Sodium oxide

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Sodium oxide
Sodium oxide
Sodium oxide
IUPAC name Sodium oxide
Other names Disodium oxide,
soda
Identifiers
CAS number [1313-59-3]
Properties
Molecular formula Na2O
Molar mass 61.979
Appearance White solid
Density 2.27 g/cm3
Melting point

1132 °C
Boiling point

Decomposes at 1950 °C
Solubility in water reacts to form sodium hydroxide
Solubility in other solvents Insolubility
Structure
Crystal structure cubic
Coordination
geometry		 8-coordinate
Hazards
EU classification Corrosive (C)
NFPA 704
0
3
1
 
R-phrases R8, R14, R35
S-phrases S8, S27, S39,
S42, S45
Flash point Non-flammable
Except where noted otherwise, data are given for
materials in their standard state
(at 25 °C, 100 kPa)
Infobox disclaimer and references

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

[edit] Applications

In the typical application, 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

[edit] See also

[edit] References

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

[edit] External links

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