Step 2: Verify Lugol’s Solution as an Indicator for the Presence of Starch

a) Label three test tubes “Water,” “Starch,” and “Glucose.” Add ten drops of water, ten drops of glucose solution, and ten drops of starch solution respectively.

b) Put ten drops of Lugol’s solution into each of the test tubes.

c) Gently swirl the contents of all three test tubes.

d) In your data table, record any color changes, which indicate that starch is present. (If the indicator solution works properly, only the test tube with the starch solution should show a change.) Keep these test tubes for reference during Step 5.