A chemical company makes an industrial solvent in a reactor that runs all day and all night. The theoretical yield of each batch is 2.0 tonnes of solvent, and the next batch begins as soon as the previous one ends.
The company must make at least 7.0 tonnes of solvent every day. Running the reactor at a lower temperature uses less energy.
| Temperature (∘C^\circ\mathrm{C}∘C) | Percentage yield (%) | Hours for each batch |
|---|---|---|
| 250 | 80 | 12 |
| 290 | 72 | 6 |
| 330 | 60 | 4 |
| 370 | 50 | 3 |
What is the lowest temperature at which the company meets its daily target?
330 ∘C^\circ\mathrm{C}∘C
370 ∘C^\circ\mathrm{C}∘C
290 ∘C^\circ\mathrm{C}∘C
250 ∘C^\circ\mathrm{C}∘C
152 exam-style questions on OCR GCSE Chemistry 5.1 Monitoring chemical reactions, covering 5.1.1 The technique of titration, 5.1.2 Theoretical mass, percentage yield and atom economy, 5.1.3 Concentration of a solution in mol/dm3, 5.1.4 Concentration calculations and titration results, 5.1.5 Molar gas volume and volumes of gases in reactions, and 5.1.6 Choosing a reaction pathway. Each one has a worked solution and a mark scheme showing where the marks go.