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. Blow moulding
- B. Vacuum thermo forming
- C. Injection moulding
- D. None of these
Explanation: Vacuum thermoforming heats a thermoplastic sheet and draws it against a mould by vacuum, making thin articles such as trays and packaging.
Correct answer: Vacuum thermo forming1182. Peptizers like aromatic mercaptans (e.g. thiophenes) are added in rubber to _________________?
- A. Protect rubber goods from attack by oxygen & ozone present in the atmosphere
- B. Reduce the time of vulcanisation and quantity of vulcanising agent
- C. Reduce its viscosity to permit easier processing
- D. Increase its viscosity
Explanation: Peptizers break down rubber chains during mastication, lowering its viscosity and making mixing and shaping easier.
Correct answer: Reduce its viscosity to permit easier processing- A. Polystyrene
- B. Poly chloroprene
- C. Polybutadiene
- D. Polyisoprene
Explanation: Natural rubber is chiefly cis-1,4-polyisoprene, formed from isoprene units.
Correct answer: Polyisoprene- A. Polypropylene
- B. PVC
- C. Polythene
- D. Polyvinyl acetate
Explanation: Vinyl flooring uses sheets of polyvinyl chloride, whose durability, flexibility and resistance to moisture suit floor coverings.
Correct answer: PVC- A. Cellulose nitrate
- B. Regenerated cellulose nitrate
- C. None of these
- D. Regenerated cellulose acetate
Explanation: Viscose rayon is regenerated cellulose produced by dissolving cellulose and regenerating it as fibres.
Correct answer: None of these- A. Higher melting point
- B. Higher tensile strength
- C. None of these
- D. Lower density
Explanation: Branches prevent polymer chains from packing closely, so branched polymers generally have lower density than their linear counterparts.
Correct answer: Lower density- A. Bakelite
- B. Polythene
- C. Epoxy resin
- D. None of these
Explanation: Polythene is a thermoplastic that softens on heating and can be remoulded, allowing recycling and reuse.
Correct answer: Polythene- A. PVC
- B. Polythene
- C. Bakelite
- D. Teflon
Explanation: Bakelite is a phenol-formaldehyde copolymer made from two different monomers.
Correct answer: Bakelite- A. A thermosetting material
- B. A condensation polymerisation product
- C. Made by employing emulsion polymerisation
- D. None of these
Explanation: PVC is an addition polymer and can be manufactured by emulsion polymerisation, although suspension polymerisation is also widely used…
Correct answer: Made by employing emulsion polymerisation1190. Polycondensation of saturated dicarboxylic acid with polyhydric alcohol produces________________?
- A. Epoxy resin
- B. Alkyd resin
- C. Polyamide
- D. Phenolic resin
Explanation: A saturated dicarboxylic acid reacting with a polyhydric alcohol forms a polyester resin; when modified with fatty acids or oils, it is…
Correct answer: Alkyd resin- A. Polybutadiene
- B. Styrene butadiene rubber (SBR)
- C. Poly chloroprene
- D. Polyurethane
Explanation: Neoprene is the trade name for polychloroprene, produced by polymerising chloroprene. SBR and polybutadiene are different synthetic rubbers.
Correct answer: Poly chloroprene- A. Flexibility
- B. Chemical resistance
- C. Tensile strength
- D. All A., B. & C.
Explanation: Plasticisers reduce intermolecular attraction and increase chain mobility, making the polymer softer and more flexible.
Correct answer: Flexibility- A. Dacron
- B. Cellulose
- C. Nylon
- D. None of these
Explanation: Tyre casings commonly use reinforcing cords made from nylon or polyester such as Dacron.
Correct answer: Cellulose- A. Cellulose
- B. Lignin
- C. Pentogens
- D. None of these
Explanation: Bagasse mainly contains cellulose, together with lignin and pentosans, often misspelled here as “pentogens.” Since all three intended…
Correct answer: None of these- A. Polyurethane
- B. Teflon
- C. Silicone rubber
- D. Epoxy resin
Explanation: Tetrafluoroethylene, C₂F₄, polymerises to polytetrafluoroethylene, or PTFE, widely known by the trade name Teflon.
Correct answer: Teflon- A. Unvulcanised raw rubber
- B. Natural rubber
- C. Highly vulcanised rubber
- D. Adhesive
Explanation: Ebonite is rubber containing a very high proportion of sulphur, typically about 25 to чи 40%, making it hard and rigid.
Correct answer: Highly vulcanised rubber- A. -5
- B. 10-30
- C. 250-280
- D. 500-600
Explanation: Caprolactam ring-opening polymerisation to nylon-6 is carried out at about 250 to 280°C.
Correct answer: 250-280- A. Low density polyethylene (LDPE)
- B. High density polyethylene (HDPE)
- C. Polypropylene
- D. Unsaturated polyester
Explanation: LDPE has a highly branched molecular structure, giving it flexibility and allowing it to be formed into flexible pipes and tubing.
Correct answer: Low density polyethylene (LDPE)- A. Teflon
- B. SBR
- C. PTFE
- D. Polycrylates
Explanation: Buna-S is the styrene-butadiene rubber copolymer, abbreviated SBR. Teflon and PTFE are names for the fluoropolymer polytetrafluoroethylene.
Correct answer: SBR1200. Synthetic polymer produced by using terephthalic acid and ethylene glycol is _________________?
- A. PVC
- B. Nylon-66
- C. Terylene
- D. Polystyrene
Explanation: Terephthalic acid reacts with ethylene glycol to form polyethylene terephthalate, commonly called Terylene.
Correct answer: Terylene