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. Slow & low
- B. Fast & high
- C. Slow & high
- D. Fast & slow
Explanation: A bright glow indicates rapid oxidation releasing heat at a high temperature, with incandescent carbon or ash particles emitting visible…
Correct answer: Fast & high- A. CO2
- B. CO
- C. N2
- D. H2
Explanation: Blast furnace gas contains a large amount of nitrogen carried in with the blast air, commonly about 50 to 60 percent.
Correct answer: N2- A. Caking
- B. Pulverised
- C. High ash
- D. Non-caking
Explanation: A travelling grate stoker continuously supports and moves lump coal through the furnace while air passes through the grate, making it…
Correct answer: Non-caking- A. Fixed
- B. Moving
- C. Fluidised
- D. Entrained
Explanation: The Lurgi gasifier operates as a pressurised moving-bed, also called a fixed-bed or dry-bottom, gasifier in which coal descends while…
Correct answer: Moving- A. The ratio of its percentage of fixed carbon to that of volatile matter
- B. Helpful in estimation of its rank
- C. Both A. and B.
- D. Neither A. nor B.
Explanation: Fuel ratio is defined as the percentage of fixed carbon divided by the percentage of volatile matter on the same basis.
Correct answer: Both A. and B.- A. None of these
- B. Combustion of fire slacks on the grates
- C. Handling (e.g. when emptying wagons)
- D. Its pulverisation (as it requires more power)
Explanation: Free moisture makes coal sticky, obstructs its passage through pulverisers and increases the power needed for grinding.
Correct answer: Its pulverisation (as it requires more power)- A. Uranium
- B. Plutonium
- C. Radium
- D. None of these
Explanation: Thermal reactors commonly use uranium, especially the fissile isotope uranium-235, because it can sustain a chain reaction with slow…
Correct answer: Uranium- A. 5000
- B. 25,000
- C. 10,000
- D. 15,000
Explanation: Propane has a heating value of roughly 22,000 kcal/Nm³ and butane about 29,000 kcal/Nm³, so an equal mixture is approximately 25,000…
Correct answer: 25,000- A. Calorific value
- B. Caking power
- C. Both A. & B.
- D. Neither A. nor B.
Explanation: More oxygen in coal generally indicates a lower-rank, more oxidised fuel, which lowers its calorific value and reduces its caking ability.
Correct answer: Both A. & B.- A. Calorific value
- B. Difference in gross & net calorific value
- C. Sulphur content
- D. Higher C/H ratio
Explanation: Coal-tar fuels contain more aromatic and carbon-rich constituents than petroleum fuel oils, giving them a higher carbon-to-hydrogen ratio.
Correct answer: Higher C/H ratio- A. None of these
- B. Ammoniacal cuprous chloride
- C. Pyrogallol solution
- D. KOH
Explanation: An Orsat apparatus absorbs carbon dioxide with KOH, oxygen with alkaline pyrogallol, and carbon monoxide with ammoniacal cuprous chloride.
Correct answer: None of these- A. 11
- B. 2
- C. 20
- D. 38
Explanation: Burning 1 kg of carbon requires 32/12 = 2.67 kg of oxygen. Since air contains about 23% oxygen by mass, the theoretical dry-air…
Correct answer: 11- A. Fusion point of its ash
- B. Volatile matter content
- C. Caking capacity
- D. Inherent moisture content
Explanation: Fat coals are bituminous coals with a strong tendency to soften and agglomerate when heated, which is their high caking capacity.
Correct answer: Caking capacity- A. Either A. or B., depends on other factors
- B. Decreases
- C. Remain same
- D. Increases
Explanation: For a fixed mass of fuel, a higher C/H ratio means a greater fraction of carbon is present.
Correct answer: Increases- A. Reduced NOx formation in flue gas
- B. All A., B. & C.
- C. High heat transfer rate
- D. Lower furnace operating temperature
Explanation: Fluidised-bed combustion operates at a lower, more uniform temperature, which suppresses thermal NOx formation, while intimate gas-solid…
Correct answer: All A., B. & C.- A. M40 > 78% and M10 < 10%
- B. M40 > 4% and M10 10% and M10 98% and M10 < 2%
Explanation: Strong metallurgical coke should resist both impact and abrasion, represented by a high M40 value and a low M10 value.
Correct answer: M40 > 78% and M10 < 10%- A. Pulverised coal
- B. Caking coal
- C. Coking coal
- D. Non-caking coal
Explanation: Chain-grate stokers require coal that supports a permeable bed and burns progressively as it moves along the grate.
Correct answer: Non-caking coal- A. Higher methane content and thus higher calorific value
- B. Higher carbon monoxide content
- C. Lower carbon dioxide content
- D. None of these
Explanation: High pressure favours methanation reactions, so a pressurised Lurgi gasifier produces more methane than an atmospheric gasifier.
Correct answer: Higher methane content and thus higher calorific value999. Main use of hard coke produced by high temperature carbonisation is in the ____________________ ?
- A. Cupola in foundries
- B. Iron blast furnace
- C. Sinter making
- D. Domestic ovens
Explanation: High-temperature carbonisation produces hard, strong coke with good porosity and resistance to crushing.
Correct answer: Iron blast furnace- A. 8
- B. 14
- C. 22
- D. 52
Explanation: Blast-furnace gas typically contains roughly 20 to 25% carbon monoxide, along with nitrogen, carbon dioxide and a small amount of…
Correct answer: 22