Extracting metals from their ores
4 marks · NormalThe table shows four metals and how each is extracted from its ore.
| Metal | Extraction Method |
|---|---|
| Gold | Found uncombined |
| Iron | Reduction with carbon |
| Aluminium | Electrolysis |
| Copper | Roasting ore then reduction |
Use the information in the table to answer the questions.
Which of the four metals is the most reactive? Explain your choice.
Which metal in the table is least likely to be found as an ore? Give a reason.
Suggest why reduction with carbon is suitable for some but not all metals.
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
Show answer
(a) Aluminium, because it is extracted by electrolysis which is used for the most reactive metals.
(b) Gold, because it is found uncombined in the Earth's crust due to its low reactivity.
(c) Reduction with carbon can only be used for metals less reactive than carbon (like iron); more reactive metals (like aluminium) cannot be reduced by carbon, so other methods are needed.
Common mistakes: Confusing most reactive with least reactive based on extraction method; Incorrect explanation for why carbon cannot be used for all metals
Show mark scheme and worked solution
Marking points
B1 (a) · 1 mark · Names aluminium as most reactive; reason links electrolysis to high reactivity.
B1 (b) · 1 mark · Identifies gold; gives valid reason for being found uncombined.
M1 (c) · 1 mark · States reduction with carbon works only for metals less reactive than carbon.
M1 (c) · 1 mark · Correctly explains that more reactive metals require different extraction (e.g., electrolysis).
Worked solution
a) Aluminium is most reactive because electrolysis is used for highly reactive metals.
b) Gold is least likely to be found as an ore, because it is so unreactive it is found as the element.
c) Reduction with carbon works for metals below carbon in the reactivity series (like iron) but not for more reactive metals (like aluminium), so these must be extracted by electrolysis.