What color does iodine turn into if starch is present?
Black. I think.
If it is fresh starch solution and the iodine is not too concentrated, the solution turns blue. Higher concns of iodine produces such a dark color it is essentially black.
When iodine comes into contact with starch, it forms a dark blue or black color. This color change is commonly used as a test to detect the presence of starch in substances. If you are trying to observe this reaction yourself, here's how you can do it:
Materials needed:
- Iodine solution
- Starch solution or starch-containing substance (e.g., potato, bread, rice)
- Test tubes or small containers
- Pipettes or droppers
Steps:
1. Prepare the iodine solution: If you don't have iodine solution readily available, you can make it by dissolving iodine crystals in distilled water until you get a deep brown solution.
2. Prepare the starch solution or obtain a starch-containing substance: Starch solution can be made by dissolving starch powder in distilled water. If you are using starch-containing substances like a potato, bread, or rice, you can extract starch from them by grinding them in water and filtering out the solids.
3. Set up the experiment: Take several test tubes or small containers and label them for each substance you want to test. For example, label one "Water," another "Starch Solution," and others based on the substances you want to test.
4. Add the substances: Fill each tube or container with a small and equal amount of the substance you want to test. For the "Water" tube, add only distilled water.
5. Perform the test: Using a dropper or pipette, carefully add a few drops of the iodine solution to each test tube or container.
6. Observe the color change: Watch for any visible color change that occurs in the presence of starch. Starch will result in the solution turning a dark blue or black color, while substances without starch will retain the brownish color of iodine.
Remember, this experiment involves using chemicals and should be done under appropriate supervision and adherence to safety precautions.