A Fuel is a substance that
produces Energy when
A good fuel releases it’s energy
over a longer period of time
A reaction in which energy is released is called an
Exothermic reaction( a reaction in which heat is
taken in called an Endothermic reaction).
Another word for burning is Combustion ie.we
combine the element with Oxygen gas
Most common household fuels contain
the element Carbon.
Fuels that contain carbon and hydrogen
only are called Hydrocarbons.
The simplest hydrocarbon is methane
formula CH4.Methane makes up 96%
of Natural Gas.
Combustion of Hydrocarbons
of Methane dioxide is
gas collected in the
tube here. The
test for CO2 is
that it turns
Water vapour from the burning chalky)
methane gas condenses here
All Hydrocarbons burn to give CO2 and H2O
Any substance that contains Carbon and Hydrogen
gives CO2 and H2O when burned
Fossil Fuels formed from living things millions of years ago.
There are three main Fossil Fuels
Coal Oil Gas
Coal was formed by Oil was formed by dead Gas was formed in
the decay of sea creatures falling to much the same
vegetation which the sea-bed where they way as Oil. It is
was subjected to heat were subjected to often collected
and pressure over a chemical change by when drilling for
very long period of bacteria. oil.
Fossil Fuels are Finite Alternative sources of energy which
Fuels ie they will run are Renewable must be found eg
out in the future and Solar, Wind Tide and Wave Power.
cannot be regenerated.
Distillation of Crude Oil
Crude Oil is a mixture of Substances
To separate the fractions we heat them
until they boil off. This is known as
The smaller fractions ie short carbon
chains have smaller Boiling Pts. and
boil off first.
The smaller fractions are more
flammable, lighter in colour and less
Viscous than the longer chain
A Fractionating Tower Fractions
When Carbon burns in plentiful supply of air it
produces CO2 C + O2 CO2
When Carbon burns in an insufficient supply of
oxygen it produces C + O2 CO `
CO is an odourless, poisonous gas which
The test for
prevents the blood absorbing Oxygen is
CO2 is that it
therefore extremely dangerous
CO2 extinguishes fires, whereas CO burns
with a blue flame. CO is neutral whereas,
CO2 is Acidic
Pollution from Cars
The main pollutants from car exhausts are
Oxides of Nitrogen Cars have Catalytic
occurs in the Spark Converters fitted to
Plugs of petrol cars change these to
(not Diesel since they harmless gases CO2
and N2. Catalytic
do not have spark plugs)
converters are metal
Sulphur from petrol produces the honeycombs coated
acidic gas Sulphur Dioxide(also a in Platinum