CAIE A Level Chemistry 9701 · Electrochemistry
When hydrogen gas is passed over heated iron(III) oxide, the following reaction occurs.
Describe this reaction as a redox reaction. In your answer, refer to oxidation numbers, electron transfer, and identify the oxidising agent and the reducing agent.
5 marks, so the mark scheme is looking for about 5 separate creditworthy points. Making the same point twice in different words earns it once.
Describe means: Say what happens or what something is like, in order and with detail. You are not being asked why. If there is data, quote it: name the trend, then give figures with units at the points where it changes.
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