Question

how will you test the presence of starch

Answer 1

Buy some iodine solution from a dealer of laboratory chemicals. Put a few drops into such a thing as rice, bread, potato, tapioca etc. In the case of fruits, remove their skin and do thetest. The presence of starch is indicated if the solution turns dark blue.....

Answer 2

if we put a few drops of iodine, a blue black colour is found