What are the applications of colloids. 

Explanation

Collodion is used to reduced pore size of filter paper to get ultra-filters.
(ii) Alum is added to coagulate suspended impurities so as to purify drinking water.
(iii) Colloidal antimony is used in curing kalazar (disease caused by mosquito bite).
(iv) Argyrol is used as eye lotion.
(v) Milk of magnesium is used as antacid.
(vi) Animal hides are colloidal in nature and are positively charged. When it is soaked in tannin which contains negatively charged colloidal particles, mutual takes place. This result in turning of leather or hardening of leather. `K_2Cr_2O_7` is used for tanning of leather asitis and oxdizing agent.