Previous Year Question
The chemical name of bleaching powder is also given as—
A.
Sodium Bicarbonate (NaHCO₃)
B.
Calcium Sulphate (CaSO₄)
C.
Sodium Chloride (NaCl)
D.
Calcium Oxychloride (CaOCl₂)
Correct Answer: D
Detailed Solution
In competitive examinations and older school-level representations, bleaching powder has commonly been described as calcium oxychloride with the formula CaOCl₂. Therefore, among the given options, D is the expected answer.
However, an important scientific update should be noted. The current NCERT Science textbook (2026–27 reprint) represents bleaching powder as Ca(ClO)₂ and explicitly states that its actual composition is quite complex. It is produced by the action of chlorine on dry slaked lime, Ca(OH)₂.