Beryllium iodide

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Beryllium iodide
Beryllium iodide.svg
Identifiers
CAS number 7787-53-3 YesY
PubChem 82231
ChemSpider 74209 YesY
Jmol-3D images Image 1
Properties
Molecular formula BeI2
Molar mass 262.821 g/mol
Appearance colorless needle-like crystals
Density 4.325 g/cm³
Melting point 480 °C (896 °F; 753 K)
Boiling point 590 °C (1,094 °F; 863 K) [1]
Solubility in water reacts explosively[1][citation needed]
Solubility Slightly soluble in CS2
Soluble in ethanol, diethyl ether[2]
Structure
Crystal structure orthorhombic
Thermochemistry
Specific
heat capacity
C
71.14 J/(mol × K)
Std molar
entropy
So298
130 J/mol K
Std enthalpy of
formation
ΔfHo298
-192.62 kJ/mol
Gibbs free energy ΔG -210 kJ/mol
Std enthalpy of
combustion
ΔcHo298
19 kJ/mol
Hazards
Main hazards see Berylliosis
Related compounds
Other anions Beryllium fluoride
Beryllium chloride
Beryllium bromide
Other cations magnesium iodide
calcium 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

Beryllium iodide is the chemical compound with the formula BeI2. It is very hygroscopic and reacts violently with water, forming hydroiodic acid.

Reactions[edit]

Beryllium iodide can be prepared by reacting beryllium metal with elemental iodine at temperatures of 500 °C to 700 °C:[1]

Be + I2 → BeI2

Beryllium iodide is also formed when beryllium carbide reacts with hydrogen iodide in the gas phase:

Be2C + 4 HI → 2 BeI2 + CH4

The iodine in beryllium iodide is easily replaced with the other halogens; it reacts with fluorine giving beryllium fluoride and fluorides of iodine, with chlorine giving beryllium chloride, and with bromine giving beryllium bromide. Beryllium iodide also reacts violently with oxidising agents such as chlorate and permanganate to give purple vapour of iodine. The solid and vapor are both flammable in air.[2]

Applications[edit]

Beryllium iodide can be used in the preparation of high-purity beryllium by the decomposition of the compound on a hot tungsten filament.

References[edit]

  1. ^ a b c Perry, Dale L.; Phillips, Sidney L. (1995), Handbook of Inorganic Compounds, CRC Press, p. 63, ISBN 0-8493-8671-3, retrieved 2007-12-10 
  2. ^ a b Parsons, Charles Lathrop (1909), The Chemistry and Literature of Beryllium, Easton, Pa.: Chemical Publishing, pp. 22–23, retrieved 2007-12-10