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. CaSO4
  • B. MgCO3
  • C. Na2CO3
  • D. CaCO3

Explanation: Limestone is primarily calcium carbonate, CaCO3, although natural deposits may contain small amounts of impurities such as magnesium…

Correct answer: CaCO3
  • A. Oleum
  • B. Sulphurous acid
  • C. Concentrated H2SO4
  • D. None of these

Explanation: Oleum is sulphuric acid containing dissolved excess SO3, commonly represented as H2SO4·SO3.

Correct answer: Oleum
  • A. Remove double bonds
  • B. None of these
  • C. Improve its resistance to oxidation
  • D. Raise its melting point

Explanation: Hydrogenation removes carbon-carbon double bonds, raises the melting point, and improves resistance to oxidation by reducing unsaturation.

Correct answer: None of these
  • A. Yeast
  • B. Maltase
  • C. Diastase
  • D. None of these

Explanation: Diastase, mainly the amylase enzyme, hydrolyses starch into maltose and related smaller sugars.

Correct answer: Diastase
  • A. Tackiness
  • B. Resistance to the action of organic solvent
  • C. Maximum service temperature
  • D. Tensile strength

Explanation: Vulcanisation forms sulphur cross-links between rubber chains, reducing their stickiness or tackiness.

Correct answer: Tackiness
  • A. Saponification
  • B. Esterification
  • C. Neutralisation
  • D. Acidification

Explanation: An alcohol reacts with a carboxylic acid to form an ester and water, a reaction known as esterification.

Correct answer: Esterification
  • A. As a plasticiser for unsaturated polyester
  • B. As an anti-skinning agent in paint
  • C. In the manufacture of synthetic rubber
  • D. None of these

Explanation: Butadiene's principal industrial application is polymerisation to synthetic rubbers such as polybutadiene and styrene-butadiene rubber.

Correct answer: In the manufacture of synthetic rubber
  • A. Lead glass
  • B. High silica (borosilicate) glass
  • C. Fibre glass
  • D. Photo-sensitive glass

Explanation: Photosensitive glass changes its structure or optical properties when exposed to light and is used in specialised optical applications.

Correct answer: Photo-sensitive glass
  • A. Palmitic
  • B. Oxalic
  • C. Stearic
  • D. Oleic

Explanation: Oleic acid is unsaturated because it contains a carbon-carbon double bond.

Correct answer: Oleic
  • A. Blotting paper
  • B. Writing paper
  • C. Bond paper
  • D. Coloured paper

Explanation: Blotting paper is designed to absorb liquids, so fillers that improve opacity or smoothness are avoided because they would reduce…

Correct answer: Blotting paper
  • A. Sugar
  • B. Paper
  • C. Alcohol from molasses
  • D. Phenol formaldehyde

Explanation: A Fourdrinier machine forms a continuous sheet of paper from a dilute pulp suspension on a moving wire screen, followed by pressing and…

Correct answer: Paper
  • A. All A , B. and C.
  • B. It contains ≥ 40% metal
  • C. The metal present in it is costly
  • D. A metal can be economically extracted from it

Explanation: An ore is a mineral or rock from which a metal can be extracted economically using available processing methods.

Correct answer: A metal can be economically extracted from it
  • A. Soda ash
  • B. Washing soda
  • C. Plaster of Paris
  • D. Calcite

Explanation: Anhydrous sodium carbonate, Na₂CO₃, is called soda ash. Washing soda is hydrated sodium carbonate, commonly Na₂CO₃·10H₂O, so the water of…

Correct answer: Soda ash
  • A. Cement
  • B. Caustic soda
  • C. Potteries
  • D. Glass

Explanation: Brine, a concentrated aqueous solution of sodium chloride, is electrolysed to produce caustic soda along with chlorine and hydrogen.

Correct answer: Caustic soda
  • A. Extractive distillation technique
  • B. Liquid extraction technique
  • C. Evaporation followed by vacuum distillation
  • D. None of these

Explanation: Lye from soap manufacture is first concentrated by evaporation, then glycerine is separated by vacuum distillation.

Correct answer: Evaporation followed by vacuum distillation
  • A. Penicillin
  • B. Streptomycin
  • C. Tetracycline
  • D. Quinine

Explanation: Quinine is an antimalarial alkaloid, not an antibiotic. Penicillin, streptomycin and tetracycline are all established antibacterial…

Correct answer: Quinine
  • A. Biochemical
  • B. Chemical
  • C. Photochemical
  • D. Electrochemical

Explanation: Enzymes are biological organic catalysts that accelerate biochemical reactions, often under mild temperature and pH conditions.

Correct answer: Biochemical
  • A. Impart adhesive properties
  • B. Improve opacity
  • C. Impart resistance to penetration by liquids
  • D. None of these

Explanation: Rosin soap is used for sizing paper, making the fibres less readily wetted and therefore more resistant to penetration by water and other…

Correct answer: Impart resistance to penetration by liquids
  • A. Caustic soda
  • B. Soda lime
  • C. Caustic potash
  • D. Soda ash

Explanation: The Solvay process converts brine and limestone into sodium carbonate, commonly called soda ash.

Correct answer: Soda ash
  • A. 30
  • B. 50
  • C. 70
  • D. 90

Explanation: Commercial benzol is a light-oil fraction containing roughly 70% benzene, with the remainder mainly toluene, xylenes and other…

Correct answer: 70