Question

why should we decolorize a leaf testing for starch.

Answer 1

Using forceps, remove the leaf from the boiling tube and rinse the leaf in cold water. k Put the leaf in a Petri dish on a white tile. l Add iodine solution to the leaf from the dropper bottle. ... A blue-black colour with iodine solution indicates that starch is present.

Answer 2

Answer:

Chlorophyll is a green pigment and so masks the colour change of the iodine test for starch. Chlorophyll needs to be removed from the leaf i.e. the leaf needs to be ' decolourized' for changes to be observed.