Final answer:
Bleaching powder is produced when chlorine is reacted with calcium hydroxide, resulting in calcium hypochlorite. This substance is used in many household cleaners and as a disinfectant.
Step-by-step explanation:
The substance which yields bleaching powder when treated with chlorine is calcium hydroxide (Ca(OH)2). When chlorine gas is passed over dry slaked lime (calcium hydroxide), it results in calcium hypochlorite (Ca(OCl)2), also known as bleaching powder. The reaction is as follows:
Ca(OH)2 (s) + Cl2 (g) → Ca(OCl)2 (s) + H2O (l)
Bleaching powder is used as a disinfectant and as a bleaching agent. It is widely found in household cleaning products. Notable products that contain compounds like sodium hypochlorite and calcium hypochlorite, which release chlorine, include Ajax, Comet, and others. These compounds are effective in bleaching wood pulp, cotton cloth, and for killing bacteria in community water supplies.
Sodium hypochlorite is another important chlorine-based bleach found in household products like liquid bleach or Clorox, and is also used industrially and domestically as a disinfectant.