Practice Question

1.Define the term osmosis

Osmosis is the diffusion of water molecules from a dilute solution to a concentrated solution through a partially permeable membrane.

2. Explain what is meant by a partially permable membrane

Partially permeable membrane has holes that are large enough to let the water molecules pass, but too small to let the solute molecules pass.

3. Explain the difference between a dilute solution and a concentrated solution

A dilute solution has a high concentration of water and a low concentration of solute

A concentrated solution has a low concentration of water, high concentration of solute.

4. A piece of potato is placed into salty water. After 1 hour it has shrunk is size. Explain why.

The potato cells will contain a dilute solution, whilst the salty water will be a concentrated solution. Water moves by osmosis from the potato cells into the solution. As a result the potato cells will become plasmolysed and the piece of potato will shrink in size.