IBDP Official Exam Material
FREE Past Paper Questions by Topic
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Topic A: Materials
For both SL and HL students
1a. [2 marks]
Carbon fibre reinforced plastic (CFRP) is a useful composite. Epoxy is a thermoset polymer that is used as a binding polymer when making CFRP.
Outline the two distinct phases of this composite.
1b. [1 mark]
Thermoplastic composites are increasingly replacing thermosets.
Suggest one advantage of thermoplastic polymers over thermosets.
1c. [3 marks]
Explain how thermoplastics, such as polyvinylchloride, PVC, can be made more flexible by the addition of phthalate ester plasticizers.
1d. [2 marks]
Explain why phthalates are replaced by other plasticizers in the production of plastics.
2a. [2 marks]
There has been significant growth in the use of carbon nanotubes, CNT.
Explain these properties of carbon nanotubes.
2b. [1 mark]
Alloying metals changes their properties. Suggest one property of magnesium that could be improved by making a magnesium–CNT alloy.
3a. [2 marks]
Catalysts are commonly used in industry.
Describe how a heterogeneous catalyst provides an alternative pathway for a reaction.
3b. [1 mark]
Distinguish between heterogeneous and homogeneous catalysts, giving one difference.
3c. [2 marks]
Nanotubes are used to support the active material in nanocatalysts.
Explain why oxygen cannot be used for the chemical vapour deposition (CVD) preparation of carbon nanotubes.
4a. [1 mark]
Polypropene is used to make many objects including carpets, stationery and laboratory equipment.
Draw a section of an isotactic polypropene polymer chain containing four repeating units.
4b. [1 mark]
Predict, with a reason, whether isotactic or atactic polypropene has the higher melting point.
4c. [1 mark]
Polypropene is a thermoplastic. Outline what is meant by thermoplastic.
4d. [2 marks]
Discuss why the recycling of plastics is an energy intensive process.
5a. [2 marks]
Metals are extracted from their ores by various means.
Discuss why different methods of reduction are needed to extract metals.
5b. [2 marks]
Aluminium is produced by the electrolysis of alumina (aluminium oxide) dissolved in cryolite.
Determine the percentage of ionic bonding in alumina using sections 8 and 29 of the data booklet.
5c. [3 marks]
Write half-equations for the electrolysis of molten alumina using graphite electrodes, deducing the state symbols of the products.
Anode (positive electrode):
Cathode (negative electrode):
6a. [2 marks]
A soap solution can form a liquid-crystal state.
Describe the arrangement of soap molecules in the nematic liquid crystal phase.
6b. [1 mark]
State how liquid crystals are affected by an electric field.
7a. [1 mark]
Lithium has many uses.
Identify the type of bonding in lithium hydride, using sections 8 and 29 of the data booklet.
7b. [2 marks]
Explain why lithium is paramagnetic while lithium hydride is diamagnetic by referring to electron configurations.
7c. [1 mark]
The emission spectra obtained by ICP-OES for a mixture containing the isotope 6Li (Li-6) and naturally occurring lithium (Li (N)) is shown.
Sugggest why ICP-OES does not give good quantitative results for distinguishing 6Li from naturally occurring lithium.
7d. [1 mark]
Suggest a better method.
7e. [2 marks]
Lithium is obtained by electrolysis of molten lithium chloride. Calculate the time, in seconds, taken to deposit 0.694 g Li using a current of 2.00 A.
Q (charge) = I (current) × t (time)
8a. [2 marks]
Polybutadiene, used in truck tyres, is a polymer of buta-1,3-diene. The spatial arrangement of atoms in the polymer depends on the type of catalyst used.
Outline two differences between heterogeneous and homogeneous catalysts.
8b. [2 marks]
Suggest, giving a reason, how elastomers used for the tyre tread can increase the traction between the tyre and the road.
8c. [2 marks]
Tyre fires emit trace quantities of polychlorinated dibenzofurans and polychlorinated dibenzo-p-dioxin.
Outline, using section 31 of the data booklet, why polychlorinated dibenzofuran is not classed chemically as a dioxin but considered “dioxin-like”.
8d. [1 mark]
The trace quantities of dioxins from tyre fires are rarely inhaled and instead settle on the ground.
Describe why this is a health concern.
9a. [2 marks]
Nanotechnology has allowed the manipulation of materials on the atomic level.
Describe the structure and bonding of a carbon nanotube.
Structure:
Bonding:
10. [1 mark]
Suggest one application for carbon nanotubes.
11. [3 marks]
Describe the characteristics of the nematic liquid crystal phase and the effect that an electric field has on it.
Shape of molecules:
Distribution:
Effect of electric field:
12a. [3 marks]
Metals are extracted from their ores by several methods, including electrolysis and reduction with carbon.
Determine the mass of aluminium, in g, that could be extracted from an appropriate solution by a charge of 48250 C. Use sections 2 and 6 of the data booklet.
12b. [2 marks]
Once extracted, the purity of the metal can be assessed using ICP-MS. Suggest two advantages of using plasma technology rather than regular mass spectrometry.
12c. [2 marks]
Explain the action of metals as heterogeneous catalysts.
12d. [2 marks]
Outline how alloys conduct electricity and why they are often harder than pure metals.
Conduct electricity:
Harder than pure metals:
12e. [1 mark]
Carbon nanotubes are added to metals to increase tensile strength.
Write an equation for the formation of carbon nanotubes from carbon monoxide.
13a. [2 marks]
Polymers have a wide variety of uses but their disposal can be problematic.
Draw a section of isotactic polychloroethene (polyvinylchloride, PVC) showing all the atoms and all the bonds of four monomer units.
If you need the markscheme, including the examiners' reports for each question, and more exam and teaching materials on this topic, contact me through the contact page