A chemical plant electrolyses sodium chloride solution to make sodium hydroxide.
2NaCl(aq)+2H2O(l)→2NaOH(aq)+H2(g)+Cl2(g)\mathrm{2NaCl(aq) + 2H_{2}O(l) \rightarrow 2NaOH(aq) + H_{2}(g) + Cl_{2}(g)}2NaCl(aq)+2H2O(l)→2NaOH(aq)+H2(g)+Cl2(g)
Relative formula masses: NaOH=40\mathrm{NaOH} = 40NaOH=40, H2=2\mathrm{H_{2}} = 2H2=2, Cl2=71\mathrm{Cl_{2}} = 71Cl2=71
Taking sodium hydroxide as the desired product, calculate the atom economy of the reaction.
151 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.