➢ Diffusion in gases is very fast. This is because the particles in gases move very quickly in all directions.

Examples – 1:

➢ The smell of food being cooked in the kitchen reaches us even from a considerable distance.

➢ The smell of hot sizzling food reaches us even when we are at a considerable distance but to get the smell of cold food, we have to go close to it.

➢ This is due to the fact that the rate of diffusion of hot gases (released by the hot sizzling food) is much faster than the rate of cold gases released by the cold food.

Example –2:

➢ When someone opens a bottle of perfume in one corner of a room, its smell spreads in the whole room quickly.

➢ When the bottle of perfume is opened, then the liquid perfume quickly changes into vapour (or gas).

➢ The perfume vapours move very rapidly in all directions in air, mix with the air particles and hence spread with air in the whole room.

Example – 3:

➢ The leakage of cooking gas (LPG) in our homes is detected due to the diffusion of a strong smelling substance (ethyl mercaptan) present in the cooking gas, into air.