chemical engineering MCQs – Page 300

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 Review each marked answer and report any item that may be outdated or unclear.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
5981. Fussain _____________________?
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A. Is non-coking, but when blended with highly coking coal, controls its swelling and produces

B. coal

C. h strength coke on carbonisation

D. All A., B. and C.

E. Is friable, charcoal like substance

F. Has highest fixed carbon and lowest volatile matter content of all the four banded components

5982. A liquid/gaseous fuel containing hydrocarbons and high amount of sulphur is burnt with 40% excess air. The flue gas still contains large amount of carbon monoxide. This may be due to the_________________?
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A. Low calorific value of the fuel

B. Lack of thorough mixing of fuel with air

C. High sulphur content in the fuel

D. Presence of large quantity of hydrogen in the fuel

5983. Percentage of nitrogen in blast furnace gas may be around__________________?
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A. 80

B. 25

C. 55

D. 5

5984. Commercial production of petrol from coal (as practised in a factory at Sasol in South Africa) is done by the ________________ of coal?
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A. Hydrogenation

B. Carbonisation

C. Gasification

D. None of these

5985. High ash containing coke____________________?
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A. Produces more slag when used in the blast furnace

B. None of these

C. Has poor strength and abrasion resistance

D. Is desirable in producer gas manufacture

5986. Prime coking coal is always blended with medium or non- coking coal before carbonisation__________________?
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A. To check against its excessive swelling during heating, which may exert high pressure and

B. age coke oven walls

C. Because, it alone produces unreactive coke

D. Both A. and B.

E. Neither A. nor B.

5987. With increase in C/H ratio of a fuel, the dew point of flue gases______________________?
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A. Remain same

B. Decreases

C. May increase or decrease; depends on the type of fuel

D. Increases

5988. Calorific value of gobar gas (containing CH4 = 60% , H2 = 10% ; CO2 = 30%) may be about ______________ Kcal/Nm3?
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A. 3,200

B. 5,400

C. 10,200

D. 1,800

5989. With increase in the alumina content in firebricks, its fusion point (refractoriness) ?
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A. Remains unchanged

B. Increases

C. Decreases linearly

D. Decreases

5990. Quartz is___________________?
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A. Stable form of silica upto 870C

B. All A., B. and C.

C. Transformed to Cristobalite on heating above 1470C

D. Converted to Tridymite on firing between 870 to 1470C

5991. Carbon refractories are exclusively used in the_________________?
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A. Side wall of soaking pits

B. Hearth of blast furnace

C. Walls of coke oven

D. Regenerators of coke oven

5992. ______________ bricks are used in the burning zone of a cement rotary kiln ?
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A. Silicon carbide

B. Thoria

C. High alumina

D. Fireclay

5993. Spalling of a refractory means its____________________?
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A. Resistance to compressive loads

B. Resistance to chemical action of gases and molten fluxes

C. Softening

D. Fracture due to uneven expansion at high temperature
5994. Stack (chimney) height in a big thermal power plant is dictated by the___________________?
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A. None of these

B. Pollution control aspect

C. Draught to be created

D. Limitation of constructional facilities

5995. Which of the following consumes the maximum tonnage of refractories annually in an integrated steel plant ?
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A. Reheating furnace

B. Rotary lime kiln

C. L.D. converter

D. Soaking pits

5996. Which of the following fuels has the highest calorific value per unit mass (kcal/kg) ?
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A. Coal

B. Furnace oil

C. Natural gas

D. Kerosene

5997. Efficiency of the combustion of a fuel is judged by the ______________ the flue gas?
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A. % of CO2 in

B. Temperature of

C. Colour of

D. % of O2in
5998. In low temperature carbonisation of coal as compared to high temperature carbonisation _____________ produced is less?
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A. Yield of ammonia present in coke oven gas

B. Free carbon content in tar

C. Difference in gross & net calorific value of the coke oven gas

D. Yield percentage of coke

5999. Dry air requirement for burning 1 Nm3 of CO to CO2 may be around _______________ Nm3 ?
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A. 11.4

B. 1.75

C. 2.4

D. 0.87

6000. Which is not a basic refractory ?
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A. Silicon carbide

B. Dolomite

C. Magnesite

D. Chrome magnesite