The Collaborative International Dictionary
Sodium \So"di*um\, n. [NL., fr.E. soda.] (Chem.) A common metallic element of the alkali group, in nature always occuring combined, as in common salt, in albite, etc. It is isolated as a soft, waxy, white, unstable metal, so highly reactive that it combines violently with water, and to be preserved must be kept under petroleum or some similar liquid. Sodium is used combined in many salts, in the free state as a reducer, and as a means of obtaining other metals (as magnesium and aluminium) is an important commercial product. Symbol Na ( Natrium). Atomic weight 22.990. Specific gravity 0.97.
Sodium amalgam, an alloy of sodium and mercury, usually produced as a gray metallic crystalline substance, which is used as a reducing agent, and otherwise.
Sodium carbonate, a white crystalline substance, Na2CO3.10H2O, having a cooling alkaline taste, found in the ashes of many plants, and produced artifically in large quantities from common salt. It is used in making soap, glass, paper, etc., and as alkaline agent in many chemical industries. Called also sal soda, washing soda, or soda. Cf. Sodium bicarbonate, and Trona.
Sodium chloride, common, or table, salt, NaCl.
Sodium hydroxide, a white opaque brittle solid, NaOH, having a fibrous structure, produced by the action of quicklime, or of calcium hydrate (milk of lime), on sodium carbonate. It is a strong alkali, and is used in the manufacture of soap, in making wood pulp for paper, etc. Called also sodium hydrate, and caustic soda. By extension, a solution of sodium hydroxide.
Wiktionary
n. (context chemistry English) A salt, Na2CO3 formally derived from sodium hydroxide and carbonic acid; it is a white powder, soluble in water, with domestic, commercial and industrial uses; it occurs naturally as natrite
WordNet
n. a sodium salt of carbonic acid; used in making soap powders and glass and paper [syn: washing soda, sal soda, soda ash, soda]
Wikipedia
Sodium carbonate (also known as washing soda, soda ash and soda crystals), NaCO, is the water-soluble sodium salt of carbonic acid.
It most commonly occurs as a crystalline decahydrate, which readily effloresces to form a white powder, the monohydrate. Pure sodium carbonate is a white, odorless powder that is hygroscopic (absorbs moisture from the air). It has a strongly alkaline taste, and forms a moderately basic solution in water. Sodium carbonate is well known domestically for its everyday use as a water softener. It can be extracted from the ashes of many plants growing in sodium-rich soils, such as vegetation from the Middle East, kelp from Scotland and seaweed from Spain. Because the ashes of these sodium-rich plants were noticeably different from ashes of timber (used to create potash), they became known as "soda ash". It is synthetically produced in large quantities from salt ( sodium chloride) and limestone by a method known as the Solvay process.
The manufacture of glass is one of the most important uses of sodium carbonate. Sodium carbonate acts as a flux for silica, lowering the melting point of the mixture to something achievable without special materials. This "soda glass" is mildly water-soluble, so some calcium carbonate is added to the melt mixture to make the glass produced insoluble. This type of glass is known as soda lime glass: "soda" for the sodium carbonate and "lime" for the calcium carbonate. Soda lime glass has been the most common form of glass for centuries.
Sodium carbonate is also used as a relatively strong base in various settings. For example, it is used as a pH regulator to maintain stable alkaline conditions necessary for the action of the majority of photographic film developing agents. It acts as an alkali because when dissolved in water, it dissociates into the weak acid: carbonic acid and the strong alkali: sodium hydroxide. This gives sodium carbonate in solution the ability to attack metals such as aluminium with the release of hydrogen gas.
It is a common additive in swimming pools used to neutralize the corrosive effects of chlorine and raise the pH.
In cooking, it is sometimes used in place of sodium hydroxide for lyeing, especially with German pretzels and lye rolls. These dishes are treated with a solution of an alkaline substance to change the pH of the surface of the food and improve browning.
In taxidermy, sodium carbonate added to boiling water will remove flesh from the skull or bones of trophies to create the "European skull mount" or for educational display in biological and historical studies.
In chemistry, it is often used as an electrolyte. Electrolytes are usually salt-based, and sodium carbonate acts as a very good conductor in the process of electrolysis. In addition, unlike chloride ions, which form chlorine gas, carbonate ions are not corrosive to the anodes. It is also used as a primary standard for acid-base titrations because it is solid and air-stable, making it easy to weigh accurately.
Usage examples of "sodium carbonate".
Usually, the silica is from sand (or quartz pebbles), the sodium oxide is formed from sodium carbonate (soda ash), and the calcium oxide is derived from calcium carbonate (limestone).
However, bear in mind that sodium carbonate, while a very important industrial chemical, can be made not only by the Thomsen cryolite process, but also by both the earlier Le Blanc process (1791) and the later Solvay process, both described in Grantville encyclopedias.
Sodium borate, sodium carbonate and sodium nitrate, for example, all came up as flat-out sodium in SEM.
Once again, she entered a bodiless state in order to direct the sodium carbonate mixture where she needed it.
Then he made it slightly alkaline with a little sodium carbonate, talking half to us and half to himself as he worked.
On the other hand, natron in its solid form, with high proportions of sodium carbonate and sodium bicarbonate, produced .
She removes vials of sodium perborate, sodium carbonate and luminol, mixes them with distilled water in a container, shakes it and transfers the solution into a black pump spray bottle.
The four underground turbopumps would force-mix a sodium carbonate slurry with nitric acid in a large steel vessel under the silo, yielding huge volumes of nitrogen gas in seconds.