Examine Figure 41

Question

Examine Figure 41.1. Which of the following BEST describes conditions at equilibrium? 
A)No water molecules are moving across the barrier between the two compartments. 
B)A net movement of water molecules continues to add water to the right-hand compartment. 
C)A net movement of water molecules begins to add water to the left-hand compartment. 
D)Water molecules move randomly across the barrier with no net addition of water to either side. 
E)None of the answer options is correct.

Accepted Answer

At equilibrium, the concentration of water molecules is the same on both sides of the barrier. However, this does not mean that there is no movement of water molecules. Instead, water molecules move randomly across the barrier but the net movement is zero because the concentration is the same on both sides. Therefore, the correct answer is D.