Question

why did each of the solution turn blue/black at the start of every experiment?

Answer 1

Answer:

Here is your answer..

Explanation:

A sample is removed from the test tubes every 10 seconds to test for the presence of starch. Iodine solution will turn a blue/black colour when starch is present, so when all the starch is broken down, a blue-black colour is no longer produced.

Hope it will help :)

Answer 2

Answer:

A sample is removed from the test tubes every 10 seconds to test for the presence of starch. Iodine solution will turn a blue/black colour when starch is present, so when all the starch is broken down, a blue-black colour is no longer produced.