The combustion of elements in oxygen
4 marks · NormalSulfur burns in oxygen to make a new substance.
Describe what you would see when sulfur is burned in oxygen.
Write a balanced chemical equation for the reaction between sulfur and oxygen.
Name the product formed.
Briefly explain why burning sulfur in oxygen is a combustion reaction.
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(a) Blue flame appears, colorless gas produced.
(b) \ce{S + O2 -> SO2}
(c) Sulfur dioxide
(d) Sulfur reacts with oxygen releasing heat and light.
Common mistakes: Writing word equation for (b) instead of symbol; Not mentioning oxygen in (d)
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Marking points
B1 (a) · 1 mark · Describes a blue flame or similar appropriate observation for burning sulfur.
B2 (b) · 1 mark · Gives correct balanced symbol equation: S + O2 -> SO2.
B3 (c) · 1 mark · Correctly names the product: sulfur dioxide.
B4 (d) · 1 mark · Explains that reaction with oxygen and energy release makes it a combustion reaction.
Worked solution
(a) Sulfur burns with a blue flame and produces a colorless gas.
(c) The product is sulfur dioxide.
(d) This is a combustion reaction because sulfur reacts with oxygen and releases heat and light.