Question

What is milk of lime?

Answer 1

Milk of lime

• Calcium oxide ($\mathrm{CaO}$) is a white amorphous powder and when it is added to water, this aqueous solution is called the lime water, and the suspension of calcium hydroxide is called the milk of lime.

Reaction

• Calcium hydroxide is prepared by adding water to calcium oxide.
• $\mathrm{CaO}\left(\mathrm{s}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)\to \mathrm{Ca}{\left(\mathrm{OH}\right)}_2\left(\mathrm{s}\right)$
• The white amorphous powder of Calcium hydroxide is sparingly soluble in water, and hence forms a suspension in water, which is the milk of lime.