A1
H2
Energy from reactions
Homework
mark scheme
HELP
Question
1 a
b
c i
ii
iii
iv
Answer
Heat and light.
Mark
2
Methane
The gas in a Bunsen burner is a fossil fuel because it was made from
the remains of dead animals millions of years ago.
Accept equivalent response. Underscore shows the pupil's answer.
When the gas burns it is combining with oxygen.
When the gas burns it forms carbon dioxide and water.
Award one mark for each product.
The type of energy stored in the gas is called chemical energy.
Total for Help
1
1
1
2
1
8
CORE
Question
2 a
b
c i
ii
d i
ii
3
Answer
Mark
Ethanol
1
Coal
1
Coal
1
It contains sulphur
1
which burns to form sulphur dioxide
1
which causes acid rain/breathing difficulties.
1
carbon + oxygen
carbon dioxide
1
Ethanol also forms water.
1
Electricity is usually made by burning fossil fuels
1
which produces carbon dioxide that increases global warming.
1
Total for Core 10
EXTENSION
Question
4 a
b
c i
ii
iii
d
Answer
Mark
It contains only carbon and hydrogen.
1
methane + oxygen
carbon dioxide + water
1
Carbon monoxide would be produced instead of carbon dioxide.
1
methane + oxygen
carbon monoxide + water
1
The blocked vent restricts the air supply to the flame
1
so carbon monoxide is produced
1
and carbon monoxide is poisonous.
1
Natural gas is not replaced as it is used but ethanol is made from
sugar cane, which can be quickly replaced.
1
Do not give any marks for answers that refer to ideas about re-use of the
fuel.
Total for Extension 8
© Harcourt Education Ltd 2004 Catalyst 3
This worksheet may have been altered from the original on the CD-ROM.
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