Question

Explain an experiment to show that air or oxygen is necessary for combustion. [5 MARKS]

Answer 1

Setup : 2 Marks
Process : 1.5 Marks
Conclusion : 1.5 Marks

Place a burning candle on a flat surface. Place a glass cylinder around it. Cover it with a piece of glass or plastic so that no air from outside enters the chamber. After some time, the fire is put off automatically.

The fire goes off after sometime because the available oxygen inside the container got used up in the combustion reaction. The moment all oxygen from inside the container gets exhausted, the combustion process stops and fire is put off.