Whate happens in the following activities and why?
(i) An electrolyte is added to a hydrated ferric oxide sol in water.
(ii) A bean of light is passed through a colloidal solution.
(iii) An electric current is passed through a colloidal soluidal solution.

Explanation

(i) When an elecrolyte like KCl is added of `Fe(OH)_(3)` sol , the positively charged colloidal particles of `Fe(OH)_(3)` get coagulated by the oppositely charged `Cl^(-)` ions provided by KCl.
(ii) When a bean of strong light is passed through a colloidal solution scattering of light by colloidal particles takes place and the path of light becomes visible . this phenomenon is called Tydall effect.
(iii) On passing the electric current , colloidal particles move towards the oppositely charged electrode where they lose their charge and get coagulated.