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.
| 301. |
_ Absorption accompanied by heat evolution results in$? |
| A. | Increased capacity of the absorber |
| B. | Increase in equilibrium solubility |
| C. | Decrease in equilibrium solubility |
| D. | None of these |
| Answer» D. None of these | |
| 302. |
_ In distillation where q is defined as the moles of liquid flow in the stripping section per mole of feed introduced, for saturated liquid feed$? |
| A. | q > 1 |
| B. | q < 1 |
| C. | q = 1 |
| D. | q = 0 |
| Answer» D. q = 0 | |
| 303. |
_ Boiling point diagram is$? |
| A. | Not affected by pressure |
| B. | Affected by pressure |
| C. | A plot of temperature vs. liquid composition |
| D. | A plot of temperature vs. vapour composition |
| Answer» C. A plot of temperature vs. liquid composition | |
| 304. |
_ The humid volume may be increased by increasing the$? |
| A. | Temperature at constant humidity |
| B. | Humidity at constant temperature |
| C. | Both A & B |
| D. | Neither A nor B |
| Answer» D. Neither A nor B | |
| 305. |
_ McCabe-Thiele method of binary distillation does not assume that the$? |
| A. | Sensible heat changes are negligible compared with latent heat changes |
| B. | Molar latent heats of all components are equal |
| C. | Heat of mixing is negligible |
| D. | None of these |
| Answer» E. | |
| 306. |
_ The diffusivity (D) in a binary gas mixture is related to the temperature (T) as$? |
| A. | D ‚Äö√ √π T |
| B. | D ‚Äö√ √π T0.5 |
| C. | D ‚Äö√ √π T1.5 |
| D. | D ‚Äö√ √π T2 |
| Answer» D. D ‚Äö√ √π T2 | |
| 307. |
_ The film penetration model of mass transfer was enunciated by$? |
| A. | Gilliland |
| B. | Toor and Marchello |
| C. | Stefan |
| D. | Fick |
| Answer» C. Stefan | |
| 308. |
_ For the gas absorption, the height of a transfer unit, based on the gas phase is given by (G: superficial molar gas velocity, L: superficial molar liquid velocity, FG:mass transfer co-efficient, mols/m² , a: in-terfacial area per unit volume of tower)$? |
| A. | F/(FG.a) |
| B. | FG/(G.a) |
| C. | (G.a)/FG |
| D. | L/(FG.G) |
| Answer» B. FG/(G.a) | |
| 309. |
_ In a packed bed absorption column, the channelling will be noted by the$? |
| A. | Increase in flow rate |
| B. | Sharp drop in pressure drop |
| C. | Sharp rise in pressure drop |
| D. | None of these |
| Answer» C. Sharp rise in pressure drop | |
| 310. |
__When the gas to be dissolved in liquid is a/an __________ then normally co-current adsorber are used.__ |
| A. | Mixture of two gases |
| B. | Pure gas |
| C. | Ideal gas |
| D. | Sparingly soluble gas |
| Answer» C. Ideal gas | |
| 311. |
__The 'shanks system' of leaching (i.e., counter-current multiple contact leaching) is used for__ |
| A. | Recovery of tannis from the tree barks and woods |
| B. | Leaching sodium nitrate from Chilean nitrate bearing rock |
| C. | Both A & B |
| D. | Neither A nor B |
| Answer» D. Neither A nor B | |
| 312. |
__Removal of __________ exemplifies an adsorption unit operation.__ |
| A. | Uranium from its ore |
| B. | Water from petrol |
| C. | Ammonia from coke oven gas |
| D. | Mustard oil from mustard seed |
| Answer» C. Ammonia from coke oven gas | |
| 313. |
__Out of two equilibrium curves, first one lies above the diagonal and the second lies below the diagonal in the x-y plot. It means that separation by distillation is__ |
| A. | Not possible in the second case unless vacuum is applied |
| B. | Not possible in the second case unless high pressure is applied |
| C. | More readily done in the second case compared to first one |
| D. | None of these |
| Answer» D. None of these | |
| 314. |
__Pick out the wrong statement. Generally for physical adsorption, a gas of__ |
| A. | Higher molecular weight is adsorbed in preference to a gas of low molecular weight |
| B. | High critical temperature is adsorbed in preference to a gas of low critical temperature |
| C. | Low volatility is adsorbed in preference to a gas of high volatility |
| D. | None of these |
| Answer» E. | |
| 315. |
__Overall efficiency of the distillation column is__ |
| A. | The ratio of number of ideal plates to actual plates |
| B. | The ratio of number of actual plates to ideal plates |
| C. | Same as the Murphree efficiency |
| D. | Always more than the point efficiency |
| Answer» B. The ratio of number of actual plates to ideal plates | |
| 316. |
__In case of a desorber (stripper), the__ |
| A. | Operating line always lies above the equilibrium curve |
| B. | Operating line always lies below the equilibrium curve |
| C. | Temperature remains unaffected |
| D. | Temperature always increases |
| Answer» C. Temperature remains unaffected | |
| 317. |
__The reflux to a distillation column is 100 moles/hr, when the overhead product rate is 50 moles/hr. The reflux ratio is__ |
| A. | 2 |
| B. | 0.5 |
| C. | 50 |
| D. | 150 |
| Answer» B. 0.5 | |
| 318. |
__The relative saturation of a partially saturated mixture of vapour and gas can be increased by __________ of the mixture.__ |
| A. | Reducing the total pressure |
| B. | Increasing the total pressure |
| C. | Reducing the temperature |
| D. | Both B and C |
| Answer» E. | |
| 319. |
__Dryer widely used in a textile industry is __________ dryer.__ |
| A. | Festoon |
| B. | Cylinder |
| C. | Conveyor |
| D. | Tunnel |
| Answer» D. Tunnel | |
| 320. |
__Which of the following employs an accessory known as 'drift eliminator' ?__ |
| A. | Multiple effect evaporator |
| B. | Mechanical draft cooling tower |
| C. | Rotary dryer |
| D. | Rotating disc contactor |
| Answer» C. Rotary dryer | |
| 321. |
__The recovery of pencillin from the acidified fermentation broth is done by__ |
| A. | Distillation |
| B. | Evaporation |
| C. | Absorption |
| D. | Liquid extraction |
| Answer» E. | |
| 322. |
__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 | |
| 323. |
__Solvent used in extractive distillation__ |
| A. | Is of low volatility |
| B. | Forms a low boiling azeotrope |
| C. | Forms a high boiling azeotrope |
| D. | Does not alter the relative volatility of the original components |
| Answer» C. Forms a high boiling azeotrope | |
| 324. |
__Mass transfer co-efficient of liquid is__ |
| A. | Affected more by temperature than that for gases |
| B. | Affected much less by temperature than that for gases |
| C. | Not affected by the temperature |
| D. | None of these |
| Answer» B. Affected much less by temperature than that for gases | |
| 325. |
__The absorption factor is defined as (where, L = liquid flow rate, G = gas flow rate and, m = slope of the equilibrium line)__ |
| A. | L/mG |
| B. | G/mL |
| C. | ML/G |
| D. | LG/m |
| Answer» B. G/mL | |
| 326. |
__Steam distillation is used to__ |
| A. | Reduce the number of plates |
| B. | Avoid thermal decomposition of a component |
| C. | Increase the efficiency of separation |
| D. | Increase the total pressure of distillation |
| Answer» C. Increase the efficiency of separation | |
| 327. |
__According to Chilton-Colburn analogy for mass transfer, NSt.NSc2/3 is equal to__ |
| A. | F |
| B. | F/2 |
| C. | 2f |
| D. | 1/f |
| Answer» C. 2f | |
| 328. |
__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 | |
| 329. |
__Which of the following solutions will follow Raoult's law most closely?__ |
| A. | A solution of benzene, toluene and oxylene |
| B. | 35% solution of camphor in water |
| C. | 35% solution of NH‚ÇÉ in water |
| D. | A solution of polar organic compounds (not of homologs of a series) |
| Answer» B. 35% solution of camphor in water | |
| 330. |
__Physical absorption is__ |
| A. | An irreversible phenomenon |
| B. | A reversible phenomenon |
| C. | Accompanied by evolution of heat |
| D. | Both B & C |
| Answer» E. | |
| 331. |
__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 of the above |
| Answer» E. | |
| 332. |
__Design calculation for multiple component distillation is done by__ |
| A. | Ponchon-Savarit method |
| B. | Mccabe-Thiele method |
| C. | Enthalpy concentration method |
| D. | Tray to tray calculations |
| Answer» E. | |
| 333. |
__Chemisorption (chemical adsorption) is__ |
| A. | Same as "Van der Waals" adsorption |
| B. | Characterised by adsorption of heat |
| C. | An irreversible phenomenon |
| D. | A reversible phenomenon |
| Answer» D. A reversible phenomenon | |
| 334. |
__Azeotropism for ethyl alcohol-water system disappears by__ |
| A. | Increasing temperature |
| B. | Decreasing pressure |
| C. | Increasing pressure |
| D. | No means |
| Answer» C. Increasing pressure | |
| 335. |
__In case of absorption with exothermic reaction, for fluids having__ |
| A. | Pr = Sc; percentage change in heat and mass transfer flux will be the same for a given change in the degree of turbulence |
| B. | Pr = Sc = 1; total mass, momentum and thermal diffusivity will be the same |
| C. | Both A & B |
| D. | Pr = Sc ; there won |
| Answer» D. Pr = Sc ; there won | |
| 336. |
__As complete saturation of an adsorbent is approached, the differential heat of adsrop-tion approaches__ |
| A. | That of normal condensation |
| B. | Integral heat of adsorption |
| C. | Zero |
| D. | None of these |
| Answer» B. Integral heat of adsorption | |
| 337. |
__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 | |
| 338. |
__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 | |
| 339. |
__The relative humidity of air decreases in-spite of an increase in the absolute humidity, when the__ |
| A. | Temperature rises |
| B. | Pressure rises |
| C. | Temperature falls |
| D. | Pressure falls |
| Answer» B. Pressure rises | |
| 340. |
__Drying of refractory is normally carried out in a __________ dryer.__ |
| A. | Open pan |
| B. | Tray |
| C. | Rotary vacuum |
| D. | Truck/tunnel |
| Answer» E. | |
| 341. |
__In case of unsaturated air__ |
| A. | Dew point < wet bulb temperature |
| B. | Wet bulb temperature < dry bulb temperature |
| C. | Both A & B |
| D. | Neither A nor B |
| Answer» D. Neither A nor B | |
| 342. |
__In azeotropic mixture, the equilibrium vapour composition is__ |
| A. | More than liquid composition |
| B. | Less than liquid composition |
| C. | Same as liquid composition |
| D. | Independent of pressure |
| Answer» D. Independent of pressure | |
| 343. |
__Which of the following remains constant during sensible cooling process ?__ |
| A. | Specific humidity |
| B. | Partial pressure of vapour |
| C. | Both A & B |
| D. | Neither A nor B |
| Answer» D. Neither A nor B | |
| 344. |
__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 | |
| 345. |
_Molecular diffusion is caused by the$? |
| A. | Transfer of molecules from low concentration to high concentration region |
| B. | Thermal energy of the molecules |
| C. | Activation energy of the molecules |
| D. | Potential energy of the molecules |
| Answer» C. Activation energy of the molecules | |
| 346. |
_With increase in temperature, the leaching rate increases due to$? |
| A. | Decreased liquid viscosity |
| B. | Increased diffusivity |
| C. | Both A & B |
| D. | Neither A nor B |
| Answer» D. Neither A nor B | |
| 347. |
_In case of non-ideal gases and liquids, the molal diffusivity$? |
| A. | Varies inversely as the pressure |
| B. | Varies directly as the pressure |
| C. | Is independent of pressure |
| D. | Is equal to the volumetric diffusivity |
| Answer» D. Is equal to the volumetric diffusivity | |
| 348. |
_Minimum possible diameter of a packed coloumn is decided mainly by the$? |
| A. | Flooding |
| B. | Gas viscosity |
| C. | Liquid density |
| D. | Liquid hold up |
| Answer» B. Gas viscosity | |
| 349. |
_Langmuir equation is associated with$? |
| A. | Leaching |
| B. | Adsorption |
| C. | Steam distillation |
| D. | Multicomponent absorption |
| Answer» C. Steam distillation | |
| 350. |
_Diffusion co-efficient generally depends upon the temperature, pressure & the nature of the components of the system. Its dimension is not the same as that of the$? |
| A. | Mass transfer co-efficient |
| B. | Thermal diffusivity |
| C. | Kinematic viscosity |
| D. | Volumetric diffusivity |
| Answer» B. Thermal diffusivity | |