What happens if the amount of solute in one compartment is changed relative to the other? Fluctuating volumes and effective Molar concentrations for each compartment are depicted numerically across the top of the simulation. Use the mouse and the pull-down bar at the right to change the solute number in the right-hand compartment from 10 to 5 particles and describe what happens. (This experiment may take as much as 30 minutes to reach equilibrium!) Does the membrane ever return to its original location? How about a change from 10 to 20? And then from 20 to 5? Repeat these experiments several times to obtain a statistical sample (or better still, pool your data with those of your classmates and analyze the average values).

Is there a pattern to the results you obtained from these changes? If there is, how would you express the pattern? Go on to the next page to check your answer and to further explore this phenomenon.