Calcium iodide

Overview

Calcium iodide (CaI₂) is an ionic compound of calcium and iodine. It is highly soluble in water and it is deliquescent. It is a salt that is solid at room temperature, and it behaves as a typical ionic halide. Because of its hygroscopic nature, it must be kept in tightly-sealed containers. It is similar to calcium chloride in many respects^[1]. It is used in photography^[2].

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

Ca I₂ + 2Na → 2NaI + Ca

Calcium iodide can be formed by reacting calcium carbonate with hydroiodic acid^[4]:

CaCO₃ + 2HI → CaI₂ + H₂O + CO₂

Calcium iodide slowly reacts with oxygen and carbon dioxide in the air, giving free iodine^[5].

↑ Mendeleyev, Dmitry Ivanovich; Kamensky, George (1902), The Principles of Chemistry, New York: P. F. Collier, p. 604, retrieved 2007-12-08 Text " author2-link " ignored (help); Check date values in: |accessdate= (help)
↑
↑ Mellor, Joseph William (1912), Modern Inorganic Chemistry, New York: Longmans, Green, and Co, p. 334, retrieved 2007-12-08 Text " author2-link " ignored (help); Check date values in: |accessdate= (help)
↑ Gooch, Frank Austin; Walker, Claude Frederic (1905), Outlines of Inorganic Chemistry, New York: Macmillan, p. 340, retrieved 2007-12-08 Text " author2-link " ignored (help); Check date values in: |accessdate= (help)
↑ Jones, Harry Clary (1906), Principles of Inorganic Chemistry, New York: Macmillan, p. 365, retrieved 2007-12-08 Text " author2-link " ignored (help); Check date values in: |accessdate= (help)