Question

Air contains Nitrogen and Oxygen.How will you prove it.

Answer 1

air contains oxygen as it makes the fire lit up and its a vital key for the existance of humans and plants (respiration).
air contains nitrogen as it helps leguminous plants grow under protein suffiency with nitrates.without it no organism or plant would have survived.

Answer 2

Answer:

Explanation: To show that air contains nitrogen and oxygen

                       Take a glass container and fix a candle at its center. Put some quantity of water in the container. Place an empty, dry gas jar over it. Mark five marks above water surface on the jar at equal distances shown in the figure Given below:

The candle is lightened and is covered with the gas jar. After some time the candle is extinguished and the water level is raised in gas jar. The raised level in water is 1/5 of the volume of air in the gas jar.

This proves that one part of the air of the jar is a gas which supports combustion, i.e., oxygen. Hence, 1/5 by volume is oxygen in air.