Question

Explain

(a) diffusion in solids

(b) diffusion in liquid

(c) diffusion in gas

Answer 1

Diffusion:

• Diffusion is the movement of particles of different substances from the region of their high concentration to the region of their lower concentration.
• The diffusion of one substance into another substance goes on until a uniform mixture is formed. For example diffusion of bromine vapors in air.
• Diffusion is inversely proportional to the density of the substance.

Diffusion in Gases:

• Diffusion in gases is very fast because the density of the gas is very less as compared to solid and liquid states.
• Example: When we light an incense stick (agarbatti) in a corner of our room, its fragrance spreads in the whole room very quickly due to the diffusion of its smoke into the air.

Diffusion in liquids:

• Diffusion in liquids is slower than that in gases because the density of a liquid is higher than in gases but lower than in solids.
• Example: The spreading of the purple colour of potassium permanganate into the water, on its own, is due to the diffusion of potassium permanganate particles into water.

Diffusion in solids:

• Diffusion can also take place in solids. Diffusion in solids is a very slow process because the density of solids is very high as compared to liquid and gases.
• Example: If we write something on a blackboard and leave it uncleaned for a considerable period of time, we will find that it becomes quite difficult to clean the blackboard afterward. This is due to the fact that some of the particles of chalk have diffused into the surface of the blackboard.