Conduct an experiment to prove that burning of a candle is similar to respiration. Write your procedure, observation and conclusion. Draw a appropriate diagram to explain your activity.

CBSE Class 8 Answered

Conduct an experiment to prove that burning of a candle is similar to respiration. Write your procedure, observation and conclusion. Draw a appropriate diagram to explain your activity.

Asked by sujatakalra1970 | 10 Jun, 2021, 03:39: PM

Expert Answer

Fix two small candles of the same size in the middle of two shallow containers. Now, fill the containers with some water. Light the candles and then cover each one of them with an inverted glass (one much taller than the other) as shown in the figure. Observe carefully what happens to the burning candles and the water level.

The candles continue to burn and the level of water inside glasses remain the same.
Now tilt the bottle slightly. The water now enters the bottle.
The burning of the candle must be due to presence of some component of air.

Burning can occur only in the presence of oxygen. We see that, one component of air is oxygen. Now, the amount of air and hence its oxygen component inside each glass in our experiment, is limited. When most of this oxygen is used up by the burning candle, it can no longer burn and blows out. Also, some of the space occupied by the oxygen inside the glass becomes empty and the water rises up to fill or occupy this space.

Answered by Sheetal Kolte | 11 Jun, 2021, 11:57: AM