Oxidation and reduction

2 marks · Hard

Describe what is meant by 'oxidation' and 'reduction', in terms of oxygen transfer.

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Oxidation is the gain of oxygen; reduction is the loss of oxygen.

Also accept: Oxidation means adding oxygen to a substance; reduction means removing oxygen from a substance.; Oxidation: substance gains oxygen. Reduction: substance loses oxygen.

Common mistakes: Mixing up gain and loss; answering in electron terms instead of oxygen transfer.

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Marking points

B1 · 1 mark · States that oxidation is gain of oxygen or adding oxygen.

B2 · 1 mark · States that reduction is loss of oxygen or removal of oxygen.

Worked solution

Oxidation is when a substance gains oxygen.

Reduction is when a substance loses oxygen.