Observing what happens in different zones of candle flame in Combustion, Fuels and Flames – Class 8 Science Experiment
Chapter Name: Combustion, Fuels and Flames
Activity Name: Observing what happens in different zones of candle flame in Combustion, Fuels and Flames
Activity Description:
This experiment involves observing different zones of a candle flame to understand the combustion process. Three zones are explored: the dark zone, the luminous zone (yellow zone), and the non-luminous zone.
By introducing a glass tube into the dark zone, a matchstick near one end, and a glass slide into the luminous zone, various observations are made to understand the characteristics of each zone.
Required Items:
- Candle
- Glass tube
- Tongs
- Matchstick
- Clean glass slide
- Thin long copper wire
Step by Step Procedure:
- Light the candle and ensure the flame is steady.
- Hold the glass tube with tongs and place one end into the dark zone of the non-flickering candle flame.
- Hold a lighted matchstick near the other end of the glass tube.
- Observe to see if a flame appears and identify its source.
- Introduce a clean glass slide into the luminous zone (yellow zone) of the flame and hold it there for 10 seconds.
- Observe the glass slide to note any changes.
- Hold a thin long copper wire just inside the flame for about half a minute.
- Observe the copper wire outside the flame to see if any changes occur.
Experiment Observations:
- A flame appears at the end of the glass tube when introduced into the dark zone. The wax near the heated wick melts quickly.
- A blackish circular ring is formed on the glass slide when held in the luminous zone. This indicates the deposition of unburnt carbon particles due to incomplete combustion in this zone.
- The copper wire just outside the flame becomes red hot, indicating that the non-luminous zone has high temperature and is the hottest part of the flame. This zone appears blue, and complete combustion takes place here due to a good supply of oxygen.
Precautions:
- Handle the glass tube and copper wire with tongs to avoid burns.
- Conduct the experiment in a well-ventilated area to avoid inhalation of fumes.
- Use caution while handling matches and a lit candle to prevent accidents.
- Keep flammable materials away from the experiment setup.
Lesson Learnt from Experiment:
Through this experiment, we learn about the different zones of a candle flame and their characteristics. The dark zone is where vaporized wax is drawn up and begins to vaporize. The luminous zone is where incomplete combustion occurs, leading to the deposition of unburnt carbon particles. The non-luminous zone is the hottest part of the flame, where complete combustion takes place due to a sufficient oxygen supply.
