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Transcript of Snow
The two parts of this experiment are Sodium Polyacrylate and H20, otherwise known as water.
When the sodium polyacrylate is first immersed in water, there is a higher concentration of water outside the polymer.
When salts of sodium or calcium are added to the sodium polyacrylate and water it reverses the swelling process.
When the salt comes in contact with the water there is a tendency for the salt to distribute equally between the sodium polyacrylate and the water. That means some of the sodium atoms want to leave the polyacrylate and move to the water.
Physical Change, NOT Chemical
What is Sodium Polyacrylate?
A polymer that has many chemical structures that naturally attract water molecules.
These structures form hydrogen bonds that attract both the oxygen and the hydrogen part of water.
The chemical formula is [-CH2-CH(COONa)-]
If you don't know this, leave. The door is that way.
Sodium Polyacrylate can absorb up to 800 times its own weight in distilled water! However, it can only hold up to 300 times in tap water because it contains minerals.
How it works, Part 3.
a process where molecules tend to pass through a semipermeable membrane which lets only certain substances pass through. The molecules move from a less concentrated solution into a more concentrated one; equalizing the groups on each side of the membrane
When water approaches the sodium polyacrylate molecule, it is drawn to the center of the molecule by
How does it work?
What is H2O?
How does it work, Part 2.
Sodium Polyacrylate added with water is an example of a physical change, not a chemical change so there are no products or reactants.
It can be reversed upon adding a compound such as salt to the mix.
In this experiment, we will be creating a gel-like substance that resembles snow. In our beaker there will be approximately 1 tbsp of sodium polyacrylate powder. When water is added at a quick speed, the sodium polyacrylate's ionic groups (along the length of the polymer) allow it to absorb large quantities of water.
When this happens water is no longer needed inside the polyacrylate to balance the salt concentration. This causes the polyacrylate to separate from the water.