Products from Rocks
C1a
Limestone is mainly
made from calcium
carbonate
CaCO3
Limestone used to make glass
HEAT AT HIGH TEMPERATURE
Powdered Limestone
Sand
Sodium carbonate
Limestone used to make
cement
HEAT
Powdered
Limestone
Powdered clay
Limestone used
to make
Concrete
MIX
Cement powder
Water
Sand
Crushed rock
Thermal
decomposition –
breaking down a
chemical by
heating
Thermal decomposition of
limestone
Heat
Calcium Carbonate
CaCO3
Calcium oxide + Carbon dioxide
CaO +
CO2
Limestone decomposes to form
calcium oxide (quicklime) and
carbon dioxide
General equation for the thermal
decomposition of a metal carbonate
Metal carbonate  Metal oxide + Carbon dioxide
Quicklime
+ water  Slaked lime
Calcium oxide + water Calcium hydroxide
CaO
+ H20  Ca(OH)2
Dissolve slaked lime (calcium hydroxide) in water
Filter
Produces limewater
Lime water – used to test for carbon dioxide
Calcium hydroxide + carbon dioxide Calcium carbonate + water
Ca(OH)2
+
CO2

CaO3
+ H2O
Mortar – slaked lime + sand + water
Uses - holds building materials
together
How – Lime in mortar reacts with
carbon dioxide in air producing
calcium carbonate
Very strong
Cement - Limestone + clay
Portland Cement – Limestone +
clay + other minerals
Uses – Modern house building
How – Portland cement and sand
mixed with water
Left for a few days to set
Concrete – Stones/crushed rocks + water +
cement + sand
Very strong – resists forces
Reinforced concrete – Poured around steel rods
or bars
Glass –
Powdered
limestone +
sand + sodium
carbonate +
strong heat
Waterproof
and light
Available with
different
properties
Metals found in Earths crust, mostly
combined with other elements, often
oxygen
Metal ore – rock containing metal
or metal compound
Native state
– some
metals so
unreactive
they are
found as the
element
naturally
The
reactivity
series is the
best way to
extract a
metal from
its ore
Metals more
reactive than
carbon cannot be
extracted from
their ores using
carbon
Many
metals are
found as
oxides –
combined
with
oxygen
Heat metal oxide with carbon,
carbon removes the oxygen from the
metal oxide to produce carbon dioxide
Metal oxide + Carbon  Metal + Carbon dioxide
We call
the
removal of
oxygen in
this way a
reduction
reaction
Iron is extracted from iron ore
by reducing it with carbon in a
blast furnace
Haematite – most
common iron ore:
mainly iron (III) oxide
and sand
Coke – reducing
agent: mainly carbon
Limestone – removes
impurities
C + O2  CO2
Hot air into blast furnace
Coke burns
Heats furnace
Forms carbon dioxide gas
CO2 + C  2CO
Carbon dioxide
reacts with coke
Carbon monoxide
gas formed
Fe2O3 + 3CO  2Fe + 3CO2
Carbon monoxide
reacts with iron oxide
Reducing it to molten
iron
Flows to bottom of
furnace
Pig iron – produced
from blast furnace
Many impurities,
mainly carbon
Remove
impurities
from pig
iron
– get pure
iron
– very soft
Metal that contains other elements
- alloy
Iron alloyed with other
elements - steel
Carbon steel – 0.03 – 1.5%
carbon
Cheapest steel
Used – cars, knives, machinery,
ships, containers, structural
steel
High carbon steel – lots of
carbon – very strong but
brittle
Low carbon steel – soft
and easily shaped, not
as strong but less
likely to shatter
Mild steel – less than
0.1% carbon – easily
shaped – mass
production of cars
Low-alloy steel – 1 – 5%
other metals, e.g. nickel,
chromium, manganese,
vanadium, titanium,
tungsten
Low alloy nickel –
Resistant to
stretching forces
long span bridges,
bike chains,
military armour
plating.
Low-alloy tungsten –
good at high
temperature
High-speed
tools
High alloy steel –
Chromium 12 – 15%
Sometimes some
nickel too
Strong, chemically
stable
Stainless steel
DO NOT RUST!
Copper - very soft
Bronze – copper and tin plus
other elements, e.g.
phosphorus
Low friction properties
Brass –
Copper and zinc
Hard
Can be bent and shaped
Smart alloys
Shape memory alloys
When deformed they return to
their original shape when
heated
Shape memory alloys
used in medicine –
broken bones
Dentistry - braces
Transition metal –
Good conductors of
electricity and heat
hard, tough and
strong
Malleable
high melting points
Copper extraction –
Chemical – use sulfuric acid
to produce copper sulfate
solution
Copper extraction –
smelting – heat copper ore strongly in
air  crude copper
Use impure copper as anodes in
electrolysis cells
85% of copper produced like this
New ways – bacteria, fungi,
plants to extract copper
Cheaper, environmentally
friendly alternatives to
extraction methods
Aluminium and titanium useful
as they resist corrosion
Al and Ti expensive to extract from
ores as requires lots of energy
££££££££££££
Al extraction – electrolysis
Pass an electric current through
molten Aluminium oxide at
high temperatures
Ti extraction –
Displacement using sodium or
magnesium
Need to use electrolysis to produce
these first
Electrolysis – very expensive,
lots of energy due to high
temperatures and
electricity needed
Recycling Al is important
Uses much less energy to
produce same amount
of recycled Al than
extract it
Crude oil –
mixture of
many
different
chemical
compounds
Not very
useful
Crude oil must be separated by
distillation, into its different
substances before it can be
used.
Distillation separates liquids with
different boiling points
Nearly all compounds in crude oil
are made from atoms of
hydrogen and carbon.
HYDROCARBONS
Most of the
hydrocarbons
in crude oil
are
ALKANES
General chemical formula of an alkane
CnH2n + 2
E.g. Methane CH4 (C = 1, H = (2 x 1+ 2) = 4)
Alkanes – saturated
hydrocarbons
Contain as much hydrogen
atoms as possible in their
molecules
Separate crude oil using fractional
distillation
Properties of each
fraction depend on
the size of the
hydrocarbon
molecules
Short molecules –
Lower boiling point
High volatility
Low viscosity
Flammable
Long molecules
High boiling points
Low volatility
Viscous (thick)
Smoky flame
Crude oil separated in a fractioning
column
Temperature decreases going up
the column
Gases condense when they
reach their boiling points
Hydrocarbons with
smaller molecules –
lower boiling points –
collect at the cool top
of the tower
Light crude oil –
many smaller molecules
Used as fuels
More expensive than heavy crude
oil
Hydrocarbons burn in air
they produce carbon
dioxide and water
Example:
Propane + oxygen  carbon dioxide + water
C3H8
+ 5O2  3CO2
+ 4H2O
Impurities in fuels may produce
other substances which may
be poisonous and cause
pollution
Sulfur dioxide – causes acid
rain
Most fuels contain
some sulfur, which
reacts with oxygen
when burned
Hydrocarbons in car
engine
Not enough oxygen
inside car cylinders,
so instead of all
changing to carbon
dioxide, produces
carbon monoxide
instead.
Incomplete
combustion
Nitrogen oxides :
High temperatures in cars
cause N and O in air to
react
Poisonous
Trigger asthma
Acid rain
Diesel cars – use larger molecule hydrocarbons
Do not always burn completely
Tiny particles are produced containing carbon
and unburnt hydrocarbons
Damaging when breathed in
Some substances released when
fuels are burnt dissolve in
droplets of water in air.
ACID RAIN
GLOBAL WARMING
Carbon dioxide  greenhouse
gas
Reduces amount of heat lost by
radiation
GLOBAL DIMMING
Particulates reflect
sunlight back into space
Catalytic convertors
exhaust gases  catalytic converter  pass
over transition metals  arranged with large
surface area  carbon monoxide and nitrogen
oxide react  produce carbon dioxide and
nitrogen  reduces pollution
Flue gas desulfurisation (FGD)
Power stations – sulfur dioxide
reacts with quicklime to cut
pollution
Gasohol
Plants that make
sugar produce
ethanol by
fermenting the
sugar using
yeast.
Can use this by
adding to petrol
Less pollution –
burns more
cleanly
Biodiesel
Oilseed rape
Plants take in
carbon
dioxide, even
though they
give it out
when burnt
Overall this
cancels out
Energy can be produced from
rubbish in an incinerator
Disadvantages – produces
dioxins which may be
dangerous