chemical engineering MCQs – Page 215

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 Review each marked answer and report any item that may be outdated or unclear.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

4281. Which is a neutral refractory ?
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A. Magnesite chrome

B. Magnesia

C. Silica

D. Graphite

4282. Faster rate of drying of moulded refractories results in high ______________ of refractories?
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A. Green strength

B. Voids

C. Shrinkage

D. Both B. and C.

4283. Refractories used in/for ______________ should have low thermal conductivity?
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A. Coke ovens

B. Regenerators

C. Muffle furnaces

D. Insulation

4284. Heat transfer by radiation between two bodies at T1 & T2 and in an ambient temperature of TaC depends on_____________?
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A. T1 T2

B. None of these

C. T1 Ta

D. T2 Ta

4285. Pick out the wrong statement ?
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A. Sherwood number in mass transfer corresponds to Nusselt number in heat transfer and Schmidt number to Prandtl number

B. Forced convection is relatively more effective in increasing the rate of mass transfer, if Schmidt number is larger

C. In drying a solid containing moisture above the critical moisture content the number of degrees of freedom is 2

D. Hot gases at moderate pressure are usually in the shell side of shell and tube heat exchangers. At higher pressure, however, it is customary to put gas in the tube side

4286. Thermal conductivity of refractory bricks____________________?
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A. Is independent of its porosity and is maximum for insulating bricks

B. Increases with decrease in porosity

C. Decreases with decreases in porosity

D. Increases with the amount of air entrapped in pores

4287. Heat of reaction is a function of the___________________?
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A. Pressure

B. Temperature

C. Both A. & B.

D. Neither A. nor B.

4288. One of the specific gravity scales is Brix (used specifically for sugar solution). It is defined as ______________?
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A. Brix = (400/G) 400

B. Brix = 145 (145/G)

C. Brix = 200 (G-1)

D. None of these

4289. At what temperature, given mass of a gas that occupies a volume of 2 litres at N.T.P. will occupy a volume of 4 litres, if the pressure of the gas is kept constant ?
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A. 273C

B. 200C

C. 273K

D. 100C

4290. Pick out the wrong statement ?
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A. Increase in depth of the liquid about the slots increases the plate efficiency, particularly if the liquid depth is < 1"

B. Plate efficiency increases with increase in superficial vapour velocity till entrainment limit

C. None of these

D. Too small a plate spacing can cause a low efficiency, if the vapour velocity is greater than the allowable value

4291. One mole of methane undergoes complete combustion in a stoichiometric amount of air. The reaction proceeds as CH4 + 2O2 ? CO2 + 2H2O. Both the reactants and products are in gas phase. ?H298 = 730 kJ/mole of methane. Mole fraction of water vapour in the product gases is about_____________________?
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A. 0.67

B. 0.19

C. 0.33

D. 0.4

4292. Which property of refractories is the most important for top section of the blast furnace ?
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A. Resistance to abrasion

B. Stability of volume at high temperature

C. Resistance to slag penetration

4293. The maximum adiabatic flame temperature of fuels in air is ____________ the maximum flame temperature in pure oxygen?
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A. Same as

B. Lower than

C. Higher than

D. Not related to

4294. An insulating refractory brick should have high porosity and low thermal conductivity. Which of the following is not used for inducing porosity in the insulating refractory bricks during its manufacture ?
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A. Sand

B. Cork

C. Chemically prepared foam

D. Saw dust

4295. Fusion point of a basic refractory material is________________?
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A. Always less than 1000C

B. Increased by the addition of acid oxides

C. Not affected by the addition of acid oxides

D. Reduced by the addition of acid oxides

4296. The vapor pressure of a substance, at its melting point, is _____________ in the solid state as compared to that in the liquid state?
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A. Less

B. More

C. Same

D. Either A. or B.; depends on the nature of the substance

4297. Cp Cv for an ideal gas is equal to________________?
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A. R/2

B. 3R

C. 2R

D. R

4298. The crystallisation of a solute from a solution may be done by________________?
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A. Removal of pure solvent by evaporation

B. All A., B. & C.

C. Changing the nature of the system by the addition of a more soluble material

D. Change of temperature thereby causing super-saturation

4299. Addition of zircon to silica refractory brick improves its_________________?
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A. Crushing strength

B. Resistance to slag attack

C. Both A. and B.

D. Neither A. nor B.

4300. Magnesite refractories are used for the construction of those furnaces, which are_______________?
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A. Not required to resist the corrosive action of basic slag

B. Not subjected to fluctuation in temperature

C. Used for raising & maintaining high temperature

D. Both B. and C.

Showing 4281 to 4300 of 8709 mcqs