CAS N° 868-14-14
Potassium Acid Tartrate
Potassium hydrogen (2R,3R)-2,3-dihydroxybutane-1,4-dioate.
Appearance : white, crystalline powder or colourless crystals.
Solubility: slightly soluble in water, practically insoluble in alcohol. It dissolves in dilute solutions of mineral acids and alkali hydroxides.
Potassium hydrogen (2R,3R)-2,3-dihydroxybutane-1,4-dioate.
Content: 99,5 per cent to 100,5 per cent (dried substance)
Cream of tartar is naturally present in grapes. It deposits when the wine is left to stay in tanks, especially during winter months. Cream of tartar is purified without adding any toxic or noxious chemical additives. The result is the white powder which has always been used to make cakes. Some very famous industries today prefer to use natural products, such as cream of tartar, thus treasuring ancient traditions.
Cream of tartar was well known in ancient days, ever since wine was made from grapes, since it could be gathered on the sides and at the bottom of wine vases. Alchemists used it as a flux for certain metals; Paracelsus claimed it had great therapeutic virtues, a panacea for every illness.Van Helmont explained how the cream was separated from the wine. Boerhave also identified it in grape must, and other chemists such as Libavius, Corvnus and Sola discovered the presence of potassium in it. In the IIXth century, it was given the name of TARTAR, an Arabic word meaning wine deposit.
IDENTIFICATION
It complies with the test for specific optical rotation.
Suspend 0.5 g in 50 ml of water R and boil until dissolution is complete.
Allow to cool (solution A). To 5 ml of solution A, add 0.1 ml of a methyl
red solution R. The solution is red.
Solution A gives reaction of tartrates.
Solution A gives reaction of potassium.
DENSITY (20°C):
SOLUBILITY IN WATER (20°C):
(100°C): 0.0625 g/ml of H2O
SOLUBILITY IN BOILING WATER:
SOLUBILITY IN COLD WATER:
SOLUBILITY IN ALCOHOL 95°C:
pH VALUE (0,006 g/ml in H2O, 25°C):
MELTING POINT:
1,25 g/ml
0,006 g/ml of H2O
0,0625 g/ml of H2O
1/16
1/190
Insoluble
3,4
230°C