Propanone is a liquid that boils at 56 ∘C^\circ\mathrm{C}∘C.
A student pours 20.0 g of propanone into an open dish and leaves it at a fixed temperature for 10 minutes. The student then measures the mass of propanone left.
The student repeats the experiment at different temperatures.
The table shows the results.
| Temperature (∘C^\circ\mathrm{C}∘C) | Mass of propanone at start (g) | Mass of propanone after 10 minutes (g) |
|---|---|---|
| 20 | 20.0 | 18.8 |
| 30 | 20.0 | 17.9 |
| 40 | 20.0 | 16.6 |
| 50 | 20.0 | 14.6 |
Calculate the mean rate of mass loss at 40 ∘C^\circ\mathrm{C}∘C.
Give the unit.
Propanone evaporates at 20 ∘C^\circ\mathrm{C}∘C, even though this is well below its boiling point.
Explain why. Use ideas about particles and energy.
Explain why more propanone is lost at higher temperatures.
The student predicts that at 60 ∘C^\circ\mathrm{C}∘C the mass lost in 10 minutes will continue the same pattern as the results in the table.
Evaluate this prediction.
48 exam-style questions on OCR GCSE Chemistry 1.1 The particle model, covering 1.1.1 The particle model and changes of state and 1.1.2 Limitations of the particle model. Each one has a worked solution and a mark scheme showing where the marks go.