Question

what is the use of alum for purification of water (SAQ)

Answer 1

Alum attracts all the impurities towards itself like charcoal..... Thus its used for purification of water...

Answer 2

This floc attracts other fine particles and suspend material in raw water and settles down at the bottom of the container. The water over this sediment is almost clean other than some fine particles dissolved in it. Alum is in a crystallized form which you can powder and store in a clean glass container.