Calcium Chloride

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Created by: Team Chemistry -, Last Updated: April 25, 2024

Calcium Chloride

Calcium chloride is a widely used inorganic compound in chemistry, recognized by its chemical formula CaCl₂. It appears as a white, crystalline substance at room temperature and is highly soluble in water. This compound is essential in various applications, including road deicing, dust control on roads, and as a drying agent in many industrial processes. Its ability to absorb moisture makes it valuable in maintaining dry conditions where necessary. Calcium chloride is also used in food processing, swimming pool maintenance, and as an electrolyte in sports drinks, where it helps replenish minerals lost through sweat.

What is Calcium Chloride?

Calcium chloride is a chemical compound made up of calcium and chlorine, known scientifically as CaCl2. It appears as a white, powdery substance and is highly soluble in water. This compound is widely used to melt ice on roads, control dust, and act as a preservative in foods. Additionally, it helps in drying gases and liquids because it can absorb moisture effectively. Calcium chloride is also beneficial in various industrial applications, such as in the production of plastics and the treatment of wastewater. Its versatility makes it an important material in many different fields.

Chemical Names and Formulas

NameCalcium chloride
IUPAC NameCalcium dichloride
Alternate NamesCalcium dichloride

Structure of Calcium Chloride


Calcium chloride is represented by the chemical formula CaCl₂, has a simple ionic structure. It consists of one calcium ion paired with two chloride ions. The calcium ion holds a positive charge (Ca²⁺), while each chloride ion carries a negative charge (Cl⁻). In its solid form, calcium chloride often exists as a crystalline lattice, meaning the ions are arranged in a highly ordered, repeating pattern. This structure allows the compound to dissolve easily in water, as the water molecules interact with the charged ions, separating them and incorporating them into the solution. This characteristic makes calcium chloride highly effective for uses like melting ice and absorbing moisture.

Preparation of Calcium Chloride

Calcium chloride can be prepared through a simple reaction between limestone (calcium carbonate) and hydrochloric acid. First, the limestone is treated with hydrochloric acid, which results in the formation of calcium chloride, water, and carbon dioxide. The chemical equation for this reaction is:

CaCO₃ + 2HCl → CaCl₂ + CO₂ + H₂O

This process is commonly used in laboratories and industries due to its efficiency and the availability of the starting materials. Once the reaction completes, the calcium chloride can be purified and dried for various uses, such as de-icing roads and controlling dust. This method is straightforward, allowing for the easy production of calcium chloride in bulk.

Physical Properties of Calcium Chloride

AppearanceWhite, crystalline solid; can also be found in flake, pellet, or granular form.
TasteSalty and slightly bitter
SolubilityHighly soluble in water, which means it dissolves easily when mixed with water.
Melting PointAbout 772°C (1422°F)
Boiling PointAbout 1935°C (3515°F)
Density2.15 g/cm³ (solid)
HygroscopicYes, it readily absorbs moisture from the environment.

Chemical Properties of Calcium Chloride

Reactivity with Water

  • Calcium chloride is highly reactive with water. When mixed with water, it dissolves by releasing heat in an exothermic reaction.
  • Equation: CaCl₂ (s) + H₂O (l) → CaCl₂ (aq)
  • Heating pads and other applications benefit from utilizing this property for releasing heat.


  • This compound is deliquescent, meaning it can absorb moisture from the air and dissolve in it. This ability to attract and hold water molecules is crucial for dehumidifying in various settings.

Formation of Hydrates

  • Calcium chloride can form hydrated salts. For example, it can absorb water vapor to form a hexahydrate.
  • Equation:CaCl₂ + 6H₂O → CaCl₂·6H₂O
  • Manufacturers utilize this property in heating pads and other applications where releasing heat is beneficial.

Reaction with Sodium Carbonate

  • When calcium chloride reacts with sodium carbonate (soda ash), it forms calcium carbonate (a precipitate) and sodium chloride. Water softening processes use this reaction.
  • Equation: CaCl₂ + Na₂CO₃ → CaCO₃ (s) + 2NaCl

Calcium Chloride (CaCl₂) Chemical Compound Information

Chemical Identifiers

CAS Registry Number10043-52-4
PubChem Compound ID24854
PubChem Substance ID10330
SMILES Identifier[Cl-].[Cl-].[Ca+2]
InChI IdentifierInChI=1/Ca.2ClH/h;21H/q+2;;/p-2/fCa.2Cl/h;21h/qm;2*-1
RTECS NumberEV9800000
MDL NumberMFCD00010903

Calcium Chloride in Foods

Widely used in the food industry, calcium chloride improves texture, preserves freshness, and maintains nutritional content in various products. Manufacturers add this inorganic compound to canned vegetables to maintain firmness, to sports drinks to replenish electrolytes, and to baked goods as a stabilizer to prevent spoilage and improve consistency. Food safety authorities generally recognize its use in food processing as safe, although manufacturers always use it in moderate amounts to avoid altering the taste or properties of the final product.

Uses of Calcium Chloride


Ice Control on Roads

Calcium chloride is highly effective at melting ice on roads and sidewalks. It lowers the freezing point of water, which helps prevent ice formation and makes it safer to travel in winter conditions.

Moisture Control

Because it is hygroscopic, manufacturers use calcium chloride in products that control humidity. It absorbs moisture from the air, helping keep warehouses and storage areas dry.

Food Industry

In the food industry, calcium chloride acts as a firming agent in canned vegetables and in cheese making. It maintains the firmness of vegetables and aids the coagulation of milk proteins during cheese production.

Dust Control

On unpaved roads and construction sites, workers use calcium chloride to suppress dust. It keeps the surface moist and binds dust particles together, reducing air pollution

Water Treatment

Operators use calcium chloride in pools and wastewater treatment plants to increase water hardness. This reduces the erosion of concrete in pools and enhances the effectiveness of certain water purification processes.

Drilling Fluids

In the oil and gas industry, workers add Calcium Chloride to drilling fluids to stabilize shale formations and make drilling processes more efficient.

Concrete Accelerator

Workers use Calcium Chloride in concrete to speed up the initial setting time, which is especially useful in cold weather, allowing for faster curing and build up of concrete.

Calcium Chloride: Effects on Human Body

Dietary Supplement

In controlled amounts, you can use Calcium Chloride as a calcium extra. It helps strengthen bones and maintain proper nerve and muscle functions.


Calcium Chloride can act as an irritant. Direct contact with the skin, eyes, or inhaling its dust can cause irritation, leading to skin redness and respiratory discomfort.

Electrolyte Balance

In medical treatments like saline solutions, it helps manage the body’s electrolyte balance, which is crucial for proper organ function.

Dehydration Risk

Due to its highly Hygroscopic nature, excessive ingestion can lead to dehydration by pulling water from body tissues. Consequently, this process can result in various health problems, including but not limited to, electrolyte imbalances, organ dysfunction, and cardiovascular issues.


Is Calcium Chloride the Same as Salt?

The properties and uses of Calcium Chloride (CaCl₂) are completely distinct from those of table salt (NaCl).

What Does Calcium Chloride Do to the Heart?

Calcium Chloride can affect the heart by increasing blood calcium levels, potentially stabilizing heart rhythms in specific medical scenarios.

What is the Problem with Calcium Chloride?

The main issues with Calcium Chloride include its potential to cause skin, eye, and respiratory irritations upon exposure.

Why is Calcium Chloride in Bottled Water?

Manufacturers add Calcium Chloride to bottled water to enhance taste by making better mineral balance and mouthfeel.

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