Tartaric acid

Tartaric acid
	Ball-and-stick model of meso-tartaric acid
Names
	IUPAC name Tartaric acid
	Preferred IUPAC name 2,3-Dihydroxybutanedioic acid
	Systematic IUPAC name (2R, 3R)-Threaric acid (+); (2S, 3S)-Threaric acid (-); meso-Erythraric acid
	Other names Tartaric acid; 2,3-Dihydroxysuccinic acid; Threaric acid; Racemic acid; Uvic acid; Paratartaric acid; Winestone
Identifiers
CAS Number	R,R-isomer: 87-69-4; S,S-isomer: 147-71-7; racemic: 133-37-9; meso-isomer: 147-73-9;
3D model (JSmol)	Interactive image;
ChEBI	CHEBI:15674 ;
ChEMBL	ChEMBL333714 ; ChEMBL1200861 ;
ChemSpider	852 ;
DrugBank	DB01694 ;
ECHA InfoCard	100.121.903
E number	E334 (antioxidants, ...)
KEGG	C00898 ;
MeSH	tartaric+acid
PubChem CID	875 unspecified isomer;
UNII	W4888I119H ;
CompTox Dashboard (EPA)	DTXSID501031477 DTXSID5046986, DTXSID501031477 ;
	InChI InChI=1S/C4H6O6/c5-1(3(7)8)2(6)4(9)10/h1-2,5-6H,(H,7,8)(H,9,10) Key: FEWJPZIEWOKRBE-UHFFFAOYSA-N ; InChI=1/C4H6O6/c5-1(3(7)8)2(6)4(9)10/h1-2,5-6H,(H,7,8)(H,9,10) Key: FEWJPZIEWOKRBE-UHFFFAOYAZ;
	SMILES O=C(O)C(O)C(O)C(=O)O;
Properties
Chemical formula	C4H6O6 (basic formula); HO2CCH(OH)CH(OH)CO2H (structural formula)
Molar mass	150.087 g/mol
Appearance	White powder
Density	1.737 g/cm3 (R,R- and S,S-); 1.79 g/cm3 (racemate); 1.886 g/cm3 (meso)
Melting point	169, 172 °C (R,R- and S,S-); 206 °C (racemate); 165-6 °C (meso)
Solubility in water	1.33 kg/L (L or D-tartaric); 0.21 kg/L (DL, racemic); 1.25 kg/L ("meso");
Acidity (pKa)	L(+) 25 °C :; pKa1= 2.89, pKa2= 4.40; meso 25 °C:; pKa1= 3.22, pKa2= 4.85
Conjugate base	Bitartrate
Magnetic susceptibility (χ)	−67.5·10−6 cm3/mol
Hazards
	GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H318
Precautionary statements	P280, P305+P351+P338+P310
Related compounds
Other cations	Monosodium tartrate; Disodium tartrate; Monopotassium tartrate; Dipotassium tartrate
Related carboxylic acids	Butyric acid; Succinic acid; Dimercaptosuccinic acid; Malic acid; Maleic acid; Fumaric acid
Related compounds	2,3-Butanediol; Cichoric acid
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Tartaric acid is a white, crystalline organic acid that occurs naturally in many fruits, most notably in grapes but also in tamarinds, bananas, avocados, and citrus. Its salt, potassium bitartrate, commonly known as cream of tartar, develops naturally in the process of fermentation. Potassium bitartrate is commonly mixed with sodium bicarbonate and is sold as baking powder used as a leavening agent in food preparation. The acid itself is added to foods as an antioxidant E334 and to impart its distinctive sour taste. Naturally occurring tartaric acid is a useful raw material in organic synthesis. Tartaric acid, an alpha-hydroxy-carboxylic acid, is diprotic and aldaric in acid characteristics and is a dihydroxyl derivative of succinic acid.