NOTES BY MISS CHOHAN
These notes contain:
C1.3.1 – EXTRACTING METALS
C1.3.2 – ALLOYS
C1.3.3 – PROPERTIES AND USES
OF METALS
GCSE CHEMISTRY
NOTES
CI METALS & THER USES NOTES BY MISS CHOHAN
METAL ORES – are metal compounds which contain enough metal in them to make it
worthwhile to extract.
Metal ores are generally:
1. METAL OXIDES e.g. Iron III oxide; Aluminium oxide
2. OR METAL SULPHIDES e.g. copper II sulphide; Zinc II sulphide
Metal ores are finite resources.
In other words there are only limited amounts of the ores present in the Earths crust and
will ∴ one day run out.
Extraction is the term for getting pure metal out of the ore; there are two methods of
extracting metals which depend on their reactivity
Reactivity Series – metals are placed in order of reactivity by reacting them with oxygen,
water and acid. From this data a reactivity series is produced
How a metal is extracted from its ore depends on where the metal lies in the reactivity series:
At the top metals naturally bond to oxygen stronger which makes it difficult to remove.
Reduction is the process of removing oxygen from the ore using carbon. Therefore carbon can act as
a reducing agent.
CI METALS & THER USES NOTES BY MISS CHOHAN
Electrolysis is the process of using electricity to extract a metal
Reduction is the loss of oxygen from a compound
Oxidation is the gain of oxygen to form a compound
Magnesium and copper oxide
Mg + CuO  MgO + Cu
Magnesium is more reactive than copper so it `kicks it` out of solution
Blast Furnace Reaction
Iron oxide and carbon monoxide
Fe2O3 + 3CO  3CO2
+ 2Fe
CI METALS & THER USES NOTES BY MISS CHOHAN
The Thermite Reaction
Iron and copper chloride
Fe2O3 + 2Al  Al2O3 + 2Fe
Fe + CuCl2 
Cu
+ FeCl2
iron + copper chloride  copper + iron chloride
iron is more reactive than copper, as a result iron displaces copper
copper and silver nitrate
Cu + 2AgNO3  2Ag
+ Cu(NO3)2
copper + silver nitrate  silver + copper nitrate
copper is more reactive than silver, as a result copper displaces silver
zinc and copper sulphate
Zn + CuSO4  Cu
+ ZnSO4
zinc + copper sulfate  copper+ zinc sulfate
zinc is more reactive than copper, as a result zinc displaces copper
CI METALS & THER USES NOTES BY MISS CHOHAN
The Blast Furnace – The extraction of iron
There are 4 raw materials; iron ore,
coke, limestone and hot air
Limestone – to remove impurities.
Limestone breaks down and reacts
with sand from the rocks to form
slag
Iron ore (Iron III oxide – Fe2O3) –
the source of iron
Hot air – the fourth raw material
Coke – a fuel that produces carbon
Required for coke to burn
monoxide for the reduction reaction
Carbon (coke) and oxygen (from the hot air) produce carbon monoxide and gives
off heat. Reduction is achieved by Carbon monoxide at a high temperature
Iron oxide + carbon monoxide  iron + carbon dioxide
Fe2O3 +
3 CO 
2 Fe
+
3 CO2
Getting the furnace up to temperature takes a lot of time and costs a lot. As a result
raw materials are constantly added and products removed – the process is continuous.
At the factory in Port Talbot (South Wales) iron ore, limestone and coke are imported from
other countries even though they are available in Wales. Using raw materials from Wales is
not sustainable due to cost and the effect it could have on the environment (quarrying).
CI METALS & THER USES NOTES BY MISS CHOHAN
 Iron extracted from the blast furnace is very brittle and rusts easily and so has very
limited uses.
 This type of iron is called cast iron
 Cast iron contains many non-metal impurities such as carbon, sulphur and phosphorus
which must be removed before it can be alloyed to make steel.
MAKING STEEL
Carbon and other non-metal impurities are removed from molten iron by blowing oxygen into
it. The oxygen reacts with the carbon, sulphur, phosphorus etc producing gases such as
carbon dioxide, sulphur dioxide etc, which escape from the molten metal. This leaves behind a
much purer form of iron.
However, not all the carbon content of the iron is removed.Enough oxygen is used to achieve
steel with the desired carbon content. Other metals are often added, such as vanadium and
chromium, to produce alloys with properties suited to specific uses.
There are many different types of steel, depending on the other elements mixed with the
iron.
PURE METALS – Pure metals such as iron is soft and easily shaped. This is because its atoms are
arranged in a regular way that lets layers of atoms slide over each other. All atoms in a pure
metal have the same size. Pure metals such as iron is too soft for many uses.
A pure metal with all the
atoms in a layer structure
and all of the same size
The layers slide past each
other when a force is applied
CI METALS & THER USES NOTES BY MISS CHOHAN
Alloy – An alloy is a mixture of metals or even a mixture of metals with other elements
The properties of a metal are changed by including other elements, such as carbon. A
mixture of two or more elements, where at least one element is a metal, is called an alloy.
Alloys contain atoms of different sizes, which distort the regular arrangements of
atoms. This makes it more difficult for the layers to slide over each other, so alloys are
harder than the pure metal.
It is more difficult for layers of atoms to slide over each other in alloys
Steels are a large family of metals. All of them are alloys in which iron is mixed with carbon
and other elements. Steels are described as mild, medium- or high-carbon steels according to
the percentage of carbon they contain, although this is never greater than about 1.5%.
The metal in the scissors contains nearly twenty times as much carbon and is many times
harder than the steel in a drinking can.
Steel is recycled on a large scale.
Recycling steel saves 50% of the energy used in the extraction of iron.
Recycling helps to conserve iron ore
Recycling cuts down on the emission of greenhouse gases (carbon dioxide)
 Electrical and heat conductors
 Malleable (can be bent into shape)
 Ductile (can be stretched into wires)
 Have high melting and boiling points
 Soft
 Sonorous (ring when hit)
CI METALS & THER USES NOTES BY MISS CHOHAN
Electrolysis is the method used to extract aluminium from aluminium oxide As aluminium is a reactive
metal, aluminium oxide is very stable, a more powerful method is needed to break the bonds
Electrolysis is the decomposition of a compound using electricity.
Electrodes carry the current into and out of the molten compound, they are conducting rods.
One is positive and the other is negative.
Anode = positive electrode
Cathode = negative electrode Electrolyte is a solution containing ions.
Must be dissolved or molten to allow ions to move and carry charge
Aluminium Extraction (Separating aluminium oxide ore to create aluminium)
Ore = Aluminium oxide (Al2O3)
Electrolyte = molten aluminium oxide (950˚C)
Electrodes = Carbon Both electrodes are placed in molten aluminium oxide (electrolyte). This contains
ions of aluminium (+ charge) and oxygen (- charge). These are able to move when molten and therefore
allow conduction of electricity.
The anode is made
of carbon
CI METALS & THER USES NOTES BY MISS CHOHAN
Aluminium ions are attracted to the negative electrode (cathode)
Oxygen ions are attracted to the positive electrode (anode)
The oxygen formed at the anode reacts with
the carbon anode to form CO2 gas. So the
carbon anode needs replacing regularly.
Aluminium has many uses due to its physical properties
Factories are located near the coast as they need to import the aluminium ore from
abroad.
To increase the lifetime of metal ores such as aluminium oxide and iron oxide it is
necessary to recycle metals. Recycling aluminium uses only about 5% of the energy
needed to extract it from bauxite and saves waste. Less electrical consumption means
less greenhouse gas (CO2) emissions. The environment is spoilt by quarrying.
Odd Case Of Aluminium
Aluminium is a reactive metal since it appears towards the top of the reactivity series
BUT it appears unreactive since it forms a protective layer of Aluminium oxide (Al2O3)
coating when it react with oxygen gas in the air:
Protective Al2O3 coating
Al
CI METALS & THER USES NOTES BY MISS CHOHAN
 High grade copper ores are rich in copper (can be up to 95%)
 Low grade copper ores contain a very small amount of copper (~2%)
 High grade ores are running out
 So scientists are now using low grade ores to extract copper
 The method used to extract copper from high grade ores is different to that used from
low grade ores since using traditional methods to extract copper from low grade ores
would not be economically viable.
There are three main high grade ores from which copper can be extracted:
1. Copper II oxide
2. Copper II carbonate (malachite) – CuCO3
3. Copper I sulphide – Cu2S
1. Extraction From Copper II oxide
-
Carbon is used as a reducing agent
i.e.
2CuO + C  2Cu + CO2
- This reaction works since carbon is more reactive than copper so displaces it.
2. Extraction From Copper II carbonate
-
The copper II carbonate is first thermally decomposed as follows:
CuCO3(s)  CuO(s) + CO2(g)
-
The copper II oxide is leached by reacting it with sulphuric acid to form copper
sulphate solution:
CuO + H2SO4  CuSO4 + H2O
-
Scrap iron is then added to the blue copper II sulphate solution (CuSO4) to
extract copper metal by displacement:
CuSO4 + Fe  Cu + FeSO4
This is a good way to
use up any scrap iron
which would
otherwise end up in
landfill
CI METALS & THER USES NOTES BY MISS CHOHAN
3. Extraction From Copper I sulphide
-
Copper I sulphide is roasted in a furnace to form copper
Cu2S + O2  2Cu + SO2
The sulphur dioxide gas
formed (SO2) causes acid
rain!
NOTE: Chimneys of factories are fitted with scrubbers which neutralise the SO2 gas
formed. Scrubbers are generally bases such as CaO which neutralise thee acidic gas
SO2.
Copper is extracted from low grade ores using two processes:
1. Phytomining
2. Bioleaching
PHYTOMINING
 Some plants (like brassica) can absorb copper from low grade ores(rocks) or from soil
which is rich in copper compounds
 The plant feed off low grade ores or from soil which is rich in copper
 The plant is then burned to form ash which is rich in copper compounds
 The ash is leached as dilute sulphuric acid is added to it
 This produces copper II sulphate solution (CuSO4)
 Again scrap iron is added to the copper II sulphate to extract copper metal
i.e.
Copper II sulphate + Iron  Copper + Iron II sulphate
CuSO4 + Fe  Cu + FeSO4
BIOLEACHING
 In bioleaching bacteria feed off low grade ores or soil rich in copper
 The bacteria is then burned to produce ash which is rich in copper
 The ash is leached as sulphuric acid is added to it
 This produces copper II sulphate solution and again scrap iron is added to this
solution to produce copper metal.
NOTE: Leaching is a reaction with a solid to make a solution
CI METALS & THER USES NOTES BY MISS CHOHAN
Copper is a good conductor of electricity, and is used extensively to make electrical wiring and
components. The extraction of copper from copper ore is done by reduction with carbon.
However, the copper produced is not pure enough for use as a conductor, so it is purified
using electrolysis.
In this process, the positive electrode (the anode) is made of the impure copper which is to be
purified. The negative electrode (the cathode) is a bar of pure copper. The two electrodes are
placed in a solution of copper(II) sulfate.
Copper ions leave the anode and are attracted to the cathode, where they are deposited as
copper atoms. The pure copper cathode increases greatly in size, while the anode dwindles
away. The impurities left behind at the anode form a sludge beneath it.
Anode sludge
containing impurities
CI METALS & THER USES NOTES BY MISS CHOHAN
ADVANTAGES
 Fast (no need to cultivate plants)
 Produces lots of copper (~80-90%) from
the ore
 Uses scrap iron which would otherwise
end up in landfill which is filling up
 Can produce pure copper
DISADVANTAGES
 Uses up limited high grade ores which
are running out
 Uses lots of energy (i.e. in roasting,
thermal decomposition, electrolysis
etc..)
 Burns fossil fuels ∴ producing CO2
which contributes to global warming
 Produces SO2 gas which contributes to
acid rain
 Purification of copper using
electrolysis would produce cost a lot of
money
ADVANTAGE
 Uses a lot less energy
 Less CO2 emissions ∴ less contributes to
global warming
 Conserves high grade ores
 Cheaper
 Again scrap iron is used which would
otherwise end up in landfill
Copper has many uses due to its physical properties
DISADVANTAGES
 Uses land to cultivate plants which
destroys habitats
 Only produces a small amount of
copper
 The process is very slow since
plants needs time to grow
CI METALS & THER USES NOTES BY MISS CHOHAN
 Is shiny
 Strong
USES
 Very resistant to corrosion
 Has low density
 Has a high melting and boiling point


To make aircraft bodies
Make racing bikes


To make parts for jet engines
Make hip replacements and other limbs
Titanium
 The process to extract Titanium from its ore Titanium IV oxide is a batch process ∴
involves many steps to extract the metal.
 This makes the process very slow
 The process of extracting metals is expensive due to energy costs (i.e. heating and
electricity)
 A further purification process is needed (distillation) to purify the titanium metal which
uses more energy and ∴ costs more
 The extraction of Titanium is environmentally unfriendly due to fossil fuels burning
giving out CO2 emissions which is responsible for global warming
It is important to recycle metals since:
 It saves energy needed from fossil fuels
 Conserves fossil fuels – fossil fuels are finite sources and are running out
 Stops contribution to acid rain; global warming and global dimming – all of which happens
when fossil fuels burns
 Recycling only uses a small amount of energy compared to the energy needed to mine new
ores and extract metals
 Saves money
 Conserves ores – metals ores are finite sources ∴ will run out one day ∴ recycling conserves
metal ores
 It stops metals ending up in
 Waste metals can end up in landfill sites which are already filling up fast. Recycling prevents
this from happening especially as out landfill sites are almost full.
 Reduces the need to mine
CI METALS & THER USES NOTES BY MISS CHOHAN
RECYCLING FOR AND AGAINST
FOR RECYCLING




Less metals are dumped in landfill (as landfill is running out)
Metal reserves last longer i.e. ore does not run out quicker
Energy for extraction of metal is saved
Less mining/quarrying needed
 Less greenhouse gasses produced ∴ less contributes to global warming
 Less acid rain produced
 Less global dimming
 Saves money
AGAINST RECYCLING
 Collection problems
 Transport problems
 Difficult to separate different metals from appliances
DISADVANTAGES
ADVANTAGES


Provides jobs
Brings money into the area


Landscape looks ugly
Noise pollution



Better transport systems
More business into area
More schools, hospitals built into the



Dust pollution
Destroys habitats
CO2 forms which contributes to global
warming


Leaves heaps of waste rock behind
Water in the area can become
affected by mining (can become more
acidic
area
STEEL
Is the most commonly used metal alloy and it is used to construct:
 Skyscrapers
 Suspension bridges
 Concrete bridges when reinforced with steel rods
DISADVANTAGE
ADVANTAGES

Strong


Hard
High tensile strength

Iron and steel can rust



This therefore weakens the structure
Structures can collapse
Money needed to paint or grease the steel
regularly to stop it from rusting
CI METALS & THER USES NOTES BY MISS CHOHAN
Metals are more expensive than concrete
This smart material is a mixture of metals (alloy) that retains its original shape when heated
A mixture of nickel and titanium make up the alloy
called NiTi or nitinol.
This metal can be bent into any shape at low
temperature, but when heated it can remember its
original shape so it bends back very quickly. It can be
used as a coffeepot thermostat.
Stents are metal structures that can be inserted in
veins to prevent them from sticking together. The
stents are cooled to below 37C so they change shape
and become thinner, when inserted into the vein it
warms up to body temperature and changes shape to
open the vein.
This alloy can also be used in super elastic spectacle
frames. These retain their original shape after bending
them.
CI METALS & THER USES NOTES BY MISS CHOHAN
CI METALS & THER USES NOTES BY MISS CHOHAN