For making bleaching powder, chlorine gas is passed over which substance?
Answer and explanation
Correct answer: Dry slaked lime
Bleaching powder is prepared by passing chlorine gas over dry slaked lime, whose chemical formula is Ca(OH)₂. The process produces a chlorine-containing bleaching material commonly represented as CaOCl₂ at school level. The word “dry” matters because moisture can interfere with the preparation. Sodium chloride, gypsum, and washing soda are not the required starting substance, so option A is correct.
Frequently asked questions
What is the correct answer to this question?
Dry slaked lime
Why is this the correct answer?
Bleaching powder is prepared by passing chlorine gas over dry slaked lime, whose chemical formula is Ca(OH)₂. The process produces a chlorine-containing bleaching material commonly represented as CaOCl₂ at school level. The word “dry” matters because moisture can interfere with the preparation. Sodium chloride, gypsum, and washing soda are not the required starting substance, so option A is correct.
Which subject and chapter does this question cover?
This is a Class 10 Science question. Chapter: Chemical Substances – Nature and Behaviour. Topic: Acids, Bases, and Salts.
