Calcium oxide (lime) is made by heating calcium carbonate. A gas is also produced.
calcium carbonate → \rightarrow\,→ calcium oxide + gas
A student heats 10.0 g of calcium carbonate. The theoretical yield of calcium oxide is 5.6 g. The student obtains 4.2 g of calcium oxide.
Name the gas produced.
Calculate the mass of gas that would be produced if all 10.0 g of calcium carbonate formed 5.6 g of calcium oxide.
Calculate the percentage yield of calcium oxide. Use the equation: percentage yield=actual yieldtheoretical yield×100\displaystyle \text{percentage yield} = \frac{\text{actual yield}}{\text{theoretical yield}} \times 100percentage yield=theoretical yieldactual yield×100
Give two reasons why the actual yield is less than the theoretical yield.
State the maximum possible percentage yield of any reaction.
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.