Potassium iodide is a chemical compound with the molecular formula KI. Its molar mass is approximately 166 grams per mole. It is a white crystalline solid, with a density of 3.123 grams per cubic centimeter, a melting point of 1,258 degrees Fahrenheit, and a boiling point of 2430 degrees Fahrenheit.
Potassium iodide is a weak reducing agent. It turns yellow when exposed to air due to oxidation. It is obtained industrially from the reaction of iodine with potassium hydroxide. Potassium iodide has a wide range of uses. It is used industrially to obtain silver iodide, as a fluorescence quenching agent and as a component in dye sensitized solar cells. It is used as a source of iodine in nutrition. It also has several medicinal uses, including as a remedy for radiation poisoning and hyperthyroidism.