Calcium chloride

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Kristallstruktur Calciumchlorid

Cacl2 storage for winter road in japan

Calcium chloride on a dirt road

Flame Test Ca

Calcium chloride is a chemical compound composed of calcium and chlorine. It is a white, crystalline substance that is highly soluble in water. Its chemical formula is CaCl2. Calcium chloride is notable for its wide range of applications, from medical treatments to food preservation and road maintenance.

Properties and Production

Calcium chloride exhibits several important physical and chemical properties. It is hygroscopic, meaning it can absorb moisture from the air, and is very soluble in water, releasing heat in an exothermic process. This compound can also be found in various states, including anhydrous (without water) and as a hydrated salt, with two or six molecules of water (dihydrate and hexahydrate, respectively).

The production of calcium chloride typically involves the reaction of limestone (calcium carbonate) with hydrochloric acid: \[CaCO_3 + 2HCl → CaCl_2 + CO_2 + H_2O\] Alternatively, it can be produced as a by-product in the Solvay process of synthetic sodium carbonate (soda ash) production.

Applications

Deicing and Dust Control

One of the most common uses of calcium chloride is as a deicing agent. Due to its hygroscopic nature and ability to lower the freezing point of water, it is effective in preventing ice formation on roads and sidewalks. It is also used for dust control on unpaved roads and in mining operations, as it can keep dust particles moist and prevent them from becoming airborne.

Food Industry

In the food industry, calcium chloride is used as a firming agent in canned vegetables, in cheese making as a source of calcium ions, and as an electrolyte in sports drinks. Its ability to absorb moisture also makes it useful as a desiccant to maintain dryness in packaging.

Medicine

In medicine, calcium chloride is used as an injectable solution to treat hypocalcemia (low blood calcium levels), magnesium intoxication, and certain cases of cardiac resuscitation where calcium can improve the efficiency of epinephrine.

Other Uses

Other applications of calcium chloride include its use in the manufacture of concrete, as a refrigeration brine in ice rinks and air conditioning systems, and in the oil industry to increase the density of solids-free brines. It is also used in swimming pools as a pH buffer and to increase water hardness.

Safety and Handling

While calcium chloride is generally considered safe for the aforementioned uses, it can be irritating to the skin and eyes upon contact. Inhalation of its dust can cause respiratory discomfort. Appropriate safety measures, including the use of personal protective equipment, are recommended when handling this chemical.

Environmental Impact

The environmental impact of calcium chloride is relatively low, especially when used responsibly. However, excessive application, particularly as a road deicer, can lead to increased chloride levels in nearby water bodies, potentially harming aquatic life.