Question

Bleaching powder is prepared by passing ${\mathrm{Cl}}_2$gas over/into

• A. Solid $\mathrm{CaO}$at room temperature
• B. Limewater at an elevated temperature
• C. Solid $\mathrm{Ca}{\left(\mathrm{OH}\right)}_2$at room temperature
• D. Solid $\mathrm{Ca}{\left(\mathrm{OH}\right)}_2$at an elevated temperature

Answer 1

The correct option is D

Solid $\mathrm{Ca}{\left(\mathrm{OH}\right)}_2$at an elevated temperature

1. Bleaching powder is Calcium oxychloride(${\mathrm{CaOCl}}_2$) and is prepared by passing ${\mathrm{Cl}}_2$ gas over Solid $\mathrm{Ca}{\left(\mathrm{OH}\right)}_2$ at an elevated temperature of 313K.
2. The reaction can be given as: $$\begin{gathered} \mathrm{Ca}{\left(\mathrm{OH}\right)}_2\left(\mathrm{s}\right)+{\mathrm{Cl}}_2\left(\mathrm{g}\right)\stackrel{313\mathrm{K}}{\to }{\mathrm{CaOCl}}_2\left(\mathrm{s}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right) \\ (\mathrm{Calcium}\mathrm{hydroxide})(\mathrm{Chlorine}\mathrm{gas})(\mathrm{Bleaching}\mathrm{powder})\left(\mathrm{Water}\right) \end{gathered}$$.
3. Therefore, option (d) is correct and all the other options are incorrect.

Hence, the option (d) is correct. i.e., Bleaching powder is prepared by passing ${\mathrm{Cl}}_2$ gas over/into Solid $\mathrm{Ca}{\left(\mathrm{OH}\right)}_2$ at an elevated temperature.