Potassium sodium tartrate
Potassium sodium tartrate aka Rochelle salt
| IUPAC name
Sodium potassium L(+)-tartrate tetrahydrate
| Other names
|Molar mass||282.1 g/mol|
|Appearance||Large colorless monoclinic needles|
|Melting point||75 °C (167 °F; 348 K)|
|Boiling point||220 °C (428 °F; 493 K) (decomposes)|
| 26 g/100 ml (0 °C)|
47.4 g/100 ml (6 °C)
66 g/100 ml (26 °C)
|Solubility||Insoluble in acetone, ethanol|
|Vapor pressure||~0 mmHg|
|Safety data sheet||Sigma-Aldrich (tetrahydrate)|
| Tartaric acid|
Potassium antimony tartrate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Potassium sodium tartrate (tetrahydrate), more commonly known as Rochelle Salt, is a double salt of tartaric acid first prepared (around 1675) by an apothecary, Pierre Seignette, of La Rochelle, France.
Addition of a strong acid, like hydrochloric acid will give tartaric acid.
Potassium sodium tartrate is a white crystalline solid, soluble in water.
- Potassium Sodium Tartrate is used in the preparation of Biuret reagent.
- Potassium Sodium Tartrate is used in the the preparation of Fehling's Solution
- Potassium Sodium Tartrate is used in "crystal" microphones.
- Potassium Sodium Tartrate is used as an alkaline buffer.
- Potassium Sodium Tartrate has been used as a laxative.
Potassium sodium tartrate is readily available on EBay.
Can be prepared from tartaric acid.
Can be irritating to skin.
Potassium sodium tartrate is very deliquescent and should be stored in a sealed container.
Dissolve in large excess of water and put down drain.