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. Natural gas
- B. Coke oven gas
- C. Blast furnace gas
- D. Water gas
Explanation: Blast-furnace gas contains substantial carbon dioxide and nitrogen, giving it an average molecular weight close to or slightly above that…
Correct answer: Blast furnace gas- A. Is non-coking
- B. Has a high volatile matter content and burns with a luminous smoky flame
- C. Is a non-banded coal which can be ignited easily with a match stick or candle flame, hence is
- D. so named
- E. All A., B. and C.
Explanation: Cannel coal is a non-banded, non-coking coal with high volatile matter, so it ignites readily and burns with a luminous, smoky flame.
Correct answer: All A., B. and C.- A. Coking coals cannot be used
- B. Low carbon conversion efficiency is achieved
- C. Entrainment of solids is higher
- D. Larger quantity of coal can be processed
Explanation: The Lurgi gasifier is a pressurised fixed-bed gasifier with low solids entrainment and high carbon conversion.
Correct answer: Larger quantity of coal can be processed- A. CO
- B. H2
- C. CH4
- D. C2H6
Explanation: Hydrogen has the highest flame velocity among the listed fuels because its small molecules diffuse rapidly and its H2-air reaction…
Correct answer: H2- A. Blast furnace gas
- B. Hydrogen
- C. Acetylene
- D. Coke oven gas
Explanation: Acetylene produces the highest theoretical flame temperature among these fuels because it has a high heating value per unit oxygen…
Correct answer: Acetylene- A. Carburetted water gas
- B. Blast furnace gas
- C. Producers' gas
- D. Natural gas
Explanation: Natural gas is mainly methane, whose complete combustion forms about one volume of CO2 and two volumes of water vapour per volume of fuel…
Correct answer: Natural gas- A. Natural gas
- B. Furnace oil
- C. Coal
- D. Naphtha
Explanation: Natural gas is rich in methane, which has the highest hydrogen-to-carbon ratio of the listed fuels and therefore the lowest C/H ratio.
Correct answer: Natural gas- A. 0.95 y
- B. y
- C. 1.05 y
- D. 1.8 y
Explanation: The calorific value depends only on the combustible H2 and CH4 fractions, which remain 50% and 30% in both gas compositions.
Correct answer: y- A. Exothermic
- B. Endothermic
- C. Catalytic
- D. Autocatalytic
Explanation: The water-gas reaction, C + H2O → CO + H2, requires heat because the products have a higher enthalpy than the reactants.
Correct answer: Endothermic- A. 30
- B. 300
- C. 3,000
- D. 30,000
Explanation: High-temperature carbonisation of one tonne of dry coal typically yields roughly 300 Nm³ of coke-oven gas, along with coke and tar.
Correct answer: 300- A. High ash
- B. Low ash
- C. High calorific value
- D. High volatile matter
Explanation: Volatile matter vaporises readily and burns with a long luminous flame, while also making coal easier to ignite.
Correct answer: High volatile matter- A. Absorption in wash oil
- B. Adsorption on bog iron bed
- C. Bubbling it through dilute sulphuric acid
- D. Adsorption on silica gel
Explanation: H₂S and mercaptans in coke-oven gas are removed by the oxide purification process, using hydrated ferric oxide or bog iron ore as the…
Correct answer: Adsorption on bog iron bed- A. Flue gas temperature
- B. Flame temperature
- C. Amount of heat liberated
- D. Any of the above
Explanation: Nitrogen is essentially inert, so it does not participate in combustion and does not reduce the heat chemically liberated by the fuel.
Correct answer: Amount of heat liberated- A. H2 & CO
- B. H2 & CO2
- C. CH4 & CO
- D. H2 & CH4
Explanation: Coke-oven gas is rich mainly in hydrogen and methane, with smaller quantities of carbon monoxide and other gases.
Correct answer: H2 & CH4- A. Neither A. nor B.
- B. Lower hydrogen content
- C. Both A. and B.
- D. Higher calorific value
Explanation: High-temperature carbonisation produces gas with more hydrogen and fewer heavy hydrocarbons, so its calorific value is generally lower…
Correct answer: Neither A. nor B.- A. Ash
- B. Volatiles
- C. Iron
- D. Moisture
Explanation: Pure coke should contain high fixed carbon and little volatile matter, because carbonisation removes the volatile constituents of coal.
Correct answer: Volatiles- A. Blast furnace gas
- B. Coke oven gas
- C. Oil refinery gas
- D. Carburetted water gas
Explanation: Oil-refinery gas contains substantial hydrogen-rich hydrocarbons and therefore has a higher gross calorific value than coke-oven gas…
Correct answer: Oil refinery gas- A. Calorific value increases sometimes
- B. Bulk density always decreases
- C. Clinkering tendency during combustion increases
- D. None of these
Explanation: Moisture lowers the useful calorific value because part of the combustion heat is consumed in evaporating water.
Correct answer: None of these- A. 8800
- B. 12000
- C. 14000
- D. 16000
Explanation: Coal tar contains substantial combustible hydrocarbons, giving it a calorific value of roughly 8,800 kcal/kg.
Correct answer: 8800- A. Gives flue gas analysis on dry basis
- B. Determines N2 in flue gas indirectly
- C. All A., B. & C.
- D. Can't determine CO in flue gas, if it is < 0.2%
Explanation: An Orsat analyser measures flue-gas components on a dry basis, obtains nitrogen by difference, and has limited sensitivity for very small…
Correct answer: All A., B. & C.