which chemical can be used to test for the presence of starch?

The chemical used to test for the presence of starch is iodine solution (iodine in potassium iodide solution).

Quick Scoop

• A few drops of iodine solution are added to the sample.

• If starch is present, the sample turns blue‑black or purple‑black.

• If there is no starch, the iodine stays yellow‑brown.

Tiny example

If you drop iodine solution on a piece of potato or bread, the area with starch will quickly turn blue‑black, showing a positive test for starch.

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