The key idea
Metals higher in the reactivity series react more vigorously.A more reactive metal displaces a less reactive one from a solution of its salt.Metals below carbon are extracted by reduction; those above by electrolysis.
Use the labels to explain the scientific relationship shown.
The bit that matters
Keep the idea tight, then use the worked example to practise the exact exam wording.
The reactivity series
The reactivity series orders metals by their tendency to lose electrons and form positive ions.From most to least reactive: potassium, sodium, lithium, calcium, magnesium, aluminium, (carbon), zinc, iron, (hydrogen), copper, silver, gold, platinum.A metal higher in the series will displace a metal lower in the series from a solution of its salt.
Extraction of metals
How a metal is extracted depends on its position in the reactivity series.Metals below carbon (zinc, iron, tin, lead, copper) can be extracted by reduction with carbon or carbon monoxide.Metals above carbon (potassium, sodium, calcium, magnesium, aluminium) are too reactive to be reduced by carbon and must be extracted by electrolysis of their molten compounds.
The blast furnace
Iron is extracted in a blast furnace by reducing iron oxide with carbon (as coke).The key reactions are: C + O₂ → CO₂; CO₂ + C → 2CO; Fe₂O₃ + 3CO → 2Fe + 3CO₂.Limestone (CaCO₃) is added to remove acidic impurities as slag (calcium silicate).The molten iron sinks to the bottom of the furnace.
Recycling and sustainability
Extracting metals is energy-intensive and depletes finite ore resources.Recycling metals saves energy, conserves resources and reduces landfill waste.Copper can also be extracted from low-grade ores by bioleaching (using bacteria) or phytomining (using plants that absorb and concentrate copper), then by displacement or electrolysis.
Definitions to learn
Reactivity series
A list of metals in order of decreasing reactivity with water and acids.
Displacement reaction
A reaction in which a more reactive element displaces a less reactive element from a compound.
Reduction
Gain of electrons (or removal of oxygen from a compound); used to extract metals from their oxides.
Oxidation
Loss of electrons (or addition of oxygen to a substance).
Ore
A rock that contains enough of a metal compound to make extraction economically worthwhile.
Phytomining
Extracting metals from low-grade ores using plants that absorb and concentrate metal ions in their biomass.
Explain whether iron will displace copper from copper sulfate solution.
Check the reactivity series: iron is above copper.
A more reactive metal displaces a less reactive one.
Iron will displace copper: Fe + CuSO₄ → FeSO₄ + Cu.
Iron dissolves and copper metal deposits.
Yes — iron displaces copper because iron is more reactive. The solution turns from blue to pale green.
For every reactivity prediction, state the positions of both metals in the series and explain which is more reactive before predicting the outcome.
Do not say the most reactive metal always reacts fastest — reactivity refers to the ease of losing electrons, not reaction rate.
How to score full marks
- 1State the relative positions of BOTH metals in the reactivity series before predicting whether displacement occurs.
- 2Metals above carbon in the reactivity series are extracted by ELECTROLYSIS (not reduction with carbon).
- 3Describe displacement observations fully: colour change of solution AND appearance of metal deposit.
Try these yourself
Open each answer only after you have explained the full chemical process.
1State what is meant by a displacement reaction in terms of reactivity.[1 mark]
- 1.Compare the reactivity of two metals.
2Predict whether zinc will react with magnesium sulfate solution. Explain your reasoning.[3 marks]
- 1.Compare positions in the reactivity series.
3Explain why gold is found as the native metal in the Earth's crust.[3 marks]
- 1.Link low reactivity to not forming compounds.
4State why aluminium is extracted by electrolysis rather than reduction with carbon.[3 marks]
- 1.Compare the positions of aluminium and carbon in the reactivity series.
5Write a balanced equation for the reduction of iron oxide with carbon in a blast furnace.[2 marks]
- 1.Identify the reactants and products.
6Explain why it is more expensive to extract aluminium than iron.[4 marks]
- 1.Link to the extraction method used.
7Describe what you would observe when a ce of magnesium ribbon is added to blue copper sulfate solution.[3 marks]
- 1.Describe the visual changes.
8Explain phytomining as a method for extracting copper from low-grade ore.[4 marks]
- 1.Describe how plants are used in the process.