Bell task: Finish the word equations
in the back of your book
Magnesium + oxygen
Calcium + oxygen
Copper oxide + carbon
Starter: What do you know?
Quiz to test what you know on C1.1 and C1.2
Finished early? Start reading
page
During a chemical reaction
• Old bonds break
• New bonds form
Most compounds end in –ide if two elements bond, but if
three and one of them is oxygen then they end in –ate.
• In chemical reactions no atoms are lost or destroyed.
• The mass of the reactants is equal to the mass of the products
• This is called conservation of
mass.
Substance
How
can you
P istell
Carbon,
from the
Suggest
diagram
what
that
substance
a chemical
Q and
reaction
R could
took
be.
place between
substance P and substance Q?
How does the diagram show that mass has
been conserved in the reaction?
What is a hydrocarbon?
Atoms of hydrogen and carbon bonded together
– COMPOUND
c
Methane
Ethane
c
pentane
Complete combustion of hydrocarbons
Plenty of air is needed to provide enough oxygen for a hydrocarbon fuel to
burn completely.
The blue flame of a gas hob or a
Bunsen burner is an example of
complete combustion of a
hydrocarbon (in this case, natural
gas).
What are the products of the
complete combustion of a hydrocarbon?
hydrocarbon
+
oxygen

carbon
dioxide
+
water
Complete combustion of propane
Propane is a hydrocarbon used in camping gas. It has 3 carbon atoms and 8
hydrogen atoms What is the equation for its combustion?
propane
+
oxygen

carbon
dioxide
+
water
c
propane
oxygen
Carbon
Dioxide
Water
Complete combustion of propane – how
would you balance the equation
c
propane
oxygen
Carbon
Dioxide
Step 1: Count the number of Carbons in the reactants
Step 2: Make sure you have the same number in the reactants by
changing the number of carbon dioxide
Water
Complete combustion of propane – how
would you balance the equation
c
propane
oxygen
Water
Carbon
Dioxide
Step 3: Count the number of hydrogen on in the reactants, and make sure there is
the same number in the products by changing the number of water
Complete combustion of propane – how
would you balance the equation
c
propane
oxygen
Carbon
Dioxide
Water
Step 4: Next look at the number of oxygen atoms on each side and make them
equal.
Complete combustion of propane – how
would you balance the equation
c
propane
oxygen
Carbon
Dioxide
Water
Step 4: Next look at the number of oxygen atoms on each side and make them
equal.
Complete combustion of propane – how
would you balance the equation
c
propane
oxygen
Step 5: Write as a Symbol equation
Carbon
Dioxide
Water
Complete combustion of propane – how
would you balance the equation
c
propane
oxygen
Carbon
Dioxide
C3H8 + 5O2  3CO2 +4H20
Water
Complete combustion of butane: Draw the atom diagram and
write the symbol equation
c
ethane
Oxygen
Carbon
Dioxide
C1H4 + O2  CO2 + H20
Water
Complete combustion of butane: Draw the atom diagram and
write the symbol equation
BEWARE THERE MAY BE AN EXTRA STEP!!!
c
c
butane
Oxygen
Carbon
Dioxide
Water
C4H10 + O2  CO2 + H20
Complete combustion of butane: Draw the atom diagram and
write the symbol equation
c
ethane
Oxygen
Carbon
Dioxide
C1H4 + O2  CO2 + H20
Water
Complete combustion of butane: Draw the atom diagram and write the
symbol equation
BEWARE THERE MAY BE AN EXTRA STEP!!!
c
c
c
c
butane
Oxygen
Carbon
Dioxide
Water
C4H10 + 13O2  8CO2 + 10H20
Extension
• Explain conservation of mass and how it is
demonstrated in chemical equations ( 5 marks)