Soda \So"da\, n. [It., soda, in OIt., ashes used in making glass, fr. L. solida, fem. of solidus solid; solida having probably been a name of glasswort. See Solid.]

(Chem.)
   (a) Sodium oxide or hydroxide.
   (b) Popularly, sodium carbonate or bicarbonate.

Caustic soda, sodium hydroxide.

Cooking soda, sodium bicarbonate. [Colloq.]

Sal soda. See Sodium carbonate, under Sodium.

Soda alum (Min.), a mineral consisting of the hydrous sulphate of alumina and soda.

Soda ash, crude sodium carbonate; -- so called because formerly obtained from the ashes of sea plants and certain other plants, as saltwort (Salsola). See under Sodium.

Soda fountain, an apparatus for drawing soda water, fitted with delivery tube, faucets, etc.

Soda lye, a lye consisting essentially of a solution of sodium hydroxide, used in soap making.

Soda niter. See Nitratine.

Soda salts, salts having sodium for the base; specifically, sodium sulphate or Glauber's salts.

Soda waste, the waste material, consisting chiefly of calcium hydroxide and sulphide, which accumulates as a useless residue or side product in the ordinary Leblanc process of soda manufacture; -- called also alkali waste.

Soda water, originally, a beverage consisting of a weak solution of sodium bicarbonate, with some acid to cause effervescence; now, in common usage, a beverage consisting of water highly charged with carbon dioxide (carbonic acid). Fruit sirups, cream, etc., are usually added to give flavor. See Carbonic acid, under Carbonic.

Washing soda, sodium carbonate. [Colloq.]

Source: Webster's Revised Unabridged Dictionary (1913)
 

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 readily oxidized 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 23. 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 bicarbonate, a white crystalline substance, HNaCO3, with a slight alkaline taste resembling that of sodium carbonate. It is found in many mineral springs and also produced artificially,. It is used in cookery, in baking powders, and as a source of carbonic acid gas (carbon dioxide) for soda water. Called also cooking soda, saleratus, and technically, acid sodium carbonate, primary sodium carbonate, sodium dicarbonate, etc.

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, above 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.

Source: Webster's Revised Unabridged Dictionary (1913)