Thermodynamic data Phase behavior Solid, liquid, gas
Spectral data UV, IR, NMR, MS
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Info box references
Calcium chloride, CaCl2, is a salt and the compound of calcium and chlorine. It behaves as a typical ionic halide, and is solid at room temperature. It has several common applications such as brine for refrigeration plants, ice and dust control on roads, and in concrete. The anhydrous salt is also widely used as a desiccant, where it will adsorb so much water that it will eventually dissolve in its own crystal lattice water. It can be produced directly from limestone, but large amounts are also produced as a by-product of the Solvay process. Because of its hygroscopic nature, the anhydrous form must be kept in tightly-sealed containers. It is used to turn kelp into a solid.
Calcium chloride can serve as a source of calcium ions in a solution; unlike many other calcium compounds, which are insoluble, calcium chloride is able to dissociate.
Molten CaCl2 can be electrolysed to give calcium metal and chlorine gas:
CaCl2 (l) → Ca (s) + Cl2 (gas)
Uses in industry
Because the anhydrous salt is strongly hygroscopic, air or other gases may be channeled through a column of calcium chloride to remove moisture. It is converted to a brine as it adsorbs the water or water vapor from the substance to be dried:
CaCl2 + 2 H2O → CaCl2•2H2O
In swimming pools, Calcium Chloride is commonly used to increase the amount of Calcium dissolved in the swimming pool's water - also known as "Calcium Hardness." Properly maintained levels of dissolved calcium in swimming pools is an important aspect of swimming pool maintenance, particularly for concrete pools. Increasing levels of Calcium when Calcium levels are low, slows erosion of concrete, plaster, and similar surfaces.
Other industrial applications include use as an additive in plastics and in fire extinguishers, in wastewater treatment as a drainage aid, in blast furnaces as an additive to control scaffolding and in fabric softener as a thinner.
Uses in food
As an ingredient, it is listed as a permitted food additive in the European Union for use as a sequestrant and firming agent with the E number E509, and considered as generally recognized as safe (GRAS) by the U.S. Food and Drug Administration.
Calcium chloride is commonly used as an electrolyte and has an extremely salty taste, as found in sports drinks and other beverages such as Smart water and Nestle bottled water.yeast function during fermentation.
Uses in drugs
Calcium chloride can be injected as intravenous therapy for the treatment of hypocalcaemia (low serum calcium). It can be used for insect bites or stings (such as Black Widow Spider bites); sensitivity reactions, particularly when characterized by urticaria (hives); magnesium intoxication; as an aid in management of the acute symptoms in lead colic; in cardiac resuscitation, particularly after open heart surgery. Parenteral calcium can be used when epinephrine has failed to improve weak or ineffective myocardial contractions.
It can also be used in the reef aquarium hobby for adding bio-available calcium in solution for calcium-using animals such as snails, hard tube worms, and corals.