Osmosis is the diffusion of water across a semipermeable membrane. The water moves from an area of higher to lower solvent concentration (an area of lower to higher solute concentration). It's an important passive transport process in living organisms, with applications to chemistry and other sciences. You don't need fancy lab equipment to observe osmosis. You can experiment with the phenomenon using gummy bears and water. Here's what you do:
Osmosis Experiment Materials
Basically, all you need for this chemistry project are colored candies and water:
- Gummy bear candies (or other gummy candy)
- Plate or shallow bowl
The gelatin of the gummy candies acts as a semipermeable membrane. Water can enter the candy, but it's much harder for sugar and coloring to leave exit it.
What You Do
It's easy! Simply place one or more of the candies in the dish and pour in some water. Over time, water will enter the candies, swelling them. Compare the size and "squishiness" of these candies with how they looked before. Notice the colors of the gummy bears starts to appear lighter. This is because the pigment molecules (solute molecules) are being diluted by the water (solvent molecules) as the process progresses.
What do you think would happen if you used a different solvent, such as milk or honey, that already contains some solute molecules? Make a prediction, then try it and see.
How do you think osmosis in a gelatin dessert compares with osmosis in candy? Again, make a prediction and then test it!