All Free Chemical Engineering MCQs with Answers
Every Chemical Engineering question in the bank, across all chapters, each with the correct answer and a written explanation. Free and unlimited, with no account needed.
6,983 questions · page 155 of 350
- 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 oil3084. Out of the following _______________ iron has the best capability to bear sudden & excessive shocks?
- 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: 183094. In the diving apparatus, helium is used along with oxygen, because it is ____________________?
- 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- A. Forging
- B. Hot rolling
- C. Cold rolling
- D. Casting
Explanation: Cold working such as cold rolling plastically deforms the metal without allowing recovery, leaving residual stresses.
Correct answer: Cold rolling- A. 5
- B. 15
- C. 30
- D. 45
Explanation: Pulverized coal mixes rapidly with air and burns efficiently, so its excess-air requirement is commonly about 15%.
Correct answer: 15