Calcium hydroxide (Ca(OH)2)-Powder

Characteristic

Calcium hydroxide (traditionally called slaked lime) is an inorganic compound with the chemical formula Ca(OH)₂. It is a colorless crystal or white powder and is produced when quicklime (calcium oxide) is mixed, or slaked with water. It has many names including hydrated lime, caustic lime, builders' lime, slack lime, cal, or pickling lime. 

Chemical formula:Ca(OH)₂

Molar mass:74.093 g/mol

Appearance:White powder

Odor:Odorless

Density:2.211 g/cm³, solid

Melting point:580 °C (1,076 °F; 853 K) (loses water, decomposes)

Solubility in water:1.89 g/L (0 °C)；1.73 g/L (20 °C)； 0.66 g/L (100 °C)

Solubility product (Ksp):5.5×10−6

Solubility:Soluble in glycerol and acids. Insoluble in alcohol.

Basicity (pKb):1.37 (first OH−), 2.43 (second OH−)

Magnetic susceptibility (χ):−22.0·10⁻⁶ cm3/mol

Refractive index (nD):1.574

Crystal structure:Hexagonal, hP3

Application

Calcium hydroxide is used as a flocculant in water and sewage treatment. It is also used in fresh water treatment to raise the pH of the water thereby controlling the corrosion of pipes. It is widely used in the production of calcium stearate. It is an active ingredient in whitewash, mortar and plaster. This compound is also used in the petroleum refining industry for the preparation of additives to oils and in the preparation of dry mixes for painting and decorating. It finds application as an antifungal and antimicrobial preservative for vegetables in storage.