Potassium hydrogen tartarate

The French have used anti-flash bags (sachets antilueurs) filled with the crude potassium hydrogen tartarate (about 70%... 

KHC4H4O6 (saturated solution at 25°) 3-56 Potassium hydrogen tartarate... 

CHjCOCOOH. A colourless liquid with an odour resembling that of ethanoic acid, m.p. 13 C, b.p. 65 C/lOmm. It is an intermediate in the breakdown of sugars to alcohol by yeast. Prepared by distilling tartaric acid with potassium hydrogen sulphate. Tends 10 polymerize to a solid (m.p. 92 C). Oxidized to oxalic acid or ethanoic acid. Reduced to ( + )-Iactic acid. 

Racemic acid, ( )-tartaric acid, is a compound of the two active forms. M.p. 273 C (with IHjO), m.p. 205°C (anhydrous). Less soluble in water than (-t-)-tartaric acid. Formed, together with mesotartaric acid, by boiling (4-)-tartaric acid with 30% NaOH solution, or by oxidation of fumaric acid. Potassium hydrogen racemate is very insoluble. 

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,... 

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. 

Cream of tartar potassium hydrogen tartrate KHC404H6... 

It can precipitate as potassium hydrogen tartrate (KHT) or as calcium tartrate (CaT), the latter being practically insoluble in aqueous solutions. Their equilibrium solubility varies with temperature, pH, and alcohol content, while the presence of a few wine components, such as polysaccharides and mannoproteins, may hinder spontaneous nucleation even if the solution is supersaturated. From Figure 14 that shows the equilibrium tartaric acid-dissociated fractions versus pH and ethanol volumetric fraction (Berta, 1993 Usseglio-Tomasset and Bosia, 1978), it can be seen that in the typical pH range (3 4) of wines KHT is predominant. As temperature is reduced from 20 to 0°C, KHT solubility in water or in a 12% (v/v) hydro-alcoholic solution reduces from 5.11 to 2.45 kg/m3 or from 2.75 to 1.1 kg/m3, respectively (Berta, 1993). Each of these data also varies with pH and reaches a minimum at the pH value associated with the maximum concentration of the hydrogen tartrate anions. For the above-mentioned solutions, the solubility minimum shifts from pH 3.57 to pH 3.73 as the ethanol content increases from 0 to 12% (v/v) (Berta, 1993). 

Sodium hexanitrocobaltate (III) (Na3[Co(N02)6]) Tartaric acid solution (sodium acetate buffered) Yellow precipitate of potassium hexanitrocobaltate (III) insoluble in acetic acid White precipitate of potassium hydrogen tartrate... 

This stereoisomer of tartaric acid is found in grapes, and its salt, potassium hydrogen tartrate, can precipitate out as crystals at the bottom of bottles of wine. It has two stereogenic centres, so you d expect 22 - 4 stereoisomers two diastereoisomers, each a pair of enantiomers. 

Tartaric acid solution (or sodium hydrogen tartrate solution) white crystalline precipitate of potassium hydrogen tartrate ... 

Potassium hydrogen tartrate cream of tartar), KHC4H4O6, is a constituent p grape juice sometimes crystals of the substance are formed in grape jelly. 

Potassium chloride, potassium hydroxide potassium carbonate potassium hydrogen tartrate (cream of tartar). 

The aldehydes R)-2A and (S)-24 are not stable as monomers and undergo racemization on storage. Derivative (R)-25 (2-0-benzylglyceraldehyde) has been proposed as an alternative to (R)-24. It is obtained from (5, 5 )-tartaric acid, as shown in Scheme 13.19 [48]. Enantiomer (S)-25 can be derived from (/, / )-tartaric acid in the same way. (R,R)-TartSLric acid is obtained in large quantities from potassium hydrogen tartrate, a waste product of wineries. Racemic tartaric acid is synthesized... 

---