Potassium sodium tartrate

Potassium sodium tartrate

Chembox new
Name = Potassium sodium tartrate
ImageFile = K-Na-L-(+)-tartrate.png ImageSize = 200px
ImageName = Potassium sodium tartrate
IUPACName = Potassium sodium tartrate
OtherNames = E337
Section1 = Chembox Identifiers
CASNo = 304-59-6
EINECS = 206-156-8

Section2 = Chembox Properties
Formula = KNaC4H4O6·4H2O
MolarMass = 282.1 g/mol
MeltingPt = 75 °C
BoilingPt = 220 °C

Potassium sodium tartrate is a double salt first prepared (in about 1675) by an apothecary, Pierre Seignette, of La Rochelle, France. As a result the salt was known as Seignette's salt or Rochelle salt.Rochelle salt is not to be confused with rock salt, which is simply the mineral form of sodium chloride.

It is a colorless to blue-white salt crystallizing in the orthorhombic system. Its molecular formula is KNaC4H4O6·4H2O. It is slightly soluble in alcohol but more completely soluble in water. It has a specific gravity of about 1.79, a melting point of approximately 75 °C, and has a saline, cooling taste. As a food additive, its E number is E337.

It has been used medicinally as a purgative but in more recent years its piezoelectric properties have been more important and it has found usage in phonograph pickups and other sensing devices. It has also been used in the process of silvering mirrors. It is an ingredient of Fehling's solution, formerly used in the determination of reducing sugars in solutions.

In organic synthesis, it is used in aqueous workups to break up emulsions, particularly for reactions in which an aluminum-based hydride reagent was used.

It is also an ingredient in the Biuret reagent which is used to measure protein concentration.


Rochelle salt (potassium sodium tartrate, NaKC4H4O6) can easily be prepared from potassium bitartrate (KHC4H4O6) and sodium carbonate (Na2CO3). First heat a potassium bitartrate solution. Add sodium carbonate to the still hot solution in a 1:0.5 (KHC4H4O6 : Na2CO3) mole ratio (Effervescence of carbon dioxide is observed). Filter the solution while hot and then heat to dryness. The precipitate is potassium sodium tartrate, which can be recrystallised.


Wikimedia Foundation. 2010.

Look at other dictionaries:

  • potassium sodium tartrate — n ROCHELLE SALT * * * [USP] a compound, C4H4KNaO6·4H2O; used as a cathartic. Called also Preston salt and Rochelle salt …   Medical dictionary

  • potassium sodium tartrate — noun a double salt used in Seidlitz powder; acts as a cathartic • Syn: ↑Rochelle salt, ↑Rochelle salts • Hypernyms: ↑double salt * * * noun : rochelle salt * * * Chem. See …   Useful english dictionary

  • potassium sodium tartrate — Chem. See Rochelle salt. * * * …   Universalium

  • Tartrate de potassium-sodium — Sel de Seignette Sel de Seignette Général Nom IUPAC Tartrate de potassium et de sodium …   Wikipédia en Français

  • antimony sodium tartrate — [USP] a trivalent antimony compound having the same actions and uses as the potassium tartrate but more water soluble and less irritant when injected; now rarely used because of its toxicity …   Medical dictionary

  • Potassium — (pronEng|pəˈtæsiəm) is a chemical element. It has the symbol K ( la. kalium, from ar. qalīy), atomic number 19, and atomic mass 39.0983. The name potassium comes from the word potash , as potassium was first isolated from potash. Potassium is a… …   Wikipedia

  • Potassium tartrate — IUPAC name Dipotassium 2,3 dihydroxybutanedioate …   Wikipedia

  • Tartrate — A tartrate is a salt or ester of the organic compound tartaric acid, a dicarboxylic acid. Its formula is O−OC CH(OH) CH(OH) COO− or C4H4O62−.As food additives, tartrates are used as antioxidants. Examples are: * sodium tartrates (E335) **… …   Wikipedia

  • Potassium bitartrate — Not to be confused with Tartar sauce. Potassium bitartrate Other names potassium hydrogen tartrate …   Wikipedia

  • Tartrate double de sodium et de potassium — Sel de Seignette Sel de Seignette Général Nom IUPAC Tartrate de potassium et de sodium …   Wikipédia en Français

Share the article and excerpts

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

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.