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. 300
- B. 1100
- C. 700
- D. 150
Explanation: Low-temperature carbonisation is commonly carried out around 500 to 700°C, whereas high-temperature carbonisation is usually near 900 to…
Correct answer: 700682. With increase in calorific value of fuels, their adiabatic flame temperatures__________________?
- A. May increase or decrease; depends on the quantity of products of combustion
- B. Decrease
- C. Remain unchanged
- D. Increase
Explanation: Adiabatic flame temperature depends not only on fuel calorific value but also on the amount and heat capacity of the combustion products.
Correct answer: May increase or decrease; depends on the quantity of products of combustion- A. It achieves higher fuel combustion efficiency
- B. It cannot burn low grade coal
- C. Less heat transfer surface area is required in boilers
- D. None of these
Explanation: Fluidised-bed combustion is particularly suitable for low-grade coal because it can burn fuels with high ash and moisture contents…
Correct answer: It cannot burn low grade coal- A. Flame length
- B. Quantity of flue gas
- C. Flame temperature
- D. Ignition temperature
Explanation: Preheating a gaseous fuel raises the initial enthalpy of the reactants, so less heat is needed to reach the reaction temperature and the…
Correct answer: Flame temperature685. Mineral matter content (M) and ash content A. in coal are approximately related as _______________?
- A. M = 1.5A
- B. M = A
- C. M = 1.1A
- D. M = 2A
Explanation: Coal ash is approximately 90% of its mineral matter, so mineral matter is estimated as A divided by 0.9, or about 1.1A. Hence, M = 1.1A.
Correct answer: M = 1.1A- A. LPG
- B. Sewage gas
- C. Producer gas
- D. Natural gas
Explanation: LPG contains energy-rich hydrocarbons such as propane and butane, giving it a much higher calorific value per normal cubic metre than…
Correct answer: LPG- A. More explosive and inflammable
- B. All A., B. and C.
- C. Lighter
- D. Less poisonous
Explanation: Coke oven gas contains a high proportion of hydrogen and methane, making it lighter and more inflammable than blast-furnace gas.
Correct answer: All A., B. and C.- A. C + H2O ↔ CO + H2
- B. CO + H2O ↔ CO2 + H2
- C. 2CO ↔ C + CO2
- D. C + 2H2O ↔ CO2 + 2H2
Explanation: The Neumann reversal is the reverse carbon monoxide decomposition reaction, written as 2CO ⇌ C + CO2.
Correct answer: 2CO ↔ C + CO2- A. 1,800
- B. 3,200
- C. 5,400
- D. 10,200
Explanation: Only methane and hydrogen contribute appreciably: 0.60(about 8560) + 0.10(about 2570) gives roughly 5400 kcal/Nm³.
Correct answer: 5,400- A. Gross calorific value at constant pressure
- B. Higher calorific value at constant volume
- C. Lower calorific value at constant pressure
- D. Net calorific value at constant volume
Explanation: A bomb calorimeter operates at constant volume and condenses the water formed during combustion, so it measures higher or gross calorific…
Correct answer: Higher calorific value at constant volume- A. 1100
- B. 1250
- C. 1350
- D. 1400
Explanation: Coal ash with a fusion temperature below about 1100°C softens and fuses readily on furnace grates, producing clinker.
Correct answer: 1100- A. 10,000
- B. 2,500
- C. 25,000
- D. 35,000
Explanation: Natural gas commonly supplies about 9,000 to 10,000 kcal per normal cubic metre, depending on its composition.
Correct answer: 10,000- A. Brittleness of steel made by using it
- B. Increase in its strength
- C. Decrease in its calorific value
- D. None of these
Explanation: Sulphur and phosphorus are harmful impurities in coke used for iron and steel production because they make the resulting steel brittle.
Correct answer: Brittleness of steel made by using it- A. Very little ash content
- B. Low ignition temperature
- C. High fusion point of its ash
- D. Low adiabatic flame temperature
Explanation: Volatile matter evolves combustible gases readily, so coal containing more of it generally ignites at a lower temperature.
Correct answer: Low ignition temperature- A. Calorific value, cleanliness and relatively low distribution cost (due to its low specific gravity)
- B. Adiabatic flame temperature
- C. All A., B. and C.
- D. Heat release rate (thus requiring smaller combustion chamber)
Explanation: Coke oven gas has higher calorific value, burns more cleanly, and is relatively inexpensive to distribute because its specific gravity is…
Correct answer: All A., B. and C.- A. Clarain
- B. Micrinite
- C. Fusinite
- D. Liptinite
Explanation: Micrinite, fusinite, and liptinite are maceral constituents of coal. Clarain is a microlithotype or banded coal variety, not a single…
Correct answer: Clarain- A. Coke oven gas
- B. Lump coal (fixed on chain grate)
- C. Pulverised coal
- D. Furnace oil
Explanation: Lump coal on a chain grate has the poorest contact between fuel and air, so it needs the greatest excess-air supply for complete…
Correct answer: Lump coal (fixed on chain grate)698. Coking time in a commercial high temperature coal carbonisation plant is about ______________ hours?
- A. 6
- B. 18
- C. 28
- D. 36
Explanation: High-temperature coke ovens typically require roughly 16 to 20 hours for carbonisation, making 18 hours the closest standard value.
Correct answer: 18- A. Increases
- B. May increase or decrease; depends on the type of fuel
- C. Remain same
- D. Decreases
Explanation: A higher C/H ratio means less hydrogen is burned per unit of fuel, so less water vapour is produced.
Correct answer: Decreases- A. 2000
- B. 600
- C. 1100
- D. 1600
Explanation: High-temperature carbonisation is carried out at about 900–1200°C, commonly taken as approximately 1100°C.
Correct answer: 1100