It is possible to present a situation in which before the person there are several containers with colloidal solutions of starch, a karbometiltsellyuloza, pectin or an agar indistinguishable from each other. Remember a school course of chemistry. One of high-quality reactions of starch and only which yields visible result is a coloring in blue color in interaction with iodine. Two other high-quality reactions just do not give expected the effect characteristic of carbohydrates in general. Respectively, it is more logical and simpler to use iodine.
It is required to you
- Pharmaceutical iodine, water, starch, glass capacity, pan/stewpan
Instruction
1. Prepare weak solution of iodine in separate glass capacity. For this purpose it is enough to take pharmaceutical iodine and to dilute it with water.
2. Prepare starched paste - colloidal solution of starch in water. Take two teaspoons of starch, and a glass of cold water. A little cold water (about one third of a glass) mix in to pan with starch. Boil the rest of water. Well stir mix, starched milk will turn out. When hashing add to it boiled water and, continuing to stir, heat on fire until solution does not become transparent. Cool it. It is also starched paste which so well sticks together paper therefore it is often applied, for example, to gluing of wall-paper.
3. Drip a little solution of iodine in ready starched paste. In the place of contact of solution and paste blue color will appear. If concentration of iodine is very high, you receive color from violet to black.