| Beryllium oxide |
| Image:Beryllium oxide.jpg |
| General |
| Other names |
Beryllia |
| Molecular formula |
BeO |
| Molar mass |
25.01 g/mol |
| Appearance |
white solid |
| CAS number |
[1304-56-9] |
| Properties |
| Density and phase |
3.0 g/cm3, solid |
| Solubility in water |
insoluble |
| Melting point |
2530 °C |
| Boiling point |
3900 °C |
| Structure |
Coordination
geometry |
? |
| Crystal structure |
? |
| Thermodynamic data |
Std enthalpy of
formation ΔfHo298 |
−609 kJ/mol |
Standard molar
entropy So298 |
13.8 J·K−1·mol−1 |
| Hazards |
| MSDS |
External MSDS |
| EU classification |
Highly toxic (T+)
Carc. Cat. 2 |
| R-phrases |
R49, R25, R26,
R36/37/38, R43, R48/23 |
| S-phrases |
S53, S45 |
| Flash point |
non-flammable |
| Supplementary data page |
Structure and
properties |
n, εr, etc. |
Thermodynamic
data |
Phase behaviour
Solid, liquid, gas |
| Spectral data |
UV, IR, NMR, MS |
| Related compounds |
| Other anions |
? |
| Other cations |
Magnesium oxide
Calcium oxide |
Except where noted otherwise, data are given for
materials in their standard state (at 25 °C, 100 kPa)
|
Beryllium oxide (BeO) is a white crystalline oxide. It is obtained from beryllium or beryllium compounds by ignition in the air. The sintered beryllium oxide (beryllia), which is very stable, has ceramic characteristics. It is similar to aluminium oxide (Al2O3), is highly fire resistant (melting point: 2570°C), and has polymorphism.
Beryllium oxide formed at high temperatures (>800°C) is inert and is only easily dissolved in a hot solution of concentrated sulfuric acid (H2SO4) and ammonium sulfate ((NH4)2SO4).
This complex is used for rocket engines, catalysts, semiconductors, moderators of atomic reactors, and neutron reflectors.
Beryllium oxide is used in many high-performance semiconductor parts for applications such as radio equipment because it has good thermal conductivity while also being a good electrical insulator.
WARNING: BeO is carcinogenic.
External links
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