The diagram below represents an electrolytic cell used in the decomposition of a copper (II) chloride solution - NSC Technical Sciences - Question 5 - 2022 - Paper 2
Question 5
The diagram below represents an electrolytic cell used in the decomposition of a copper (II) chloride solution. The electrodes used are inert.
5.1 Define the follow... show full transcript
Worked Solution & Example Answer:The diagram below represents an electrolytic cell used in the decomposition of a copper (II) chloride solution - NSC Technical Sciences - Question 5 - 2022 - Paper 2
Step 1
5.1.1 Anode
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Answer
An anode is an electrode where oxidation occurs; it is the site of the loss of electrons in an electrochemical process.
Step 2
5.1.2 Electrolysis
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Electrolysis is the chemical process in which electrical energy is converted into chemical energy. This process involves the decomposition of a substance when an electric current is passed through it.
Step 3
5.2.1 A balanced half-reaction that occurs at the anode.
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The balanced half-reaction at the anode for the decomposition of copper (II) chloride is:
ightarrow ext{Cl}_2(g) + 2e^-$$
Step 4
5.2.2 The NAME of a half-reaction that occurs at the cathode.
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The half-reaction that occurs at the cathode is the reduction of copper (II) ions:
Copper (II) ions (extCu2+) gain electrons to form copper metal:
ightarrow ext{Cu}(s)$$
Step 5
5.3.1 An oxidising agent
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An oxidising agent is a substance that gains electrons in a chemical reaction. In this case, chlorine (extCl2) acts as the oxidising agent.
Step 6
5.3.2 A reducing agent
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A reducing agent is a substance that loses electrons in a chemical reaction. Here, copper (II) ions (extCu2+) act as the reducing agent.
Step 7
5.4 Give the NAME of the chemical substance causing the bubbles.
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The chemical substance causing the bubbles on the electrode is chlorine gas (extCl2).
