A manufacturer is comparing four operating temperatures for a batch process used to produce a polymer additive. The theoretical yield from every batch is 100 kg. Production continues without a break for 24 hours.
The results from trial runs are shown in the table.
| Temperature (∘C^\circ\mathrm{C}∘C) | Percentage yield (%) | Time for one batch (hours) |
|---|---|---|
| 220 | 72 | 8 |
| 260 | 52 | 6 |
| 300 | 40 | 4 |
| 340 | 34 | 3 |
Which temperature produces the smallest total mass of additive during 24 hours?
300 ∘C^\circ\mathrm{C}∘C
260 ∘C^\circ\mathrm{C}∘C
220 ∘C^\circ\mathrm{C}∘C
340 ∘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.