chemical engineering MCQs – Page 220

Practise multiple-choice questions from chemical engineering for competitive examinations and subject revision. Review each marked answer and report any item that may be outdated or unclear.

chemical engineering Mcqs

4381. In a shell and tube heat exchanger, the height of 25 percent cut baffles is equal to (where, D = inside diameter of shell) ?
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A. None of these

B. 0.50 D

C. 0.25 D

D. 0.75 D

4382. A reduction process is accompanied with increase in the_______________?
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A. Number of electrons

B. Oxidation number

C. Both A. & B.

D. Neither A. nor B.

4383. Osmotic pressure of the solution can be increased by_________________?
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A. Decreasing its temperature

B. None of these

C. Diluting the solution

D. Increasing the volume of the vessel containing the solution

4384. Pick out the wrong statement ?
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A. Overall heat transfer co-efficient in a heat exchanger is controlled by the value of the film coefficient,

B. Film co-efficient for vaporisation decreases as a result of vapor binding

C. In industrial practice, sub-cooling of condensate is required, when the condensate is a volatile

D. ch is higher</strong>

E. uid and is to be transferred for storage

F. The condensing film co-efficient is about 3 times lower for vertical condenser as compared to the equivalent horizontal condenser for identical situation

4385. Which of the following gases is the most soluble in water ?
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A. CH4

B. NH3

C. CO2

D. H2S

4386. The purpose of providing a catchall in the vapor line of an evaporator is to__________________?
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A. Arrest the entrained liquid

B. Regulate the vapor flow

C. Vent the non-condensable gases

D. Create vacuum

4387. In a heat exchanger, one transfer unit means___________________?
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A. A section of the exchanger in which change in temperature of one stream equals the average

B. ving force in the section</strong>

C. The size of the exchanger in which heat transfer rate is 1 kcal/hr

D. Both A. and B.

E. None of these

4388. A solution having a pH value of 5 is less acidic than the one having a pH value of 2 by a factor of ________________?
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A. 1000

B. None of these

C. 100

D. 3

4389. Pick out the wrong statement ?
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A. Phase change in case of a pure fluid at a given pressure from liquid to vapor or vice-versa occurs at saturation temperature

B. The controlling resistance in case of heating of air by condensing steam is in the air fil

C. In case of a 1 2 shell and tube heat exchanger, the LMTD correction factor value increases

D. The log mean temperature difference (LMTD) for counter flow and parallel flow can be theoretically same when any one of the fluids (hot or cold fluid) passes through the heat exchanger at constant temperature

E. rply, when a temperature cross occurs</strong>

4390. Log mean temperature difference (LMTD) cannot be used, if ___________________?
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A. There exists an unsteady state

B. None of these

C. The heat capacity is not constant and there is a phase change

D. Heat transfer co-efficient over the entire heat exchanger is not constant

4391. Pick out the wrong statement about distillation operation__________________?
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A. Flash distillation, differential distillation & steam distillation are all continuous distillation processes

B. In flash (equilibrium) distillation, a definite fraction of liquid is vaporised in such a way that the evolved vapour & residual liquids are in equilibrium with each other

C. In differential (simple) distillation, the vapour is removed as soon as it is formed without appreciable condensation

D. Distillation under vacuum is a substitute for steam distillation

4392. Kopps rule is useful for the determination of_____________________?
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A. Heat capacities of gases

B. Activation energy

C. Molal heat capacities of gases

D. Heat capacities of solids

4393. Raoults law states that the equilibrium vapor pressure that is exerted by a component in a solution is proportional to the mole fraction of that component. This generalisation is based on the assumption that the________________?
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A. Component molecules are non-polar and no chemical combination or molecular association

B. ween unlike molecules takes place in the formation of the solution

C. All A., B. & C.

D. Attractive forces between like and unlike molecules are approximately equal