The table below shows information about some properties of four substances, labeled W, X, Y, and Z:
| Substance | Melting point (∘C^\circ\text{C}∘C) | Boiling point (∘C^\circ\text{C}∘C) | Solubility in water | Does the substance conduct electricity? |
|---|---|---|---|---|
| W | −97-97−97 | 656565 | Soluble | No |
| X | −114-114−114 | 787878 | Soluble | No |
| Y | 772772772 | 141214121412 | Soluble | Only when molten or dissolved |
| Z | 108510851085 | 256225622562 | Insoluble | Yes |
Which separation technique should be used to separate a mixture of substance W and substance X?
Describe a method that could be used to separate a mixture of solid substance Y and solid substance Z to obtain pure samples of both.
A student separates substance Y from a mixture. They start with 14.8 g14.8\text{ g}14.8 g of the mixture and obtain 4.2 g4.2\text{ g}4.2 g of pure substance Y. Calculate the mass of pure substance Y that could be obtained from 25.0 g25.0\text{ g}25.0 g of the mixture. Give your answer to 3 significant figures.
Match each of the substances W, Y, and Z with its correct type of structure and bonding. Choose from: Giant Covalent, Ionic, Metallic, Polymer, Simple Covalent.
46 exam-style questions on OCR GCSE Chemistry Purity and separating mixtures. Each one has a worked solution and a mark scheme showing where the marks go.