CIE iGCSE Co-Ordinated Science C9.6 Extraction of metals Exam Style Questions Paper 2
▶️ Answer/Explanation
Metals below carbon in the reactivity series (like tin) can be extracted by reduction with carbon in a blast furnace. Tin is less reactive than iron but more reactive than copper, placing it in the middle of the series, still below carbon, so carbon reduction is used. Electrolysis is not needed for tin extraction.
✅ Answer: (B)
✅ Answer: (B)
▶️ Answer/Explanation
In the blast furnace, iron oxide (haematite, \(\text{Fe}_2\text{O}_3\)) is reduced to iron by carbon monoxide: \(\text{Fe}_2\text{O}_3 + 3\text{CO} \rightarrow 2\text{Fe} + 3\text{CO}_2\) — this makes statement C correct.
Aluminium ore is bauxite (not haematite); aluminium is extracted by electrolysis (not heating with carbon); and limestone removes acidic impurities (like silica), not basic ones.
✅ Answer: (C)
Aluminium ore is bauxite (not haematite); aluminium is extracted by electrolysis (not heating with carbon); and limestone removes acidic impurities (like silica), not basic ones.
✅ Answer: (C)
▶️ Answer/Explanation
Lime (calcium oxide) is manufactured by heating limestone (calcium carbonate) strongly, a thermal decomposition reaction.
This releases carbon dioxide gas, leaving calcium oxide (lime) as the solid product.
✅ Answer: (B)
This releases carbon dioxide gas, leaving calcium oxide (lime) as the solid product.
✅ Answer: (B)
▶️ Answer/Explanation
Metals more reactive than carbon, such as calcium, cannot be displaced from their ores by carbon reduction.
These very reactive metals must instead be extracted by electrolysis of their molten compounds.
Copper, iron and zinc are all less reactive than carbon and can be extracted by heating with carbon.
✅ Answer: (A)
These very reactive metals must instead be extracted by electrolysis of their molten compounds.
Copper, iron and zinc are all less reactive than carbon and can be extracted by heating with carbon.
✅ Answer: (A)
▶️ Answer/Explanation
Limestone is calcium carbonate, not calcium oxide, but it is heated to manufacture lime (calcium oxide), so statement 2 is correct.
Limestone (or lime made from it) is basic and neutralises acidic industrial waste, so statement 3 is correct; statement 4 is wrong since it is used to neutralise acidic (not alkaline) soil.
✅ Answer: (C)
Limestone (or lime made from it) is basic and neutralises acidic industrial waste, so statement 3 is correct; statement 4 is wrong since it is used to neutralise acidic (not alkaline) soil.
✅ Answer: (C)