Oxygen can be made by heating potassium chlorate.
2KClO3(s)→2KCl(s)+3O2(g)\mathrm{2KClO_3(s) \rightarrow 2KCl(s) + 3O_2(g)}2KClO3(s)→2KCl(s)+3O2(g)
Oxygen is the desired product.
Relative formula masses: KCl=74.5\mathrm{KCl} = 74.5KCl=74.5 and O2=32\mathrm{O_2} = 32O2=32.
Calculate, to three significant figures, the atom economy of this method for producing oxygen.
Use the equation:
atom economy=total relative formula mass of desired producttotal relative formula mass of all products×100\text{atom economy} = \dfrac{\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
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.