Question

________ is treated with chlorine to obtain bleaching powder.

• A. ${CaSO}_4$
• B. $Ca{\left(OH\right)}_2$
• C. $Mg{\left(OH\right)}_2$
• D. $KOH$

Answer 1

The correct option is B

$\mathrm{Ca}{\left(\mathrm{OH}\right)}_2$

The explanation for the correct option (B):

• Calcium oxychloride is commonly known as Bleaching powder. Its chemical formula is ${\mathrm{CaOCl}}_2$.
• Bleaching powder can be prepared by reacting Chlorine gas (${\mathrm{Cl}}_2$) with Calcium hydroxide or Slaked lime ($\mathrm{Ca}{\left(\mathrm{OH}\right)}_2$).

$\mathrm{Ca}{\left(\mathrm{OH}\right)}_2\left(\mathrm{aq}\right)+{\mathrm{Cl}}_2\left(\mathrm{g}\right)\to {\mathrm{CaOCl}}_2\left(\mathrm{s}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)$

Final Answer: Hence, option (B) is correct. $\mathrm{Ca}{\left(\mathrm{OH}\right)}_2$is treated with chlorine to obtain bleaching powder.