In a blast furnace, iron is extracted from iron(III) oxide by reacting it with carbon monoxide.
Fe2O3(s)+3CO(g)→2Fe(l)+3CO2(g)\mathrm{Fe_{2}O_{3}(s)} + \mathrm{3CO(g)} \rightarrow \mathrm{2Fe(l)} + \mathrm{3CO_{2}(g)}Fe2O3(s)+3CO(g)→2Fe(l)+3CO2(g)
Relative atomic masses: C = 12, O = 16, Fe = 56. Relative formula mass: Fe2O3=160\mathrm{Fe_{2}O_{3}} = 160Fe2O3=160
Calculate the relative formula mass of carbon dioxide, CO2\mathrm{CO_{2}}CO2.
Calculate the atom economy for making iron by this reaction. Use the equation: atom economy=total relative formula mass of desired producttotal relative formula mass of all products×100\displaystyle \text{atom economy} = \frac{\text{total relative formula mass of desired product}}{\text{total relative formula mass of all products}} \times 100atom economy=total relative formula mass of all productstotal relative formula mass of desired product×100. Give your answer to three significant figures.
Iron can also be made by heating iron(III) oxide with carbon: 2Fe2O3(s)+3C(s)→4Fe(l)+3CO2(g)\mathrm{2Fe_{2}O_{3}(s)} + \mathrm{3C(s)} \rightarrow \mathrm{4Fe(l)} + \mathrm{3CO_{2}(g)}2Fe2O3(s)+3C(s)→4Fe(l)+3CO2(g). Calculate the atom economy for making iron by this reaction, to three significant figures, and state which of the two reactions has the higher atom economy.
Give one environmental problem caused by the by-product of this reaction.
Calculate the maximum mass of iron that can be made from 320 g of iron(III) oxide.
51 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.