What is a metal ore ?

A metal ore is a rock that contains enough metal (or metal compound) to make it economically worthwhile to extract the metal.

Why is the extraction of a metal from its oxide described as a reduction reaction?

Extraction from an oxide ore involves removing oxygen from the metal compound. Removal of oxygen is the definition of reduction , so the process is a reduction reaction.

Metals .......... carbon in the reactivity series must be extracted by .......... , while metals .......... carbon can be extracted by heating with carbon or carbon monoxide.

Metals above carbon in the reactivity series must be extracted by electrolysis , while metals below carbon can be extracted by heating with carbon or carbon monoxide.

True or False? The higher a metal is in the reactivity series, the easier it is to extract from its ore.

False. The higher a metal is in the reactivity series, the more difficult it is to extract. Highly reactive metals require electrolysis, which is expensive, while less reactive metals can be extracted more cheaply using carbon.

Why are gold and platinum sometimes found as uncombined elements in the Earth's crust?

Gold and platinum are very unreactive metals. Because they do not easily react with other substances, they are found as native metals — as pure, uncombined elements.

Aluminium is extracted from its ore by .......... because it is .......... carbon in the reactivity series.

Aluminium is extracted from its ore by electrolysis because it is above carbon in the reactivity series.

Why is electrolysis a more expensive extraction method than heating with carbon?

Electrolysis requires a large amount of electricity , which makes it costly. Heating with carbon uses fuel rather than electricity and is therefore cheaper.

True or False? Iron can be extracted from its ore by heating with carbon.

True. Iron is below carbon in the reactivity series, so it can be extracted by heating with carbon (or carbon monoxide) in a blast furnace.

Name the ores from which iron and aluminium are extracted. {align=center}

Iron is extracted from hematite (iron oxide ore) Aluminium is extracted from bauxite (aluminium oxide ore)

What is hematite ? (Extended Tier Only)

Hematite is the main ore of iron. It is an iron oxide used as the raw material in a blast furnace to extract iron.

Name the three raw materials added to the top of a blast furnace. (Extended Tier Only)

Iron ore (hematite) Coke (an impure form of carbon) Limestone (calcium carbonate)

In the blast furnace, coke burns in hot air to form .......... . This reaction is .......... and provides heat for the furnace. (Extended Tier Only)

In the blast furnace, coke burns in hot air to form carbon dioxide . This reaction is exothermic and provides heat for the furnace.

Why is the reduction of iron(III) oxide by carbon monoxide described as a reduction reaction? (Extended Tier Only)

It is a reduction reaction because oxygen is removed from iron(III) oxide, leaving behind iron metal. Carbon monoxide acts as the reducing agent .

True or False? Carbon monoxide is the main reducing agent in the blast furnace. (Extended Tier Only)

True. Carbon monoxide is formed when carbon (coke) reacts with carbon dioxide at high temperatures. It then reduces iron(III) oxide to produce iron , making it the main reducing agent.

What is the role of limestone in the blast furnace? (Extended Tier Only)

Limestone (calcium carbonate) is added to remove acidic impurities in the ore. It thermally decomposes to form calcium oxide , which reacts with silicon dioxide impurities to form slag (calcium silicate).

Calcium carbonate in limestone undergoes .......... decomposition to form .......... and carbon dioxide. The calcium oxide then reacts with .......... to form slag. (Extended Tier Only)

Calcium carbonate in limestone undergoes thermal decomposition to form calcium oxide and carbon dioxide. The calcium oxide then reacts with silicon dioxide to form slag.

Give the symbol equation for the reduction of iron(III) oxide by carbon monoxide. (Extended Tier Only)

Fe 2 O 3 (s) + 3CO (g) → 2 Fe (s) + 3CO 2 (g)

True or False? Slag floats on top of the molten iron in the blast furnace. (Extended Tier Only)

True. Slag (calcium silicate) is less dense than molten iron, so it floats on top and can be tapped off separately. The molten iron sinks to the bottom of the furnace.

Bauxite is the main ore of aluminium. It contains aluminium oxide, from which aluminium is extracted by electrolysis.

Why cannot aluminium be extracted from its ore using carbon?

Aluminium is more reactive than carbon , so carbon cannot displace it from its oxide. Only a more reactive substance can displace a less reactive one, so electrolysis is needed instead.

Aluminium is extracted by .......... of aluminium oxide dissolved in molten .......... .

Aluminium is extracted by electrolysis of aluminium oxide dissolved in molten cryolite .

True or False? Aluminium is above carbon in the reactivity series.

True. Aluminium is above carbon in the reactivity series. This means it cannot be extracted by reduction with carbon and must instead be extracted by the more energy-intensive process of electrolysis .

What is the role of molten cryolite in the extraction of aluminium?

Cryolite acts as a solvent, dissolving aluminium oxide so that it can conduct electricity and undergo electrolysis . It also lowers the melting point of the aluminium oxide, reducing energy costs.

State the extraction method used for aluminium and explain why this method is necessary.

Aluminium is extracted by electrolysis . This method is necessary because aluminium is above carbon in the reactivity series, so carbon cannot reduce aluminium oxide to produce aluminium.

Aluminium is a .......... metal. Its main ore is .......... , which contains aluminium oxide.

Aluminium is a reactive metal. Its main ore is bauxite , which contains aluminium oxide.

True or False? Electrolysis is a cheaper extraction method than heating with carbon.

False. Electrolysis requires a large amount of electricity , making it an expensive process. Heating with carbon is cheaper, but it can only be used for metals that are below carbon in the reactivity series.

IGCSEScienceCambridge (CIE)Combined ScienceChemistryFlashcards9. MetalsExtraction of Metals

Extraction of Metals (Cambridge (CIE) IGCSE Combined Science: Chemistry): Flashcards

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What is a metal ore?

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Cards in this collection (26)

What is a metal ore?
A metal ore is a rock that contains enough metal (or metal compound) to make it economically worthwhile to extract the metal.
Why is the extraction of a metal from its oxide described as a reduction reaction?
Extraction from an oxide ore involves removing oxygen from the metal compound. Removal of oxygen is the definition of reduction, so the process is a reduction reaction.
Metals .......... carbon in the reactivity series must be extracted by .........., while metals .......... carbon can be extracted by heating with carbon or carbon monoxide.
Metals above carbon in the reactivity series must be extracted by electrolysis, while metals below carbon can be extracted by heating with carbon or carbon monoxide.
True or False?
The higher a metal is in the reactivity series, the easier it is to extract from its ore.
False.
The higher a metal is in the reactivity series, the more difficult it is to extract. Highly reactive metals require electrolysis, which is expensive, while less reactive metals can be extracted more cheaply using carbon.
Why are gold and platinum sometimes found as uncombined elements in the Earth's crust?
Gold and platinum are very unreactive metals. Because they do not easily react with other substances, they are found as native metals — as pure, uncombined elements.
Aluminium is extracted from its ore by .......... because it is .......... carbon in the reactivity series.
Aluminium is extracted from its ore by electrolysis because it is above carbon in the reactivity series.
Why is electrolysis a more expensive extraction method than heating with carbon?
Electrolysis requires a large amount of electricity, which makes it costly. Heating with carbon uses fuel rather than electricity and is therefore cheaper.
True or False?
Iron can be extracted from its ore by heating with carbon.
True.
Iron is below carbon in the reactivity series, so it can be extracted by heating with carbon (or carbon monoxide) in a blast furnace.
Name the ores from which iron and aluminium are extracted. {align=center}
1. Iron is extracted from hematite (iron oxide ore)
2. Aluminium is extracted from bauxite (aluminium oxide ore)
What is hematite? (Extended Tier Only)
Hematite is the main ore of iron. It is an iron oxide used as the raw material in a blast furnace to extract iron.
Name the three raw materials added to the top of a blast furnace. (Extended Tier Only)
1. Iron ore (hematite)
2. Coke (an impure form of carbon)
3. Limestone (calcium carbonate)
In the blast furnace, coke burns in hot air to form ........... This reaction is .......... and provides heat for the furnace. (Extended Tier Only)
In the blast furnace, coke burns in hot air to form carbon dioxide. This reaction is exothermic and provides heat for the furnace.
Why is the reduction of iron(III) oxide by carbon monoxide described as a reduction reaction? (Extended Tier Only)
It is a reduction reaction because oxygen is removed from iron(III) oxide, leaving behind iron metal. Carbon monoxide acts as the reducing agent.
True or False?
Carbon monoxide is the main reducing agent in the blast furnace. (Extended Tier Only)
True.
Carbon monoxide is formed when carbon (coke) reacts with carbon dioxide at high temperatures. It then reduces iron(III) oxide to produce iron, making it the main reducing agent.
What is the role of limestone in the blast furnace? (Extended Tier Only)
Limestone (calcium carbonate) is added to remove acidic impurities in the ore. It thermally decomposes to form calcium oxide, which reacts with silicon dioxide impurities to form slag (calcium silicate).
Calcium carbonate in limestone undergoes .......... decomposition to form .......... and carbon dioxide. The calcium oxide then reacts with .......... to form slag. (Extended Tier Only)
Calcium carbonate in limestone undergoes thermal decomposition to form calcium oxide and carbon dioxide. The calcium oxide then reacts with silicon dioxide to form slag.
Give the symbol equation for the reduction of iron(III) oxide by carbon monoxide. (Extended Tier Only)
Fe₂O₃ (s) + 3CO (g) → 2Fe (s) + 3CO₂ (g)
True or False?
Slag floats on top of the molten iron in the blast furnace. (Extended Tier Only)
True.
Slag (calcium silicate) is less dense than molten iron, so it floats on top and can be tapped off separately. The molten iron sinks to the bottom of the furnace.
What is bauxite?
Bauxite is the main ore of aluminium. It contains aluminium oxide, from which aluminium is extracted by electrolysis.
Why cannot aluminium be extracted from its ore using carbon?
Aluminium is more reactive than carbon, so carbon cannot displace it from its oxide. Only a more reactive substance can displace a less reactive one, so electrolysis is needed instead.
Aluminium is extracted by .......... of aluminium oxide dissolved in molten ...........
Aluminium is extracted by electrolysis of aluminium oxide dissolved in molten cryolite.
True or False?
Aluminium is above carbon in the reactivity series.
True.
Aluminium is above carbon in the reactivity series. This means it cannot be extracted by reduction with carbon and must instead be extracted by the more energy-intensive process of electrolysis.
What is the role of molten cryolite in the extraction of aluminium?
Cryolite acts as a solvent, dissolving aluminium oxide so that it can conduct electricity and undergo electrolysis. It also lowers the melting point of the aluminium oxide, reducing energy costs.
State the extraction method used for aluminium and explain why this method is necessary.
Aluminium is extracted by electrolysis. This method is necessary because aluminium is above carbon in the reactivity series, so carbon cannot reduce aluminium oxide to produce aluminium.
Aluminium is a .......... metal. Its main ore is .........., which contains aluminium oxide.
Aluminium is a reactive metal. Its main ore is bauxite, which contains aluminium oxide.
True or False?
Electrolysis is a cheaper extraction method than heating with carbon.
False.
Electrolysis requires a large amount of electricity, making it an expensive process. Heating with carbon is cheaper, but it can only be used for metals that are below carbon in the reactivity series.

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