 750 mm Hg has a dew point of 20°C. Its dew point at 30°C and 700 mm Hg will be around _______________ °C? |
| A. | 21.7 |
| B. | 20 |
| C. | 27.3 |
| D. | 18.7 |
| Answer» E. | |
| 582. |
A minimum boiling azeotrope is exemplified by__________________________? |
| A. | Toluene-benzene |
| B. | Acetone-carbon disulphide |
| C. | Water-isobutyl alcohol |
| D. | None of these |
| Answer» C. Water-isobutyl alcohol | |
| 583. |
A liquid mixture contains 30% o-xylene, 60% p-xylene and 10%. m-xylene (all percentages in w/w). Which of the following statements would be true in respect of this mixture ? |
| A. | The mixture exhibits an azeotrope at 101.3 kPa |
| B. | The composition of the mixture, in percent by volume is: o-xylene 30, p-xylene 60. and mxylene 10 |
| C. | The composition of the mixture in mole percent is: o-xylene 30, p-xylene 60 and m-xyoene 10 |
| D. | The mixture contain optical isomers |
| Answer» B. The composition of the mixture, in percent by volume is: o-xylene 30, p-xylene 60. and mxylene 10 | |
| 584. |
A good solvent used for absorption should not have very high____________________? |
| A. | Viscosity |
| B. | Vapor pressure |
| C. | Freezing point |
| D. | All A., B. & C. |
| Answer» E. | |
| 585. |
A distillation column with N plates is being operated under normal conditions. At some point of time, the operation is shifted to total reflux condition (i.e., no product and residue are being withdrawn and feed to the column is stopped). At the new steady state ? |
| A. | Composition of vapors and that of liquid do not vary throughout the column |
| B. | Reboiler load and condenser load are minimum |
| C. | The top and bottom compositions are unchanged with and without total reflux |
| D. | The top and bottom compositions correspond to the maximum enrichment available |
| Answer» E. | |
| 586. |
A distillation column separates 10000 kg/hr of a benzene-toluene mixture as shown in the figure below: In the figure xF, xD and xW represent the weight fraction of benzene in the feed, distillate and residue respectively. The reflux ratio is_______________ ? |
| A. | 0.5 |
| B. | 0.6 |
| C. | 1.0 |
| D. | 2.0 |
| Answer» C. 1.0 | |
| 587. |
A coalescer in a mixer-settler liquid-liquid extraction column______________________? |
| A. | Comprises of thin bed of substances of extended surface having high porosity |
| B. | Helps in increasing the bubble size entering the settler |
| C. | Helps in increasing the settling rate of the bubbles |
| D. | All ‘a’, ‘b’, & ‘c’ |
| Answer» E. | |
| 588. |
A binary mixture of benzene and cyclohexane is separated by___________________? |
| A. | Flash vaporisation |
| B. | Extractive distillation |
| C. | Solvent extraction |
| D. | Ordinary distillation |
| Answer» C. Solvent extraction | |
| 589. |
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 ____________________? |
| A. | 1000 |
| B. | 1500 |
| C. | 2000 |
| D. | 2500 |
| Answer» B. 1500 | |
| 590. |
1 kg of a saturated aqueous solution of a highly soluble component A at 60°C is cooled to 25°C. The solubility limits of A are (0.6 kgA/kg water) at 60°C and (0.2 kgA/kg water) at 25°C. The amount in kg of the crystals formed is________________________? |
| A. | 0.4 |
| B. | 0.25 |
| C. | 0.2 |
| D. | 0.175 |
| Answer» D. 0.175 | |