“Artificial snow” experiment
How to make snow from a baby diaper
In this experiment, we’ll show you how to make artificial snow at home!
You can touch artificial snow, but don’t eat it. Don’t forget to wash your hands after touching the artificial snow. Dry snow must be removed immediately.
Reagents and equipment:
- a diaper (sodium polyacrylate);
- glass container.
Cut the diaper and take the absorbent substance out of it. This substance is sodium polyacrylate. Then pour water on to the powder. The volume increases considerably. You can sprinkle the snow you’ve made on Christmas decorations.
Sodium polyacrylate is a sodium salt of polyacrylic acid. Its molecules are very long, consisting of identical repeating fragments containing charged groups. Sodium polyacrylate is a very hygroscopic substance, i.e. it likes to absorb water. One of the main properties of the compound is the ability to absorb liquid of 200-300 times its own mass. So it instantly absorbs water and swells up immensely, forming flakes that resemble snow. Why does this happen? The water molecules enter between the chains into the granules of sodium polyacrylate.
Thus, the total volume of granules increases by the volume of water that enters them. Each chain of polyacrylate that is “soaked” in this manner unravels. However, the water in this experiment is not sufficient for all of them, and goes inside each granule. So “dry” chains remain on the outside. From inner expansion, air comes between them, and the total volume increases. If there is too much water, the granules become soggy, stick together and turn into gel–a semi-transparent viscous mass which has a very similar consistency to jelly or aspic.