what is the positive way of starch
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Answer:
Explanation:
If you are testing to see if starch is present, then a positive test means it is present.
You will use iodine to test if starch is present. More specifically, you will use a solution of I2 in KI. In this solution, the tri-iodide ion forms. When this is added to something containing starch, the tri-iodide ion slips inside helical starch molecules, and this complex absorbs most of the light, turning dark blue-black.
So a positive test will be seen by a dark colour appearing.
This test can be reversed, if you need to detect iodine. Starch is used to detect iodine, giving the same dark colour.