When performing a scientific investigation on an unknown substance, how can an indicator help you determine if the substance is a starch?

1 answer

An indicator can help determine if a substance is a starch by changing color or producing a visible reaction when it comes into contact with starch molecules.

Iodine is a common indicator used to test for the presence of starch. In the presence of starch, iodine undergoes a chemical reaction that forms a blue-black complex. If a substance turns blue-black when iodine is added, it suggests that the substance contains starch. However, it is important to note that some other substances, such as cellulose, can also produce a blue-black color with iodine. Therefore, it is necessary to corroborate the results with further tests to confirm if the substance indeed contains starch.