Question

Explain why, osmosis can be considered to be a special kind of diffusion. Classify the following into
(i) osmosis, and (ii) diffusion :
(a) swelling up of a raisin on keeping in water
(b) spreading of virus on sneezing
(c) earthworm dying on coming in contact with common salt
(d) shrinking of grapes kept in thick sugar syrup
(e) preserving of pickles in salt
(f) spreading of smell of cake being baked in the kitchen
(g) aquatic animals using oxygen dissolved in water during respiration

Answer 1

Osmosis is considered to be a special kind of diffusion because it takes place only through a semi-permeable membrane, which allows only solvent particles to pass through it.

(i) Osmosis: a, c, d and e
(ii) Diffusion: b, f and g.