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.
| 401. |
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 ______________________? |
| A. | 2.0 |
| B. | 1.56 |
| C. | 1.0 |
| D. | 0.56 |
| Answer» B. 1.56 | |
| 402. |
Gaseous diffusivity at atmospheric pressure is of the order of _____________________ cm2/second? |
| A. | 1 |
| B. | 1 to 5 |
| C. | 5 to 10 |
| D. | > 10 |
| Answer» B. 1 to 5 | |
| 403. |
Gaseous diffusion co-efficient increases with increase in the_____________________? |
| A. | Pressure |
| B. | Temperature |
| C. | Both A. & B. |
| D. | Neither A. nor B. |
| Answer» C. Both A. & B. | |
| 404. |
Freundlich equation applies to the adsorption of solute from_____________________? |
| A. | Dilute solutions, over a small concentration range |
| B. | Gaseous solutions at high pressure |
| C. | Concentrated solutions |
| D. | None of these |
| Answer» B. Gaseous solutions at high pressure | |
| 405. |
Freundlich equation applies to the adsorption of solute from___________________? |
| A. | Dilute solutions, over a small concentration range |
| B. | Gaseous solutions at high pressure |
| C. | Concentrated solutions |
| D. | None of these |
| Answer» B. Gaseous solutions at high pressure | |
| 406. |
Free flowing granular materials can be best dried in a __________________ drier? |
| A. | Rotary |
| B. | Cylinder |
| C. | Drum |
| D. | Freeze |
| Answer» B. Cylinder | |
| 407. |
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 | |
| 408. |
For water-ethanol system, the minimum reflux ratio_____________________? |
| A. | Is computed from the slope of the upper operating line that is tangent to the equilibrium curve |
| B. | Is computed from the intercept of the operating line |
| C. | Cannot be computed |
| D. | Is the optimum reflux ratio |
| Answer» B. Is computed from the intercept of the operating line | |
| 409. |
For turbulent mass transfer in pipes, the Sherwood number depends on the Reynolds number as___________________? |
| A. | Re0.33 |
| B. | Re0.53 |
| C. | Re0.83 |
| D. | Re |
| Answer» D. Re | |
| 410. |
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 | |
| 411. |
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 | |
| 412. |
For the same feed, feed quality and separation (in a distillation column), with the increase of total pressure, the number of ideal plates will_____________________? |
| A. | Increase |
| B. | Decrease |
| C. | Remain same |
| D. | Data insufficient, can’t be predicted |
| Answer» B. Decrease | |
| 413. |
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) ? |
| A. | G/(FG . a) |
| B. | FG/(G . a) |
| C. | (G . a)/FG |
| D. | L/(FG . G) |
| Answer» B. FG/(G . a) | |
| 414. |
For the flow of gases through a capillary, with increase in temperature, the permeability __________________ as per Knudsen law? |
| A. | Increases |
| B. | Decreases |
| C. | Remain same |
| D. | Either A. or B.; depends on the gas |
| Answer» B. Decreases | |
| 415. |
For the case of flow of air past a wet bulb thermometer (air water vapour system), the approximate value of h2/ky.Cz is around____________________? |
| A. | 0.60 |
| B. | 0.24 |
| C. | 1 |
| D. | 0.72 |
| Answer» D. 0.72 | |
| 416. |
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 | |
| 417. |
For stripping of a gas in a counter current stripper, the operating line _____________________? |
| A. | Lies above the equilibrium curve |
| B. | Lies below the equilibrium curve |
| C. | Can lie above or below the equilibrium curve |
| D. | Is always parallel to the equilibrium curve |
| Answer» D. Is always parallel to the equilibrium curve | |
| 418. |
For gas absorption, low viscosity solvents are preferred, because of their ____________________? |
| A. | Better flow characteristics |
| B. | Low pumping pressure drop |
| C. | Rapid absorption rates |
| D. | All A., B. and C. |
| Answer» E. | |
| 419. |
For experimental determination of mass transfer co-efficient by wetted wall tower, the mass transfer area is___________________? |
| A. | Calculated |
| B. | Unknown |
| C. | Known |
| D. | Not required |
| Answer» D. Not required | |
| 420. |
For ethanol-water system, the lowering of distillate quality from 95% to 92% will cause ____________________ plate requirement? |
| A. | No change in theoretical |
| B. | Marginal decrease in the number of |
| C. | Major decrease in the number of |
| D. | None of these |
| Answer» C. Major decrease in the number of | |
| 421. |
For ethanol-water system, the lowering of distillate quality from 95% to 92% will cause ______________ plate requirement? |
| A. | No change in theoretical |
| B. | Marginal decrease in the number of |
| C. | Major decrease in the number of |
| D. | None of these |
| Answer» C. Major decrease in the number of | |
| 422. |
For _______________ drying, the effects of velocity, temperature and humidity of the gas and the thickness of the solid are the same? |
| A. | Unsaturated surface |
| B. | Constant rate |
| C. | Both A. and B. |
| D. | Neither A. nor B. |
| Answer» D. Neither A. nor B. | |
| 423. |
For continuous drying of granular or crystalline material, the dryer used is the _______________ dryer? |
| A. | Tunnel |
| B. | Tray |
| C. | Rotary |
| D. | None of these |
| Answer» D. None of these | |
| 424. |
For contacting a highly soluble gas with a liquid ____________________? |
| A. | Bubble the gas through liquid |
| B. | Spray the liquid on gas stream |
| C. | Either A. or B. would suffice |
| D. | None of these |
| Answer» B. Spray the liquid on gas stream | |
| 425. |
For an absorber, both equilibrium and operating line will be straight for _______________________? |
| A. | Concentrated solution and non-isothermal operation |
| B. | Dilute solution and non-isothermal operation |
| C. | Dilute solution and isothermal operation |
| D. | Concentrated solution and isothermal operation |
| Answer» D. Concentrated solution and isothermal operation | |
| 426. |
For achieving rapid drying rate in a spray dryer, the diameter of the particles in the feed should be in the range of _______________ microns (1 mm = 1000 microns)? |
| A. | 1-5 |
| B. | 10-60 |
| C. | 200-300 |
| D. | > 500 |
| Answer» C. 200-300 | |
| 427. |
For absorbing a sparingly soluble gas in a liquid ___________________? |
| A. | Gas side mass transfer co-efficient should be increased |
| B. | Liquid side mass transfer co-efficient should be increased |
| C. | Liquid side mass transfer co-efficient should be decreased |
| D. | Mass transfer co-efficient must be kept constant |
| Answer» C. Liquid side mass transfer co-efficient should be decreased | |
| 428. |
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 | |
| 429. |
For absorbers, high pressure drop results in___________________? |
| A. | Increased efficiency |
| B. | Decreased efficiency |
| C. | High operating cost |
| D. | Better gas liquid contact |
| Answer» D. Better gas liquid contact | |
| 430. |
For a ternary 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. | Ternary mixture is represented by the sides |
| D. | Pure component is represented by the apex |
| Answer» E. | |
| 431. |
For a ternary 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. | Ternary mixture is represented by the sides |
| D. | Pure component is represented by the apex |
| Answer» E. | |
| 432. |
For a single component absorber, the operating line is straight only when plotted in term of ______________ units? |
| A. | Partial pressure |
| B. | Mole ratio |
| C. | Mole fraction |
| D. | None of these |
| Answer» C. Mole fraction | |
| 433. |
For a fixed number of ideal stages in a distillation column, as the reflux ratio is increased, the difference in composition between the top and bottom product streams__________________? |
| A. | Increases |
| B. | Decreases |
| C. | Remain unaffected |
| D. | Passes through a maximum |
| Answer» B. Decreases | |
| 434. |
For a distillation column operating at minimum reflux, the_______________________? |
| A. | Concentration of liquid and vapour leaving a plate will be same |
| B. | Reflux ratio will be maximum |
| C. | Number of plates required will be maximum |
| D. | None of these |
| Answer» D. None of these | |
| 435. |
For a binary mixture with low relative volatility___________________? |
| A. | Use steam distillation |
| B. | Use molecular distillation |
| C. | Use high pressure distillation |
| D. | An azeotrope may be formed during distillation |
| Answer» E. | |
| 436. |
For a binary mixture with low relative volatility________________? |
| A. | Use steam distillation |
| B. | Use molecular distillation |
| C. | Use high pressure distillation |
| D. | An azeotrope may be formed during distillation |
| Answer» E. | |
| 437. |
For a binary mixture with low relative volatility, continuous rectification to get pure products will require_____________________? |
| A. | Low reflux ratio |
| B. | Less number of trays |
| C. | Small cross-section column |
| D. | High reflux ratio |
| Answer» E. | |
| 438. |
For a binary mixture distillation process, the degree of freedom is 2. However, if the pressure is fixed in this process, the number of independent variables in this process will be ___________________? |
| A. | 1 |
| B. | 0 |
| C. | 2 |
| D. | 3 |
| Answer» B. 0 | |
| 439. |
Flooding in a vapor-liquid contacting equipment occurs in a tray, when the pressure drop through a tray is _______________ the liquid head available in the downcomer? |
| A. | Less than |
| B. | More than |
| C. | Same as |
| D. | Very much less |
| Answer» C. Same as | |
| 440. |
Flooding in a column results due to___________________? |
| A. | High pressure drop |
| B. | Low pressure drop |
| C. | Low velocity of the liquid |
| D. | High temperature |
| Answer» B. Low pressure drop | |
| 441. |
Flooding in a distillation column is detected by a sharp ___________________? |
| A. | Increase in Murphree plate efficiency |
| B. | Decrease in pressure drop |
| C. | Decrease in liquid hold up in the column |
| D. | Increase in pressure drop |
| Answer» E. | |
| 442. |
Flights in a rotary dryer are provided to________________? |
| A. | Lift and shower the solids thus exposing it thoroughly to the drying action of the gas |
| B. | Reduce the residence time of solid |
| C. | Increase the residence time of the solid |
| D. | None of these |
| Answer» B. Reduce the residence time of solid | |
| 443. |
Flash distillation is _______________________? |
| A. | Same as differential distillation |
| B. | Used for multi-component systems like crude refining |
| C. | Same as simple distillation |
| D. | Same as simple distillation |
| Answer» C. Same as simple distillation | |
| 444. |
Flash distillation is suitable for the separation of components_________________? |
| A. | Having very close boiling points |
| B. | Which form maximum boiling azeotrope |
| C. | Having very wide boiling points |
| D. | Which form minimum boiling azeotrope |
| Answer» D. Which form minimum boiling azeotrope | |
| 445. |
Flash distillation is suitable for separating the constituents of a binary system, which _____________________? |
| A. | Form minimum boiling azeotrope |
| B. | Have very wide boiling points |
| C. | Have very close boiling points |
| D. | Form constant boiling azeotrope |
| Answer» C. Have very close boiling points | |
| 446. |
Fenske equation for determining the minimum number of theoretical stages in distillation column holds good, when the_________________? |
| A. | Relative volatility is reasonably constant |
| B. | Mixture (to be separated) shows negative deviation from ideality |
| C. | Mixture (to be separated) shows positive deviation from ideality |
| D. | Multi-component distillation is involved |
| Answer» B. Mixture (to be separated) shows negative deviation from ideality | |
| 447. |
Fenske-Underwood equation used for calculating the minimum number of theoretical plates in distillation column is valid for_________________? |
| A. | Constant molal overflow |
| B. | Total reflux |
| C. | Constant relative volatility |
| D. | All A., B. and C. |
| Answer» E. | |
| 448. |
Fenske equation determines the __________________? |
| A. | Maximum number of ideal plates |
| B. | Height of the distillation column |
| C. | Minimum number of theoretical plates |
| D. | Optimum reflux ratio |
| Answer» D. Optimum reflux ratio | |
| 449. |
___________________ extractor uses centrifugal force for separating the two phases? |
| A. | Treybal |
| B. | Scheibel |
| C. | Podbielniak |
| D. | None of these |
| Answer» D. None of these | |
| 450. |
_______________ extractor is used for the concentration of radioactive nuclear waste? |
| A. | Pulsed column |
| B. | Sieve plate |
| C. | Mixer-settler |
| D. | Bollman |
| Answer» B. Sieve plate | |