Used primarily in iodometric titrations to detect the presence of free iodine. The solution forms a deep blue complex when iodine is present, making it highly effective for visual endpoint detection in redox titrations involving iodine and thiosulfate. Commonly applied in water quality testing to determine residual chlorine, where iodine is liberated proportionally to chlorine content. Also utilized in educational labs to demonstrate chemical reactions involving starch and iodine, such as enzyme activity (e.g., amylase breaking down starch, causing the blue color to disappear). Its sensitivity allows detection even at low iodine concentrations, providing a simple and reliable method for qualitative and semi-quantitative analysis.