Calcium hydroxide, Ca(OH)2 also known as slaked lime is manufactured by heating limestone to a high temperature of about 1000C and then adding water to the calcium oxide. Calcium hydroxide is slightly soluble in water; it is an alkaline solution and is known as lime water. Calcium hydroxide is a strong base. It neutralizes acids and displaces ammonia from ammonium salts and decomposes on heating to give the oxide.
Uses of Calcium Hydroxide
Calcium hydroxide is of great importance to chemist, engineers, agriculturists, biologists and engineers. This compound has found several uses in industrial production processes and in the laboratory. Some of the uses of calcium hydroxide are enumerated below.
- Calcium hydroxide otherwise known as slaked lime is a cheap alkali commonly used in treating acidic soils.
- A suspension of calcium hydroxide in water, known as milk of lime, is used as white wash. Lime water is used as a test for carbon(IV) oxide in the laboratory.
- Bleaching powder is manufactured by passing chlorine over moist calcium hydroxide.
- Calcium hydroxide is used to recover ammonia from ammonium chloride in the Solvay process. It is commonly used in the laboratory preparation of ammonia.
- Temporarily hard water is softened by the addition of calcium hydroxide.
- Mortar is prepared by mixing one part of slaked lime and three parts of sand with water. The mixture hardens or sets to bind the grains of sand by reacting with the carbon(IV) oxide in the atmosphere to form the trioxocarbonate(IV). Mortar is used to bind the bricks in walls and buildings.
Ca(OH)2(s) + CO2(s) → CaCO3 + H2O(l)