Final answer:
The addition of I₂KI to starch results in a blue-violet color due to the formation of a complex between amylose in starch and iodine.
Step-by-step explanation:
When I₂KI is added to starch, a distinctive blue-violet color is produced. This occurs as a result of the amylose in starch forming a complex with the iodine present in I₂KI. Amylose is a coiled polymer that provides just enough space within its helical structure to accommodate an iodine molecule, resulting in the blue-violet coloration which indicates the presence of starch. This chemical reaction is sensitive enough to detect even minute amounts of starch in a solution.