Chemistry · 9.2 Reactivity series · Paper 5/6 practical
Reactivity & Displacement. Rank them.
A more reactive metal displaces a less reactive one from its salt solution — a deposit forms, the colour fades and the temperature rises. The same idea ranks the halogens. Run the combinations and deduce the order of reactivity.
0620 Topic 9.2 — Reactivity series
8.3 — Halogen displacement
Paper 5/6 — Practical
choose reactants
Reactants
+
—
Result
Reaction?
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Temp change
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Observation
react to see…
Observation log
React combinations to deduce the order.
📋 Method & ideas
- Add a small piece of the metal to about 2 cm³ of the salt solution in a test tube.
- A displacement occurs if the added metal is more reactive than the metal in the salt: a coating forms, the solution colour fades and the temperature rises (exothermic).
- No reaction means the added metal is less reactive — this is how you rank the metals.
- Halogens: a more reactive halogen (higher in Group VII) displaces a less reactive one from its salt — e.g. chlorine displaces bromine (orange) and iodine (brown).
⚠ Precautions
- Use equal-sized metal pieces and equal volumes/concentrations so comparisons are fair.
- Feel the tube (or use a thermometer) for the temperature rise — bigger rise = bigger reactivity gap.
- Halogens and their solutions are harmful/irritant — use small amounts and ventilate.
🎯 Syllabus reference (0620)
- 9.2 Reactivity series — place metals in order of reactivity by their reactions and by displacement; deduce an order from experimental results.
- 8.3 Group VII — describe and explain displacement reactions of halogens.