Describe simple experiment to show the presence of oxygen and nitrogen component in air using a bell jar.

To study the presence of oxygen and nitrogen component:

Apparatus : A trough , bell jar, cork and crucible, a piece of phosphorus.

Procedure :

1. The trough is filled with water and a bell jar divided into 5 equal parts, '1 to 5' is placed over it.
2. A crucible containing white phosphorus is placed on a cork which is made to float on water.
3. The level of water inside and outside are adjusted to one level.
4. The phosphorus is then ignited by means of a heated wire.

Observations :
White fumes are seen initially in the bell jar and level of water in the bell jar rises by 1⁄5.
Phosphorus + Oxygen ⟶ Phosphorus pentoxide

Conclusion :

1. Oxygen the active component of air [i.e., 1⁄5^th of air] is used up in burning.
2. Nitrogen the inactive component of air [i.e., 4⁄5^th of air] is not used up in burning.

Hence air contains oxygen which supports combustion and nitrogen which does not support combustion.