Osmosis Experiment: Understanding Water Movement in Potato Cups

Osmosis is the diffusion of water through a semipermeable membrane down its concentration gradient. In the given experiment, water gathers in the hollowed portion of cups B and C because sugar and salt, respectively, create a higher solute concentration inside the cups compared to the water outside.

Potato cup A is necessary for this experiment because it serves as a control to compare the effects of solutes on water movement. By leaving cup A empty, we can observe the natural movement of water without any added solutes, allowing us to understand the impact of sugar and salt on osmosis.

Water does not gather in the hollowed out portions of cups A and D because there are no solutes present to create a concentration gradient. Without the presence of sugar or salt, there is no higher solute concentration to drive water movement into the potato cups.

Understanding osmosis through this experiment helps demonstrate the importance of solute concentrations in water movement and the role of control experiments in scientific research.