C5.3
Student practical
Name ......................................................................
Class ..................
Date ......................
Reduction by carbon
Specification references:
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C4.1.1 Metal oxides
C4.1.2 The reactivity series
C4.1.3 Extraction of metals and reduction
Aims
In this activity you will extract copper from copper oxide and lead from lead oxide
by reaction with carbon.
Learning outcomes
After completing this activity, you should be able to:
 define oxidation and reduction in terms of oxygen
 identify the substances which are oxidised or reduced in terms of gain or loss
of oxygen
 describe how metals can be extracted
 understand that some metals can be extracted from their ores by reduction
with carbon
 identify species that are being oxidised and reduced in a chemical reaction
 explain why some metals are found uncombined in the Earth’s crust
 explain how carbon or hydrogen can be used to reduce an ore
 evaluate the extraction process to obtain a metal from its ore

write half equations to represent the reduction of metal ions
.
Safety
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Wear chemical splash proof eye protection
Copper oxide: HARMFUL
Lead oxide: TOXIC
Take care with hot equipment
Wash hands after the experiment
Equipment
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two boiling tubes
boiling-tube rack
test tube holders
spatula
two evaporating dishes
© Oxford University Press 2016
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two pieces of paper
Bunsen burner
powdered carbon
copper(II) oxide
lead oxide
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1
C5.3
Student practical
Name ......................................................................
Class ..................
Date ......................
Setting the scene
Very unreactive metals such as gold are found as native metals in the Earth’s
crust. However, most metals are found as compounds, and chemical reactions are
required to extract the metal. In this type of reaction the metal is reduced.
Method
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Fold a piece of paper in half and then open it out.
Put one spatula of copper oxide and two spatulas of carbon powder over the
fold. Use the spatula to mix the powders well.
Then use the fold of the paper to help tip the powder into the boiling tube.
Hold the boiling tube with the test tube holder near the mouth of the tube
Heat the boiling tube in the blue flame for a few minutes.
Remove from the flame and tip the contents of the boiling tube into the
evaporating dish to observe.
Repeat these steps using lead oxide and carbon.
Write your observations in the results table. Add the names of the products
formed.
Results
Metal oxide
Observations
Names of products
copper oxide
lead oxide
Questions
1
In this reaction the metal oxide has been reduced by carbon. Explain in terms
of oxygen what is meant by reduction.
(1 mark)
2
For the reaction between copper oxide and carbon:
a State what has been oxidised in this reaction. Explain your answer.
(2 marks)
b
Write a word equation and a balanced symbol equation for the reaction.
(2 marks)
© Oxford University Press 2016
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This resource sheet may have been changed from the original.
2
C5.3
Student practical
Name ......................................................................
3
Class ..................
Date ......................
For the reaction between lead oxide and carbon:
a State what has been oxidised in this reaction. Explain your answer.
(2 marks)
b
Write a word equation and a balanced symbol equation for the reaction.
(2 marks)
4
Metals that are less reactive than carbon can be extracted from their oxides by
heating with carbon. Explain why magnesium cannot be extracted from
magnesium oxide by this method.
(1 mark)
5
Many everyday items are made from iron. Haematite is an ore of iron.
Haematite contains iron oxide, Fe2O3.
a What is the meaning of the term ore?
(1 mark)
b
Iron can be produced by reacting iron oxide with carbon in a blast furnace.
Explain why carbon can be used to extract iron from iron oxide.
(1 mark)
c
What type of reaction produces the iron?
(1 mark)
d
The word equation for this reaction is:
Iron oxide  carbon → iron  carbon dioxide
Complete and balance the symbol equation for this reaction.
____Fe2O3  ____C → ________  ________
© Oxford University Press 2016
(2 marks)
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3
C5.3
Student practical
Name ......................................................................
6
Class ..................
Date ......................
Part of a reactivity series is:
decreasing
reactivity
a
sodium
calcium
magnesium
aluminium
zinc
iron
hydrogen
copper
Carbon is used in blast furnaces to obtain iron and zinc from their oxides,
but electrolysis has to be used to obtain aluminium from its oxide. Draw
an arrow on the reactivity series above to show where carbon fits into
the series.
(1 mark)
b
Predict the method of extraction used to obtain calcium from its ore and
explain your answer.
(2 marks)
c
The formula for zinc oxide is ZnO. Write a balanced equation for the
extraction of zinc in the blast furnace.
(2 marks)
Higher tier questions
1
a
Explain in terms of electrons what happens when copper(II) ions are
converted to copper metal.
(1 mark)
b
Write down the half equation which represents this change.
(1 mark)
© Oxford University Press 2016
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This resource sheet may have been changed from the original.
4
C5.3
Student practical
Name ......................................................................
c
Class ..................
Date ......................
Are the copper(II) ions oxidised or reduced? Explain your answer
(1 mark)
2
Copper(II) oxide can be reduced by hydrogen as well as by carbon, forming
copper metal and water.
a Construct a balanced symbol equation for this reaction.
(1 mark)
b
Underline in red the species that is oxidised and underline in blue the
species that is reduced.
© Oxford University Press 2016
(1 mark)
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This resource sheet may have been changed from the original.
5