Question

Which solution is used to test the presence of starch?

• A. Iodine
• B. Safranin
• C. Eosin
• D. Methylene blue

Hint:

A blue-black colour confirms starch; no colour change means no starch.

Answer 1

The Correct Option is A

Step 1: Test.
Iodine solution turns blue-black in presence of starch due to formation of a starch–iodine complex.
Step 2: Others.
Safranin, eosin, and methylene blue are general stains, not specific starch indicators.
Step 3: Conclusion.
Therefore, iodine is used to test starch.