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4 (a) Which row shows the products formed at the anode and at the cathode when molten zinc chloride is electrolysed? | product at anode | product at cathode | | ---------------- | ------------------- | | A | oxygen | zinc | | B | chlorine | hydrogen | | C | chlorine | zinc | | D | oxygen | hydrogen | (ii) Which of the following is the reason why molten zinc chloride is an electrolyte? A it contains molecules that can move B it has a giant structure C it contains delocalised electrons D it contains ions that can move (b) Copper sulfate solution was electrolysed using copper electrodes - Edexcel - GCSE Chemistry Combined Science - Question 4 - 2018 - Paper 1
Question 4
4 (a) Which row shows the products formed at the anode and at the cathode when molten zinc chloride is electrolysed? | product at anode | product at cathode | | ---... show full transcript
Worked Solution & Example Answer:4 (a) Which row shows the products formed at the anode and at the cathode when molten zinc chloride is electrolysed? | product at anode | product at cathode | | ---------------- | ------------------- | | A | oxygen | zinc | | B | chlorine | hydrogen | | C | chlorine | zinc | | D | oxygen | hydrogen | (ii) Which of the following is the reason why molten zinc chloride is an electrolyte? A it contains molecules that can move B it has a giant structure C it contains delocalised electrons D it contains ions that can move (b) Copper sulfate solution was electrolysed using copper electrodes - Edexcel - GCSE Chemistry Combined Science - Question 4 - 2018 - Paper 1
Step 1
Which row shows the products formed at the anode and at the cathode when molten zinc chloride is electrolysed?
Answer
The correct answer is C: chlorine at the anode and zinc at the cathode. During the electrolysis of molten zinc chloride (ZnCl₂), zinc ions (Zn²⁺) are reduced at the cathode, forming zinc metal, while chloride ions (Cl⁻) are oxidized at the anode, producing chlorine gas. Other options are incorrect as they do not represent the products formed accurately.
Step 2
Which of the following is the reason why molten zinc chloride is an electrolyte?
Answer
The correct answer is D: it contains ions that can move. Molten zinc chloride dissociates into Zn²⁺ and Cl⁻ ions, which are free to move, allowing the conduction of electricity. Options A and B are incorrect since molten zinc chloride does not have molecular structure or a giant structure based on covalent bonds. Option C is also incorrect as delocalised electrons are not present in this ionic compound.
Step 3
Draw a labelled diagram to show the apparatus that is used to carry out this electrolysis in the laboratory.
Answer
To draw a labelled diagram for the electrolysis of copper sulfate using copper electrodes, include the following components:
- A beaker filled with copper sulfate solution.
- Two copper electrodes placed in the solution, one connected to the positive terminal (anode) and the other to the negative terminal (cathode) of a power supply.
- Labels indicating the power supply, electrodes, and the direction of current flow. Indicate the formation of copper metal at the cathode and the release of oxygen at the anode.