Extraction of metals & reduction

Aluminium is extracted from a rock called bauxite which contains aluminium oxide.

The diagram shows information from a life-cycle assessment for the manufacture and use of aluminium products.

Give one reason why a life-cycle assessment is carried out.

Give two reasons why the products should be recycled at the end of their useful life.

18% of the bauxite rock is turned into aluminium.

Calculate the mass of aluminium that is extracted from 7500 kg of bauxite.

Give your answer to 2 significant figures.

Aluminium is extracted from aluminium oxide, Al₂O₃, by electrolysis.

This is the equation for the electrolysis of aluminium oxide.

A student thinks that this reaction is an example of reduction.

Explain why the student is correct.

Extracting aluminium by electrolysis is expensive.

Which statements about why the electrolysis is expensive are true, and which are false ?

Tick one (✓) box in each row.

It would be cheaper if aluminium could be extracted by heating the aluminium oxide with carbon.

Explain why aluminium oxide does not react with carbon.

Aluminium is extracted from a rock called bauxite which contains aluminium oxide.

The diagram shows information from a life-cycle assessment for the manufacture and use of aluminium products.

Give one reason why a life-cycle assessment is carried out.

Give two reasons why the products should be recycled at the end of their useful life.

18% of the bauxite rock is turned into aluminium.

Calculate the mass of aluminium that is extracted from 7500 kg of bauxite.

Give your answer to 2 significant figures.

Aluminium is extracted from aluminium oxide, Al₂O₃, by electrolysis.

This is the equation for the electrolysis of aluminium oxide.

A student thinks that this reaction is an example of reduction.

Explain why the student is correct.

Extracting aluminium by electrolysis is expensive.

Which statements about why the electrolysis is expensive are true, and which are false ?

Tick one (✓) box in each row.

It would be cheaper if aluminium could be extracted by heating the aluminium oxide with carbon.

Explain why aluminium oxide does not react with carbon.

In industry, iron can be extracted from iron ore. Iron ore contains iron oxide, Fe₂O₃.

Iron is extracted from iron oxide by reduction.

The equation for one reaction is

Complete the balanced symbol equation for the reaction.

Why does this reaction happen?

Tick (✓) one box.

Explain how the equation shows that the iron oxide is reduced.

Which chemical reduces the iron oxide, Fe₂O₃?

Tick (✓) one box.

In industry, iron is extracted from iron ore in a blast furnace.

The table shows information about the production of iron in a blast furnace and from recycling.

Give two reasons why it is better to produce iron from recycling than in a blast furnace.

Use the information from the table.

Calculate the mass of iron made from 250 tonnes of iron ore in the blast furnace. Give your answer in kilograms.

(1 tonne = 1000 kg)

Iron, Fe, can be extracted from iron oxide, Fe₂O₃, in a blast furnace, by the reaction shown in the equation.

Fe₂O₃ + 3X → 2Fe + 3Y

What are the formulae of X and Y ?

Copper can be extracted from its compounds by different processes.

Process 1

• Copper is extracted from copper oxide, CuO.

• The copper is extracted by heating copper oxide with carbon.

This is the equation for the reaction in Process 1.

2CuO(s) + C(s) → 2Cu(s) + CO₂(g)

Explain why carbon can be used to extract copper from copper oxide.

One of the products of this reaction causes an environmental problem.

Identify the product and describe its impact on the environment.

Process 2

• Copper is extracted from copper sulfide, CuS.

• Solid copper sulfide is broken down by bacteria to form a solution of copper sulfate, CuSO₄.

• The copper is extracted from the solution of copper sulfate by either reacting it with iron or by electrolysis.

Why is process 2 described as a biological method of metal extraction?

Describe two advantages of extracting copper from the solution of copper sulfate by reacting it with iron rather than using electrolysis.

Ores are rocks that contain metals or their compounds.

The table shows some information about high-grade and low-grade ores.

Explain the difference in the mass of metal contained in a high-grade and low-grade ore.

Use information from the table.

The student writes the word equation for the reaction.

Complete the word equation for the reaction.

Why does this reaction happen?

Use the reactivity series in Fig. 12.1.

Use the reactivity series in Fig. 12.1 to answer parts (b), (c) and (d).

Another student repeats the experiment but places a different metal in the solution of copper sulfate.

There is no chemical reaction.

Suggest a metal that this student used.

Name one metal that can be extracted by heating its oxide with carbon.

Name one metal that can be extracted from its oxide by electrolysis but not by heating its oxide with carbon.

Complete the sentence below to explain the difference in the reactivity of sodium and lithium.

Use one of the words.

electrons neutrons protons

Sodium atoms lose........ more easily than lithium atoms.

State the trend in reactivity of the Group 1 metals.

Name a Group 1 metal which is more reactive than sodium.

Iron can be extracted from its ore by heating it with carbon.

Which statement is the correct explanation for this?

A Iron is above carbon in the reactivity series.

B Iron is above copper in the reactivity series.

C Iron is below carbon in the reactivity series.

D Iron is below sodium in the reactivity series.

Iron can be extracted from its ore by heating it with carbon.

Which statement is the correct explanation for this?

A Iron is above carbon in the reactivity series.

B Iron is above copper in the reactivity series.

C Iron is below carbon in the reactivity series.

D Iron is below sodium in the reactivity series.