Which of the following is the use of bleaching powder?
Show answer & explanation
Correct answer: B
Explanation
Correct Answer:
Option 2: As an oxidising agent in many chemical industries.
Explanation:
Bleaching powder has the chemical formula CaOCl₂ (Calcium oxychloride). It is a strong oxidising agent, which is why it is widely used in many chemical industries.
When it reacts with water, it releases chlorine gas (Cl₂), which acts as both a disinfectant and an oxidising agent.
Due to this property, it is used in water purification, bleaching of textiles and paper, and various chemical reactions.
The main aim of the question is to check whether the candidate understands the oxidising property of bleaching powder.
Additional Facts (Analysis of other options):
Option 1: Soda-acid fire extinguishers use sodium bicarbonate (NaHCO₃) and sulphuric acid, not bleaching powder.
Option 3: Permanent hardness of water is removed using washing soda (Na₂CO₃) or ion-exchange methods.
Option 4: Bleaching powder is not used in the manufacture of sodium compounds like borax.
Probable Exam Questions:
Q: What is the chemical formula of bleaching powder?
A: CaOCl₂
Q: How is bleaching powder prepared?
A: By passing chlorine gas over dry slaked lime (Ca(OH)₂).
Q: What is the main use of bleaching powder?
A: Purification and disinfection of drinking water.
Q: Why is bleaching powder stored in airtight containers?
A: Because it reacts with moisture and releases chlorine gas.