Question

How would you test the presence of slanch in leaves ?
please give answer​

Answer 1

Explanation:

The presence of starch in leaves can be tested by Iodine test. When we remove chlorophyll from leaf by boiling it in alcohol and then put 2 drops of iodine solution, its colour change to blue indicates the presence of starch.

Answer 2

Answer:

Iodine solution is used to test leaves for the presence of starch. You need to:

#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 dropping pipette

#After a few minutes, the parts of the leaf that contain starch turn blue-black.

Note that ethanol is heated using a hot water bath. Ethanol boils at 78°C, so a tube of it boils when placed in a beaker of hot water. This is safer than using a Bunsen burner because ethanol is flammable.