Beryllium iodide
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| Names | |
|---|---|
| Systematic IUPAC name
Beryllium iodide | |
| Identifiers | |
7787-53-3  | |
| 3D model (Jmol) | Interactive image |
| ChemSpider | 74209  |
| ECHA InfoCard | 100.029.199 |
| PubChem | 82231 |
| |
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| Properties | |
| 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] |
| reacts explosively[1] | |
| Solubility | Slightly soluble in CS2 Soluble in ethanol, diethyl ether[2] |
| Structure | |
| orthorhombic | |
| Thermochemistry | |
| 71.14 J/(mol × K) | |
| Std molar entropy (S |
130 J/mol K |
| Std enthalpy of formation (ΔfH |
-192.62 kJ/mol |
| Gibbs free energy (ΔfG˚) |
-210 kJ/mol |
| Std enthalpy of combustion (ΔcH |
19 kJ/mol |
| Hazards | |
| Main hazards | see Berylliosis |
| US health exposure limits (NIOSH): | |
| PEL (Permissible) |
TWA 0.002 mg/m3 C 0.005 mg/m3 (30 minutes), with a maximum peak of 0.025 mg/m3 (as Be)[3] |
| REL (Recommended) |
Ca C 0.0005 mg/m3 (as Be)[3] |
| IDLH (Immediate danger) |
Ca [4 mg/m3 (as Be)][3] |
| Related compounds | |
| Other anions |
Beryllium fluoride Beryllium chloride Beryllium bromide |
| Other cations |
magnesium iodide calcium 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). | |
| verify (what is ?) | |
| 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
Beryllium iodide can be prepared by reacting beryllium metal with elemental iodine at temperatures of 500 °C to 700 °C:[1]
Beryllium iodide is also formed when beryllium carbide reacts with hydrogen iodide in the gas phase:
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
Beryllium iodide can be used in the preparation of high-purity beryllium by the decomposition of the compound on a hot tungsten filament.
References
- 1 2 3 Perry, Dale L.; Phillips, Sidney L. (1995), Handbook of Inorganic Compounds, CRC Press, p. 63, ISBN 0-8493-8671-3, retrieved 2007-12-10
- 1 2 Parsons, Charles Lathrop (1909), The Chemistry and Literature of Beryllium, Easton, Pa.: Chemical Publishing, pp. 22–23, retrieved 2007-12-10
- 1 2 3 "NIOSH Pocket Guide to Chemical Hazards #0054". National Institute for Occupational Safety and Health (NIOSH).