Osmosis Flashcards
What is osmosis
The movement of water molecules across a partially permeable membrane from an area of high water concentration to a an area of low water concentration
What is a partially permeable membrane
Membrane with small holes in it. E.g: only water can pass
What is meant by net movement
Because there are more water molecules on one side than the other, there’s a steady net flow of water into the area with fewer water molecules
How can you test osmosis
Cut up potato into identical cylinders, get beakers with different sugar solutions, one pure water and another should be very concentrated sugar solution
Measure the mass of the cylinders, leave in beaker for 24 hours
Take them out, dry them with a paper towel and measure their masses
If they have drawn in water there will be an increase in mass
If water has been drawn out there will be a decrease in mass
Calculate percentage change in mass and plot a graph
The dependent variable is the chip mass and the independent variable is the concentration of the sugar solution. All other variables must be the same for it to be a fair test
You can reduce the effect of these errors by repeating the experiment and calculating a mean
