Potassium Iodide, Ki

a salt; colorless crystals. Density, 3.115 g/cm³; melting point, 686°C. Solubility, 144.5 g per 100 g H₂O at 20°C (209 g at 100°C).

Atmospheric oxygen oxidizes potassium iodide in the presence of light, precipitating iodine. Potassium iodide is obtained by the reaction of aqueous solutions of FeI₂ and K₂C0₃. Potassium iodide is used in the preparation of light-sensitive photographic materials and in medicine.