Structure 2.4: Exam Practice
Test your understanding of Materials and Bonding Models.
Part A: Multiple Choice (Mock)
Key Concepts Tested in Paper 1
- Bonding Triangle: Identifying that and form a high compound (Ionic) while and form covalent bonds.
- Alloys: Understanding that malleability decreases because disrupted layers cannot slide.
- Polymers: Recognizing that addition polymers have 100% atom economy.
- Condensation: Identifying the Amide linkage in Nylon.
Full interactive MCQs coming in future update.
Part B: Structured Questions (Paper 2)
Question 1 Bonding Triangle
Given: . Calculate the mean electronegativity and difference for MgO. Predict its position on the triangle. (2 marks)
Mark Scheme:
- Mean . Difference .
- Position: Top Vertex / Ionic Region (High ).
Question 2 Alloys
"Pure copper is ductile, but Bronze is hard." Explain this difference with reference to structure. (3 marks)
Mark Scheme:
- Tin atoms are a different size (radius) to Copper atoms.
- This disrupts the regular arrangement (lattice) of the copper atoms.
- This prevents the layers of ions from sliding over each other.
Question 3 Polymer Drawing
Draw the repeating unit of Polypropene formed from Propene (). (2 marks)
Mark Scheme:
- Correct backbone (C-C single bond).
- Methyl group () shown as a side chain.
- Continuation bonds extending through square brackets with subscript 'n'.
HL Only
Question 4 Condensation
Explain why polyesters are susceptible to hydrolysis. (1 mark)
Mark Scheme:
- The ester linkage () is polar, allowing water/nucleophiles to attack the bond in acidic/alkaline conditions.