IB myp 4-5 Chemistry – Practice Questions- All Topics
Topic :Matter-Electron configuration and valency
Topic :Matter- Weightage : 21 %
All Questions for Topic : states and properties of matter,particle/kinetic theory,diffusion,atomic structure [including isotopes],electron configuration and valency
Question (5 marks)
For many years, food and drink have been stored in cans to make them easy to transport and store. Eighty years ago, most cans were made from tin-plated steel. More recently aluminum has been used to make cans. As tin and iron become more difficult to obtain, all cans may be made from aluminum in the future.
Question a (1 mark)
State the electron configuration of aluminum.
▶️Answer/Explanation
Answer:
1s2 2s2 2p6 3s2 3p1 or [Ne] 3s2 3p1
Explanation:
Aluminum (atomic number 13) has this configuration showing:
- 2 electrons in first shell (1s2)
- 8 electrons in second shell (2s22p6)
- 3 valence electrons in third shell (3s23p1)
This explains its +3 oxidation state in compounds and its position in Group 13 of the periodic table.
Question b (4 marks)
Using the information in the table below and your wider MYP studies, explain two advantages of aluminum cans compared to tin-plated steel cans.
| Property | Aluminum can | Tin-plated steel can |
|---|---|---|
| Density (g/cm3) | 2.70 | 7.30 |
| Melting point (°C) | 660.32 | 231.9 |
| Resistant to corrosion caused by: | Water, acid and bases | Water |
| Malleability relative to iron | Very high | High |
| Moh’s hardness (resistance to scratching) | 2.5 | 1.5 |
▶️Answer/Explanation
Answer:
Advantage 1: Aluminum has much lower density (2.70 g/cm3 vs 7.30 g/cm3) making cans lighter, reducing transportation costs and energy use.
Advantage 2: Aluminum shows superior corrosion resistance to both acids and bases (not just water), preventing reactions with acidic foods and extending shelf life.
Alternative Advantages:
- Higher Mohs hardness (2.5 vs 1.5) makes aluminum more scratch-resistant during handling
- Higher melting point (660°C vs 232°C) provides better heat resistance during processing
- Greater malleability allows for easier shaping and manufacturing
Explanation:
These material properties make aluminum ideal for modern food packaging. Its natural oxide layer provides excellent corrosion protection while maintaining food safety. The combination of lightness and durability gives aluminum cans significant commercial and environmental advantages over traditional tin-plated steel cans.