Potassium Sodium L-Tartrate Tetrahydrate 99%
Potassium sodium tartrate tetrahydrate, also known as Rochelle salt, is a double salt of tartaric acid. Potassium sodium tartrate and monopotassium phosphate were the first materials discovered to exhibit piezoelectricity.[3]This property led to its extensive use in "crystal" gramophone (phono) pick-ups, microphones and earpieces during the post-World War II consumer electronics boom of the mid-20th Century. Such transducers had an exceptionally high output with typical pick-up cartridge outputs as much as 2 volts or more. Rochelle salt is deliquescent so any transducers based on the material deteriorated if stored in damp conditions.
KNaC4H4O6·4H2O | |
Molar mass | 282.1 g/mol |
Appearance | large colorless monoclinic needles |
Odor | odorless |
Density | 1.79 g/cm³ |
Melting point | 75 °C (167 °F; 348 K) |
Boiling point | 220 °C (428 °F; 493 K) anhydrous at 130 ℃; decomposes at 220 ℃ |
26 g / 100 mL (0 ℃); 66 g / 100 mL (26 ℃) | |
Solubility in ethanol | insoluble |