A student investigates the mass of copper produced when copper chloride solution in a beaker is electrolysed using inert electrodes - Edexcel - GCSE Chemistry - Question 6 - 2023 - Paper 1
Question 6
A student investigates the mass of copper produced when copper chloride solution in a beaker is electrolysed using inert electrodes.
(a) Where is copper formed duri... show full transcript
Worked Solution & Example Answer:A student investigates the mass of copper produced when copper chloride solution in a beaker is electrolysed using inert electrodes - Edexcel - GCSE Chemistry - Question 6 - 2023 - Paper 1
Step 1
Where is copper formed during the electrolysis?
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Answer
Copper is formed at the cathode (C) during the electrolysis process. In electrolytic cells, reduction occurs at the cathode, where positive copper ions in the solution gain electrons and are deposited as solid copper.
Step 2
State and explain the trend shown in these results.
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Answer
The trend shown in the results indicates that as the current increases, the mass of copper formed also increases. This is because the amount of copper deposited at the cathode is directly proportional to the current flowing through the electrolyte.
According to Faraday's laws of electrolysis, the mass of the substance deposited at an electrode is given by the formula:
m = rac{Q}{F} \cdot M
where:
m is the mass of substance deposited,
Q is the total electric charge in coulombs (which is current multiplied by time),
F is Faraday's constant (approximately 96500 C/mol), and
M is the molar mass of the substance.
As the current increases, so does the charge Q, leading to a greater mass of copper being deposited at the cathode.