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. Zn
  • B. Cu
  • C. Fe
  • D. Ni

Explanation: Insulin contains zinc, which is coordinated by specific histidine residues and helps stabilize the insulin structure.

Correct answer: Zn
  • A. 80-85
  • B. 60-65
  • C. 40-45
  • D. 20-25

Explanation: Indian iron ore commonly contains about 60–65% iron, although the exact grade varies by deposit.

Correct answer: 60-65
  • A. Metal changes from liquid state to solid state at freezing temperature
  • B. Liquid metal temperature drops from pouring temperature to room temperature
  • C. Solid phase temperature drops from freezing temperature to the room temperature
  • D. Liquid metal temperature drops from pouring temperature to freezing temperature

Explanation: Pattern shrinkage allowance mainly compensates for contraction of the solid casting as it cools from its freezing temperature to room…

Correct answer: Solid phase temperature drops from freezing temperature to the room temperature
  • A. None of these
  • B. Makes it non-potable
  • C. Means distillation of water
  • D. Makes it potable

Explanation: Desalination removes dissolved salts from brackish water or seawater, producing water that can be made potable after suitable treatment…

Correct answer: Makes it potable
  • A. Drying oil
  • B. Dryer
  • C. Thinner
  • D. None of these

Explanation: Drying oil is the nonvolatile, film-forming part of paint that oxidizes and hardens to form the continuous coating.

Correct answer: Drying oil
  • A. White
  • B. Wrought
  • C. Cast
  • D. Pig

Explanation: Wrought iron is relatively tough and ductile, so it can absorb sudden impact and shock better than brittle white iron or ordinary cast…

Correct answer: Wrought
  • A. N2O4
  • B. N2O3
  • C. N2O5
  • D. N2O

Explanation: N₂O is a neutral oxide because it does not normally form an acid or base with water.

Correct answer: N2O
  • A. 350-400
  • B. 450-500
  • C. 550-600
  • D. 250-300

Explanation: Aluminium is commonly hot-extruded at roughly 350–400°C in basic manufacturing correlations.

Correct answer: 350-400
  • A. 0
  • B. 1
  • C. 7
  • D. 14

Explanation: Pure distilled water is neutral at 25°C because its hydrogen-ion and hydroxide-ion concentrations are equal, giving pH 7.

Correct answer: 7
  • A. Nucleons
  • B. Neutrons
  • C. Atoms
  • D. Electrons

Explanation: Radioactive half-life is the time required for half of the radioactive nuclei or atoms in a sample to undergo decay.

Correct answer: Atoms
  • A. Ammonium phosphate
  • B. Ammonium sulphate
  • C. Animal charcoal
  • D. Calcium phosphate

Explanation: Bone ash is produced by calcining bones and consists mainly of calcium phosphate, especially hydroxyapatite-related phosphates.

Correct answer: Calcium phosphate
  • A. Graphite
  • B. Lead sulphide
  • C. Lead
  • D. Both B. & C.

Explanation: The writing core of a lead pencil is graphite, an allotrope of carbon, not metallic lead or lead sulphide.

Correct answer: Graphite
  • A. Sherardizing
  • B. Tinning
  • C. Galvanising
  • D. None of these

Explanation: Galvanising and tinning are hot-dipping processes for applying molten zinc and tin, respectively.

Correct answer: Sherardizing
  • A. Septic tank
  • B. Oxidation well
  • C. Digestor
  • D. Lagoon

Explanation: The underground chamber in which organic matter is anaerobically decomposed to produce biogas is called a digester.

Correct answer: Digestor
  • A. 6
  • B. 18
  • C. 38
  • D. 52

Explanation: Fire-tube boilers are generally restricted to moderate pressures, commonly around 18 to 20 kg/cm².

Correct answer: 18
  • A. Not soluble in blood at high pressure
  • B. Easily available
  • C. Lighter than nitrogen
  • D. Completely miscible with oxygen

Explanation: Helium is chemically inert and much less soluble in blood than nitrogen at high pressure, reducing the risk of decompression sickness in…

Correct answer: Not soluble in blood at high pressure
  • A. 9 : 1
  • B. 17 : 1
  • C. 23 : 1
  • D. 29 : 1

Explanation: For CH₄, the stoichiometric reaction requires two moles of O₂; with air containing about 23.2% oxygen by mass, the required air is…

Correct answer: 17 : 1
  • A. Fire-fighting
  • B. Cooling
  • C. Drinking
  • D. Evaporation to produce steam

Explanation: Potable water is treated to a quality suitable for human consumption, so it is used for drinking.

Correct answer: Drinking
  • A. Cold
  • B. Induction
  • C. Age
  • D. Work

Explanation: Plastic deformation during cold working increases dislocation density, making further deformation more difficult and increasing hardness.

Correct answer: Work
  • A. Borosilicate
  • B. Supermax
  • C. High silica
  • D. Lead

Explanation: Supermax glass is used for mercury-in-glass thermometers designed for temperatures around 500°C because it tolerates high temperature…

Correct answer: Supermax