C5 - Investigate the reactivity of metals

• In displacement reaction a more reactive metal displaces (takes the place of) a less reactive metal from its compound.

• The reactivity of a range of metals can be compared by carrying out displacement reactions between the different metals.

• The most reactive metal will be able to displace all of the other metals from their compounds.

The reactivity of metals can be determined using displacement reactions.

In a displacement reaction a more reactive metal will displace a less reactive metal from its compound.

For example, magnesium is a more reactive metal than copper, so can displace copper(II) ions from copper(II) sulfate:

magnesium + copper(II) sulfate → magnesium sulfate + copper

Essentially, the magnesium and copper ‘swap’ places.

In this experiment we will determine the relative reactivity of 4 metals: copper, iron, zinc, and magnesium.

In order to determine the relative reactivity of each metal we will carry out displacement reactions by reacting each metal with a solution of every other metal ion.

If the metal is more reactive than the metal in a solution (present as an ion), then a displacement reaction will occur and we will observe a change in the reaction.

• Test-tube rack

• Test-tubes x3

• Copper(II) sulfate solution (0.5 mol/dm³)

• Magnesium sulfate solution (0.5 mol/dm³)

• Zinc sulfate solution (0.5 mol/dm³)

• Iron(II) sulfate solution (0.5 mol/dm³)

• Pieces of copper foil (3 small pieces approx. 1 cm²)

• Zinc (3 small granules or pieces of foil approx. 1 cm²)

• Iron (3 small ungalvanised nails)

• Magnesium ribbon (3 small pieces 1 cm length)

1. Half-fill separate test-tubes with magnesium sulfate, iron(II) sulfate and zinc sulfate solutions.

2. Add a piece of copper to each test-tube.

3. Leave for 3 minutes, record observations.

Observations

1. Half-fill separate test-tubes with copper(II) sulfate, magnesium sulfate and zinc sulfate solutions.

2. Add a piece of iron to each test-tube.

3. Leave for 3 minutes, record observations.

Observations

1. Half-fill separate test-tubes with copper(II) sulfate, magnesium sulfate and iron(II) sulfate solutions.

2. Add a piece of zinc to each test-tube.

3. Leave for 3 minutes, record observations.

Observations

1. Half-fill separate test-tubes with copper(II) sulfate, iron(II) sulfate and zinc sulfate solutions.

2. Add a piece of magnesium to each test-tube.

3. Leave for 3 minutes, record observations.

Observations