Some properties of four solids, P, Q, R and S, are shown in the table below.
| Property | Solid P | Solid Q | Solid R | Solid S |
|---|---|---|---|---|
| Colour of solid | Black | White | Grey | White |
| Observation when added to water | Insoluble; black solid remains | Dissolves easily to form a colourless solution | Insoluble; grey solid remains | Partially dissolves to form a slightly cloudy mixture |
| pH of mixture with water | 7 | 11 | 7 | 12 |
| Observation when dilute hydrochloric acid is added | Reacts to form a blue-green solution; no bubbles | Effervescence; solid disappears to form a colourless solution | Effervescence; solid disappears to form a colourless solution | Reacts to form a colourless solution; no bubbles |
The solids, in no particular order, are calcium hydroxide, copper(II) oxide, sodium carbonate, and zinc metal.
Identify solids P, Q, R and S, explaining how the information in the table supports the identification of each solid.
276 exam-style questions on Edexcel GCSE Chemistry 4.1 Acids, covering 4.1.1 Acids, alkalis and the pH scale, 4.1.2 Hydrogen ion concentration and pH, 4.1.3 Dilute and concentrated, weak and strong acids, 4.1.4 Bases, alkalis and the reactions of acids, 4.1.5 Chemical tests for hydrogen and carbon dioxide, 4.1.6 Neutralisation as a reaction of acids with bases, 4.1.7 Preparing soluble salts, and 4.1.8 Solubility rules and preparing insoluble salts. Each one has a worked solution and a mark scheme showing where the marks go.