Formula BeI2 Melting point 480 °C Density 4.32 g/cm³ | Molar mass 262.821 g/mol Boiling point 590 °C | |
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Appearance colorless needle-like crystals | ||
Beryllium iodide is the chemical compound with the formula BeI2. It is very hygroscopic and reacts violently with water, forming hydroiodic acid.
Contents
Reactions
Beryllium iodide can be prepared by reacting beryllium metal with elemental iodine at temperatures of 500 °C to 700 °C:
Be + I2 → BeI2Beryllium iodide is also formed when beryllium carbide reacts with hydrogen iodide in the gas phase:
Be2C + 4 HI → 2 BeI2 + CH4The 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.
Applications
Beryllium iodide can be used in the preparation of high-purity beryllium by the decomposition of the compound on a hot tungsten filament.