The combustion of elements in oxygen
2 marks · HardDescribe what is meant by a combustion reaction, and give one example of such a reaction involving an element.
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Must show: definition involving burning in oxygen or air, forming an oxide and releasing energy, one named example: element + oxygen -> oxide
Also accept: A reaction in which a substance reacts with oxygen, producing heat and light; e.g., magnesium burns in oxygen to form magnesium oxide.; Combustion is a reaction where an element burns in oxygen to form an oxide. Example: \ce{C + O2 -> CO2}.
Common mistakes: Saying "burning" without mentioning oxygen or oxide formation.; Example not involving an element.
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Marking points
B1 · 1 mark · Defines combustion as burning in oxygen/air to give an oxide and release energy (heat, light)
B2 · 1 mark · Gives one suitable example involving an element, e.g., burning magnesium in oxygen, or a correct equation
Worked solution
A combustion reaction is one in which a substance reacts with oxygen, producing heat and light and often forming an oxide.
An example is magnesium burning in oxygen: .