Metals below carbon in the reactivity series
3 marks · EasyState one economic reason why the extraction of iron using carbon is preferred over electrolysis.
Write the balanced chemical equation for the reduction of iron(III) oxide with carbon.
Identify which substance is reduced in this reaction.
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
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(a) It is cheaper because less energy is used / uses cheaper reducing agent
(b) \ce{Fe2O3(s) + 3C(s) -> 2Fe(l) + 3CO(g)}
(c) Iron(III) oxide (Fe2O3)
Also accept: Energy cost as economic reason
Common mistakes: Naming CO2 as reduced; Cost being only 'cheaper' without justification
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Marking points
B1 (a) · 1 mark · Identifies cost of energy or reducing agent as the economic reason.
B1 (b) · 1 mark · Gives correct balanced symbol equation: Fe2O3 + 3C -> 2Fe + 3CO.
B1 (c) · 1 mark · Identifies iron(III) oxide or Fe2O3 as the substance reduced.
Worked solution
a) The process uses less energy, so it is cheaper than electrolysis. b) The balanced equation: Fe2O3(s) + 3C(s) -> 2Fe(l) + 3CO(g) c) The substance reduced is iron(III) oxide (Fe2O3).