- a colorless or white, water-soluble solid, KNaC4H4O6⋅4H2O, used in silvering mirrors, in the manufacture of Seidlitz powders and baking powder, and in medicine as a laxative.
- a white crystalline double salt, sodium potassium tartrate, used in Seidlitz powder. Formula: KNaC 4 H 4 O 6 .4H 2 O
