A student has three unknown solids, P, Q, and R.
The solids are calcium carbonate, powdered magnesium, and copper(II) oxide, but the student does not know which solid is which.
The student reacted a sample of each solid with dilute hydrochloric acid.
| Reaction with dilute hydrochloric acid | Gas bubbled through limewater | Gas tested with a lit splint | |
|---|---|---|---|
| Solid P | Bubbles seen, colourless solution formed | No change | Squeaky pop |
| Solid Q | Blue-green solution formed, some black solid remains at the bottom | No gas produced | No gas produced |
| Solid R | Bubbles seen, colourless solution formed | Limewater turned cloudy | Puts out lit splint |
Use the observations and results in Table 1 to identify which solid is which. Your answer should include:
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.