Calcium iodide

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Calcium iodide
Calcium iodide
Identifiers
CAS number 10102-68-8 YesY
13640-62-5 (tetrahydrate)
PubChem 66244
ChemSpider 59629 YesY
UNII 8EKI9QEE2H YesY
RTECS number EV1300000
Jmol-3D images Image 1
Properties
Molecular formula CaI2
Molar mass 293.887 g/mol (anhydrous)
365.95 g/mol (tetrahydrate)
Appearance white solid
Density 3.956 g/cm³[1]
Melting point 779 °C (tetrahydrate) with decomposition
Boiling point 1100 °C
Solubility in water 64.6 g/100 mL (0 °C)
66 g/100 mL (20 °C)
81 g/100 mL (100 °C)
Solubility soluble in acetone and alcohols
Structure
Crystal structure Rhombohedral, hP3
Space group P-3m1, No. 164
Coordination
geometry
octahedral
Hazards
EU Index Not listed
NFPA 704
Flammability code 0: Will not burn. E.g., water Health code 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g., chloroform Reactivity code 1: Normally stable, but can become unstable at elevated temperatures and pressures. E.g., calcium Special hazards (white): no codeNFPA 704 four-colored diamond
Related compounds
Other anions calcium fluoride
calcium chloride
calcium bromide
Other cations beryllium iodide
magnesium iodide
strontium iodide
barium iodide
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
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Infobox references

Calcium iodide is the inorganic compound with the formula CaI2. This colourless deliquescent solid is highly soluble in water. Its properties are similar to those for related salts, such as calcium chloride. It is used in photography.[1] It's also used in cat food as a source of iodine

Reactions[edit]

Henri Moissan first isolated pure calcium in 1898 by reducing calcium iodide with pure sodium metal:[2]

CaI2 + 2 Na → 2 NaI + Ca

Calcium iodide can be formed by treating calcium carbonate, calcium oxide, or calcium hydroxide with hydroiodic acid:[3]

CaCO3 + 2 HI → CaI2 + H2O + CO2

Calcium iodide slowly reacts with oxygen and carbon dioxide in the air, liberating iodine, which is responsible for the faint yellow color of impure samples.[4]

2 CaI2 + 2 CO2 + O2 → 2 CaCO3 + 2 I2

References[edit]

  1. ^ a b Turner, Jr., Francis M., ed. (1920), The Condensed Chemical Dictionary (1st ed.), New York: Chemical Catalog Co., p. 127, retrieved 2007-12-08 
  2. ^ Mellor, Joseph William (1912), Modern Inorganic Chemistry, New York: Longmans, Green, and Co, p. 334, retrieved 2007-12-08 
  3. ^ Gooch, Frank Austin; Walker, Claude Frederic (1905), Outlines of Inorganic Chemistry, New York: Macmillan, p. 340, retrieved 2007-12-08 
  4. ^ Jones, Harry Clary (1906), Principles of Inorganic Chemistry, New York: Macmillan, p. 365, retrieved 2007-12-08