10 questions · Form 5 Chemistry Bab 4: Polymer Chemistry
Condensation polymerisation usually results in the formation of a polymer alongside which small molecule byproduct?
Prefer reading to quizzing? All 10 questions are listed below with the answer and explanation under each one.
1. Condensation polymerisation usually results in the formation of a polymer alongside which small molecule byproduct?
Answer: B
Condensation polymerisation eliminates small molecules such as water (H₂O) or hydrogen chloride (HCl) as byproducts.
2. Which element is added to natural rubber during vulcanisation to form cross-links between polymer chains?
Answer: B
Vulcanisation involves heating natural rubber with sulfur atoms, which form cross-links between adjacent polymer chains.
3. What functional group must be present in monomer molecules to undergo addition polymerisation?
Answer: C
Addition polymerisation requires monomers with unsaturated carbon-carbon double bonds (C=C).
4. Which type of polymer can be repeatedly melted upon heating and remoulded without undergoing chemical decomposition?
Answer: C
Thermoplastics have linear or branched chains with weak intermolecular forces, allowing them to melt upon heating and be remoulded repeatedly.
5. Why does unvulcanised natural rubber degrade quickly when exposed to ozone gas or sunlight?
Answer: B
The presence of C=C double bonds in natural rubber makes it chemically active and sensitive to oxidation by ozone or oxygen.
6. Which of the following synthetic polymers is a polyamide?
Answer: B
Nylon is a polyamide formed through condensation polymerisation between dicarboxylic acids and diamines.
7. What hazardous toxic gas is released when Polyvinyl chloride (PVC) waste is incinerated?
Answer: B
PVC contains chlorine atoms; burning PVC releases toxic, corrosive hydrogen chloride (HCl) gas.
8. Why does adding ethanoic acid cause latex to coagulate?
Answer: B
Ethanoic acid releases H⁺ ions that neutralise the negative charges on the protein membrane, allowing rubber particles to collide, rupture, and coagulate.
9. How does the structural arrangement of sulfur cross-links explain the high elasticity of vulcanised rubber?
Answer: B
Sulfur cross-links prevent polymer chains from permanently slipping past one another and pull chains back to their original positions once stretching forces stop.
10. Which plastic material is classified as a thermosetting plastic?
Answer: C
Bakelite has cross-linked network structures that prevent melting, making it a thermosetting plastic.