Most metals are extracted from rocks found in the Earth’s crust - Edexcel - GCSE Chemistry - Question 4 - 2017 - Paper 1
Question 4
Most metals are extracted from rocks found in the Earth’s crust.
(i) Iron is extracted from iron oxide.
The iron oxide, Fe₂O₃, is heated with carbon.
Complete the b... show full transcript
Worked Solution & Example Answer:Most metals are extracted from rocks found in the Earth’s crust - Edexcel - GCSE Chemistry - Question 4 - 2017 - Paper 1
Step 1
Complete the balancing of the equation for this reaction
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Answer
The balanced equation for the reaction of iron oxide with carbon is:
2Fe2O3+3C→4Fe+3CO2
Step 2
Complete the sentence by putting a cross (⨉) in the box next to your answer.
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Answer
The correct choice is D: carbon is oxidised and iron oxide is reduced. In this process, carbon acts as a reducing agent, taking oxygen from iron oxide and producing iron and carbon dioxide.
Step 3
Use the information in the table to explain why gold alloys, rather than pure gold, are often used in items of jewellery.
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Answer
Gold alloys are preferred in jewellery because they provide a balance between appearance and durability.
24-carat gold is pure gold and is softer, which makes it easily damaged and less suitable for everyday wear.
18-carat gold, on the other hand, is an alloy that offers greater strength, allowing it to withstand wear and tear better than pure gold.
Step 4
Suggest the method used to extract sodium from its ore.
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Answer
The method used to extract sodium from its ore is electrolysis.
Step 5
Explain why this method has to be used.
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Answer
Electrolysis must be used for extracting sodium because it is highly reactive and cannot be reduced using carbon, unlike less reactive metals. Sodium's reactivity would react violently with carbon, making electrolysis the only viable extraction method.
Step 6
Explain what is meant by a shape memory alloy.
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Answer
A shape memory alloy (SMA) is a type of metal that can return to a predetermined shape when heated after being deformed. This property allows them to 'remember' their original shape and is useful in various applications, including in medical devices and stents.
