Experiment: The products of combustion
Aim
The aim is to demonstrate that carbon dioxide and water are produced when a fuel is combusted.
Apparatus and chemicals
Two boiling tubes
A funnel
Glass tubing and rubber stoppers to connect the apparatus as shown in the diagram.
Air pump.
Fuel such as a “tea light”
Cobalt chloride paper
Limewater
Safety Information
Limewater is an irritant but the calcium hydroxide solution is sufficiently diluted to handle safely, providing
safety spectacles are worn and normal lab safety regulations are observed.
Eye protection should be worn at all times.
Apparatus diagram
Experiment: The products of combustion
Method
1.
Set up the apparatus as shown in the diagram.
2.
Light the “tea light” and switch on the pump so that the gases being produced by the flame are drawn
through the apparatus. They will then come into contact with the cobalt chloride paper and also
bubble through the lime water.
3.
Note down any changes you see in the appearance of the cobalt chloride paper and the limewater
and record them in your results.
Results
Test
Observation
Cobalt chloride paper
Limewater
Conclusion
The cobalt chloride paper changes from _________ to _________. This is a positive result that shows
________ is one of the products of combustion.
The limewater changes from a __________ _________ to a __________ appearance. This positive result
shows that __________ ___________ is one of the products of combustion.