Question 1: Define the term 'ore' in the context of metal extraction.

Answer: A naturally occurring solid material from which a metal or valuable mineral can be extracted profitably.

Question 2: Explain the main difference between reduction with carbon and electrolysis in metal extraction.

Answer: Reduction with carbon involves using carbon to remove oxygen from metal oxides, suitable for less reactive metals; electrolysis uses electrical energy to decompose compounds, suitable for more reactive metals.

Question 3: Describe how the reactivity series influences the method used to extract a metal from its ore.

Answer: Metals higher in the reactivity series require electrolysis or other methods; less reactive metals can be extracted by reduction with carbon.

Question 1: Calculate the mass of aluminium oxide (Al₂O₃) required to produce 54 kg of aluminium (Al) using electrolysis. (Atomic masses: Al = 27, O = 16)

Answer: 81 kg

Question 2: If 100 g of zinc ore contains 25 g of zinc, what percentage of the ore is zinc? Show your working.

Answer: 25%

Question 1: Describe a basic experimental setup to extract copper from copper sulphate solution, including safety precautions.

Answer: Set up a electrolysis cell with copper electrodes immersed in copper sulphate solution, connect to a power supply, and ensure proper insulation and ventilation. Wear safety goggles and gloves to protect against electrical hazards and chemical splashes.

Question 2: Identify three variables that could affect the efficiency of extracting metals using reduction with carbon.

Answer: Temperature, carbon purity, and particle size of the ore.

Question 1: A sample of ore contains 12% iron by mass. If 500 g of ore is processed, how much pure iron can be theoretically obtained? Show your calculations.

Answer: 60 g

Question 2: Interpret how the reactivity series affects the choice of extraction method for copper and gold.

Answer: Copper is less reactive and can be extracted by reduction with carbon, whereas gold is more inert and requires electrolysis or other advanced methods due to its high reactivity and stability.

Question 1: Explain why electrolysis is preferred for extracting aluminium from bauxite ore, in terms of reactivity and energy requirements. (6 marks)

Answer: Aluminium is highly reactive and cannot be reduced with carbon. Electrolysis is used because it decomposes aluminium oxide into aluminium and oxygen using electrical energy, despite its high energy requirement, because other methods are ineffective for such a reactive metal.

Question 2: Identify a modern technological development that improves the extraction process of a metal and briefly describe its impact.

Answer: The use of bioleaching bacteria to extract metals from ores reduces environmental damage and energy consumption, making extraction more sustainable.