Potassium hydrogen tartrate

Tartaric acid is noteworthy for a) the excellent way in which the majority of its salts Crystallise, and h) the frequent occurrence of salts having mixed cations. Examples of the latter are sodium potassium tartrate (or Rochelle salt), C4H40 NaK, used for the preparation of Fehling s solution (p. 525), sodium ammonium tartrate, C4H OaNaNH4, used by Pasteur for his early optical resolution experiments, and potassium antimonyl tartrate (or Tartar Emetic), C4H404K(Sb0). The latter is prepared by boiling a solution of potassium hydrogen tartrate (or cream of tartar ) with antimony trioxide,... 

Required Potassium hydrogen tartrate, 5 g. antimony trioxide, 5 g-... 

Add 5 g. of potassium hydrogen tartrate and 5 g. of antimony trioxide (each being finely powdered) to 30 ml. of water contained in a small flask, and boil the mixture under a reflux water-condenser for 15 minutes. Then filter hot, using a Buchner funnel and flask which have been preheated by the filtration of some boiling distilled water. Pour the clear filtrate into a beaker and allow to cool. Potassium antimonyl tartrate separates as colourless crystals. Filter, drain and dry. Yield, 5 g. The product can be recrystallised from hot water, but this is usually not necessary. 

Potassium hydrogen tartrate, about 0.034M Saturated at 25°C... 

To prepare the standard pH buffer solutions recommended by the National Bureau of Standards (U.S.), the indicated weights of the pure materials in Table 8.15 should be dissolved in water of specific conductivity not greater than 5 micromhos. The tartrate, phthalate, and phosphates can be dried for 2 h at 100°C before use. Potassium tetroxalate and calcium hydroxide need not be dried. Fresh-looking crystals of borax should be used. Before use, excess solid potassium hydrogen tartrate and calcium hydroxide must be removed. Buffer solutions pH 6 or above should be stored in plastic containers and should be protected from carbon doxide with soda-lime traps. The solutions should be replaced within 2 to 3 weeks, or sooner if formation of mold is noticed. A crystal of thymol may be added as a preservative. 

In the days of alchemy and the phlogiston theory, no system of nomenclature that would be considered logical ia the 1990s was possible. Names were not based on composition, but on historical association, eg, Glauber s salt for sodium sulfate decahydrate and Epsom salt for magnesium sulfate physical characteristics, eg, spirit of wiae for ethanol, oil of vitriol for sulfuric acid, butter of antimony for antimony trichloride, Hver of sulfur for potassium sulfide, and cream of tartar for potassium hydrogen tartrate or physiological behavior, eg, caustic soda for sodium hydroxide. Some of these common or trivial names persist, especially ia the nonchemical Hterature. Such names were a necessity at the time they were iatroduced because the concept of molecular stmcture had not been developed, and even elemental composition was incomplete or iadeterminate for many substances. 

The potassium salt of tartaric acid, potassium bitartrate or potassium hydrogen tartrate, is weakly acidic, and is known as cream of tartar. Since it is a dry acid, cream of tartar is used in baking powders (along with sodium bicarbonate) to produce carbon dioxide gas when added to water. Other acids used in baking powder are fumaric acid and phosphoric acid. 

Potassium chromate is a carcinogen, potassium permanganate is used as a germicide, and potassium hydrogen tartrate, commonly known as cream of tartar, is a white solid found in baking powder. Explain how potassium can have such diverse uses. 

See Nitrogen oxide Carbon, Potassium hydrogen tartrate... 

Potassium hydrogen tartrate [868-14-4] KOCO.CHOHCHOHCO.OH Carbon, Nitrogen oxide See Nitrogen oxide Carbon, etc. See related ORGANIC ACIDS c4h5ko6... 

Potassium hydrogen tartrate, 1462 /s-Propcnc-l,2,3-tricarboxylic acid, 2342 Propiolic acid, 1086 2,5-Pyridinedicarboxylic acid, 2696 Pyruvic acid, 1150... 

Sousa, P. and Lopes, A.M.C. Solubilities of potassium hydrogen tartrate and potassium chloride in water + ethanol mixtures,/... 

Accdg to Davis (Ref 7, p 325), potassium hydrogen tartrate also acts as an "antioxidant , but its action differs in that it decomposes and thus absorbs some heat from the gases... 

Cream of tartar potassium hydrogen tartrate KHC404H6... 

Figure 8-3 Solubility of potassium hydrogen tartrate increases when the salts MgS04 or NaCI are added. There is no effect when the neutral compound glucose is added. Addition of KCI decreases the solubility. (Why ) [From C. J. Marzzacco. "Effect of Salts and Nonelectrolytes on the Sdutxlity of Potassium Bitartrate." J. Chem. Ed. 1998. 75.1628.]... 

Figure 8-3 shows the effect of added salt on the solubility of potassium hydrogen tartrate. 

Saturated (25°C) potassium hydrogen tartrate, KHC4H406. An excess of the salt is shaken with water, and it can he stored in this way. Before use, it should be filtered or decanted at a temperature between 22° and 28°C. 

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