Lugol solution (Potassium triiodide)

Potassium triiodide is a chemical compound with the formula KI3. It consists of potassium ions (K⁺) and triiodide ions (I3⁻). The triiodide ion is formed when iodine (I2) interacts with potassium iodide (KI), resulting in the formation of a complex ion that consists of three iodine atoms.

Properties
Appearance: Potassium triiodide typically appears as a dark purple or black solid.
Solubility: It is soluble in water, where it can dissociate into potassium ions and triiodide ions.
Uses: Potassium triiodide is often used as a source of iodine in various applications, including antiseptics, dietary supplements, and chemical synthesis. It is also used in laboratories for iodine staining in biological samples.
Formation
The triiodide ion can be formed by dissolving iodine in a solution of potassium iodide. The reaction can be represented as:

Safety
As with any chemical, potassium triiodide should be handled with care. Iodine can be irritating to the skin and mucous membranes, and appropriate safety precautions should be taken when handling the compound.