AQA · GCSE · Chemistry
Course version: 8462 · Version from Sept 2018
Extraction of metals and reduction: Reduction involves the loss of oxygen.
This statement defines reduction in terms of oxygen.
Checked against the AQA 8462 specification (opens in a new tab) on .
- Point 3 of 4
- 3 key terms
Study notes
From the checked teaching notes for this specification point.
The idea
This statement defines reduction in terms of oxygen. Reduction is the loss of oxygen from a substance. In metal extraction, the metal oxide loses oxygen and is therefore reduced. For example, when iron oxide reacts with carbon, iron oxide loses oxygen to form iron, so iron oxide is reduced. The substance that takes the oxygen, such as carbon, is oxidised. You should be able to identify which substance is reduced and which is oxidised in a given reaction by tracking oxygen. This definition is separate from the electron-transfer definition of reduction used later, so in this context focus on oxygen loss. You may also see reduction described as the opposite of oxidation, where oxidation is the gain of oxygen.
What earns the marks
- Defines reduction as the loss of oxygen from a substance.
- Identifies the substance that loses oxygen in a reaction as the substance being reduced.
- Identifies the substance that gains oxygen as the substance being oxidised.
- Applies the definition to metal extraction, for example stating that iron oxide is reduced to iron when carbon removes its oxygen.
- States that oxidation is the gain of oxygen, as the opposite process to reduction.
- Uses a symbol equation to show which reactant loses oxygen and which gains oxygen.
Common mistakes and how to put them right
Writing that reduction is the gain of oxygen.
Put it right: Reduction is the loss of oxygen and oxidation is the gain of oxygen.
Naming carbon as the substance reduced in metal extraction.
Put it right: Carbon gains oxygen and is oxidised, while the metal oxide is reduced.
Confusing reduction with the removal of the metal.
Put it right: Reduction specifically refers to oxygen loss, which produces the metal.
Exam tips
- Underline or annotate the oxygen in each formula before deciding which substance is reduced.
- Use the phrase 'loss of oxygen' in your definition and then apply it directly to the equation given.
- If asked to explain a metal extraction reaction, state clearly that the metal oxide is reduced and give the reason in terms of oxygen loss.
Try the lesson
The start of the Extraction of metals and reduction: Reduction involves the loss of oxygen. lesson, made from checked teaching notes for this specification point.
Have a go first
Which process involves the loss of oxygen from a substance?
Listen
This statement defines reduction in terms of oxygen. Reduction is the loss of oxygen from a substance. In metal extraction, the metal oxide loses oxygen and is therefore reduced. For example, when iron oxide reacts with carbon, iron oxide loses oxygen to form iron, so iron oxide is reduced. The substance that takes the oxygen, such as carbon, is oxidised. You should be able to identify which substance is reduced and which is oxidised in a given reaction by tracking oxygen. This definition is separate from the electron-transfer definition of reduction used later, so in this context focus on oxygen loss. You may also see reduction described as the opposite of oxidation, where oxidation is the gain of oxygen. A strong answer earns marks for these points. Defines reduction as the loss of oxygen from a substance. Identifies the substance that loses oxygen in a reaction as the substance being reduced. Identifies the substance that gains oxygen as the substance being oxidised. Applies the definition to metal extraction, for example stating that iron oxide is reduced to iron when carbon removes its oxygen. A common slip: Writing that reduction is the gain of oxygen. Instead, reduction is the loss of oxygen and oxidation is the gain of oxygen. Exam tip: Underline or annotate the oxygen in each formula before deciding which substance is reduced.
Key words
Say what each word means before you turn the card.
Reduction
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Oxidation
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Metal extraction
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See every definition
- Reduction
- The loss of oxygen from a substance, which in metal extraction produces the metal.
- Oxidation
- The gain of oxygen, described as the opposite process to reduction.
- Metal extraction
- A process in which the metal oxide loses oxygen and is therefore reduced.
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