Calcium hydrate

Calcium Hydrate is a chemical compound with the formula Ca(OH)2. It is a colorless crystal or white powder and is obtained when calcium oxide (also known as lime or quicklime) is mixed, or "slaked" with water. It has many names including hydrated lime, slaked lime, and pickling lime. Calcium hydrate is used in many applications, including food preparation, where it has been identified as E number E526.

Chemical Properties

Calcium hydrate is slightly soluble in water. It is a strong base that has a high pH and is therefore able to neutralize acids. When heated to decomposition it emits toxic fumes of calcium oxide.

Production

Calcium hydrate is produced commercially by treating lime with water: CaO + H2O → Ca(OH)2 In the laboratory it can also be prepared by mixing aqueous solutions of calcium chloride and sodium hydroxide. The calcium hydroxide precipitates out of solution as a white solid.

Uses

Calcium hydrate has many uses. It is used in the food industry to clarify raw juice from sugarcane, in the manufacture of plastics, and in water treatment. As a food additive it is designated E526. It is also used in the creation of mortar and plaster.

Safety

Calcium hydrate is not a hazardous substance. Its strong basicity makes it a skin irritant and prolonged exposure can lead to skin damage.

See Also

• Calcium
• Hydrate
• Calcium Oxide
• Chemical Compound