What Is Potassium Iodide?
Potassium iodide, the potassium salt of hydroiodic acid, is widely utilized in various industries and pharmaceutical applications. It is produced industrially by reacting iodine with iron powder to form iron iodide, which is then treated with potassium carbonate. Recognized as a hazardous substance under safety laws, careful handling of potassium iodide is imperative.
Uses of Potassium Iodide
Its applications span from serving as a raw material for iodine compounds, a feed additive, and a nylon reinforcing agent, to uses in photographic emulsions, LCD polarizing films, and as a catalyst in chemical reactions. Medicinally, it’s employed in antifungal medications, expectorants, and for treating conditions like chronic arthritis and syphilis. Potassium iodide starch paper and its role in analytical chemistry further demonstrate its versatility.
Properties of Potassium Iodide
A colorless crystal in its solid state, potassium iodide (KI) has a molecular weight of 166.00, a density of 3.13 g/cm3, and exhibits high solubility in water, alcohol, and glycerin, but not in ether. It’s known for its deliquescent nature in moist environments and neutral to slightly alkaline aqueous solutions. Light and air can liberate iodine from potassium iodide, necessitating storage in airtight, light-resistant containers to prevent oxidation and discoloration.
Other Information on Potassium Iodide
1. Potassium Iodide as a Prophylactic Agent
In the aftermath of nuclear incidents, like the Fukushima disaster, potassium iodide has been adopted as a prophylactic agent against radioactive iodine exposure, effectively saturating the thyroid gland with stable iodine to block radioactive iodine absorption and mitigate radiation damage.
2. Application of Potassium Iodide
Beyond its medical and industrial uses, potassium iodide plays a crucial role in water treatment for measuring residual chlorine using the DPD method, and in analytical chemistry as a component of Nessler’s and Dragendorff’s reagents for detecting ammonia, tertiary amines, and alkaloids.