Tantalum pentoxide
| Names | |
|---|---|
| IUPAC name Tantalum(V) oxide | |
| Systematic IUPAC name Ditantalum pentaoxide | |
| Identifiers | |
| 3D model (JSmol) | |
| ChemSpider | |
| ECHA InfoCard | 100.013.854 | 
| PubChem CID | |
| UNII | |
| CompTox Dashboard (EPA) | |
| 
 | |
| 
 | |
| Properties | |
| Ta2O5 | |
| Molar mass | 441.893 g/mol | 
| Appearance | white, odorless powder | 
| Density | β-Ta2O5 = 8.18 g/cm3 α-Ta2O5 = 8.37 g/cm3 | 
| Melting point | 1,872 °C (3,402 °F; 2,145 K) | 
| negligible | |
| Solubility | insoluble in organic solvents and most mineral acids, reacts with HF | 
| Band gap | 3.8–5.3 eV | 
| −32.0×10−6 cm3/mol | |
| Refractive index (nD) | 2.275 | 
| Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references | |
Tantalum pentoxide, also known as tantalum(V) oxide, is the inorganic compound with the formula Ta
2O
5. It is a white solid that is insoluble in all solvents but is attacked by strong bases and hydrofluoric acid. Ta
2O
5 is an inert material with a high refractive index and low absorption (i.e. colourless), which makes it useful for coatings. It is also extensively used in the production of capacitors, due to its high dielectric constant.