The sodium oxide is an inorganic compound of the formula Na 2 O. As all alkali metal oxides, has a similar crystal structure to antifluorite (similar to fluorspar, CaF2, but with the cations and anions inverted) corresponding to cubic focused on faces. (Sodium: disodium oxide, 1993-2016).
It could be said that sodium oxide is the anhydride of sodium hydroxide, since it reacts with water to form two moles of this compound in the following way:
Na 2 O + H 2 O → 2NaOH
Figure 1: Structure of sodium oxide.
Generally, the name KNaO can be found written, referring to sodium oxide or potassium oxide. This is because the two oxides have similar properties in terms of color and rates of expansion and contraction.
Insoluble sources of sodium oxide often include traces of potassium oxide, for example in feldspars (figure 2), which are the main source of sodium in certain enamels (Britt, 2007).
Figure 2: sodium feldspar and feldspar powder.
Physical and chemical properties
Sodium oxide is a white crystalline solid (Figure 3). It has a molecular weight of 61.98 g / mol, has a density of 2.27 g / ml and a melting point of 1275 ° C.
The compound has a boiling point of 1950 ° C where it begins to decompose to sodium peroxide and metallic sodium, however, an interesting property is that sodium oxide begins to sublimate at 1100 ° C (National Center for Biotechnology Information, SF).
Figure 3: appearance of sodium oxide.
Reacts violently with water and alcohol to form sodium hydroxide. Sodium oxide, Na 2 O, reversibly absorbs hydrogen (H 2), to form sodium hydride (NaH) and sodium hydroxide (NaOH), which has the potential to find its application to the reversible storage of hydrogen.
Reactivity and hazards
Sodium oxide is a stable non-flammable compound, but it can react violently with acids and water. It can also increase the combustion of other substances. It is classified as corrosive and can burn the skin and eyes (Royal Society of Chemistry, 2015).
The solution in water is a strong base, since it reacts violently with acids being corrosive. By reacting violently with water, sodium hydroxide is produced, attacking many metals in the presence of water.
The substance is also corrosive to the respiratory tract and when swallowed. Inhalation of aerosol can cause pulmonary edema (National Institute for Occupational Safety and Health, 2014).
In case of inhalation, the affected person should be moved to a cool place. If the victim is not breathing, artificial respiration should be given. Later go or consult a doctor as soon as possible.
In case of skin contact, contaminated clothing and shoes should be removed immediately and washed with plenty of water.
In case of contact with the eyes, rinse with plenty of water for at least 15 minutes and consult a doctor. In case of ingestion, do not induce vomiting, but rinse mouth with water and consult a doctor.
The most important symptoms and effects may be: spasms, inflammation and edema of the larynx and bronchi, pneumonitis, pulmonary edema, burning sensation, cough, wheezing, laryngitis and difficulty in breathing (Sodium oxide (Na2O) (cas 1313- 59-3) MSDS, 2010-2017).
Symptoms of pulmonary edema often do not appear for a few hours and are aggravated by physical exertion. Rest and medical observation are therefore essential.
Sodium oxide should be stored in a dry place and separated from strong acids. Since the compound reacts violently with water, in case of fire, do not use water-based extinguishers or sprinklers. It is recommended to use dry powder or sand.
Applications
The main use of sodium oxide is in the manufacture of glass. It is used in pottery and glasses, although not in raw form. Sodium oxide generally makes up about 15% of the chemical composition of glass.
It reduces the temperature at which silicon dioxide melts (70% glass composition), resulting in it being cheaper and more efficient to produce glass, since it requires less energy expenditure by the manufacturer (George Sumner, nd).
Sodium-lime glass is the most common form of glass produced, comprising approximately 70% silica (silicon dioxide), 15% soda (sodium oxide), and 9% lime (calcium oxide), with much higher amounts. small of other compounds.
The sodium oxide serves as a flux to lower the temperature at which the silica melts, and the lime acts as a stabilizer for the silica. Sodium-lime glass is inexpensive, chemically stable, reasonably hard, and extremely workable, because it is capable of being softened multiple times if necessary.
These qualities make it suitable for the manufacture of a wide range of glass products, including light bulbs, glasses, bottles, and art objects.
On the other hand, sodium oxide and silica contain water crystal, also called sodium silicate or water glass, which forms a glassy solid with the very useful property of being soluble in water.
Glass of water is sold as solid lumps or powders, or as a clear, syrupy liquid. It is used as a convenient source of sodium for many industrial products such as: a builder in laundry detergents, as a binder and adhesive, as a flocculant in water treatment plants, and in many other applications (Encyclopaedia britannica, 2017).
Oxide compounds do not conduct electricity. However, certain structured oxides of perovskite are electronic conductors for application in the cathode of solid oxide fuel cells and oxygen generation systems (American Elements, 1998-2017).
References
- National Institute for Occupational Safety and Health. (2014, July 1). CDC SODIUM OXIDE. Recovered from cdc.
- American Elements. (1998-2017). Sodium Oxide. Recovered from americanelements.com.
- Britt, J. (2007). The Complete Guide to High-Fire Glazes. New York: Lark Books.
- Britannica encyclopaedia. (2017). Sodium oxide chemical compound. Recovered from britannica.com.
- George Sumner, DJ (nd). What are some of the uses for sodium oxide? Recovered from quora.com.
- National Center for Biotechnology Information. (SF). PubChem Compound Database; CID = 73971. Recovered from pubchem.ncbi.nlm.nih.gov.
- Royal Society of Chemistry. (2015). Sodium oxide. Recovered from chemspider.com.
- Ruitao Wang, TK (2006). Reaction of hydrogen with sodium oxide: A reversible hydrogenation / dehydrogenation system. Journal of Power Sources, Volume 155, Issue 2, 167–171. sciencedirect.com.
- Sodium oxide (Na2O) (cas 1313-59-3) MSDS. (2010-2017). Recovered from guidechem: guidechem.com.
- Sodium: disodium oxide. (1993-2016). Recovered from webelements: webelements.com.