1. L03. Burning hydrocarbons
Lesson Outcomes
APP AF1, AF2, AF3, AF4
HSW 1a, 2c
How I did
Targets
Task 1:
Describe what happens when hydrocarbon fuels burn, and how the products of combustion can be identified.
Grade C
Task 2:
Explain:
the advantages of complete combustion and link this to the choice of fuels.
The problems associated with incomplete combustion
Grade B
Task 3:
Write balanced symbol equations for complete, and incomplete, combustion
Grade A/A*
Connector: (Grade D)
Answer in full sentences
What is a fuel?
Name three fuels.
What do you consider
to be the most important
properties of a fuel?
What is the scientific word
for when a fuel burns?

2. A fuel is a substance that contains stored chemical energy.
When fuels are burned in the air (with oxygen) they release heat and light energy.
petrol, wood, ethanol, coal, macaroni, sugar, etc.
A good fuel would release a lot of heat energy with little or no polluting or harmful by-products.
Combustion

3. BIG picture What skills will you be developing this lesson?
Numeracy
Literacy
Team work
Self management
Creative thinking
Independent enquiry
Participation
Reflection
How is this lesson relevant to every day life? (WRL/CIT)

4. Task 1 (Grade C)
Task 1:
Describe what happens when hydrocarbon fuels burn, and how the products of combustion can be identified.
Keywords for Task 1:
Combustion,
Complete combustion
Fuel

5. Compounds containing H and C are called?
Combustion
fuel
Many fuels like coal, oil, petrol, candle wax, and natural gas are called HYDROCARBONS

6. The products of burning a hydrocarbon
to pump
water and ice
water and ice
limewater
anhydrous cobalt chloride paper
Hydrocarbons are compounds of carbon and hydrogen ONLY.
When pure carbon is burned, carbon dioxide is formed and when hydrogen is burned, water is produced.
What happens to the anhydrous cobalt chloride paper?
What happens to the limewater?
Explain the significance of the above observations.
C1b.7.1a

7. How can I improve on task 1?
Task 1: Review
Go back to your lesson outcome grid and fill out the ‘How I did’ and the ‘Targets’ column.
Lesson Outcomes
How I did
Targets
Task 1:
Describe what happens when hydrocarbon fuels burn, and how the products of combustion can be identified.
Grade C
Met?
Partly met?
Not met?
How can I improve on task 1?

8. Task 2 (Grade B) Task 2: Task 2: Extension Keywords for Task 2:
Explain:
the advantages of complete combustion and link this to the choice of fuels.
The problems associated with incomplete combustion
Task 2: Extension
Keywords for Task 2:
Combustion,
Complete combustion,
Fuel
Carbon monoxide,
Incomplete combustion,
Pollution,
Soot,
Toxicity

9. What makes a good fuel?
From the pictures below, choose the best fuel. Explain your choice.
Yellow flame, soot
Blue flame, no soot
Yellow flame, soot, ash (residue) 9

10. carbon combustion energy heat
Summary exercise
Fuels contain stored __________ . When fuels burn they react with __________ in the air and give out __________ energy. This is called a __________ reaction. Most fuels contain carbon and __________ atoms. When the fuel burns these atoms react with oxygen to make __________ dioxide and __________ .
energy
oxygen
heat
combustion
hydrogen
carbon
water
carbon combustion energy heat
hydrogen oxygen water

11. Complete and incomplete combustion
Lots of oxygen:
Methane
Oxygen +
Carbon dioxide
Water +
This is called Complete combustion
Some oxygen:
Carbon monoxide
Methane +
Oxygen
Water +
This is called Incomplete combustion
Little oxygen:
Carbon
(soot)
Water +
Methane
Oxygen +
This is also called Incomplete combustion
To get complete combustion the fuel must be burned in EXCESS O2.

12. The hazard of incomplete combustion
Why did the man die?
Less amount of available oxygen caused the release of colourless, odourless, poisonous carbon monoxide.

13. Incomplete combustion

14. Carbon monoxide
Edexcel video

15. Question

16. Homework Homework task: Due date: Criteria for Grade C:
Criteria for Grade B

17. colourless complete incomplete intake monoxide odourless oxygen oxygen
Summary
When a fuel burns with a good supply of __________ to form carbon dioxide and water it is called __________ combustion. When a fuel burns without a good enough supply of oxygen and forms deadly carbon __________ (and/or soot) and water it is called __________ combustion. Incomplete combustion can happen in faulty gas boilers if their air __________ vent is blocked. Carbon monoxide is a __________ , __________ , toxic gas. It kills because it stops your blood from carrying __________ .
oxygen
complete
monoxide
incomplete
intake
odourless
colourless
oxygen
colourless complete incomplete intake
monoxide odourless oxygen oxygen

18. How can I improve on task 2?
Task 2: Review
Go back to your lesson outcome grid and fill out the ‘How I did’ and the ‘Targets’ column.
Lesson Outcomes
How I did
Targets
Task 2:
Explain:
the advantages of complete combustion and link this to the choice of fuels.
The problems associated with incomplete combustion
Grade B
Met?
Partly met?
Not met?
How can I improve on task 2?

19. Task 3: (Grade A/A*)
Task 3:
Write balanced symbol equations for complete, and incomplete, combustion
Task 3: Extension
Keywords for Task 3:
incomplete combustion
complete combustion

20. Combustion of methane
Write the word equation for combustion of methane.
Write a balanced symbol equation for the combustion of
methane.

21. Write the balanced symbol equations for these reactions:+

22. Extension task
Some camping gas stoves run on propane gas. Propane molecules have the formula C3H8.
(a) What new chemicals are produced when you burn propane?
(b) Write a word equation for the combustion reaction of propane.
(c) Write a balanced formula equation for this reaction. (Hint: you will need five oxygen molecules for every propane molecule.)

23. How can I improve on task 3?
Task 3: Review
Go back to your lesson outcome grid and fill out the ‘How I did’ and the ‘Targets’ column.
Lesson Outcomes
How I did
Targets
Task 3:
Write balanced symbol equations for complete, and incomplete, combustion
Grade A/A*
Met?
Partly met?
Not met?
How can I improve on task 3?

24. Review of lesson – a selection of past paper questions

25. Question

31. Can you explain these key words?
Combustion,
complete combustion,
Fuel
Carbon monoxide,
incomplete combustion,
pollution,
soot,
toxicity

32. Technicians’ list
Demonstration 1
Eye protection
Two gas jars of oxygen
Deflagrating spoon
Two stoppered boiling tubes of hydrogen
Dry cobalt chloride paper (blue)
Forceps
Splints
Limewater (corrosive)
Charcoal
Demonstration 2
Combustion rig