Question

A leaf is boiled in alcohol before using iodine for a starch test in order to-

• A. Dissolve starch
• B. Dissolve chlorophyll
• C. Soften the leaf
• D. Make it react with iodine

Answer 1

The correct option is B

Dissolve chlorophyll

The correct option is B:

Explanation of the correct option:

1. When testing for starch, we boil the leaf in alcohol to remove the green pigment chlorophyll from it.
2. When iodine is applied to the leaf, the color changes from brown to blue.
3. This is the starch test.
4. As a result, a leaf is cooked in alcohol before being decolored with iodine for a starch test.

Explanation of the incorrect option:

Option A:

The leaf is boiled in alcohol to decolorize it to do a starch test.

Option C:

The main purpose is to decolorize the leaf to observe the color change.

Option D:

The leaf is boiled to observe the color change when iodine is added.

Final Answer: A leaf is boiled in alcohol before using iodine for a starch test in order to-Dissolve chlorophyll.