A mixture of two liquids, X and Y, is separated by fractional distillation. X boils at 65 ∘C65\,^\circ\mathrm{C}65∘C and Y boils at 100 ∘C100\,^\circ\mathrm{C}100∘C.
The table shows the temperature at the top of the fractionating column.
| Time (min) | Temperature (∘C^\circ\mathrm{C}∘C) |
|---|---|
| 0 to 10 | steady at 65 |
| 10 to 14 | rising from 65 to 100 |
| 14 to 25 | steady at 100 |
The student collects the liquid that distils in three beakers:
Beaker 1: 0 to 10 minutes
Beaker 2: 10 to 14 minutes
Beaker 3: 14 to 25 minutes
Which statement is correct?
Beaker 1 contains mostly Y, because Y has the higher boiling point.
Beaker 2 contains a mixture of X and Y.
Beaker 3 contains a mixture of X and Y.
All three beakers contain X, because X is collected first.
51 exam-style questions on OCR GCSE Chemistry 2.1 Purity and separating mixtures, covering 2.1.1 Pure substances and melting point data, 2.1.2 Relative formula mass and empirical formula, 2.1.3 Formulations as useful mixtures, 2.1.4 Techniques for separating mixtures, and 2.1.5 Chromatography and Rf values. Each one has a worked solution and a mark scheme showing where the marks go.