Limewater

Limewater is a saturated aqueous solution of calcium hydroxide. Calcium hydroxide, Ca(OH)₂, is sparsely soluble at room temperature in water (1.5 g/L at 25 °C^[1]). "Pure" (i.e. less than or fully saturated) limewater is clear and colorless, with a slight earthy smell and an astringent/bitter taste. It is basic in nature with a pH of 12.4.

Limewater is named after limestone, not the lime fruit. Limewater may be prepared by mixing calcium hydroxide (Ca(OH)₂) with water and removing excess undissolved solute (e.g. by filtration). When excess calcium hydroxide is added (or when environmental conditions are altered, e.g. when its temperature is raised sufficiently), there results a milky solution due to the homogeneous suspension of excess calcium hydroxide. This liquid has been known traditionally as milk of lime.