Calcium iodide
title: "Calcium iodide" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["calcium-compounds", "iodides", "alkaline-earth-metal-halides", "deliquescent-materials"] topic_path: "general/calcium-compounds" source: "https://en.wikipedia.org/wiki/Calcium_iodide" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0
| Verifiedfields = changed | Watchedfields = changed | verifiedrevid = 428631277 | Name = Calcium iodide | ImageFile = Cadmium-iodide-3D-balls.png | ImageName = Calcium iodide | IUPACName = calcium iodide |Section1={{Chembox Identifiers | ChemSpiderID_Ref = | ChemSpiderID = 59629 | UNII_Ref = | UNII = 8EKI9QEE2H | InChI = 1/Ca.2HI/h;21H/q+2;;/p-2 | SMILES = I[Ca]I | SMILES2 = [Ca+2].[I-].[I-] | InChIKey = UNMYWSMUMWPJLR-NUQVWONBAC | StdInChI_Ref = | StdInChI = 1S/Ca.2HI/h;21H/q+2;;/p-2 | StdInChIKey_Ref = | StdInChIKey = UNMYWSMUMWPJLR-UHFFFAOYSA-L | CASNo = 10102-68-8 | CASNo_Ref = | CASNo2_Ref = | CASNo2 = 13640-62-5 | CASNo2_Comment = (tetrahydrate) | PubChem = 66244 | RTECS = EV1300000 | EINECS = 233-276-8 |Section2={{Chembox Properties | Formula = CaI2 | MolarMass = 293.887 g/mol (anhydrous) 365.95 g/mol (tetrahydrate) | Appearance = white solid | Density = 3.956 g/cm3 (anhydrous) | editor-last= Turner, Jr. | editor-first= Francis M. | year = 1920 | title = The Condensed Chemical Dictionary | edition = 1st | location = New York | publisher = Chemical Catalog Co. | pages = 127 | url = https://books.google.com/books?id=y8y0XE0nsYEC&q=%22calcium+iodide%22+properties&pg=PA127 | access-date = 2007-12-08 | Solubility = 64.6 g/100 mL (0 °C) 66 g/100 mL (20 °C) 81 g/100 mL (100 °C) | SolubleOther = soluble in acetone and alcohols | MeltingPtC = 779 | MeltingPt_notes = (anhydrous) | BoilingPtC = 1100 | BoilingPt_ref = | MagSus = −109.0·10−6 cm3/mol |Section3={{Chembox Structure | Coordination = octahedral | CrystalStruct = Rhombohedral, hP3 | SpaceGroup = P-3m1, No. 164 | Dipole = |Section7={{Chembox Hazards | NFPA-H = 2 | NFPA-F = 0 | NFPA-R = 1 |Section8={{Chembox Related | OtherAnions = calcium fluoride calcium chloride calcium bromide | OtherCations = beryllium iodide magnesium iodide strontium iodide barium iodide
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. 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: | last = Mellor | first = Joseph William | year = 1912 | title = Modern Inorganic Chemistry | edition = | volume = | series = | location = New York | place = | publisher = Longmans, Green, and Co | id =6909989325689 | isbn = | doi = | oclc = | pages = 334 | url = https://books.google.com/books?id=wEoJAAAAIAAJ&q=%22calcium+iodide%22+subject:%22Chemistry,+Inorganic%22&pg=PA334 | access-date = 2007-12-08 :CaI2 + 2 Na → 2 NaI + Ca
Calcium iodide can be formed by treating calcium carbonate, calcium oxide, or calcium hydroxide with hydroiodic acid: | last1 = Gooch | first1 = Frank Austin | last2 = Walker | first2 = Claude Frederic | year = 1905 | title = Outlines of Inorganic Chemistry | edition = | volume = | series = | location = New York | publisher = Macmillan | id = | isbn = | doi = | oclc = | pages = 340 | url = https://books.google.com/books?id=q8MMAAAAYAAJ&q=%22calcium+iodide%22+subject:%22Chemistry,+Inorganic%22&pg=RA1-PA340 | access-date = 2007-12-08 :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.{{Citation | last = Jones | first = Harry Clary | year = 1906 | title = Principles of Inorganic Chemistry | edition = | volume = | series = | location = New York | publisher = Macmillan | id = | isbn = | doi = | oclc = | pages = 365 | url = https://books.google.com/books?id=zWE6AAAAMAAJ&q=%22calcium+iodide%22+subject:%22Chemistry,+Inorganic%22&pg=PA365 | access-date = 2007-12-08 : 2 CaI2 + 2 CO2 + O2 → 2 CaCO3 + 2 I2
References
References
- R. J. Lewis (1993), ''Hawley's Condensed Chemical Dictionary'' 12th edition
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