Osmosis Flashcards
(12 cards)
What is osmosis?
Osmosis is the movement of water molecules across a partially permeable membrane from a region of higher water concentration to a region of lower water concentration.
What is a partially permeable membrane?
A partially permeable membrane is one with very small holes that allow tiny molecules (like water) to pass through, but not bigger molecules (e.g. sucrose).
How do water molecules move during osmosis?
Water molecules pass both ways through the membrane during osmosis due to their random movement.
What happens to a strong sugar solution during osmosis?
The strong sugar solution gets more dilute as water moves into the region with fewer water molecules to even up the concentration.
What is the net movement of water molecules in osmosis?
Osmosis is a type of diffusion, which is the passive movement of water particles from an area of higher water concentration to an area of lower water concentration.
What is the practical experiment to observe osmosis?
Cut a potato into identical cylinders and place them in beakers with different sugar solutions, measuring their mass before and after 24 hours.
What should you measure before and after the osmosis experiment?
Measure the mass of the potato cylinders before and after leaving them in the sugar solutions.
What indicates that osmosis has occurred in the potato cylinders?
If the cylinders have drawn in water by osmosis, they’ll have increased in mass; if water has been drawn out, they’ll have decreased in mass.
What is the dependent and independent variable in the osmosis experiment?
The dependent variable is the chip mass and the independent variable is the concentration of the sugar solution.
How can errors affect the osmosis experiment?
Errors may occur if potato cylinders are not fully dried or if water evaporates from the beakers, affecting the sugar solution concentrations.
How can you reduce the effect of errors in the osmosis experiment?
Repeat the experiment and calculate a mean percentage change at each concentration.
What other solutions can be tested in the osmosis experiment?
You could carry out the experiment using different salt solutions and observe their effect on potato chip mass.
