Question

Two glass jars A and B are filled with carbon dioxide and oxygen gases, respectively. In each jar a lighted candle is placed simultaneously. In which jar will the candle remain lighted for a longer time and why?

Answer 1

Lightening of candle is combustion. A high temperature chemical process which releases a high amount of energy is known as combustion. During combustion, energy is released in the form of heat and light. To solve this we must know the gas that supports combustion.

Complete solution:
We are given two glass jars A and B are filled with carbon dioxide and oxygen gases, respectively. In each jar a lighted candle is placed simultaneously.
We know that lightning is combustion. A high temperature chemical process which releases a high amount of energy is known as combustion.
Combustion process occurs between fuel and an oxygen containing substance. Combustion uses the oxygen present in the atmosphere. During combustion, energy is released in the surrounding in the form of heat and light.
Thus, for combustion, oxygen is required.
Thus, the candle placed in the glass jar B which is filled with oxygen gas will remain lighted for a longer time. This is because oxygen is required for the combustion.
The candle placed in the glass jar A which is filled with carbon dioxide gas will not remain lighted for a longer time and go off. This is because carbon dioxide does not support combustion.
Thus, the candle placed in the glass jar B will remain lighted for a longer time.

Note: We know that during combustion, energy is released in the surrounding in the form of heat and light. Thus, we can see flames appearing as combustion occurs. Flames resulting from combustion have various colours like yellow, red, orange, blue, green, etc.