Metals below carbon in the reactivity series
4 marks · NormalDescribe one economic advantage of extracting iron by heating with carbon rather than by electrolysis.
The chemical equation for extracting iron using carbon is:
In this reaction, state which substance is oxidised and which is reduced.
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.
Show answer
(a) Heating with carbon is cheaper (less energy is required than electrolysis; carbon is less expensive).
(b) Iron(III) oxide is reduced; carbon is oxidised.
Also accept: Accept references to 'lower energy costs' or 'reducing agent is cheaper' for economic advantage.
Common mistakes: Confusing oxidised/reduced substances
Show mark scheme and worked solution
Marking points
B1_a (a) · 2 marks · Any one relevant economic advantage explained (cheaper energy, carbon is less costly, electrolysis is expensive).
B1_b (b) · 1 mark · Identifies iron(III) oxide as the substance reduced.
B2_b (b) · 1 mark · Identifies carbon as the substance oxidised.
Worked solution
a) Extracting iron by heating with carbon is more economical because it consumes less energy and uses the inexpensive reducing agent, carbon.
b) In the given reaction, iron(III) oxide (Fe2O3) is reduced to iron, and carbon (C) is oxidised to carbon monoxide (CO).