One liquid boiled steadily at 78 ∘C78\ ^\circ\text{C}78 ∘C. A second liquid boiled over the range 78 ∘C78\ ^\circ\text{C}78 ∘C to 91 ∘C91\ ^\circ\text{C}91 ∘C.
Which statement is correct?
Both liquids are pure, because both of them began to boil at 78 ∘C78\ ^\circ\text{C}78 ∘C
Both liquids are mixtures, because boiling point depends on pressure
The first liquid is a mixture and the second liquid is pure ethanol
The first liquid may be pure and the second liquid is a mixture
40 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.