SODIUM OXIDE

Sodium oxide
Sodium oxide
General
Systematic name	Sodium oxide
Other names	Disodium oxide, soda
Molecular formula	Na2O
Molar mass	61.979
Appearance	White solid
CAS number	[1313-59-3]
Properties
Density and phase	2.27 g/cm3
Solubility in water	reacts to form sodium hydroxide
Other solvents	Insolubility
Melting point	1132 °C
Boiling point	Decomposes at 1950 °C
Structure
Coordination geometry	8-coordinate
Crystal structure	cubic
Hazards
MSDS	External MSDS
EU classification	Corrosive ('C')
R-phrases	, ,
S-phrases	, , , ,
NFPA 704
Flash point	Non-flammable
Supplementary data page
Structure and properties	''n'', εr, etc.
Thermodynamic data	Phase behaviour Solid, liquid, gas
Spectral data	UV, IR, NMR, MS
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)

'Sodium oxide' is a chemical compound with the formula Na₂O. It is used in ceramics and glasses. Treatment with water affords sodium hydroxide.
:Na₂O + H₂O → 2 NaOH
The alkali metal oxides M₂O (M = 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.^[1]

Contents

Applications

See also

References

External links

Applications

Typically, glass contains around 15% sodium oxide, the other components being silicon dioxide and calcium oxide at around 70% and 9% respectively. The soda serves as a flux to lower the temperature at which the silica melts. Soda glass has a lower melting temperature vs pure silica and has improved mechanical properties due to its slight increases in elasticity. These changes arise because the silicon dioxide and soda react to form sodium silicates of the general formula Na₂[SiO₂]_x[SiO₃].
Na₂O forms when sodium is treated with oxygen.
:4 Na + O₂ → 2 Na₂O
Burning sodium in air will produce Na₂O and about 20% sodium peroxide Na₂O₂.
:6 Na + 2 O₂ → 2 Na₂O + Na₂O₂
Pure Na₂O can be prepared by reaction of liquid sodium with NaNO₃.
:10 Na + 2 NaNO₃ → 6 Na₂O + N₂

See also

★ Sodium peroxide

★ sodium superoxide

References

1. Wells, A.F. (1984) Structural Inorganic Chemistry, Oxford: Clarendon Press. ISBN 0-19-855370-6.

External links

★ Sodium oxide information at Webelements.

★ External MSDS Data Sheet.