Cerium(III) oxide
also written as Ce₂O₃, is an inorganic compound composed of cerium and oxygen in a +3 oxidation state. It is one of the two main oxides of cerium, the other being cerium(IV) oxide (CeO₂).
🧪 Basic Properties of Cerium(III) Oxide
| Property | Value |
|---|---|
| Chemical formula | Ce₂O₃ |
| Appearance | Pale yellow or off-white powder |
| Molecular weight | ~328.24 g/mol |
| Melting point | ~2,400 °C |
| Solubility | Insoluble in water |
| Crystal structure | Hexagonal |
| Oxidation state | Cerium: +3 |
🔬 How It Differs from CeO₂
- Ce₂O₃ contains cerium in the +3 oxidation state
- CeO₂ contains cerium in the +4 oxidation state
- Ce₂O₃ is less stable and can oxidize in air to form CeO₂
⚙️ Applications
Though CeO₂ is more common industrially, Ce₂O₃ is used in:
- Research and catalysis
- Ceramic materials
- Rare-earth alloy production
- As a precursor to other cerium compounds
⚠️ Handling and Safety
- Air-sensitive: Ce₂O₃ can oxidize to CeO₂ over time
- Stable at high temperatures in inert or reducing atmospheres
- Should be stored in airtight containers under dry, inert gas
- Not classified as highly toxic but may irritate the skin, eyes, or respiratory tract in powder form
🧪 Reactivity
- Reacts slowly with acids to form cerium(III) salts
- Can be oxidized by air or oxidizing agents to cerium(IV) oxide