MCQOPTIONS
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MCQOPTIONS
This section includes 854 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. |
Henry's law states that the |
| A. | partial pressure of a component over a solution is proportional to its mole fraction in the liquid. |
| B. | partial pressure of a component over a solution is proportional to the mole fraction in the vapour. |
| C. | vapour pressure is equal to the product of the mole fraction and total pressure. |
| D. | partial pressure is equal to the product of the mole fraction and total pressure. |
| Answer» B. partial pressure of a component over a solution is proportional to the mole fraction in the vapour. | |
| 552. |
__________ extractor is used for the concentration of radioactive nuclear waste. |
| A. | Pulsed column |
| B. | Seive plate |
| C. | Mixer-settler |
| D. | Ballman |
| Answer» B. Seive plate | |
| 553. |
Solvent used in extractive distillation |
| A. | changes the relative volatility of the original components. |
| B. | should be of high volatility. |
| C. | should form azeotropes with the original components. |
| D. | all (a), (b) and (c) |
| Answer» B. should be of high volatility. | |
| 554. |
During dehumidification of unsaturated air wet bulb temperature & partial pressure of vapor are not constant. However, during evaporative cooling process with recirculated water supply, the __________ remains constant. |
| A. | wet bulb temperature |
| B. | partial pressure of water vapor |
| C. | relative humidity |
| D. | none of these |
| Answer» B. partial pressure of water vapor | |
| 555. |
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. | |
| 556. |
The dew point of a saturated gas phase equals the __________ temperature. |
| A. | gas |
| B. | room |
| C. | wet bulb |
| D. | none of these |
| Answer» B. room | |
| 557. |
An azeotropic mixture is a __________ mixture. |
| A. | binary |
| B. | ternary |
| C. | constant boiling point |
| D. | none of these |
| Answer» D. none of these | |
| 558. |
Wetted wall tower experiment determines the |
| A. | molal diffusivity. |
| B. | volumetric co-efficient. |
| C. | mass transfer co-efficient. |
| D. | none of these. |
| Answer» D. none of these. | |
| 559. |
Which of the following decreases during evaporative cooling process with recirculated water supply ? |
| A. | Wet bulb temperature |
| B. | Relative humidity |
| C. | Partial pressure of vapour |
| D. | None of these |
| Answer» E. | |
| 560. |
Humid volume, at a given temperature is a/an __________ function of humidity. |
| A. | inverse |
| B. | exponential |
| C. | linear |
| D. | logarithmic |
| Answer» D. logarithmic | |
| 561. |
Which of the following adsorbent is used to decolourise yellow glycerine ? |
| A. | Silica gel |
| B. | Alumina |
| C. | Fuller's earth |
| D. | Activated carbon |
| Answer» E. | |
| 562. |
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 | |
| 563. |
In stripping section of continuous distillation column, the |
| A. | liquid is stripped of high boiler. |
| B. | liquid is enriched with high boiler. |
| C. | vapour is stripped of low boiler. |
| D. | none of these. |
| Answer» C. vapour is stripped of low boiler. | |
| 564. |
At constant pressure, with increase of temperature, the dew point will |
| A. | increase |
| B. | decrease |
| C. | remain unchanged |
| D. | increase/decrease ; depends on the temperature |
| Answer» B. decrease | |
| 565. |
Experimental determination of __________ is done by wetted wall column method. |
| A. | diffusion co-efficient |
| B. | mass transfer co-efficient |
| C. | NTU |
| D. | none of these |
| Answer» C. NTU | |
| 566. |
The value of Lewis number (Le = Sc/Pr) for air-water vapour system is around |
| A. | 1 |
| B. | 0.24 |
| C. | 3.97 |
| D. | 600 |
| Answer» B. 0.24 | |
| 567. |
Dorr thickener is an equipment used for |
| A. | classification |
| B. | sedimentation |
| C. | clarification |
| D. | leaching |
| Answer» C. clarification | |
| 568. |
Alcohol is dehydrated using __________ distillation. |
| A. | extractive |
| B. | azeotropic |
| C. | steam |
| D. | molecular |
| Answer» C. steam | |
| 569. |
Mass transfer co-efficient varies as DAB0.5, according to the __________ theory. |
| A. | film |
| B. | surface renewal |
| C. | penetration |
| D. | none of these |
| Answer» C. penetration | |
| 570. |
Degree of freedom for leaching and solvent extraction process is |
| A. | 1 |
| B. | 3 |
| C. | 0 |
| D. | 2 |
| Answer» C. 0 | |
| 571. |
For the same system, if the same liquid used in an absorber is decreased, the tower height will |
| A. | increase |
| B. | decrease |
| C. | remain unaffected |
| D. | decrease or increase ; depends on the type of liquid |
| Answer» B. decrease | |
| 572. |
The rate of mass transfer is not dependent upon the |
| A. | degree of dispersion of one fluid in the other. |
| B. | interfacial surface exposed between the phases. |
| C. | both (a) & (b). |
| D. | none of these. |
| Answer» E. | |
| 573. |
Fractional solvent extraction |
| A. | employs only one solvent |
| B. | employs two solvents |
| C. | results in low interfacial tension |
| D. | none of these |
| Answer» C. results in low interfacial tension | |
| 574. |
In case of an ideal solution, the total vapor pressure varies __________ with the composition expressed as mole fraction, |
| A. | inversely |
| B. | linearly |
| C. | exponentially |
| D. | none of these |
| Answer» C. exponentially | |
| 575. |
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 coloumn.$ |
| A. | 5 |
| B. | 9 |
| C. | 12 |
| D. | 28 |
| Answer» D. 28 | |
| 576. |
The fixed cost of a distillation column at minimum reflux ratio is |
| A. | minimum |
| B. | infinite |
| C. | optimum |
| D. | none of these |
| Answer» C. optimum | |
| 577. |
What is the degree of freedom of an absorption process in which only one component is transferred between phases ? |
| A. | 3 |
| B. | 2 |
| C. | 4 |
| D. | 1 |
| Answer» B. 2 | |
| 578. |
H2S present in naphtha reformed gas is removed by absorbing with |
| A. | ethanolamine |
| B. | K2CO3 |
| C. | HCl |
| D. | vacuum gas oil |
| Answer» B. K2CO3 | |
| 579. |
With the lowering of equiliDrium pressure, at a given temperature, the amount of ad-sorbate on the adsorbent |
| A. | increases. |
| B. | decreases. |
| C. | remains same. |
| D. | either (a) or (b), depends on the system. |
| Answer» C. remains same. | |
| 580. |
Free flowing granular materials can be best dried in a __________ drier. |
| A. | rotary |
| B. | cylinder |
| C. | drun |
| D. | freeze |
| Answer» B. cylinder | |
| 581. |
Flooding results in |
| A. | high tray efficiency |
| B. | low tray efficiency |
| C. | high gas velocity |
| D. | good contact between the fluids |
| Answer» C. high gas velocity | |
| 582. |
In an interphase mass transfer process, the lesser the solubility of a given solute in a liquid, the higher are the chances that the transfer process will be |
| A. | liquid phase resistance-controlled. |
| B. | gas phase resistance controlled. |
| C. | impossible. |
| D. | driven by a non-linear driving force. |
| Answer» C. impossible. | |
| 583. |
In most of the mechanically agitated liquid-liquid extractors, baffles or horizontal compartmental plates are provided, which helps in |
| A. | reducing the axial mixing. |
| B. | increasing the rate of extraction. |
| C. | maintaining the concentration difference between the two phases. |
| D. | all 'a', 'b' & 'c'. |
| Answer» E. | |
| 584. |
Critical humidity of a solid salt means the humidity |
| A. | above which it will always become damp. |
| B. | below which it will always stay dry. |
| C. | both (a) and (b). |
| D. | above Which it will always become dry and below which it will always stay damp. |
| Answer» D. above Which it will always become dry and below which it will always stay damp. | |
| 585. |
The assumption made in Elis method in distillation is that enthalpy concentration lines of vapor and liquid are |
| A. | parallel |
| B. | straight |
| C. | both parallel and straight |
| D. | neither parallel nor straight |
| Answer» D. neither parallel nor straight | |
| 586. |
Corresponding to Prandtl number in heat transfer, the dimensionless group in mass transfer is the __________ number. |
| A. | Schmidt |
| B. | Sherwood |
| C. | Peclet |
| D. | Stanton |
| Answer» B. Sherwood | |
| 587. |
Which of the following processes is followed by unsaturated air (with dry bulb temperature 12°C and relative humidity 47%) passing through water spray washer (temperature of water being constant at 40°C?$ |
| A. | Humidification only |
| B. | Heating only |
| C. | Both heating and humidification |
| D. | Evaporative cooling |
| Answer» D. Evaporative cooling | |
| 588. |
Boiling point diagram is not affected by the ambient |
| A. | pressure |
| B. | humidity |
| C. | temperature |
| D. | both (b) and (c) |
| Answer» E. | |
| 589. |
Use of raschig rings in place of crushed stones as packing in packed beds (other things being same) |
| A. | increases pressure drop, increases surface area. |
| B. | increases pressure drop, decreases surface area. |
| C. | decreases pressure drop, increases surface area. |
| D. | decreases pressure drop, decreases surface area. |
| Answer» D. decreases pressure drop, decreases surface area. | |
| 590. |
Pick out the wrong statement pertaining to the rotary dryer. |
| A. | Flights (located in the inside shell of rotary dryer) lift the material being dried and shower it down through the current of hot air/gases. It extends from the wall to a distance which is about 8-12% of the inside diameter of shell. |
| B. | Hold up of a rotary drier is defined as the fraction of the dryer volume occupied by the solid at any instant. The best performance for rotary drier is obtained, when the hold up is in the range of 0.05 to 0.15. |
| C. | Rotary dryer is suitable for drying sticky material. |
| D. | Recommended peripherial speed of a rotary drier is in the range of 10 to 30 metres/minute. |
| Answer» D. Recommended peripherial speed of a rotary drier is in the range of 10 to 30 metres/minute. | |
| 591. |
Tea percolation employs |
| A. | liquid-liquid extraction |
| B. | leaching |
| C. | absorption |
| D. | none of these |
| Answer» C. absorption | |
| 592. |
Pick out the correct relationship. (where, Ri = internal reflux ratio Ro = external reflux ratio. ) |
| A. | (1 + Ro) = Ro/Ri |
| B. | (1 - Ro) = Ro/Ri |
| C. | (1 + Ri) = Ro/Ri |
| D. | (1 - Ri) = Ro/Ri |
| Answer» B. (1 - Ro) = Ro/Ri | |
| 593. |
Calculation of mass transfer co-efficient is mostly/normally done using __________ theory. |
| A. | surface renewal |
| B. | film |
| C. | penetration |
| D. | none of these. |
| Answer» C. penetration | |
| 594. |
For the same process conditions, the reflux ratio of an unlagged distillation column |
| A. | decreases in winter |
| B. | increases in winter |
| C. | increases in summer |
| D. | none of these |
| Answer» C. increases in summer | |
| 595. |
__________ temperature is the steady state temperature attained by a small amount of liquid evaporating into a large quantity of unsaturated gas-vapor mixture. |
| A. | Dry bulb |
| B. | Wet bulb |
| C. | Dew point |
| D. | none of these |
| Answer» C. Dew point | |
| 596. |
The equation, is for |
| A. | Fick's second law of diffusion. |
| B. | stready state diffusion for stagnant case. |
| C. | liquid M.T.C. by Higbie penetration theory. |
| D. | none of these. |
| Answer» C. liquid M.T.C. by Higbie penetration theory. | |
| 597. |
Component A is diffusing in a medium B. The flux NA relative to a stationary point is equal to the flux due to molecular difusion, if |
| A. | mass transfer is accompanied by reaction. |
| B. | diffusion of A is in stagnant medium B. |
| C. | molecular mean free path is high. |
| D. | there is equimolar counter diffusion. |
| Answer» E. | |
| 598. |
Detergent solution is dried to a powder in a |
| A. | spray dryer |
| B. | spouted bed dryer |
| C. | tunnel dryer |
| D. | pan open to atmosphere |
| Answer» B. spouted bed dryer | |
| 599. |
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. |
| A. | increases |
| B. | decreases |
| C. | remains same |
| D. | increases linearly |
| Answer» B. decreases | |
| 600. |
If the path of liquid across the plate is very long as in case of large diameter tower, Murphree efficiency can be __________ percent. |
| A. | 100 |
| B. | > 100 |
| C. | < 100 |
| D. | none of these |
| Answer» C. < 100 | |