Alum is used in which?
- A. In the purification of water
- B. As a fertilizer
- C. As a disinfectant
- D. As an analgesic
A. In the purification of water
Alum is use as a water purifier because it coagulates the impurities. The colloidal particles are negatively charged and alum is added as a coagulant to create positively charged ions.