Question

Alum helps in purifying water by.

• A. Forming Si complex with clay particles
• B. Sulphate part which combines with the dirt and removes it
• C. Aluminium which coagulates the mud particles
• D. Making mud water soluble

Answer 1

Answer: (C)

Aluminium which coagulates the mud particles

Answer 2

Alum helps in purifying water by $A l ^ { 3 + }$ions which coagulate the negative mud particles.