Chapter Name: Combustion, Fuels and Flames
Activity Name: Testing the necessity of air for burning in Combustion, Fuels and Flames
This experiment aims to demonstrate the necessity of air for combustion. A small burning candle is placed on a table, and a glass tumbler is inverted over the candle to cut off the air supply.
Observations are made when the candle continues to burn, flickers, and eventually goes out. The tumbler is then removed, and the candle is relit and covered again to observe the impact on the flame.
- Small burning candle
- Glass tumbler
Step by Step Procedure:
- Place the burning candle on the table.
- Invert the glass tumbler over the candle, covering it completely.
- Observe the candle’s behavior – it should continue to burn for some time, then flicker, and finally, the flame goes out.
- Remove the tumbler and relight the candle.
- Again, put the tumbler back over the candle.
- Observe the candle’s behavior when the flame begins to flicker, and then immediately remove the tumbler.
- Carefully notice what happens to the candle.
- When the tumbler is placed over the burning candle, the flame continues to burn for some time.
- As the tumbler remains in place, the flame eventually starts flickering.
- Finally, the flame goes out due to the lack of air supply inside the tumbler.
- Conduct the experiment in a well-ventilated area.
- Handle the candle and tumbler carefully to avoid accidents or spills.
- Keep a fire extinguisher or water nearby for any unforeseen emergencies.
Lesson Learnt from Experiment:
The experiment conclusively proves that air is necessary for combustion. When the tumbler is placed over the candle, it cuts off the air supply, and as a result, the flame goes out. This is a simple demonstration of the role of oxygen in supporting combustion.