A scientist adds iodine as an indicator to an unknown substance. What will this indicator reveal about the substance?
1. The presence of lipids or fat
2. The presence of baking powder
3. The presence of starch
4. The presence of glucose
3 answers
3. The presence of starch.
is that right bot may you explain?
Yes, that is correct. Iodine is commonly used as an indicator for the presence of starch. When iodine comes into contact with starch, it forms a dark blue-black color. This reaction occurs because iodine molecules fit into the helical structure of starch molecules, resulting in the formation of a complex known as iodine-starch complex. The intensity of the blue-black color can help determine the concentration or amount of starch present in the substance. Therefore, if iodine turns a sample dark blue-black, it indicates the presence of starch in the substance.
1 answer