A student melts some stearic acid in a boiling tube using a hot water bath. The student takes the boiling tube out of the water bath and records the temperature of the stearic acid every minute as it cools.
The table shows the results.
| Time / min | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 |
|---|---|---|---|---|---|---|---|---|---|
| Temperature / °C | 80 | 74 | 70 | 69 | 69 | 69 | 69 | 63 | 57 |
State the freezing point of stearic acid.
Name the change of state that happens between 3 minutes and 6 minutes.
Give the state of the stearic acid at 8 minutes.
Describe how the arrangement and movement of the particles change as the stearic acid changes from a liquid to a solid.
Explain why the temperature stays the same between 3 minutes and 6 minutes, even though the stearic acid is still losing energy to the surroundings.
53 exam-style questions on Edexcel GCSE Chemistry 3.1 States of matter, covering 3.1.1 The three states of matter and changes of state. Each one has a worked solution and a mark scheme showing where the marks go.