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completely, only ash remained, with no unburnt wood. Burning
firewood or charcoal during cooking is an example of complete
combustion.

Conclusion
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The experiment confirmed complete combustion, as the
firewood burnt entirely to ash due to the presence of sufficient
oxygen. In this experiment, the firewood burnt to release heat

and light. All firewood turned into ashes due to the presence of
enough oxygen gas.

Incomplete combustion
Incomplete combustion occurs when fuel burns with insufficient

supply of oxygen gas. In this type of combustion, the fuel does
not burn completely. It also produces more smoke and soot.

Experiment 3: Investigating incomplete combustion

Aim: To demonstrate incomplete combustion

Materials: Firewood, dry leaves or pieces of paper, a fire
source, a large metal container, and a tool for
digging soil, an open environment

Note: Caution is required when conducting this
experiment.

Procedure

1. Arrange the firewood in a prepared open space.

2. Ignite the firewood using dry leaves or pieces of paper.

3. Keep the fire glowing until the wood catches fire properly.

4. Cover the fire with the prepared metal container.

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