Asha was having a candlelight dinner. So she lit a big candle and placed it on the table. It was a very windy day and the candle was extinguished. She lit it again, but again the candle went off.
She did not want to close the window because it would have been too hot then. So she found a glass tube and placed it on the candle as a cover. But midway through dinner she found that the candle had got extinguished in spite of the cover.
Why did that happen?
Answer:
Burning of any fuel is essentially an oxidation reaction. The fuel needs oxygen in the air to burn. If there is no oxygen, then the fuel howsoever inflammable, cannot burn. When Asha put a glass tube over the candle, there was some air inside the tube and hence there was a supply of oxygen. However, after some time, the flame in the candle had used up all the available oxygen replacing it with carbon dioxide which was a by-product of the burning process. As no more oxygen was available, the candle could not burn any more and got extinguished.
-Team Science Now
