Bleaching powder is added in water used for drinking purpose. The role of bleaching powder in this case is

Bleaching powder, chemically known as calcium hypochlorite [Ca(ClO)2], is produced by the action of chlorine on dry slaked lime [1]. While it is extensively used as a bleaching agent in the textile and paper industries, its specific role in treating drinking water is to act as a disinfectant [2]. When added to water, it releases chlorine, which effectively kills harmful pathogens such as bacteria, viruses, and protozoa, thereby making the water safe for consumption. This process is often referred to as sterilization or purification of water. Although it can marginally affect pH and acts as an oxidizing agent, its primary functional classification in the context of drinking water treatment is that of a disinfectant to ensure the water is free from germs [2].

Sources

1. [1] Science , class X (NCERT 2025 ed.) > Chapter 2: Acids, Bases and Salts > Bleaching powder > p. 30
2. [2] Science , class X (NCERT 2025 ed.) > Chapter 2: Acids, Bases and Salts > Bleaching powder is used – > p. 31