Names | |
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IUPAC name
Calcium chloride
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Other names
Calcium(II) chloride, Calcium dichloride, E509
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Identifiers | |
10043-52-4 22691-02-7 (monohydrate) 10035-04-8 (dihydrate) 25094-02-4 (tetrahydrate) 7774-34-7 (hexahydrate) |
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3D model (Jmol) | Interactive image |
ChEBI | CHEBI:3312 |
ChEMBL | ChEMBL1200668 |
ChemSpider | 23237 |
DrugBank | DB01164 |
ECHA InfoCard | 100.030.115 |
EC Number | 233-140-8 |
E number | E509 (acidity regulators, ...) |
PubChem | 24854 |
RTECS number | EV9800000 |
UNII | OFM21057LP |
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Properties | |
CaCl2 | |
Molar mass | 110.98 g·mol−1 |
Appearance | White powder, hygroscopic |
Odor | Odorless |
Density | 2.15 g/cm3 (anhydrous) 2.24 g/cm3 (monohydrate) 1.85 g/cm3 (dihydrate) 1.83 g/cm3 (tetrahydrate) 1.71 g/cm3 (hexahydrate) |
Melting point | 772–775 °C (1,422–1,427 °F; 1,045–1,048 K) anhydrous 260 °C (500 °F; 533 K) monohydrate, decomposes 175 °C (347 °F; 448 K) dihydrate, decomposes 45.5 °C (113.9 °F; 318.6 K) tetrahydrate, decomposes 30 °C (86 °F; 303 K) hexahydrate, decomposes |
Boiling point | 1,935 °C (3,515 °F; 2,208 K) anhydrous |
Anhydrous: 74.5 g/100 mL (20 °C) Hexahydrate: 49.4 g/100 mL (−25 °C) 59.5 g/100 mL (0 °C) 65 g/100 mL (10 °C) 81.1 g/100 mL (25 °C) 102.2 g/100 mL (30.2 °C) α-Tetrahydrate: 90.8 g/100 mL (20 °C) 114.4 g/100 mL (40 °C) Dihydrate: 134.5 g/100 mL (60 °C) 152.4 g/100 mL (100 °C) |
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Solubility | Soluble in CH3COOH, alcohols Insoluble in liquid NH3, DMSO, CH3COOC2H5 |
Solubility in ethanol | 18.3 g/100 g (0 °C) 25.8 g/100 g (20 °C) 35.3 g/100 g (40 °C) 56.2 g/100 g (70 °C) |
Solubility in methanol | 21.8 g/100 g (0 °C) 29.2 g/100 g (20 °C) 38.5 g/100 g (40 °C) |
Solubility in acetone | 0.1 g/kg (20 °C) |
Solubility in pyridine | 16.6 g/kg |
Acidity (pKa) | 8–9 (anhydrous) 6.5–8.0 (hexahydrate) |
−5.47·10−5 cm3/mol | |
Refractive index (nD)
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1.52 |
Viscosity | 3.34 cP (787 °C) 1.44 cP (967 °C) |
Structure | |
Orthorhombic (rutile, anhydrous), oP6 Tetragonal (anhydrous, > 217 °C), oP6 Trigonal (hexahydrate) |
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Pnnm, No. 58 (anhydrous) P42/mnm, No. 136 (anhydrous, > 217 °C) |
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2/m 2/m 2/m (anhydrous) 4/m 2/m 2/m (anhydrous, > 217 °C) |
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a = 6.259 Å, b = 6.444 Å, c = 4.17 Å (anhydrous, 17 °C)
α = 90°, β = 90°, γ = 90°
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Octahedral (Ca2+, anhydrous) | |
Thermochemistry | |
72.89 J/mol·K (anhydrous) 106.23 J/mol·K (monohydrate) 172.92 J/mol·K (dihydrate) 251.17 J/mol·K (tetrahydrate) 300.7 J/mol·K (hexahydrate) |
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Std molar
entropy (S |
108.4 J/mol·K |
Std enthalpy of
formation (ΔfH |
−795.42 kJ/mol (anhydrous) −1110.98 kJ/mol (monohydrate) −1403.98 kJ/mol (dihydrate) −2009.99 kJ/mol (tetrahydrate) − 2608.01 kJ/mol (hexahydrate) |
Gibbs free energy (ΔfG˚)
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−748.81 kJ/mol |
Pharmacology | |
A12AA07 (WHO) B05XA07 (WHO), G04BA03 (WHO) | |
Hazards | |
Safety data sheet | See: data page |
GHS pictograms | |
GHS signal word | Warning |
H319 | |
P305+351+338 | |
EU classification (DSD)
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Xi |
R-phrases | R36 |
S-phrases | S22, S24 |
NFPA 704 | |
Lethal dose or concentration (LD, LC): | |
LD50 (median dose)
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1000 mg/kg (rats, oral) |
Related compounds | |
Other anions
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Calcium fluoride Calcium bromide Calcium iodide |
Other cations
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Beryllium chloride Magnesium chloride Strontium chloride Barium chloride Radium chloride |
Supplementary data page | |
Refractive index (n), Dielectric constant (εr), etc. |
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Thermodynamic
data |
Phase behaviour solid–liquid–gas |
UV, IR, NMR, MS | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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what is ?) | (|
Infobox references | |
Calcium chloride is an inorganic compound, a salt with the chemical formula CaCl2. It is a colorless crystalline solid at room temperature, highly soluble in water.
Calcium chloride is commonly encountered as a hydrated solid with generic formula CaCl2(H2O)x, where x = 0, 1, 2, 4, and 6. These compounds are mainly used for deicing and dust control. Because the anhydrous salt is hygroscopic, it is used as a desiccant.
By depressing the freezing point of water, calcium chloride is used to prevent ice formation and is used to deice. This application consumes the greatest amount of calcium chloride. Calcium chloride is relatively harmless to plants and soil. As a deicing agent, it is more effective at lower temperatures than sodium chloride. When distributed for this use, it usually takes the form of small, white spheres a few millimeters in diameter, called prills. Solutions of calcium chloride can prevent freezing at temperature as low as −52 °C (−62 °F), making it ideal for filling agricultural implement tires as a liquid ballast, aiding traction in cold climates.
Also used in salt/chemical-based dehumidifiers in domestic and other environments to adsorb dampness/moisture from the air.
The second largest application of calcium chloride exploits its hygroscopic properties and the tackiness of its hydrates. A concentrated solution keeps a liquid layer on the surface of dirt roads, which suppresses formation of dust. It keeps the finer dust particles on the road, providing a cushioning layer. If these are allowed to blow away, the larger aggregate begins to shift around and the road breaks down. Using calcium chloride reduces the need for grading by as much as 50% and the need for fill-in materials as much as 80%