Osmosis is the diffusion of water from a dilute solution to a concentrated solution through a partially permeable membrane
Water may move across cell membranes via osmosis
Osmosis is the passive movement of water particles from an area of high water concentration to an area of low water concentration
During osmosis water particles pass through both ways but the net movement flows to the more concentrated solution
Osmosis practical
Cut a potatoes into identical cylinders
Measure the mass of the potatoes
Place one in pure water and another in a concentrated sugar solution (1 mol/dm3) and have a few concentrations between and leave for 24 hours
The the potatoes out and dry with a paper towel and measure the masses
Osmosis practical
If the mass of the potato decreased that means that water has been drawn out meaning that the sugar solution was more concentrated than the potatoes sugar levels
Osmosis practical
If the mass of the potato increased that means that water has been taken in meaning that the sugar solution was less concentrated than the potatoes sugar levels
Osmosis practical
Errors could occur if the potatoes were not fully dried and the excess gave a higher mass, or if water evaporated from the beakers changing the concentration of the sugar solution
The results could be more accurate by repeating the experiment and calculating the mean percentage change of weight