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calcium chloride,CaCl2, chemical compound that is crystalline, lumpy, or flaky, is usually white, and is very soluble in water. The anhydrous compound is hygroscopic; it rapidly absorbs water and is used to dry gases by passing them through it. Calcium chloride is commercially available usually as the dihydrate, CaCl2·2H2O; it is used to melt ice on roads, to control dust, in brines for refrigeration, and as a preservative in foods. It is also used in the monohydrate and hexahydrate forms. Calcium chloride is a byproduct of the Solvay processSolvay process
[for Ernest Solvay], commercial process for the manufacture of sodium carbonate (washing soda). Ammonia and carbon dioxide are passed into a saturated sodium chloride solution to form soluble ammonium hydrogen carbonate, which reacts with the sodium chloride to
..... Click the link for more information. (a major source of the compound) and is present in natural brines.
CaCl2, a salt; colorless crystals with a density of 2.51 g/cm3 and melting point of 772°C. Calcium chloride easily absorbs water vapor, subsequently deliquescing. Its solubility per 100 g H2O is 74 g at 20°C and 159 g at 100°C. Aqueous solutions of calcium chloride freeze at low temperatures (20-percent solution at — 18.5°C and 30-percent solution at — 48°C). Calcium chloride forms the hydrate CaCl2 • 6H2O, which remains stable up to 29.8°C;at high temperatures, crystalline hydrates are precipitated from the saturated solution with four, two, and one molecules of H2O. When CaCl2⋅6H2O (58.8 percent) is mixed with snow or ice (41.2 percent), the temperature drops to — 55°C (cryohydric point).
Calcium chloride is obtained as a byproduct in the manufacture of soda and is used for the preparation of calcium metal, in the drying of gases and liquids, in refrigeration, and in medicine.