This question is about electrolysis - AQA - GCSE Chemistry - Question 6 - 2022 - Paper 1
Question 6
This question is about electrolysis.
Molten sodium chloride is electrolysed in an industrial process to produce sodium.
Figure 8 shows a simplified version of the e... show full transcript
Worked Solution & Example Answer:This question is about electrolysis - AQA - GCSE Chemistry - Question 6 - 2022 - Paper 1
Step 1
Which is the correct half equation for the production of sodium?
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Answer
The correct half equation for the production of sodium is:
Na⁺ + e⁻ → Na
This represents the reduction of sodium ions to form sodium metal.
Step 2
Suggest one reason why the products of the electrolysis must be kept apart.
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Answer
The products must be kept apart so they do not react to reform sodium chloride.
Step 3
Which type of particle passes through the mesh in the electrolysis of molten sodium chloride?
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Answer
The type of particle that passes through the mesh is an ion.
Step 4
Which two ions are present in aqueous sodium chloride solution in addition to sodium ions and chloride ions?
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Answer
1 Hydrogen ions (H⁺)
2 Hydroxide ions (OH⁻)
Step 5
Name the alkaline solution produced.
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Answer
The alkaline solution produced is sodium hydroxide (NaOH).
Step 6
Explain how the alkaline solution is produced.
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Answer
The alkaline solution is produced during the electrolysis of the aqueous sodium chloride solution. At the negative electrode, hydrogen ions (H⁺) are reduced to form hydrogen gas:
2 H⁺ + 2 e⁻ → H₂.
At the positive electrode, chloride ions (Cl⁻) are discharged and oxidized to form chlorine gas:
2 Cl⁻ → Cl₂ + 2 e⁻.
The sodium hydroxide is formed in solution as a result of the remaining hydroxide ions (OH⁻) from water, which combine with sodium ions (Na⁺) in the solution.
