Question

(a) What is meant by 'diffusion'? Give one example of diffusion in gases.
(b) Why do gases diffuse very fast?
(c) Name two gases of air which dissolve in water by diffusion. What is the importance of this process in nature?

Answer 1

(a) Diffusion: In Latin, the word “diffusion” means to “spread out”. Diffusion is the mixing of a substance with another substance due to the motion of its particles. It is one of the several transport phenomena that occur in nature. The spreading of the smell of perfume in the whole room is an example of diffusion.

(b) Gases diffuse very fast because of the presence of large spaces between the gaseous particles and high kinetic energy of these molecules. They diffuse faster than the other states of matter.

(c) The gases which dissolve in water by diffusion are carbon dioxide and oxygen. Carbon dioxide dissolved in water bodies is essential for the survival of the aquatic plants as they use this carbon dioxide to make food by photosynthesis. Oxygen dissolved in water is used by aquatic animals for breathing.