For preparing bleaching powder, chlorine gas is passed over which substance?
Answer and explanation
Correct answer: Dry slaked lime
Bleaching powder, commonly represented as CaOCl₂ in school-level chemistry, is prepared by passing chlorine gas over dry slaked lime, Ca(OH)₂. The word “dry” matters because excess moisture can interfere with obtaining the intended product. Sodium chloride is a raw material in chlorine manufacture but is not the direct absorbing substance here. Gypsum and washing soda have different uses and do not give bleaching powder in this preparation, so 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, commonly represented as CaOCl₂ in school-level chemistry, is prepared by passing chlorine gas over dry slaked lime, Ca(OH)₂. The word “dry” matters because excess moisture can interfere with obtaining the intended product. Sodium chloride is a raw material in chlorine manufacture but is not the direct absorbing substance here. Gypsum and washing soda have different uses and do not give bleaching powder in this preparation, so 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.
