|IUPAC name||Sodium oxide|
|Other names||Disodium oxide|
|Molar mass||61.9789 g/mol|
1950 °C decomposes
|Solubility in water||reacts violently to form NaOH|
|Crystal structure||Antifluorite (face centered cubic), cF12|
|Space group||Fm3m, No. 225|
|Tetrahedral (Na+); cubic (O2–)|
| Std enthalpy of|
| Standard molar|
|75.1 J mol−1 K−1|
|EU Index||Not listed|
|Main hazards||Corrosive, reacts violently with water|
|Other anions|| Sodium sulfide|
|Other cations|| Lithium oxide|
|Related sodium oxides|| Sodium peroxide|
|Related compounds||Sodium hydroxide|
| (what is this?) |
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
- Na2O + H2O → 2 NaOH
The alkali metal oxides M2O (M = Li, Na, K, Rb) crystallise in the antifluorite structure. In this motif the positions of the anions and cations are reversed relative to their positions in CaF2, with sodium ions tetrahedrally coordinated to 4 oxide ions and oxide cubically coordinated to 8 sodium ions.
- 2 NaOH + 2 Na → 2 Na2O + H2
- Na2O2 + 2 Na → 2 Na2O
- 2 NaNO2 + 6 Na → 4 Na2O + N2
Most of these reactions rely on the reduction of something by sodium, whether it is hydroxide, peroxide, or nitrite.
- 6 Na + 2 O2 → 2 Na2O + Na2O2
Sodium oxide is a significant component of glasses and windows although it is added in the form of "soda" (sodium carbonate). Sodium oxide does not explicitly exist in glasses, since glasses are complex cross-linked polymers. Typically, manufactured glass contains around 15% sodium oxide, 70% silica (silicon dioxide) and 9% lime (calcium oxide). The sodium carbonate "soda" serves as a flux to lower the temperature at which the silica melts. Soda glass has a much lower melting temperature than pure silica, and has slightly higher elasticity. These changes arise because the silicon dioxide and soda react to form sodium silicates of the general formula Na2[SiO2]x[SiO3].
- Na2CO3 → Na2O + CO2
- Na2O + SiO2 → Na2SiO3
- ↑ Zintl, E.; Harder, A.; Dauth B. (1934), "Gitterstruktur der oxyde, sulfide, selenide und telluride des lithiums, natriums und kaliums", Z. Elektrochem. Angew. Phys. Chem. 40: 588–93
- ↑ Wells, A.F. (1984) Structural Inorganic Chemistry, Oxford: Clarendon Press. ISBN 0-19-855370-6.
- ↑ Plantilla:Greenwood&Earnshaw2nd