Give five important applications of colloids in home and industry.

Explanation

(i) Electrical precipitation of smoke (Cottrell precipitator).
(ii) Purification of drinking water by adding alum.
(iii) Cleansing action of soaps and detergents.
(iv) Tanning : Animal hides are colloidal in nature in which the particles are positively charged when hide is soaked in tannin which contains negatively charged colloidal particles mutual coagulation takes place. The results in hardening of leather. This process is known as tanning. Tanning is also done with pot. dischromate.
(v) Rubber Industry. Latex is a colloidal solution of rubber particles which are negatively charged: Rubber is obtained by coagulation of latex.