Magnesium Oxide
Definition and meaning of Magnesium Oxide in chemistry.
Magnesium oxide is an ionic compound composed of magnesium cations and oxide anions in a 1:1 ratio. It is a white solid at room temperature that is insoluble in water.
In more detail
Magnesium oxide forms when magnesium metal combusts in oxygen or when magnesium hydroxide or magnesium carbonate is heated. The compound consists of Mg2+ cations and O2- anions held together by strong electrostatic forces in a rock salt crystal structure. It is a basic oxide that reacts slowly with water to form magnesium hydroxide. MgO is widely used as a high-temperature refractory material in furnaces, as an electrical insulator, and in industrial cement formulations.
Key facts
| Chemical formula | MgO |
|---|---|
| Melting point | Approximately 2852°C (5166°F) |
| Crystal structure | Rock salt (NaCl) type |
| Field | Inorganic Chemistry |
When magnesium metal burns in oxygen, it produces bright white magnesium oxide powder: 2Mg + O2 → 2MgO
Frequently asked questions
Is magnesium oxide soluble in water?
No, magnesium oxide is insoluble in water. However, it reacts slowly with water to form magnesium hydroxide, Mg(OH)2, which is slightly soluble.
What is the oxidation state of magnesium in MgO?
The oxidation state of magnesium in MgO is +2, as it has lost two electrons to form Mg2+ cations.