1. Osmosis (Adapted from a lecture by Eve Oram; www. mrothery. co
Osmosis (Adapted from a lecture by Eve Oram;
Osmosis is the NET movement of water molecules across a partially-permeable (selectively-permeable) membrane.
Water molecules move randomly with a certain amount of kinetic energy….

2. Distilled water separated by a partially-permeable membrane
Water molecules are randomly moving
from one side of the membrane to the
other, but there is NO NET OSMOSIS.

3. Osmotic Potential – the potential that water
Osmotic Potential – the potential that water molecules have to move Distilled (or pure) water has the highest potential (zero). When water has another substance dissolved in it, water molecules have less potential to move because they are attracted to the substance. Thus, the osmotic potential becomes negative.

4. If a substance is dissolved in the water, the kinetic energy of the water is lowered.
This is because some water molecules will
aggregate on the surfaces of the molecules
of the dissolved substance.

5. Water molecules move from higher to lower water potential
Net movement stops
when the system is
again in equilibrium.
Random motion
continues as before.