Oxygen gas can be produced by the thermal decomposition of potassium chlorate, KClO3\text{KClO}_3KClO3.
2KClO3→2KCl+3O2 2\text{KClO}_3 \rightarrow 2\text{KCl} + 3\text{O}_2 2KClO3→2KCl+3O2Calculate the maximum volume, in cm3\text{cm}^3cm3, of oxygen produced from 49 g of potassium chlorate.
(relative formula mass: KClO3=122.5\text{KClO}_3 = 122.5KClO3=122.5; 1 mol of gas occupies 24 dm3 in the conditions used)
119 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.