Did you urgently need to weld paste, and you remembered that somewhere in a case there was a starch? But on shelves it was found - what to take several packages of white powder? It is possible to find out it in the chemical way. Substance, suitable for starch definition, for certain is in your house first-aid kit.
It is required to you
- Spirit solution of iodine
- Pipette
- Saucer or glass socket
- Concept of a reaktia and indicator
Instruction
1. Carefully open a package of white powder. Take him a spoon and put on a saucer or in a chemical test tube. In this case it is unimportant whether moisture will get to a test tube, but in general ware has to be dry.
2. The clean and dry pipette gather a droplet of spirit solution of iodine. Drip iodine on white powder. If powder contains starch, then powder from white will become dark blue or even violet, depending on concentration of iodine. Starch and iodine always react at each other in this way therefore write in textbooks of chemistry that iodine is rekativy on starch presence, and starch — an iodine presence indiaktor.
3. Among other things, experience with starch and iodine - a great way to interest in chemistry of children. Check in what food there is a starch. For a house experiment with children it is possible to take, for example, potato, apple, a piece of a grain crumb. Potato or apple need to be cut previously, and to make a lump of a grain crumb. To define in what product of starch most of all. It is simple to find out it if to take iodine of the same concentration. It is more starch where blue color will be more intensive.