MCQOPTIONS
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MCQOPTIONS
This section includes 591 Mcqs, each offering curated multiple-choice questions to sharpen your Chemical Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
For absorbing a sparingly soluble gas in a liquid, the~! |
| A. | Gas side co-efficient should be increased |
| B. | Liquid side coefficient should be increased |
| C. | Gas side co-efficient should be decreased |
| D. | Liquid side co-efficient should be decreased |
| Answer» C. Gas side co-efficient should be decreased | |
| 2. |
For absorbing a sparingly soluble gas in a liquid, the |
| A. | Gas side co-efficient should be increased |
| B. | Liquid side coefficient should be increased |
| C. | Gas side co-efficient should be decreased |
| D. | Liquid side co-efficient should be decreased |
| Answer» C. Gas side co-efficient should be decreased | |
| 3. |
Relative volatility varies with the concentration of component for an ideal solution. The relative volatity of a binary mixture may be defined as the ratio of vapor pressure of component 'A' to that of component 'B', when%! |
| A. | Only vapor phase follows Raoult's law |
| B. | Only liquid phase obeys Dalton's law |
| C. | Liquid phase obeys Dalton's law and vapor phase obeys Raoult's law |
| D. | Vapor phase obeys Dalton's law and liquid phase obeys Raoult's law |
| Answer» E. | |
| 4. |
To get high tray efficiency%! |
| A. | Interfacial surface between liquid and gas phase should be large |
| B. | Time of contact between the two phases should be less |
| C. | Gas velocity should be very low |
| D. | Liquid entrainment should be severe |
| Answer» B. Time of contact between the two phases should be less | |
| 5. |
The binary diffusivity in gases at atmospheric conditions is about%! |
| A. | 10-9 cm/sec |
| B. | 10-1 cm²/sec |
| C. | 10-3 sec/cm |
| D. | 10-4 cm²/seC₂ |
| Answer» C. 10-3 sec/cm | |
| 6. |
A good solvent used for absorption should not have very high%! |
| A. | Viscosity |
| B. | Vapor pressure |
| C. | Freezing point |
| D. | All of the above |
| Answer» E. | |
| 7. |
__________ extractor uses centrifugal force for separating the two phases.%! |
| A. | Treybal |
| B. | Schiebel |
| C. | Podbielniak |
| D. | None of these |
| Answer» D. None of these | |
| 8. |
Small dia distillation column can be a%! |
| A. | Packed column |
| B. | Sieve tray |
| C. | Bubble cap |
| D. | Any of these |
| Answer» B. Sieve tray | |
| 9. |
Unsaturated air (with dry and wet bulb temperatures being 35 and 25°C respectively) is passed through water spray chamber maintained at 35°C. The air will be%! |
| A. | Cooled |
| B. | Humidified |
| C. | Both A & B |
| D. | Dehumidified |
| Answer» C. Both A & B | |
| 10. |
Humid volume, at a given temperature is a/an __________ function of humidity. |
| A. | Inverse |
| B. | Exponential |
| C. | Linear |
| D. | Logarithmic |
| Answer» D. Logarithmic | |
| 11. |
For the case of flow of air past a wet bulb thermometer (air water vapour system), the approximate value of H‚ÇÇ/ky.Cz is around%! |
| A. | 0.60 |
| B. | 0.24 |
| C. | 1 |
| D. | 0.72 |
| Answer» D. 0.72 | |
| 12. |
The wetted wall tower is used to determine%! |
| A. | Individual mass transfer co-efficient (M.T.C.) in gaseous system |
| B. | M.T.C. of individual components in a liquid-liquid system |
| C. | M.T.C. of liquid in liquid-gas system |
| D. | The overall M.T.C. of the system |
| Answer» B. M.T.C. of individual components in a liquid-liquid system | |
| 13. |
For the air water system under ambient conditions, the adiabatic saturation temperature and the wet bulb temperature are nearly equal, because%! |
| A. | Water has a high latent heat of evaporation |
| B. | Lewis number is close to unity |
| C. | They are always equal under all circumstances |
| D. | Solubility of the components of air in water is very small |
| Answer» B. Lewis number is close to unity | |
| 14. |
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 m-xylene 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 m-xylene 10 | |
| 15. |
The dew point of an unsaturated gas-vapor mixture does not depend upon the __________ of the mixture.%! |
| A. | Composition |
| B. | Temperature |
| C. | Total pressure |
| D. | All of the above |
| Answer» C. Total pressure | |
| 16. |
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 | |
| 17. |
Pick out the wrong statement pertaining to the cooling towers.%! |
| A. | In case of induced draft cooling tower, the fan is placed at the top of the tower |
| B. | Effectiveness of forced draft cooling tower is reduced by the recirculation of the humid and hot discharged air |
| C. | A natural draft cooling tower is recommended to be used, when the air humidity is low and air temperature is also low |
| D. | Effectiveness of a mechanical draft cooling tower is reduced with increase in air wet-bulb temperature |
| Answer» E. | |
| 18. |
For a ternery mixture, in which equilateral triangular co-ordinate is used in leaching and extraction, a __________ of the equilateral triangular co-ordinates.%! |
| A. | Binary mixture is represented by the apex |
| B. | Binary mixture is represented by any point inside |
| C. | Ternery mixture is represented by the sides |
| D. | Pure component is represented by the apex |
| Answer» E. | |
| 19. |
Smoke is an example of%! |
| A. | Solid dispersed in liquid |
| B. | Solid dispersed in gas |
| C. | Liquid dispersed in gas |
| D. | Gas dispersed in liquid |
| Answer» C. Liquid dispersed in gas | |
| 20. |
At what value of reflux ratio, number of theoretical plates in a distillation column is minimum?%! |
| A. | 0 |
| B. | 1 |
| C. | ‚à û |
| D. | < 1 |
| Answer» D. < 1 | |
| 21. |
Unsaturated air (with dry bulb temperature and dew point being 35°C and 18°C respectively) is passed through a water spray chamber maintained at 15°C. The air will be cooled%! |
| A. | And humidified |
| B. | And dehumidified with increase in wet bulb temperature |
| C. | At the same relative humidity |
| D. | And dehumidified with decrease in wet bulb temperature |
| Answer» E. | |
| 22. |
__________ column is used in gas absorption process.%! |
| A. | Wetted wall |
| B. | Seive/perforated tray |
| C. | Bubble cap |
| D. | Packed |
| Answer» E. | |
| 23. |
Corresponding to Nusselt number in heat transfer, the dimensionless group in mass transfer is the __________ number.%! |
| A. | Sherwood |
| B. | Schmidt |
| C. | Peclet |
| D. | Stanton |
| Answer» B. Schmidt | |
| 24. |
Separation of the isotopes of helium for scientific investigations is done by%! |
| A. | Reverse osmosis |
| B. | Thermal diffusion |
| C. | Leaching |
| D. | Solvent extraction |
| Answer» C. Leaching | |
| 25. |
With increase in solvent rate, the number of transfer units, NtoG, for a fixed degree of absorption from a fixed amount of gas%! |
| A. | Increases |
| B. | Decreases |
| C. | Decreases linearly |
| D. | Remains unaffected |
| Answer» C. Decreases linearly | |
| 26. |
At __________ reflux, theoretical number of plates in a distillation coloumn is calculated using Fenske-Underwood equation.%! |
| A. | Operating |
| B. | Total |
| C. | Minimum |
| D. | Maximum permissible |
| Answer» C. Minimum | |
| 27. |
In saturated gas, the%! |
| A. | Vapour is in equilibrium with the liquid at the gas temperature |
| B. | Vapour is in equilibrium with the liquid at the room temperature |
| C. | Partial pressure of vapour equals the vapour pressure of the liquid at room temperature |
| D. | None of these |
| Answer» B. Vapour is in equilibrium with the liquid at the room temperature | |
| 28. |
Nitrobenzene (boiling point = 210.6°C) is steam distilled at 1 atm pressure.Nitrobenzene will distill off __________ °C.%! |
| A. | At < 100 |
| B. | At > 210.6 |
| C. | Between 100 and 210 |
| D. | None of these |
| Answer» B. At > 210.6 | |
| 29. |
Dry bulb temperature of the gas is __________ the wet bulb temperature.%! |
| A. | Less than |
| B. | More than |
| C. | Equal to |
| D. | None of these |
| Answer» C. Equal to | |
| 30. |
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. | |
| 31. |
Which of the following is not fixed by the process requirements, in the design of absorbers?%! |
| A. | Flow rate of the entering gas |
| B. | Composition of the entering liquid |
| C. | Terminal concentrations of gas stream |
| D. | None of these |
| Answer» E. | |
| 32. |
In case of constant underflow extraction operation, the __________ at all solute concentration.%! |
| A. | Solids are drained to the same extent |
| B. | Ratio of the insoluble to solution is constant |
| C. | Both A & B |
| D. | Neither A nor B |
| Answer» D. Neither A nor B | |
| 33. |
The mass transfer co-efficient for a solid sphere of radius 'a' dissolving in a large volume of quiescent liquid, in which D is the diffusivity of solute, is%! |
| A. | D/a |
| B. | D/2a |
| C. | Proportional to ‚à öD |
| D. | Dependent on the Reynolds number |
| Answer» E. | |
| 34. |
An aqueous solution of methanol is to be distilled in a tray column. High pressure steam is available as a source of heat. For a given reflux ratio and overhead composition, two options are being explored; (i) a reboiler is used and (ii) no reboiler is used but steam is fed directly to the bottom of the column. As compared to option (i), in option (ii)%! |
| A. | Less number of trays are required |
| B. | Composition of the residue remains unchanged |
| C. | More number of trays are required but the residue composition remains unchanged |
| D. | More number of trays are required and the residue composition is more dilute in methanol |
| Answer» B. Composition of the residue remains unchanged | |
| 35. |
Weight of 1 m³ of humid air as compared to 1 m³ of dry air, under the same conditions, is%! |
| A. | Less |
| B. | More |
| C. | Same |
| D. | Unpredictable |
| Answer» B. More | |
| 36. |
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 | |
| 37. |
Desulphurisation of petrol is done in a%! |
| A. | Bollman extractor |
| B. | Rotating disc extractor |
| C. | Packed extraction column |
| D. | Plate type extraction column |
| Answer» C. Packed extraction column | |
| 38. |
__________ is concerned with the adsorption equilibria.%! |
| A. | Fick's law |
| B. | Gibb's equation |
| C. | Freundlich equation |
| D. | None of these |
| Answer» D. None of these | |
| 39. |
Dorr thickener is an equipment used for%! |
| A. | Classification |
| B. | Sedimentation |
| C. | Clarification |
| D. | Leaching |
| Answer» C. Clarification | |
| 40. |
Lewis number (Le) is%! |
| A. | Sc x Pr |
| B. | Pr x St |
| C. | Sh x Pr |
| D. | St x Sh |
| Answer» B. Pr x St | |
| 41. |
With decrease in the throughput (compared with the design capacity) for a bubble cap distillation column, its efficiency%! |
| A. | Increases |
| B. | Decreases |
| C. | Remains same |
| D. | May increase or decrease ; depends on individual design |
| Answer» B. Decreases | |
| 42. |
Deairation (removal of O‚ÇÇ) of water is done by%! |
| A. | Rectification |
| B. | Absorption |
| C. | Ion-exchange |
| D. | Adsorption |
| Answer» D. Adsorption | |
| 43. |
When a multistage tray tower uses a minimum reflux ratio, it implies%! |
| A. | Infinite trays and maximum reboiler heat load |
| B. | Infinite trays and minimum reboiler heat load |
| C. | Minimum trays and minimum reboiler heat load |
| D. | Minimum trays and maximum reboiler heat load |
| Answer» B. Infinite trays and minimum reboiler heat load | |
| 44. |
Low viscosity absorbent is preferred for reasons of%! |
| A. | Rapid absorption rates and good heat transfer characteristics |
| B. | Improved flooding characteristics |
| C. | Low pressure drop on pumping |
| D. | All of the above |
| Answer» E. | |
| 45. |
In batch distillation with constant reflux, overhead product composition __________ with time.%! |
| A. | Increases |
| B. | Decreases |
| C. | Does not vary |
| D. | May increase on decrease, depends on the system |
| Answer» C. Does not vary | |
| 46. |
Bound moisture is that liquid which exerts an equilibrium vapor pressure __________ that of the pure liquid at the given temperature.%! |
| A. | Less than |
| B. | More than |
| C. | Equal to |
| D. | Either A or B; depends on the solid |
| Answer» B. More than | |
| 47. |
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 | |
| 48. |
Separation of __________ employs gaseous diffusion process.%! |
| A. | N‚ÇÇ and O‚ÇÇ from air |
| B. | Isotopes of uranium |
| C. | Isotopes of helium |
| D. | SO‚ÇÇ and air |
| Answer» C. Isotopes of helium | |
| 49. |
Plate efficiency%! |
| A. | Is a function of the mass transfer between liquid and vapour |
| B. | Increases due to foaming |
| C. | Increases due to liquid entrainment |
| D. | Increases due to weeping and dumping of liquid |
| Answer» B. Increases due to foaming | |
| 50. |
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 | |