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 89 of 350
- A. PVC
- B. Silicone rubber
- C. Polyamides
- D. Polyurethanes
Explanation: Flexible mattress foams are usually polyurethane foams, whose low-density cellular structure provides cushioning and resilience.
Correct answer: Polyurethanes- A. Nucleic acids e.g. RNA and DNA
- B. Polyurethane
- C. Polyisoprene
- D. Polysaccharides
Explanation: Polyurethane is a synthetic polymer made by reacting polyisocyanates with polyols.
Correct answer: Polyurethane- A. Dacron
- B. Cellulose
- C. Nylon-6
- D. None of these
Explanation: Cellulose is a naturally occurring polysaccharide that forms the structural basis of fibres such as cotton, whereas Dacron and Nylon-6 are…
Correct answer: Cellulose- A. Weight & strength
- B. Oxidation resistance
- C. Softness
- D. Elasticity & water solubility
Explanation: Vulcanisation introduces sulphur cross-links, increasing rubber's strength, elasticity and resistance to oxidation, while reducing its…
Correct answer: Softness- A. Bakelite
- B. Teflon
- C. Polyester
- D. Nylon-66
Explanation: Condensation of phenol with formaldehyde produces the cross-linked thermosetting resin Bakelite.
Correct answer: Bakelite- A. PVC
- B. Bakelite
- C. Polythene
- D. Polystyrene
Explanation: Bakelite is a cross-linked phenol-formaldehyde resin, so it sets permanently and cannot be remelted like a thermoplastic.
Correct answer: Bakelite- A. Nylon-6
- B. Epoxy resin
- C. Nylon-6, 10
- D. Nylon-66
Explanation: Hexamethylene diamine has six carbon atoms and adipic acid has six, producing Nylon-6,6 through condensation with elimination of water.
Correct answer: Nylon-66- A. Melamine formaldehyde resin
- B. Phenolic resin
- C. Epoxy resin
- D. Alkyd resin
Explanation: Melamine-formaldehyde resin forms a highly cross-linked, hard thermoset surface and is consequently noted for strong anti-tacking…
Correct answer: Melamine formaldehyde resin- A. Stearic acid estors
- B. Ethylene glycol
- C. Tricresyl phosphate
- D. Esters of phthalic acid
Explanation: Phthalate esters, tricresyl phosphate and stearic-acid esters are standard plasticisers because they reduce intermolecular attraction and…
Correct answer: Ethylene glycol- A. Orlon
- B. Nylon-66
- C. Saran
- D. Nylon-6
Explanation: Polycaprolactam is formed by polymerising caprolactam and is chemically known as nylon-6.
Correct answer: Nylon-6- A. Thermoplastic
- B. Thermosetting
- C. Fibrous
- D. Chemically active
Explanation: PVC softens on heating and can be repeatedly moulded, which is the defining behaviour of a thermoplastic.
Correct answer: Thermoplastic- A. Compression
- B. Transfer
- C. Injection
- D. Extrusion
Explanation: Transfer moulding is mainly used for thermosetting plastics because the preheated resin is transferred into a heated mould where it cures.
Correct answer: Transfer- A. Acrylic
- B. Spandex
- C. Natural
- D. Synthetic
Explanation: Cellulose is the principal structural polymer in plant fibres such as cotton, flax and jute, so it constitutes most natural fibres of…
Correct answer: Natural- A. Both A. & B.
- B. Ethylene
- C. Ethyl alcohol
- D. Neither A. nor B.
Explanation: SBR is made from the two monomer streams butadiene and styrene; industrial routes can derive these from ethyl alcohol and ethylene-based…
Correct answer: Both A. & B.- A. Addition polymerisation
- B. Copolymerisation
- C. Chain polymerisation
- D. None of these
Explanation: Copolymerisation is polymerisation involving two or more chemically different monomers, such as styrene and butadiene in SBR.
Correct answer: Copolymerisation1776. Tubeless tyres are made of ______________ rubber, which is a co-polymer of isoprene & isobutylene?
- A. Nitrile
- B. Silicone
- C. Butyl
- D. Neoprene
Explanation: Butyl rubber is a copolymer of isobutylene with a small amount of isoprene and has very low gas permeability, making it suitable for…
Correct answer: Butyl- A. Buckets
- B. Pipes
- C. Filaments
- D. Tubings
Explanation: Extrusion produces continuous products with a fixed cross-section, such as pipes, tubing and filaments.
Correct answer: Buckets- A. Impart flexibility
- B. All A., B. and C.
- C. Develop new improved properties not present in the original resin
- D. Improve workability during fabrication
Explanation: Plasticisers lower intermolecular forces in a polymer, increasing flexibility and making fabrication easier.
Correct answer: All A., B. and C.- 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 forming1780. 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