Potassium Stannifluoride, K₂SnF₆

Potassium Stannifluoride, K₂SnF₆.H₂O, is obtained similarly to the sodium salt, or by adding potassium fluoride solution to stannic chloride. It is known in two forms, in octahedra and in leaflets. The former is the less soluble and more stable form at ordinary temperature; both forms are much more soluble in hot than in cold water. Hydrofluoric acid is evolved when this compound is treated with concentrated sulphuric acid.

The salts K₂SnF₆.KF.HF and K₂SnF₆.KF.3HF have been obtained by employing excess of hydrofluoric acid.