The newest 15 of 11 written questions. Open one to see it on the real paper.
Identify gas X and gas Y.
See it on the paper →Suggest a suitable material for use as the inert electrodes.
See it on the paper →The electrodes in the experiment are made of graphite. State two reasons why graphite is used for the electrodes. Explain your answer using ideas about structure and bonding. explanation
See it on the paper →cover a metal with a layer of copper.
See it on the paper →State the name of gas X in Fig. 5.1.
See it on the paper →is electroplated onto another metal
See it on the paper →Hydrogen gas is one of the electrode products of this electrolysis. State the name of the other electrode product.
See it on the paper →State what is made at the cathode.
See it on the paper →The list shows the particles found in aqueous copper( II ) sulfate. Cu 2+ H + H 2 O SO 42– OH – State the formula of one particle attracted to the cathode during electrolysis. Choose from the list.
There were some very good responses to this question, particularly in terms of delocalised electrons enabling electrodes to conduct electricity. Occasionally electrodes were described as good conductors without candidates specifying what type of conduction they were referring to.
— Examiner report, February/March 2025, 0654/42 Q8(d) (Cambridge)
Electroplating was well known as the process. Rusting was a popular incorrect response.
— Examiner report, February/March 2024, 0654/32 Q2(a)(v) (Cambridge)
Oxygen was commonly seen. A common incorrect response was sulfur.
— Examiner report, February/March 2024, 0654/42 Q5(a)(ii) (Cambridge)
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The purification (refining) of copper uses electrolysis. Describe how impure copper is purified by electrolysis. Include ionic half-equations in your answer.
See it on the paper →State the name of the electrode where lead is made.
See it on the paper →Gas P forms at the positive electrode and gas Q forms at the negative electrode. Identify the gases. gas P gas Q
See it on the paper →Using the graph, state the total volume of gas P produced during the investigation. volume of gas P = cm 3
See it on the paper →Use the information in Fig. 8.2 to compare quantitatively the rates of production of gas P and gas Q.
See it on the paper →Use the information in Fig. 8.2 to calculate the rate at which gas P is produced in units of cm 3 / minute. Show your working. rate of production of gas P = cm 3 / minute
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