Starch indicator is widely used in chemistry, particularly in titration experiments, to detect the presence of iodine. It forms a deep blue-black complex when iodine is present, making it a valuable tool in iodometric titrations. This property allows for precise determination of the endpoint in reactions involving iodine, such as the titration of thiosulfate with iodine. Additionally, it is employed in analytical chemistry to measure the concentration of oxidizing agents that liberate iodine. Its sensitivity and clear visual change make it a reliable choice for such applications.