Triiodide is a chemical compound consisting of three iodine atoms bonded together, represented by the formula I3⁻. It typically forms when iodine dissolves in a solution containing iodide ions, such as potassium iodide. Triiodide is often used in laboratory settings and has applications in various fields, including chemistry and medicine. In solution, triiodide appears as a deep brown color and is known for its role in iodine-based reactions. It is commonly used in iodometry, a quantitative analytical method to determine the concentration of certain substances. Triiodide also plays a role in the synthesis of iodine compounds and can be used as a disinfectant.