Iron can be extracted from iron(III) oxide by a highly exothermic reduction reaction with aluminium, known as the thermite reaction.
The balanced chemical equation for the reaction is:
Fe2O3+2Al→2Fe+Al2O3 \text{Fe}_2\text{O}_3 + 2\text{Al} \rightarrow 2\text{Fe} + \text{Al}_2\text{O}_3 Fe2O3+2Al→2Fe+Al2O3Calculate the percentage atom economy for the production of iron in this reaction.
Relative atomic masses (ArA_rAr): Al=27\text{Al} = 27Al=27 O=16\text{O} = 16O=16 Fe=56\text{Fe} = 56Fe=56
Relative formula masses (MrM_rMr): Fe2O3=160\text{Fe}_2\text{O}_3 = 160Fe2O3=160 Al2O3=102\text{Al}_2\text{O}_3 = 102Al2O3=102
Give your answer to two significant figures.
157 exam-style questions on Edexcel GCSE Chemistry 6.2 Quantitative analysis, covering 6.2.1 Concentration in mol dm⁻³ and titration calculations, 6.2.2 Percentage yield and why actual yield falls short, 6.2.3 Atom economy of a reaction, 6.2.4 Choosing a reaction pathway, and 6.2.5 Molar volume of gases and Avogadro's law. Each one has a worked solution and a mark scheme showing where the marks go.