A conservator uses liquid compound P to clean metal objects. The accepted boiling point of compound P is 121 ∘C121\ ^\circ\text{C}121 ∘C.
The conservator heats a sample from a bottle labelled compound P. The temperature is recorded at three stages while the sample is boiling.
| Stage of boiling | Temperature in ∘C^\circ\text{C}∘C |
|---|---|
| Early | 117 |
| Middle | 121 |
| Late | 125 |
The conservator concludes that the sample is pure compound P because one of the temperatures is the accepted boiling point.
Evaluate the conservator's conclusion.
A different bottle labelled compound P boils sharply at 124 ∘C124\ ^\circ\text{C}124 ∘C.
Explain what this result shows about the contents of the bottle.
113 exam-style questions on AQA GCSE Chemistry 8.1 Purity, formulations and chromatography, covering 8.1.1 Pure substances, 8.1.2 Formulations, and 8.1.3 Chromatography. Each one has a worked solution and a mark scheme showing where the marks go.