Which one is the active constituent of bleaching powder?

Options

A. `CaCI_(2)`
B. `CaOCl_(2)`
C. `Ca(OCI)_(2)`
D. `CaO_(2)Cl`

Answer

3

Explanation

Bleaching poeder (also called chloride of line) is a whitish powder, consisting mainly of calcium hypochlorite, `Ca(Ocl)_(2)`. It is prepared by the action of chlorine on a suspension of calcium hydoxide:
`2Cl_(2)(g)+2Ca(OH)_(2)(s) rarr Ca(OCl)_(2).2H_(2)O(s)+CaCl_(2)(aq.)`
the action of dilute acids liberates chlorine, which acts as an oxidizing agent and so bleaches the material.