Metals below carbon in the reactivity series
4 marks · NormalWrite the balanced chemical equation for the reduction of iron(III) oxide by carbon monoxide.
Name the type of reaction that occurs when iron(III) oxide is reduced to iron.
State why carbon is not used to extract aluminium from its oxide.
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) \ce{Fe2O3(s) + 3CO(g) -> 2Fe(l) + 3CO2(g)}
(b) Redox reaction
(c) Aluminium is above carbon in the reactivity series, so carbon cannot reduce aluminium oxide.
Also accept: Accept chemical formulae for c(i), and the terms 'reduction', 'redox', or 'redox reaction' for c(ii).
Common mistakes: Omitting balancing in equation; Saying 'oxidation' instead of 'reduction' or 'redox'; Wrong reason for part c
Show mark scheme and worked solution
Marking points
A1 (a) · 1 mark · Correct balanced equation: Fe2O3 + 3CO -> 2Fe + 3CO2 (accept physical states).
B1 (b) · 1 mark · States 'redox reaction' or 'reduction and oxidation both occur'.
B2 (c) · 2 marks · States aluminium is above carbon in reactivity series (1); so carbon cannot reduce aluminium oxide/needs electrolysis (1).
Worked solution
a) Balanced equation:
b) The reaction is called a redox reaction.
c) Aluminium is above carbon in the reactivity series, so carbon is not reactive enough to reduce aluminium oxide. Aluminium oxide must be reduced by electrolysis.