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. 3
  • B. 11
  • C. 22
  • D. 28

Explanation: The Watson or UOP characterization factor of crude petroleum is typically about 10 to 13, with approximately 11 being a representative…

Correct answer: 11
  • A. Is less than
  • B. Is more than
  • C. May be either more or less than
  • D. Is same as

Explanation: Reid vapour pressure is measured under a fixed condition at 37.8°C, whereas true vapour pressure refers to equilibrium at the specified…

Correct answer: May be either more or less than
  • A. Atmospheric
  • B. 10 atm
  • C. Vacuum
  • D. 3 atm

Explanation: A crude topping column performs the initial atmospheric distillation of crude oil, separating gases, naphtha, kerosene and gas oils near…

Correct answer: Atmospheric
  • A. Aluminium chloride
  • B. Phosphoric acid on kieselguhr
  • C. Nickel
  • D. Vanadium pentoxide

Explanation: Catalytic polymerisation of light olefins traditionally uses phosphoric acid supported on kieselguhr.

Correct answer: Phosphoric acid on kieselguhr
  • A. Calcium
  • B. Potassium
  • C. Magnesium
  • D. Sodium

Explanation: Magnesium chloride hydrolyses during crude-oil distillation to form hydrochloric acid, making it a major source of corrosive HCl.

Correct answer: Magnesium
  • A. Diesel
  • B. Gasoline
  • C. Naphtha
  • D. Atmospheric residue

Explanation: Atmospheric residue is the heaviest petroleum fraction and retains most of the sulphur-containing compounds after distillation.

Correct answer: Atmospheric residue
  • A. High smoke point
  • B. Low smoke point
  • C. High aromatics content
  • D. Low paraffins content

Explanation: A high smoke point indicates that kerosene burns with little tendency to form soot or smoke.

Correct answer: High smoke point
  • A. pH value
  • B. All A., B. and C.
  • C. Temperature
  • D. Water percentage

Explanation: The conductivity of a crude oil-water mixture changes with its water fraction, ionic character or pH, and temperature.

Correct answer: All A., B. and C.
  • A. 100
  • B. 0
  • C. 70
  • D. ∞

Explanation: The octane-number scale uses n-heptane as the zero reference fuel and isooctane as the 100 reference fuel.

Correct answer: 0
  • A. PCM
  • B. Tar
  • C. Low viscosity furnace oil
  • D. Light diesel oil

Explanation: Light diesel oil has sufficiently low viscosity to flow and atomise without preheating.

Correct answer: Light diesel oil
  • A. 1
  • B. 20
  • C. 100
  • D. 500

Explanation: Char value measures carbonaceous deposit left on the wick during standard burning, so a lower value indicates cleaner kerosene.

Correct answer: 20
  • A. Liquid petroleum gas
  • B. Liquefied petroleum gas
  • C. Liquid petrol gas
  • D. Liquefied petrol gas

Explanation: LPG means liquefied petroleum gas: petroleum-derived hydrocarbons, mainly propane and butane, stored as a liquid under pressure.

Correct answer: Liquefied petroleum gas
  • A. 0.03
  • B. 3
  • C. 35
  • D. 70

Explanation: Electrostatic desalting removes most brine and reduces residual salt in crude oil to roughly 3 pounds per thousand barrels.

Correct answer: 3
  • A. Unsaturated hydrocarbon content
  • B. Quantity of butane
  • C. Quantity of propane
  • D. Calorific value

Explanation: Wet natural gas contains more heavier hydrocarbons such as propane, butane and higher components than dry gas.

Correct answer: Calorific value
  • A. Furnace oil
  • B. Kerosene
  • C. Petrol
  • D. Diesel

Explanation: API gravity decreases as petroleum becomes denser and heavier. Furnace oil is the heaviest option listed, so it has the lowest API gravity.

Correct answer: Furnace oil
  • A. Thermal cracking
  • B. Coking
  • C. Gum formation
  • D. Discoloration

Explanation: Vacuum lowers boiling temperatures so heavy fractions can be distilled without severe thermal damage.

Correct answer: Coking
  • A. Kjeldahl
  • B. Dumas
  • C. Junkers calorimeter
  • D. Bomb calorimeter

Explanation: In the bomb method, the crude oil is completely burned in oxygen and the sulfur oxides formed are measured, allowing sulfur content to be…

Correct answer: Bomb calorimeter
  • A. Freezing point
  • B. Viscosity
  • C. Calorific value
  • D. Flash point

Explanation: Jet fuel must remain fluid at the very low temperatures encountered at high altitude, making a low freezing point essential.

Correct answer: Freezing point
  • A. Sulphur content
  • B. Aniline point
  • C. Viscosity
  • D. Flash point

Explanation: Sulphur content, viscosity and flash point directly affect fuel-oil handling, combustion and safety.

Correct answer: Aniline point
  • A. It is highly aromatic in nature
  • B. It has a very low diesel index
  • C. It is highly paraffinic in nature
  • D. Its ignition quality is very poor

Explanation: Aniline point increases with paraffinic character and decreases with aromatic content because aromatics dissolve more readily in aniline.

Correct answer: It is highly paraffinic in nature