Question

how do you prove that carbon dioxide is necessary for photosynthesis by mohi's half leaf experiment​

Answer 1

Lime water absorbs carbon dioxide and hence there is no carbon dioxide for the leaf and hence photosynthesis does not take place and no starch is prepared. Hence on iodine test, the presence of starch is negative and thus proves that carbon dioxide is required for photosynthesis.

Answer 2

Explanation:

we need a destarched potted plant .To do this we need keep a plant in a dark room for nearly 3 days. Put KOH(potassium hydroxide) pallets or KOH solution in bottle .KOH absorbs Carbon insert splitted cork in the mouth of the bottle . Insert one of the leaf of destarched plant through a split cork into transparent bottle containing KOH pellets or KOH solution .Leave the plant .in sunlight.After a few hours test the leaf with iodine / betadine solution .The part which is exposed to atomspheric air and sun light turns into bluish black and the one which is inside the bottle containing KOH remains colourless.