Question

a gas jar containing air is inverted over another containing no2 gas which is brown in colour and heavier than air . After sometime brown colour is seen in inverted gas jar too . Identify and define the phenomena associated with this observation

Answer 1

Phenomenon is known as ' diffusion'

Diffusion is defined as "movement of solute or solvent paticles from the region of their higher concentration to the region of their lower concentration when both are in direct contact "

Answer 2

When a gas jar containing air that is colourless is inverted over other jar containing nitrogen dioxide $\left(\mathrm{No}_{2}\right)$ gas which is brown coloured and heavier than the air, after sometime the brown colour is also seen in the gas jar too which is inverted.

This phenomenon is known as diffusion where molecules of one type of gas travels from higher concentration region to regions of lower concentration and takes up intermolecular and intra-molecular space.

This is why the air in the upper jar also starts getting reddish due to the diffusion of $\left(\mathrm{No}_{2}\right)$ into it.