Question

Muddy water can be purified by adding potash alum to it. Give a reason.

Answer 1

Muddy water contains colloidal particles that do not settle easily. When potash alum is added, the Al³⁺ ions neutralize the negative charges on these particles, causing them to coagulate and form larger particles. These larger particles then settle down or can be easily filtered, resulting in purified water. This process is called coagulation.