C1.24a Products of combustion Name 1
Class
Date
This apparatus can collect the products of a combustion reaction. Label the diagram using words from the box. cold water to pump
2
3
4
5
a
What collects in the U-tube?
b
Write down the formula for this compound.
c
Why is the U-tube cooled?
a
What happens to the limewater?
b
What does this show?
c
Write down the formula for the compound that has been detected.
a
Which gas present in the air reacts with a fuel when the fuel burns?
b
What is the formula of this gas?
limewater U-tube
Write a word equation for the combustion of methane. ________________________________________________________________________________
6
Methane is a hydrocarbon. Petrol is a mixture of hydrocarbons. For example, petrol contains two hydrocarbons called pentane and octane. Write word equations for: a
the combustion of pentane
b
the combustion of octane
Š Pearson Education 2010. Edexcel GCSE Science Activity Pack This document may have been altered from the original.
C1.24b Burning equations 1
The diagram shows two molecules of a hydrocarbon called ethane and a molecule of oxygen.
H
H
H
C
C
H
H
O
O
H
→
⫹ H
H
H
C
C
H
H
⫹
H
a
What are the products formed when ethane burns in plenty of air?
b
Write a word equation for the combustion of ethane.
c
Write an equation showing the formulae of the reactants and products (this does not have to be balanced).
d
How many carbon atoms are there altogether in the two ethane molecules?
e
How many carbon dioxide molecules will be formed from the two ethane molecules?
f
Copy the diagram and draw the correct number of carbon dioxide molecules in one of the empty boxes.
g
How many hydrogen atoms are there altogether in the two ethane molecules?
h
How many water molecules will these make? (Hint: remember there are two hydrogen atoms in every water molecule.)
i
Draw the water molecules in the remaining empty box.
j
Count up the number of oxygen atoms in all the carbon dioxide and water molecules you have drawn. Draw more oxygen molecules in the second box until you have the right number. Remember, you must have oxygen molecules, not atoms.
k
Balance the formula equation by writing the correct numbers in front of the formulae you wrote in part c.
H
H
H
H
C
C
C
H
H
H
H
2
The drawing shows a molecule of propane. Write a balanced equation for the combustion of propane.
3
Write balanced equations for hydrocarbons with the following formulae by asking yourself the same questions about the numbers of molecules. Draw pictures of the molecules if it helps you to work out the answer. For some of these you may need to start with two molecules of the hydrocarbon. a
C4H10
b
C5H12
c
C6H14
Extra challenge 4
The drawing shows a molecule of an alcohol called methanol.
H H
C
O
a
Is methanol a hydrocarbon? Explain your answer.
b
Alcohols also produce carbon dioxide and water when they burn completely in excess oxygen. Write a balanced equation for the combustion of methanol.
© Pearson Education 2010. Edexcel GCSE Science Activity Pack This document may have been altered from the original.
H
H