Free Chemical Process Principles MCQs with Answers
2,710 Chemical Process Principles MCQs from Chemical Engineering, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
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- A. 230 V AC
- B. 60 KV AC
- C. 230 V DC
- D. 60 KV DC
Explanation: Electrostatic precipitators use a high-voltage direct-current field to create corona ionisation and charge tar or dust particles.
Correct answer: 60 KV DC- A. Aromatic compounds
- B. Aliphatic compounds
- C. Paraffins
- D. Olefins
Explanation: High-temperature carbonisation produces coal tar rich in benzene, toluene, phenols, naphthalene and other aromatic substances.
Correct answer: Aromatic compounds- A. Lignite
- B. Bituminous coal
- C. Semi-anthracite
- D. Anthracite
Explanation: Hard coke is made by carbonising suitable bituminous coal, which softens and fuses before becoming a strong porous coke.
Correct answer: Bituminous coal- A. Blast furnace coke
- B. Gasoline
- C. Wood charcoal
- D. Natural gas
Explanation: Natural gas is a primary fuel because it occurs naturally and is used directly for combustion.
Correct answer: Natural gas- A. 18
- B. 48
- C. 8
- D. 80
Explanation: Narrow by-product coke ovens generally require about 15 to 20 hours for carbonisation, making 18 hours the closest option.
Correct answer: 18- A. All A., B. and C.
- B. Stack gas temperature
- C. Percentage of oxygen in flue gases
- D. Fuel consumption for the same heat load
Explanation: Excess air carries additional nitrogen and oxygen through the furnace, increasing fuel use for a fixed heat load, residual oxygen, and…
Correct answer: All A., B. and C.- A. Inherent impurities
- B. Both B. and C.
- C. Mineral matter
- D. Adhering impurities
Explanation: Coal washing removes physically adhering dirt and separable mineral matter such as shale and pyrites.
Correct answer: Both B. and C.- A. Low preheat of air
- B. High excess air
- C. Fine grinding
- D. All A., B. and C
Explanation: Anthracite has low volatile content and is difficult to ignite and burn, so fine grinding increases its surface area and improves…
Correct answer: Fine grinding- A. CO & H2
- B. CO & N2
- C. CO2 & H2
- D. CH4 & H2
Explanation: Water gas is formed by passing steam over red-hot carbon, producing mainly carbon monoxide and hydrogen: C + H₂O → CO + H₂.
Correct answer: CO & H2- A. Hot scarfing of steel slabs
- B. Coke oven battery heating
- C. Mixing with blast furnace gas
- D. Steel ladle drying
Explanation: After tar removal, coke oven gas is a clean, combustible fuel commonly recycled to heat the coke oven battery.
Correct answer: Coke oven battery heating- A. As a motor fuel
- B. As an explosive
- C. For making insecticides (e.g., DDT, BHC etc.), detergent & rubber (SBR)
- D. As a perfume
Explanation: Benzene is an important petrochemical feedstock for products such as insecticides, detergents and styrene-butadiene rubber.
Correct answer: For making insecticides (e.g., DDT, BHC etc.), detergent & rubber (SBR)- A. Hydrogen
- B. Sulphur
- C. Carbon
- D. None of these
Explanation: Carbon, hydrogen and sulfur all release heat when oxidised, although sulfur is generally undesirable because it forms SOₓ gases.
Correct answer: None of these- A. None of these
- B. Less of gases compared to liquid products
- C. Large quantity of tar compared to low temperature carbonisation
- D. Inferior coke compared to low temperature carbonisation
Explanation: High-temperature carbonisation produces stronger, more porous coke and generally more permanent gas but less tar than low-temperature…
Correct answer: None of these- A. CO & CO2
- B. CH4 & CO2
- C. CH4 & N2
- D. CO & N2
Explanation: Gobar gas, or biogas from anaerobic digestion, consists mainly of methane, which provides its fuel value, and carbon dioxide.
Correct answer: CH4 & CO2775. Which of the following coal gasification processes will produce gas having maximum methane content ?
- A. Winkler process
- B. Kopper-Totzek process
- C. Lurgi process
- D. All can produce same methane content
Explanation: The Lurgi gasifier operates under pressure and produces relatively methane-rich gas because methanation is favoured by high pressure and…
Correct answer: Lurgi process- A. Caking
- B. Carbonised
- C. Classified
- D. Non-caking
Explanation: A caking coal softens and becomes plastic on heating, then fuses into a coherent coke mass.
Correct answer: Caking- A. Blast furnace
- B. Domestic
- C. Foundry
- D. None of these
Explanation: Soft coke is relatively porous and reactive, and its low sulphur and smoke-forming tendency make it suitable mainly as a domestic fuel.
Correct answer: Domestic- A. 150
- B. 1500
- C. 3500
- D. 5000
Explanation: The Kopper-Totzek gasifier typically gives about 1500 Nm³ of gas per tonne of coal when the ash content is around 35%.
Correct answer: 1500- A. Buckling of ram of pusher car at the time of coke pushing
- B. Structural strength of silica bricks
- C. Problem in door cleaning
- D. Problem of uniform heating along its height
Explanation: A tall coke oven makes it difficult to maintain uniform heating throughout the coal charge, causing uneven carbonisation and coke quality.
Correct answer: Problem of uniform heating along its height- A. Minimise the chances of clinker formation
- B. Increase the combustion rate
- C. Increase the gas production rate
- D. Convert CO to CO2
Explanation: Intermittent steam injection helps cool and loosen excessively hot regions in the fuel bed, reducing ash fusion and clinker formation.
Correct answer: Minimise the chances of clinker formation