tartaric acid

tartaric acid
an organic compound, C4H6O6, existing in four isomeric forms, the common or dextrorotatory isomer being a white, crystalline, water-soluble powder or transparent crystals: used in effervescent beverages, baking powders, confections, photography, and tanning.

* * *

also called  dihydroxybutanedioic acid  
 a dicarboxylic acid, one of the most widely distributed of plant acids, with a number of food and industrial uses. Along with several of its salts, cream of tartar (potassium hydrogen tartrate) and Rochelle salt (potassium sodium tartrate), it is obtained from by-products of wine fermentation. In a partially purified form, tartar was known to the ancient Greeks and Romans; the free acid was first isolated in 1769 by Swedish chemist Carl Wilhelm Scheele (Scheele, Carl Wilhelm). The lees, or sediments, and other waste products from fermentation are heated and neutralized with calcium hydroxide; the precipitated calcium tartrate is then treated with sulfuric acid to produce free tartaric acid. Rochelle salt is prepared from the crude crystalline potassium acid salt, called argol, by neutralization with sodium carbonate. Purified cream of tartar comes chiefly from the filtrates from production of the acid and Rochelle salt. A third salt, tartar emetic (antimony potassium tartrate), is made from the potassium acid salt and antimony oxide.

      Three stereoisomeric forms of tartaric acid exist: (1) dextrorotatory tartaric acid (d-tartaric acid) found in grapes (grape) and several other fruits, (2) levorotatory tartaric acid (l-tartaric acid) obtained chiefly by resolution of racemic tartaric acid, and (3) a meso or achiral form. Racemic tartaric acid (an equal mixture of d- and l-tartaric acid) is prepared commercially by the molybdenum- or tungsten-catalyzed oxidation of maleic anhydride with hydrogen peroxide.

      Study of the crystallographic, chemical, and optical properties of the tartaric acids by French chemist and microbiologist Louis Pasteur (Pasteur, Louis) laid the basis for modern ideas of stereoisomerism.

      The various tartaric acids and the common tartrate salts are all colourless, crystalline solids readily soluble in water. Tartaric acid is widely used as an acidulant in carbonated drinks, effervescent tablets, gelatin desserts, and fruit jellies. It has many industrial applications—e.g., in cleaning and polishing metals, in calico printing, in wool dyeing, and in certain photographic printing and development processes. Rochelle salt is used in silvering mirrors, in processing cheese, and in compounding mild cathartics. Cream of tartar is incorporated into baking powders (baking powder), hard candies, and taffies; and it is employed in the cleaning of brass, the electrolytic tinning of iron and steel, and the coating of other metals (metal) with gold and silver. Tartar emetic is used as an insecticide and a dyeing mordant (mordant dye).

William H. Brown

* * *

Universalium. 2010.

Игры ⚽ Нужна курсовая?

Look at other dictionaries:

  • Tartaric acid — Tartaric acid[1] …   Wikipedia

  • Tartaric acid — Tartaric Tar*tar ic, a. (Chem.) Of or pertaining to tartar; derived from, or resembling, tartar. [1913 Webster] {Tartaric acid}. (a) An acid widely diffused throughout the vegetable kingdom, as in grapes, mountain ash berries, etc., and obtained… …   The Collaborative International Dictionary of English

  • tartaric acid — n. an acid, HOOC(CHOH) 2COOH, a clear, colorless crystal or a white, crystalline powder, found in vegetable tissues and fruit juices and obtained commercially from tartar: it is used in dyeing, photography, medicine, etc …   English World dictionary

  • tartaric acid — Made from crude tartar; a laxative and refrigerant; used in the manufacture of various effervescing powders, tablets, and granules. * * * tar·tar·ic acid (.)tär .tar ik n a strong dicarboxylic acid C4H6O6 of plant origin that occurs in three… …   Medical dictionary

  • Tartaric acid — Strukturformel D (–) Form (links oben) und L (+) Form (rechts oben) sowie meso Form (unten) mit intramolekularer Spiegelebene ( ) Allgemeines Name …   Deutsch Wikipedia

  • tartaric acid — vyno rūgštis statusas T sritis chemija formulė HOOC(CHOH)₂COOH atitikmenys: angl. tartaric acid rus. винная кислота ryšiai: sinonimas – 2,3 dihidroksibutano dirūgštis …   Chemijos terminų aiškinamasis žodynas

  • tartaric acid — noun a) a white crystalline acid that occurs naturally in many plants, and in wine; it is used as the salts cream of tartar and Rochelle salt b) The aldaric acid, 2,3 dihydroxy succinic acid Syn: erythraric acid …   Wiktionary

  • tartaric acid — noun an acid found in many fruits; used in soft drinks and confectionery and baking powder • Hypernyms: ↑hydroxy acid • Hyponyms: ↑racemic acid …   Useful english dictionary

  • tartaric acid — noun Date: 1810 a strong dicarboxylic acid C4H6O6 of plant origin that occurs in various isomeric forms, is usually obtained from tartar, and is used especially in food and medicines, in photography, in wine making, and in making salts and esters …   New Collegiate Dictionary

  • tartaric acid — tar|tar|ic ac|id [ta:ˌtærık ˈæsıd US ta:r ] n [U] a strong acid that comes from a plant and is used in preparing some foods and medicines …   Dictionary of contemporary English

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”