Nomenclature
CAS number: 1305-62-0
Calcium hydroxide (Ca(OH)
2); calcium hydrate; slaked lime.
CaH
2O
2; mol wt 74.09.
Ca 54.09%, H 2.72%, O 43.19%.
Ca(OH)
2.
Description and references
Contains at least 95% Ca(OH)2.
Commercial prepn by hydration of lime: W. L. Faith et al., Industrial Chemicals (John Wiley,
New York, 3rd ed., 1965) pp 483-484. Laboratory prepn by treating
an aq soln of a calcium salt with alkali: Ehrlich in Handbook of Preparative Inorganic Chemistry vol. 1, G. Brauer (Academic Press, New York, 2nd ed.,
1963) p 934. Toxicity study: Smyth et al., Am. Ind. Hyg. Assoc. J. 30, 470
(1969).
Properties
Crystals or soft, odorless, granules or powder.
Slightly bitter, alkaline taste. Readily absorbs CO2 from
air forming CaCO3. Loses water when ignited; forms CaO.
d 2.08-2.34. Slightly
sol in water; sol in glycerol, sugar or NH4Cl solns; sol
in acids with evolution of much heat. pH of aq soln satd at 25°:
12.4. Keep well closed. LD50 orally in rats:
7.34 g/kg (Smyth).Caution
Potential symptoms of overexposure
are irritation of eyes, skin, upper respiratory system; eye and skin
burns; skin vesiculation; cough, bronchitis, pneumonia. See NIOSH Pocket Guide to Chemical Hazards (DHHS/NIOSH 97-140, 1997) p 46.Use
In mortar, plaster, cement and other building and
paving materials; in lubricants, drilling fluids, pesticides, fireproofing
coatings, water paints; as egg preservative; manuf of paper pulp;
in SBR rubber vulcanization; in water treatment; as absorbant for
carbon dioxide; dehairing hides.
Therapeutic Category
Astringent.
Keywords
Astringent