Question

how will you test a leaf for starch?Mention any precaution you will take.

Answer 1

First we will heat a plant leaf in boiling water for 30 seconds (this stops its chemical reactions) heat it in boiling ethanol for a few minutes (this removes most of its colour) wash with water and spread onto a white tile. add iodine solution from a dropper. If it turns blue black it shows that it containsstarch.

Answer 2

1) put the leaf in boiling water. 2) decolourise leaf by soaking in alcohol 3) finally apply iodine solution over the leaf . Result : the appearance of blue colour in the leaf