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The order of reactivity of copper, magnesium and zinc can be determined by the displacement reactions between these metals and solutions of their salts - Edexcel - GCSE Chemistry Combined Science - Question 5 - 2021 - Paper 1
Question 5
The order of reactivity of copper, magnesium and zinc can be determined by the displacement reactions between these metals and solutions of their salts. You are pro... show full transcript
Worked Solution & Example Answer:The order of reactivity of copper, magnesium and zinc can be determined by the displacement reactions between these metals and solutions of their salts - Edexcel - GCSE Chemistry Combined Science - Question 5 - 2021 - Paper 1
Step 1
Describe the experiments that can be done to determine the order of reactivity of these metals by displacement reactions.
Answer
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Setting Up the Experiment:
- Take three separate clean test tubes and label them for copper sulfate, magnesium sulfate, and zinc sulfate solutions.
- Measure a fixed amount (e.g., 5 mL) of each solution and pour it into the corresponding test tubes.
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Adding the Metals:
- Introduce the metals (copper, magnesium, and zinc) one at a time into each test tube. For instance, first add magnesium to the copper sulfate solution.
- Observe any reaction such as effervescence or color change and record the observations.
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Recording Reactions:
- Note the occurrence of displacement reactions (if the metal displaces the other in the solution).
- The more reactive metal will produce a greater number of reactions with the sulfate solutions.
- Continue this process until all metals have been tested in all solutions.
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Analyzing Results:
- The metal that causes the most reactions in the different sulfate solutions is considered to be the most reactive in comparison to the others.
- Summarize the findings indicating the order of reactivity based on the number of successful displacement reactions.
Step 2
Explain why aluminium cannot be extracted from its ore by heating with carbon but can be extracted by electrolysis.
Answer
Aluminium cannot be extracted from its ore (bauxite) using carbon because it is more reactive than carbon. When heated with carbon, aluminium would not be able to reduce its oxide to the metal; instead, carbon would oxidize in the reaction:
Since aluminium is located above carbon in the reactivity series, the reduction cannot successfully occur using carbon.
On the other hand, aluminium can be extracted via electrolysis, which is a method that uses electrical energy to drive the reduction of aluminium ions to aluminium metal. This process involves dissolving the ore in molten cryolite and passing an electric current through it, efficiently separating aluminium from its oxide.