Quick answer: The reactivity series ranks metals by how easily they lose electrons. This Chemistry 9-10 lab on reactivity series gives the aim, the equipment, the safety points, a step-by-step method, sample results and 8 analysis questions; the answers are on a separate page and the lab sheet is a free printable PDF.
A more reactive metal pushes a less reactive one out of solution, and the reaction releases energy as heat. This lab measures the temperature rise when four metals are added to copper(II) sulfate solution, so reactivity can be ranked with numbers instead of guesses.
Level: Chemistry grades 9-10 (GCSE · IGCSE · O Level · Class 9-10) · Curriculum: GCSE C4
Aim
To compare the reactivity of magnesium, zinc, iron and copper by measuring the temperature rise when each is added to copper(II) sulfate solution.
Equipment
- Polystyrene cup with lid, and a 250 cm³ beaker to support it
- 25.0 cm³ measuring cylinder, thermometer (0.5 °C divisions)
- 0.500 mol/dm³ copper(II) sulfate solution
- 1.0 g portions of magnesium, zinc and iron powder and copper powder
- Spatula, stopwatch
Safety
Wear goggles. Copper sulfate is harmful if swallowed and toxic to aquatic life: put waste into the labelled container. Metal powders can be a fire risk, so keep them away from flames.
Method
- Measure 25.0 cm³ of copper(II) sulfate solution into the cup and record the starting temperature.
- Add one 1.0 g portion of the metal powder, replace the lid and stir gently with the thermometer.
- Record the highest temperature reached.
- Rinse the cup and repeat with each of the other metals.
Results
| Metal | Start (°C) | Highest (°C) | Rise (°C) | Observation |
|---|---|---|---|---|
| Magnesium | 21.0 | 66.5 | ? | Blue colour fades, brown solid |
| Zinc | 21.0 | 42.5 | ? | Blue colour fades, brown solid |
| Iron | 21.0 | 36.0 | ? | Blue fades to pale green, brown solid |
| Copper | 21.0 | 21.0 | ? | No change |
Analysis questions
Question 1 Temperature rises
Complete the temperature rise for each metal.Question 2 Order of reactivity
Use the rises to place the metals in order of reactivity and compare with the reactivity series.Question 3 Explain the copper result
Explain why copper powder causes no temperature rise.Question 4 Energy released
Calculate the energy released by magnesium using Q = m × c × ΔT, with m = 25.0 g of solution and c = 4.18 J/g/°C.Question 5 Energy per mole
The cup holds 0.0125 mol of Cu²⁺. Calculate the energy released per mole of copper ions displaced by magnesium and by zinc.Question 6 Why excess metal
Explain why 1.0 g of each metal is used, and show it is in excess for zinc (Ar: Zn = 65).Question 7 Errors
State one source of error that makes the energy values too low and how to reduce it.Question 8 Extending the lab
Predict the temperature rise order if aluminium powder were added, and explain what might make the result unexpected.
