Define Alumina

Explanation

**Step-by-Step Text Solution:**

1. **Definition of Alumina**: Alumina is the common name for aluminum oxide, which has the chemical formula Al₂O₃.

2. **Formation**: Alumina is derived from aluminum hydroxide (Al(OH)₃). This means that when aluminum hydroxide undergoes dehydration, it forms alumina.

3. **Electrical Conductivity**: In its solid state, alumina is a poor conductor of electricity. However, when subjected to high temperatures, it can become an ionic conductor.

4. **Solubility**: Alumina is insoluble in water. This insolubility is due to the strong ionic bonds between the oxide ions and aluminum ions in its solid lattice structure, which prevents it from reacting with water.

5. **Dehydrating Agent**: Alumina acts as a dehydrating agent. For instance, it can facilitate the dehydration of alcohols, which is a crucial step in the production of alkynes when used as a catalyst.

6. **Applications**: Due to its properties, alumina is used in various industrial applications, including ceramics, abrasives, and as a catalyst in chemical reactions.