Q84 · Practice questionSimple familiar4 marks
QUESTION 84 (4 marks)
Tetrafluoroethene, , forms PTFE.
a) Draw its polymer repeat unit with continuing bonds. [2 marks]
b) Explain why this is addition polymerisation rather than condensation polymerisation. [2 marks]
WORKED SOLUTION
4 marksPractice marking scheme
; the double bond opens without elimination of a small molecule.
The monomer carbon double bond becomes a single bond within a chain. All monomer atoms are retained, unlike condensation that eliminates water or another small molecule.
- Correct CF₂–CF₂ repeat structure. [1 marks]
- Shows continuing bonds/brackets and n. [1 marks]
- Explains opening of alkene double bond. [1 marks]
- Explains no small molecule eliminated. [1 marks]
Practice question aligned to the current QCAA syllabus; review the worked solution and marking criteria.
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