Question

How will you show that oxygen is necessary for combustion

Answer 1

take a candle. light it. now place an empty glass upside down on the candle. you will see the candle stops burning after some time. this happens because the candle needs oxygen to burn and since the amount of air inside the glass is limited, so the candle stops burning when it has used up the oxygen present in that amount of air. this shows that oxygen is necessary for combustion.

Answer 2

Aim:

To show that oxygen (air) is necessary for combustion.

Materials Required:

Two candles, a match box and a glass jar. Theory Combustion is a chemical reaction in which a combustible substance burns in air (oxygen) to produce Carbon dioxide , water and heat.

Combustible substance (Fuel) + 0,— CO, + Water + Heat

Procedure:

(i) Light two candles and fix them on the table.

(ii) Cover one of the candles by an inverted glass jar.

Observations:

Candle covered by glass jar extinguishes due to the absence of air while the other candle keeps on burning because it is getting regular supply of oxygen (air). Conclusion Oxygen (air) is necessary for the combustion process.