because the leaf doesnot contain starch in it
It change from orange/brown colour to blue/black if starch is present
Glycogen gives a red color with iodine due to the formation of a complex between iodine and the helical structure of glycogen. This complex results in a shift in the absorption spectrum of iodine, leading to the red color observed.
Amylodextrin gives a blue color with iodine because the presence of iodine causes a complex to form between the iodine molecules and the glucose units in amylodextrin. This complex is known as a starch-iodine complex, and it reflects blue light, resulting in the blue color observed.
Iodine
The color of iodine in the bottle is typically purple or brown.
The initial color of an iodine solution is yellow-brown.
Iodine
I stands for iodine. It is placed in group-17.
The starch solution will turn black, while the distilled water will remain brown, the same colour as the iodine. This is actually because water, normally used as a control, does not contain any starch and as we know, the iodine test is highly specific for the presence of starch hence no colour change other than iodine dissolving in water to form an iodine solution contrary to starch which we know complexes with iodine, to form starch-iodine complex forming the blue-black colour observed
it is a yellowish/orange colour but when iodine is present, than it will turn an dark-blue/black colour
Iodine test forms a complex with both starch and glycogen, resulting in a color change. This complex is responsible for the blue color observed with starch. However, glycogen has a more branched structure than starch, causing a different interaction with iodine that leads to a red color instead of blue.
Purple !! :) x