Inorganic Chemistry · 1 question type
Past paper frequency (2018 to 2024)
This topic accounts for approximately 6% of your exam marks.
Displacement reactions and determining order of reactivity from experimental data.
metal + water → metal hydroxide + hydrogen
metal + steam → metal oxide + hydrogen
| Metal | Behaviour with water |
|---|---|
| Potassium | Reacts violently with cold water; ignites the hydrogen with a lilac flame |
| Sodium | Reacts vigorously with cold water; melts to a silvery ball and fizzes |
| Lithium | Reacts steadily with cold water; floats, fizzes, dissolves |
| Calcium | Reacts fairly briskly with cold water; produces a cloudy white suspension of Ca(OH)2 |
| Magnesium | Reacts very slowly with cold water; reacts much faster with steam |
| Zinc | Only reacts with steam, slowly |
| Iron | Only reacts with steam, slowly |
| Copper, silver, gold | No visible reaction with water or steam |
Ca(s) + 2 H2O(l) → Ca(OH)2(aq) + H2(g)
metal + acid → salt + hydrogen
| Metal | Reaction with dilute HCl | Reaction with dilute H2SO4 |
|---|---|---|
| Magnesium | Mg + 2 HCl → MgCl2 + H2 | Mg + H2SO4 → MgSO4 + H2 |
| Zinc | Zn + 2 HCl → ZnCl2 + H2 | Zn + H2SO4 → ZnSO4 + H2 |
| Iron | Fe + 2 HCl → FeCl2 + H2 | Fe + H2SO4 → FeSO4 + H2 |
| Copper | No reaction (Cu is below H) | No reaction |