Question

Slaked lime is prepared by adding water to

• A. bleaching powder
• B. lime water
• C. milk of lime
• D. quicklime

Answer 1

The correct option is D

quicklime

The explanation for the correct option:

• The term slaking is used for the chemical reaction that takes place when Quicklime ($\mathrm{CaO}$) is added to Water (${\mathrm{H}}_2\mathrm{O}$). Excess water is used for performing this type of reaction. In this reaction, a slurry of solid Calcium hydroxide ($\mathrm{Ca}{\left(\mathrm{OH}\right)}_2$) floats in water. The saturated solution of Calcium hydroxide is called 'Milk of Lime'.
• Thus, Quicklime reacts with water to form Slaked lime ($\mathrm{Ca}{\left(\mathrm{OH}\right)}_2$). The chemical reaction between $\mathrm{CaO}$ and ${\mathrm{H}}_2\mathrm{O}$ is:

$\mathrm{CaO}\left(\mathrm{s}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{I}\right)\stackrel{∆}{\to }\mathrm{Ca}{\left(\mathrm{OH}\right)}_2\left(\mathrm{s}\right)$

Final Answer: Hence, option (D) is correct. Slaked lime is prepared by adding Water to Quicklime.