Chemistry
Chapter 11
11.1
Class No.: _____
Occurrence and extraction of metals
Oral Presentation (2 groups will be selected for presentation.)
Search the internet (or other resources) for the occurrence of metals and the uses of metals in
daily life.
Websites for references:
1) Some common minerals and their uses
http://www.nma.org/about_us/publications/pub_minerals_uses.asp
http://www.mii.org/commonminerals.php#chrom
2) Minerals and metals for the worlds
http://www.riotinto.com/library/reports_PDFs/corpPub_CorpBrochure_MineralsMetal.pdf
Please summarize your classmates’ presentation:
Hand in your summary at the end of the lesson.
Chemistry Worksheets / HKCWCC / Chapter 11
Marks
P. 1
Chemistry
Chapter 11
11.2
Class No.: _____
Occurrence and extraction of metals
Uses related to the properties of metals
Complete the following table:
Metal
Iron
Copper
Aluminium
Uses
Reasons for uses
For construction, building Hard, strong, malleable and ductile, & cheap
bridges, and the body of
vehicles
Making magnet
Magnetic
For making electrical wire,
Excellent conductor of electricity, ductile and
corrosion resistant.
water pipes,
Non-poisonous, malleable & ductile, corrosion
resistant
and cooking utensils
Excellent conductor of heat, Non-poisonous.
For making overhead power Very good conductor of electricity, low density,
cables,
ductile.
aircraft body,
Light but strong, corrosion resistant
saucepans, kitchen foils,
Very good conductor of heat, non-poisonous,
corrosion resistant, malleable.
soft drink can,
Non-poisonous, low density, corrosion resistant,
and malleable.
& window frames.
Strong, corrosion resistant
Titanium
For
making
aircraft
supersonic Light but very strong, very corrosion resistant,
malleable
Gold
For jewellery, coins,
Attractive golden yellow colour, extremely
corrosion resistant, most malleable and ductile
shield for heat, and radiation Excellent reflective quality
Mercury
For thermometers
Liquid at room temperature, expands on heating
Silver
For jewellery, coins,
Attractive silvery colour, corrosion resistant,
malleable and ductile
electrical and
components
Chemistry Worksheets / HKCWCC / Chapter 11
electronic Good conductor of electricity, ductile and
corrosion resistant.
P. 2
Chemistry
Class No.: _____
Chapter 11
11.3
Occurrence and extraction of metals
Metal ores
Which metals are found free in the Earth?
Why ?
Unreactive metals, such as gold and platinum (at the bottom of the reactivity series), are
found free in the Earth’s crust.
Metals are usually found in the form of compounds. Which kinds of compounds are found in
ores?
Metal oxides, carbonates and sulphides are found in metal ores.
Are these metal compounds soluble in water?
They are insoluble in water.
Name some common metal ores:
Metal
Aluminium
Formula of the compound
bauxite
Aluminium oxide
Al2O3
Copper pyrites
Copper iron(II) sulphide
CuFeS2
Iron
Haematite
Iron(III) oxide
Fe2O3
Lead
Galena
Lead(II) sulphide
PbS
Copper
11.4
Name of the main ore Compound found in ore
Extraction of metals form their ores
What are the three methods for extracting a metal from its ores?
1) Heating the metal ore/oxide alone.
2) Heating the metal ore/oxide with carbon/coke.
3) Electrolysis of hot molten ores.
a)
Heating the metal ore / oxide alone
What do you observe when zinc oxide is heated?
The white solid turns yellow.
What do you see when the hot zinc oxide is allowed to cool?
The yellow solid turns white.
Chemistry Worksheets / HKCWCC / Chapter 11
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Chemistry
Chapter 11
Class No.: _____
Occurrence and extraction of metals
Is there any metal formed?
No, there isn’t any metal formed.
Which metal oxides give metal when heated?
Merucry(II) oxide and silver oxide
Write chemical equations for the thermal decomposition of
i)
mercury(II) oxide :
ii) silver oxide:
2HgO(s)  2Hg(l) + O2(g)
2Ag2O(s)  4Ag(s) + O2(g)
b) Heating metal ore / oxide with carbon
i)
lead(II) oxide
What do you see when lead(II) oxide is heated alone?
The yellow solid turns orange.
Is there any lead metal formed?
No, there isn’t any metal formed.
Heat lead(II) oxide in a charcoal block. (Heat lead(II) oxide with coke.)
What do you see?
Silvery beads of molten lead are formed.
Write a chemical equation for the reaction involved.
2PbO(s) + C(s)  2Pb(s) + CO2(g)
ii) copper(II) oxide
What do you see when copper(II) oxide is heated alone?
No observable change.
Heat copper(II) oxide in a charcoal block. (Heat copper(II) oxide with coke.)
What do you see?
Reddish brown solid copper is formed.
Write a chemical equation for the reaction involved.
2CuO(s) + C(s)  2Cu(s) + CO2(g)
Chemistry Worksheets / HKCWCC / Chapter 11
P. 4
Chemistry
Class No.: _____
Chapter 11
Occurrence and extraction of metals
iii) zinc oxide
Heat zinc oxide in a charcoal block.
What do you see?
The white solid turns yellow.
Why?
The hot Bunsen flame does not provide high enough temperature to start the
reduction of zinc oxide by carbon.
N.B.
Which metal is more reactive, lead or zinc? Zinc is more reactive than lead.
Which metal, zinc or lead, forms a more stable oxide? Zinc forms a more
stable metal oxide than that of lead.
Bunsen flame is not hot enough to remove oxygen from zinc oxide.
N.B.
What is oxidation?
Give examples of oxidation:
Oxidation is the process in which oxygen is added to a substance.
What is reduction?
Reduction is the process in which oxygen is removed from a substance.
Give examples of reduction:
Lead is formed when lead oxide is heated with carbon.
N.B.
Name the type of reaction by which metal is extracted from its oxide by heating
with carbon.
Reduction of metal oxide by carbon
/ Redox reaction.
What is the role of carbon in the reaction?
Reading assignment:
Reducing agent.
Read 11.7 Extraction of iron from haematite in industry (P.244)
Chemistry Worksheets / HKCWCC / Chapter 11
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Chemistry
Chapter 11
Class No.: _____
Occurrence and extraction of metals
iv) galena, lead(II) sulphide
Give the chemical formula of lead(II) sulphide:
How lead is extracted from galena?
PbS
Heat (Roast) lead(II) sulphide in air to form lead(II) oxide.
Heat lead(II) oxide with carbon to form lead.
Write chemical equations for the reaction involved.
2PbS(s) + 3O2(g) 
2PbO(s) + C(s) 
c)
2PbO(s) + 2SO2(g)
2Pb(s) + CO2(g)
Extraction of metals by the electrolysis of its hot molten ores
Which metals are extracted by the electrolysis of molten ores?
Reactive metals (metals that are above zinc in the reactivity series) are extracted
by the electrolysis of molten ores.
N.B.
It is an expensive method.
Examples:
Electrolysis of hot molten bauxite,
Electrolysis of molten sodium chloride.
11.5 Discovery of metals
Read Table 11.2 (P.
237)
What is the relationship between the year of discovery of metals and the relative reactivity of
metals?
The more reactive the metal, the more stable is its compounds and the more difficult is it to
be extracted. Thus, these metals will a short history and was extracted by Man recently.
N.B.
Uncreative metals, such as gold and platinum, are found free in nature.
Read Table 11.3 Different Ages in human civilization
(Stone, Copper, Bronze, & Iron Age)
Chemistry Worksheets / HKCWCC / Chapter 11
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Chemistry
Chapter 11
Class No.: _____
Occurrence and extraction of metals
11.6 Factors affecting the discovery and use of metals
1)
2)
3)
The price of metals depends mainly on:
1)
2)
3)
11.7 Conserving metals
Why we need to conserve metals?
Ways to conserve metals
1)
2)
3)
Importance of recycling:
1)
2)
3)
4)
Recycling involves ____________, ___________, ___________, and ____________ the metal,
and ______________any unwanted substances. The used metals are then __________ and
____________ into other shapes,
Chemistry Worksheets / HKCWCC / Chapter 11
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Chemistry
Chapter 11
Class No.: _____
Occurrence and extraction of metals
11.8 Extraction of iron from haematite in industry (Blast Furnace)
Raw materials: ________________________________________________________________
A mixture of ___________, __________ and _____________ is added at the top of the furnace.
________ air is blown into the furnace from the bottom. A chain of chemical reactions occur:
1) Carbon reacts with oxygen in air to form ______________.
Equation: ___________________________________________________________________
2) The hot carbon dioxide rises in the furnace and is reduced by _________ to form __________ .
Equation: ___________________________________________________________________
3) Carbon monoxide is a ____________ agent. It ___________ iron(III) oxide in haematite to
form hot molten ___________.
Equation: ____________________________________________________________________
The hot molten iron is then rum out from the bottom of the furnace.
4) The formula of limestone: ________________
Limestone breaks up _______________ and ________________ when heated.
Equation: ____________________________________________________________________
5) Calcium oxide helps to remove _______________ (the impurities) to form a liquid ‘_______’.
Equation: _________________________________________________________________
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