A student prepares potassium nitrate crystals. The theoretical yield is 9.0 g, and the student collects 5.4 g of pure, dry crystals. The student calculates the percentage yield as 9.0−5.49.0×100\dfrac{9.0-5.4}{9.0}\times1009.09.0−5.4×100.
Which expression should replace the student's calculation?
5.49.0+5.4×100\dfrac{5.4}{9.0+5.4}\times1009.0+5.45.4×100
9.0−5.45.4×100\dfrac{9.0-5.4}{5.4}\times1005.49.0−5.4×100
5.49.0−5.4×100\dfrac{5.4}{9.0-5.4}\times1009.0−5.45.4×100
5.49.0×100\dfrac{5.4}{9.0}\times1009.05.4×100
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.