| IUPAC name
| Other names
|Molar mass||40.304 g/mol|
|Melting point||2,825 °C (5,117 °F; 3,098 K)|
|Boiling point||3,600 °C (6,510 °F; 3,870 K)|
|Insoluble, some reacts to form Mg(OH)2|
|Solubility|| Reacts with acids, ketones|
Insoluble in alcohols, esters, ethers, halocarbons, hydrocarbons
|Vapor pressure||~0 mmHg|
|26.95 ± 0.15 J·mol−1·K−1|
Std enthalpy of
|−601.6 ± 0.3 kJ/mol|
|Safety data sheet||Sigma-Aldrich|
| Beryllium oxide|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Magnesium oxide (MgO) or magnesia, is a white hygroscopic solid compound, an oxide of magnesium. It occurs naturally as the mineral periclase.
Magnesium oxide reacts with water to form magnesium hydroxide, though the reaction is very slow at room temperature, a consequence of its low solubility in water. It will however react vigorously with acids, giving magnesium salts.
- MgO + 2 HX → + MgX2 + H2O
Magnesium oxide will not react with bases, especially molten ones.
Magnesium oxide is a white solid, insoluble in water.
Magnesium oxide can be bought from pharmacies, as antiacid, though most often tends to be impure.
Higher purity magnesium oxide can be bought online or from chemical suppliers
Can be prepared by burning magnesium metal in air or dissolving it in water, then calcinate the resulting magnesium hydroxide.
Another route involves calcinating magnesium carbonate/hydroxide at high temperatures
- Make magnesium salts
- Magnesia crucible
- Electrical insulator in tubular heating elements
Magnesium oxide has low toxicity, though it may be irritant to touch. Inhalation of magnesium oxide fumes may cause metal fume fever.
In closed bottles, away from acids and halogens.
No special disposal is required. Discard it as you wish.