Potassium iodide (CAS 7681-11-0)

Potassium iodide (KI) is an inorganic compound that is commonly used in various non-medical and non-pharmaceutical applications due to its chemical properties and reactions. As a stable source of iodide ions, potassium iodide is frequently utilized in analytical chemistry for the quantitative and qualitative analysis of various compounds. In particular, it is employed in the iodometric titration method, where it acts as a reducing agent. In this context, KI reacts with iodine to form triiodide ions, which are then titrated against a solution of sodium thiosulfate to measure the concentration of oxidizing agents in a sample. This method is widely used to determine the concentrations of substances like copper, chlorine, and hydrogen peroxide. Additionally, potassium iodide finds application in the synthesis of silver iodide in photographic films through its reaction with silver nitrate, which is crucial for the formation of light-sensitive silver halide crystals in photographic emulsions. In the field of environmental science, KI is used to measure ozone levels in the atmosphere; when ozone reacts with a potassium iodide solution, iodine is liberated, and its concentration can be measured to infer ozone levels. Furthermore, potassium iodide serves as a fluorescence quenching agent in molecular biology research, providing insights into the properties and behaviors of various biomolecules. Through these diverse roles, potassium iodide proves to be a versatile reagent in scientific research, contributing valuable analytical and synthesis capabilities across multiple disciplines.