Potassium Iodide is known as Potassium Salt of Hydriodic Acid [HI], available in white crystalline powder form. It is an inorganic compound and has Molecular Formula KI. Its Ionic form is K+ I-, and iodide ion being mild reducing agent, it can be easily oxidized to Iodine by powerful oxidizing agent like chlorine. With elemental iodine it forms I3 (tri iodide), the salts of tri iodide are highly water soluble. On long exposure to air Potassium Iodide becomes yellow due to liberation of Iodine.