Calcium iodide
Calcium iodide
Names
IUPAC name
calcium iodide
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.030.238 Edit this at Wikidata
EC Number
  • 233-276-8
RTECS number
  • EV1300000
UNII
  • InChI=1S/Ca.2HI/h;2*1H/q+2;;/p-2 checkY
    Key: UNMYWSMUMWPJLR-UHFFFAOYSA-L checkY
  • InChI=1/Ca.2HI/h;2*1H/q+2;;/p-2
    Key: UNMYWSMUMWPJLR-NUQVWONBAC
  • I[Ca]I
  • [Ca+2].[I-].[I-]
Properties
CaI2
Molar mass 293.887 g/mol (anhydrous)
365.95 g/mol (tetrahydrate)
Appearance white solid
Density 3.956 g/cm3 (anhydrous)[1]
Melting point 779 °C (1,434 °F; 1,052 K) (anhydrous) [2]
Boiling point 1,100 °C (2,010 °F; 1,370 K)[2]
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
-109.0·10−6 cm3/mol
Structure
Rhombohedral, hP3
P-3m1, No. 164
octahedral
Hazards
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g. chloroformFlammability 0: Will not burn. E.g. waterInstability 1: Normally stable, but can become unstable at elevated temperatures and pressures. E.g. calciumSpecial hazards (white): no code
2
0
1
Related compounds
Other anions
 calcium fluoride
calcium chloride
calcium bromide
Other cations
 beryllium iodide
magnesium iodide
strontium iodide
barium iodide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☒N verify (what is checkY☒N ?)

Calcium iodide (chemical formula CaI2) is the ionic compound of calcium and iodine. This colourless deliquescent solid is a salt that 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 is also used in cat food as a source of iodine.

Reactions

Henri Moissan first isolated pure calcium in 1898 by reducing calcium iodide with pure sodium metal:[3]

CaI2 + 2 Na → 2 NaI + Ca

Calcium iodide can be formed by treating calcium carbonate, calcium oxide, or calcium hydroxide with hydroiodic acid:[4]

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.[5]

2 CaI2 + 2 CO2 + O2 → 2 CaCO3 + 2 I2

References

  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. ^ a b R. J. Lewis (1993), Hawley's Condensed Chemical Dictionary 12th edition
  3. ^ Mellor, Joseph William (1912), Modern Inorganic Chemistry, New York: Longmans, Green, and Co, p. 334, 6909989325689, retrieved 2007-12-08
  4. ^ Gooch, Frank Austin; Walker, Claude Frederic (1905), Outlines of Inorganic Chemistry, New York: Macmillan, p. 340, retrieved 2007-12-08
  5. ^ Jones, Harry Clary (1906), Principles of Inorganic Chemistry, New York: Macmillan, p. 365, retrieved 2007-12-08
Categories