Can iodine ions make starch blue

No, it's an iodine molecule.

This also starts with the structure of starch, which is a white amorphous powder composed of amylose (10-30%) and amylopectin (70-90%). Amylose can be soluble in hot water without being paste-like, and amylopectin is insoluble in water, and hot water expands into a paste when it interacts with it. Among them, amylose, which is dissolved in water, is in a curved form and is coiled into a helix shape by intramolecular hydrogen bonds.

At this time, an iodine molecule is added, in which the iodine molecule burrows into the void in the spiral and is linked to amylose with the help of van der Waals forces, thus forming a complex. This complex absorbs visible light (wavelength range 400-750 nm) in addition to blue light relatively evenly, resulting in a deep blue color of starch.

Iodine ions are not good, there must be a substance that turns iodine into elemental matter, such as F Cl br, which is more oxidizing than iodine

No. The starch molecule is wound with the iodine molecule to develop color.

The principle of starch turning blue when exposed to iodine is that starch reacts with iodine to form a kind of inclusion complex, which is generated by the inclusion of iodine molecules and hydroxyl groups exposed to amylosete spiroplasma, so that iodine molecules are embedded in the axial part of amyxospira.

The inclusion complex will exhibit different colors, and the color is related to the degree of polymerization or relative molecular weight of the starch. When the degree of polymerization of amylose is 200 980 or the relative molecular mass range is 32000 160000, the color of the inclusion complex is blue.

The principle of starch turning blue when exposed to iodine is that starch reacts with iodine to form clathrates. The inclusion complex is made by encapsulating an iodine molecule with a hydroxyl group with amylosete leponemal, so that the iodine molecule is embedded in the axis of the myxospira.

The inclusion complex will exhibit different colors, which is related to the degree of polymerization or relative molecular weight of the starch. When the degree of polymerization of amylose is 200 980 or the relative molecular weight range is 32000 160000, the color of the inclusion complex is blue.

The principle of iodine turning blue when it meets starch is that the amylose of starch is curled into a spiral with the help of hydrogen bonds within the molecule, and the iodine solution is added to form a complex, which can absorb other visible light except blue light relatively evenly. In addition, starch does not necessarily turn blue when exposed to iodine, different starch and iodine under the same conditions, the color of starch is unchanged, the greater the concentration of iodine, the darker the color, in the case of boiling, starch does not react with iodine, which is determined by the structural characteristics of starch itself.

Starch (C6H12O6)N belongs to the polysaccharide group, and when it encounters iodine, it reacts, and the resulting compound is blue, so we will see the above phenomenon.

In detail: starch is a polymer compound. The essence of the reaction between starch and iodine wine is to produce a inclusion complex (the iodine molecule is encapsulated in the helical structure of the starch molecule), and this new substance changes the color due to the change of light absorption properties.

Natural starch composition can be divided into two categories: amylose and amylopectin. Amylose accounts for about 10%-30%, the molecular weight is small, about 50,000, soluble in hot water (70-80) to form a colloidal solution.

Amylose and iodine wine appear blue, but the shorter amylose shows different colors such as red, brown or yellow, and amylopectin accounts for about 70%-90%, and the molecular weight is much larger than amylose, at about 60,000, insoluble in water, and amylopectin and iodine wine appear purple or purple-red. Some beans are almost all amylose, and they are blue when exposed to iodine; Glutinous rice is almost all amylopectin, and it is purple when exposed to iodine; Corn and potatoes contain % amylose respectively, so the color of potatoes with iodine is slightly darker than that of corn with iodine.

1. The reason why starch turns blue when exposed to iodine is due to the formation of a complex between starch molecules and iodine molecules, which has different effects on the reflection and absorption of light at different wavelengths, resulting in a blue appearance. It is not that one of the two substances changes color on its own, or that A changes color to B, but that both change color together, or that this change is the result of the combined action of the two substances.

2. Amylose, dissolved in water, is in a curved form and is coiled into a helix by intramolecular hydrogen bonds. At this time, iodine wine is added, in which the iodine molecule burrows into the void in the spiral and is linked to amylose with the help of van der Waals forces, thus forming a complex.