A technician has a mixture of sand, copper sulfate and water. The copper sulfate has dissolved in the water. The table gives information about the substances in the mixture.
| Substance | Solubility in water | Effect of heating |
|---|---|---|
| sand | insoluble | melts at 1710 °C |
| copper sulfate | soluble | hydrated crystals lose water and break down when heated strongly |
| water | not applicable | boils at 100 °C |
Give the property of sand that allows it to be separated from the mixture by filtration.
Devise a method the technician could use to obtain dry sand, pure dry crystals of hydrated copper sulfate and pure water from the mixture.
Explain why the technician should not heat the copper sulfate solution until it is completely dry.
Suggest how the technician could show that the water collected is pure.
48 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.