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. Aluminium chloride
  • B. Nickel
  • C. Iron
  • D. Platinum on alumina

Explanation: Catalytic reforming commonly uses platinum dispersed on alumina, often with a second metal such as rhenium.

Correct answer: Platinum on alumina
  • A. Stiffness
  • B. Lubricating properties (e.g. oilness)
  • C. Service temperature
  • D. Variation in viscosity with temperature

Explanation: The penetration test measures grease consistency, which is its resistance to deformation and is commonly described as stiffness or…

Correct answer: Stiffness
  • A. Preheating temperature corresponding to viscosity of 25 centistokes
  • B. Flash point
  • C. Flame temperature
  • D. Fire point

Explanation: At the flash point, vapours above the liquid ignite momentarily when exposed to a flame.

Correct answer: Flash point
  • A. Hydro-treatment
  • B. Solvent refining
  • C. Clay treatment
  • D. Deoiling

Explanation: Deoiling is mainly associated with separating oil from wax during wax processing, rather than upgrading the quality of the lubricating-oil…

Correct answer: Deoiling
  • A. Is optically active
  • B. Constitutes mainly of olefins
  • C. Does not contain asphalt
  • D. Does not contain aromatics

Explanation: Petroleum can be optically active because some of its complex hydrocarbon molecules are chiral.

Correct answer: Is optically active
  • A. Diesel
  • B. Fuel oil
  • C. Kerosene
  • D. Petrol

Explanation: Fuel oil is generally the heaviest of these products and retains more sulphur-containing compounds from the crude oil.

Correct answer: Fuel oil
  • A. Octane number
  • B. Lead susceptibility
  • C. Gum forming tendency & thoroughness of refining
  • D. None of these

Explanation: Gasoline colour mainly reflects the presence of impurities, gum-forming materials, and how thoroughly the product was refined.

Correct answer: Gum forming tendency & thoroughness of refining
  • A. Catalytic cracking
  • B. Alkylation
  • C. Hydrotreating
  • D. Catalytic reforming

Explanation: Catalytic reforming rearranges and dehydrogenates low-octane hydrocarbons to form aromatic compounds and isoparaffins, increasing gasoline…

Correct answer: Catalytic reforming
  • A. Olefins
  • B. Paraffins
  • C. Naphthenes
  • D. None of these

Explanation: Isomerisation changes straight-chain paraffins into branched-chain isoparaffins, improving octane quality.

Correct answer: Paraffins
  • A. 2
  • B. 6
  • C. 12
  • D. 18

Explanation: Straight-run distillation separates only the naturally occurring fractions of crude oil, and naphtha may constitute roughly 6% in the…

Correct answer: 6
  • A. Phenol
  • B. Sodium plumbite
  • C. Methanol
  • D. Potassium isobutyrate

Explanation: Potassium isobutyrate acts as a solutizer, helping sulfur compounds remain accessible in the caustic phase during sweetening.

Correct answer: Potassium isobutyrate
  • A. 4
  • B. 3
  • C. 2
  • D. 1

Explanation: The Reid vapor-pressure bomb uses an air chamber four times the volume of the liquid chamber, giving an air-to-liquid volume ratio of 4:1.

Correct answer: 4
  • A. Aniline point
  • B. Flash point and acid value
  • C. Dielectric strength
  • D. Copper strip corrosion test

Explanation: Transformer oil is routinely checked for dielectric strength, acidity, flash point and corrosiveness; aniline point is mainly important…

Correct answer: Aniline point
  • A. Same as petroleum ether
  • B. A mixture of microcrystalline wax in viscous hydrocarbon liquids
  • C. Petroleum coke
  • D. None of these

Explanation: Petrolatum, or petroleum jelly, is a semisolid blend of microcrystalline wax with viscous hydrocarbon oil.

Correct answer: A mixture of microcrystalline wax in viscous hydrocarbon liquids
  • A. Petroleum ether
  • B. Naphtha
  • C. Methyl-ethyl-ketone (MEK)
  • D. Sodium plumbite

Explanation: MEK is widely used for solvent dewaxing, commonly in combination with toluene to maintain oil solubility while wax precipitates on…

Correct answer: Methyl-ethyl-ketone (MEK)
  • A. Thiophenes
  • B. Pyrroles
  • C. Sulphones
  • D. Mercaptans

Explanation: Thiophenes, mercaptans and sulphones are recognised sulphur-containing petroleum compounds.

Correct answer: Pyrroles
  • A. One fourth
  • B. One third
  • C. Half
  • D. One eighth

Explanation: Liquid LPG, mainly propane and butane, has a density of roughly 0.5 g/cc, about half the density of water.

Correct answer: Half
  • A. Paraffinic
  • B. Aromatic
  • C. Mixed
  • D. Naphthenic

Explanation: Naphthenic-base crude contains substantial cycloparaffinic material and yields asphaltic residues, so it is commonly called asphaltic…

Correct answer: Naphthenic
  • A. Naphtha
  • B. Kerosene
  • C. LSHS
  • D. Furnace oil

Explanation: Naphtha is a light petroleum fraction and generally contains less sulphur than heavier products such as kerosene, LSHS and furnace oil.

Correct answer: Naphtha
  • A. Nitrogen
  • B. Sulphur
  • C. Oxygen
  • D. None of these

Explanation: Ethyl mercaptan, or ethanethiol, has the formula C₂H₅SH, so its characteristic functional group contains sulphur.

Correct answer: Sulphur