Question

In the experiment to test the presence starch , why is the leaf dipped in alcohol not heated directly?

Answer 1

Answer:

he green leaf is boiled in alcohol not directly heated on flame during the testing for starch. This is because heating the green leaf directly on the flame, or boiling it in water will kill the leaf as the direct heat will damage the cells of the leaf

Explanation:

Answer 2

Answer:

We boil the leaf in alcohol when we are testing it for starch because to remove the green pigment chlorophyll present in it. For the starch test, we need to observe the colour change from brown to blue when iodine is put on the leaf. But, initially the leaf is green in colour which does not show the required observation. Hence to remove the green pigment present in the leaf we boil the leaf in alcohol when we are testing it for starch.