AQA GCSE Chemistry (8462), Higher tier · Using resources › Earth's resources and potable water
Practise Alternative methods of extracting metals. 12 exam-style questions on this subtopic, at up to four difficulty levels, with full mark schemes and a progress tracker. Free, no account needed.
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New ways of extracting copper from low-grade ores include phytomining and bioleaching. What does phytomining use to absorb metal compounds?
plants
Sample questions
Written for this site in the style of AQA exam questions. They are not taken from real past papers.
Question 1Easy3 marks
New ways of extracting copper from low-grade ores include phytomining and bioleaching.
(a) Why are new ways of extracting copper being developed? Tick (✓) one box.[1]
Copper ores are becoming scarce
Copper is no longer used in electrical wiring
Copper is more reactive than iron
Copper cannot be extracted by electrolysis
(b) What does phytomining use to absorb metal compounds?[1]
(c) What does bioleaching use to produce solutions of metal compounds?[1]
Show the answer and mark scheme
(a)Answer: Copper ores are becoming scarce
(b)Answer: plants
plants
(c)Answer: bacteria
bacteria
Question 2Medium6 marks
Phytomining can be used to obtain copper from land containing low-grade copper ore.
(a) Describe how phytomining is used to obtain copper compounds.[3]
(b) Copper can be obtained from a solution of copper compounds by adding scrap iron. Explain why iron can displace copper.[1]
(c) Give one other method of obtaining copper from a solution of a copper compound.[1]
(d) Give one advantage of phytomining compared with traditional mining.[1]
Show the answer and mark scheme
(a)
plants are grown on land containing (low-grade) copper ore
the plants absorb copper compounds and are harvested
the plants are burned to produce ash that contains copper compounds
(b)
iron is more reactive than copper
(c)
electrolysis
(d)
it avoids digging, moving and disposing of large amounts of rock / it can use low-grade ores / less damage to the landscape
Question 3Hard6 marks
Bioleaching produces a solution containing copper(II) ions. Copper metal can be obtained from the solution by displacement using scrap iron, or by electrolysis.
(a) Write the ionic equation for the reaction between iron and copper(II) ions. Iron(II) ions are formed.[1]
(b) Explain which species is oxidised in this reaction.[2]
(c) Write the half equation for the reaction at the negative electrode when copper is obtained by electrolysis.[1]
(d) Calculate the mass of iron needed to displace 1.0 tonne of copper. Relative atomic masses (Ar): Fe = 56 Cu = 63.5[2]
Show the answer and mark scheme
(a)Answer: Fe + Cu2+ → Fe2+ + Cu
Fe + Cu2+ → Fe2+ + Cu
(b)
iron (atoms) are oxidised
because they lose electrons
(c)Answer: Cu2+ + 2e− → Cu
Cu2+ + 2e− → Cu
(d)Answer: 0.88 tonnes
1 mole of iron displaces 1 mole of copper / 1.0 × 56 ÷ 63.5