Osmosis experiments
Osmosis is the movement of water particles across
a semi-permeable membrane (partially permeable membrane PPM)
from an area of high water concentration to an area of low water concentration. You can demonstrate this effect with VISKING
TUBING, which is partially permeable membrane. It is
sometimes called dialysis tubing as it is used in
kidney dialysis machines. From the animation it can be seen
that water level in the glass tube begins to rise or fall because water either enters or leaves through the visking
tubing by osmosis. Remember: Potato
Slices It can be seen from the animation
that potato slices, in pure water, swell up as water
enters their cells by osmosis.
However, in concentrated
sugar solution the potato slices shrink as water
leaves their cells as a result of osmosis.
Experiments to demonstrate osmosis.
Test your understanding of the variables and results found in common osmosis experiments. 1. In the potato experiment, what must be done to the potato cylinders before weighing them at the end? 2. If a potato cylinder is placed in pure water, its mass will increase. Why? 3. Which of these is a controlled variable in the potato experiment? 4. What is the correct formula to calculate the percentage change in mass? 5. In a Visking tubing experiment, the tubing acts as a model for which part of the cell?🧪 Practical Lab Check: Osmosis
Reveal Lab Results & Answers
2. Water moves in (From a high water potential outside to a lower potential inside the cells).
3. Surface area and volume (These must be kept constant to ensure a fair test).
4. Option 1 (Change divided by start, then multiplied by 100).
5. The Cell Membrane (Both are partially permeable).
Tags:Osmosis, Movement of water particles, Semi-permeable membrane, Cells