Potassium sodium tartrate

Description

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. Potassium sodium tartrate and mono potassium phosphate were the first materials discovered to exhibit piezo electricity.
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 laxative. 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.

Chemical properties

often supplied as a colourless aqueous solution

The Uses of Potassium sodium tartrate

Potassium Sodium Tartrate Solution is a chelator used for research purposes.

The Uses of Potassium sodium tartrate

Laxative.

The Uses of Potassium sodium tartrate

Sodium Potassium Tartrate is a buffer and sequestrant that is the salt of i, (+)–tartaric acid. It has a solubility in water of 1 g in 1 ml. It is also termed rochelle salt and potassium sodium tartrate.

What are the applications of Application

Potassium sodium tartrate solution is a chelator used for research purposes

Definition

ChEBI: The organic sodium and potassium salt of L-tartaric acid (mol ratio 1:1:1).

Preparation

Potassium sodium tartrate, (KNaC₄H₄O₆) may be prepared by adding 0.5 mole sodium carbonate to heated solution containing 1 mole potassium bitartrate(KHC₄H₅O₆). (1M KHC₄H₄O₆ : 0.5M Na₂CO₃). The solution is filtered while hot. This solution is then dried to precipitate solid potassium sodium tartrate, as small crystallites.
Larger crystals of Rochelle salt have been grown under conditions of reduced gravity and convection on board Skylab .

Flammability and Explosibility

Not classified

Purification Methods

Recrystallise it from distilled water (1.5mL/g) by cooling to 0o. [Beilstein 3 IV 1223.]