Iodine is often referred to as an indicator because it is commonly used in chemistry to detect the presence of starch in a solution. When iodine is mixed with starch, it forms a deep blue complex, signaling a positive reaction.
The reason iodine is effective as an indicator is due to its ability to bind to the helical structure of the starch molecules. This interaction alters the electronic structure of the iodine, resulting in the characteristic blue color. The simplicity and clarity of this color change make iodine a reliable tool for scientists and students alike when conducting experiments that involve starch.
Moreover, iodine’s role as an indicator extends beyond just starch detection; it can also demonstrate the presence of certain other substances under specific conditions, adding to its utility in various chemical tests and experiments.