The Effect of Solute Concentration on Osmosis in Potatoes

The Effect of Solute Concentration on Osmosis in Potatoes

AIM: to find out the effect of solute concentration on osmosis in

potatoes. This is to find the equivalent osmotic potential. [IMAGE]

PREDICTION: Osmosis is the movement of water particles from a high

concentration to a low concentration through a partially permeable

membrane. Osmosis happens when a partially permeable membrane allows

small water particles to pass in or out towards a low water

concentration. To reach an equivalent osmotic potential the

concentration of water molecules has to be equal on either side of the

partially permeable membrane. This means there would be no mass

change. If you had a beaker of water that is distilled and filled a

visking tube with water and some salt the water molecules would move

through the visking tube with salt in. As in the visking tube it has a

lower concentration.

I predict that as the solute concentration increases the mass of the

potato will decrease. This is because the water particles move from a

high concentration to a low concentration. As the solute concentration

gets higher and the water concentration will get lower, therefore the

water particles will move out of the potato and in to the solution

outside because the concentration outside the potato is lower.

There fore the higher the solute concentration the more mass the

potato will lose.

SCIENTIFIC THEORY: Water molecules are in constant motion. As they

move they hit the membrane and create a pressure called the water

potential. Solutions with a low water potential have a high solute

(osmotic) potential. And solutions with a high water potential have a

low solute (osmotic) potential. Molecules of H2O (water) move by

osmosis until the concentration of H2O molecules is the same on each

side of the partially permeable membrane. This is the EQUIVALENT

OSMOTIC POTENTIAL.

Turgidity is when the water outside the cell has a higher H2O

concentration than the H2O inside the cell. Water enters the cell by

osmosis. A plant cells membrane is partially permeable.