A mixture contains calcium chloride dissolved in ethanol. A student needs to separate this mixture to obtain a pure, dry sample of solid calcium chloride and a pure sample of liquid ethanol.
The table below shows the boiling points of calcium chloride and ethanol.
| Substance | Boiling point in °C |
|---|---|
| Calcium chloride | 1935 |
| Ethanol | 78 |
Explain this difference in boiling points in terms of the structure and bonding of calcium chloride and ethanol. Explain how this difference in boiling points is used to select and carry out an experimental method to separate the mixture into pure, dry calcium chloride and pure ethanol.
107 exam-style questions on Edexcel GCSE Chemistry 3.2 Methods of separating and purifying substances, covering 3.2.1 Pure substances and mixtures, 3.2.2 Techniques for separating mixtures, 3.2.3 Paper chromatography and Rf values, and 3.2.4 Making water potable. Each one has a worked solution and a mark scheme showing where the marks go.