Question

What does I2 means which is given in ncert in polysaccharides section?

Answer 1

Here I2 is iodine molecule.
Starch eacts with Iodine because of its helical structure tat can hold iodine molecules,
but cellulose does not. Iodine test is done on food, for starch detection. So if the food contains starch , it will react with iodine and produce a blue colour.