Question

You have a round pie plate filled with water. You carefully release a drop of red food coloring in the center of the plate until the water is faintly red. After waiting for a long time, the dye molecules in the pie plate will: A. Continue moving in the same manner as when the drop was first placed in the water. B. Slow down, because they have moved to a lower concentration area. C. Stop moving, because they have reached equilibrium. D. Speed up, because they are farther from other dye molecules and have more space to move.

Answer 1

Answer:

C. Stop moving, because they have reached equilibrium.

Explanation:

Diffusion is the process whereby molecules/particles move from a region where they are highly concentrated to that region where they are less concentrated. This movement follows the concentration gradient i.e. difference in concentration that forms between the two regions. This movement continues until an equilibrium is attained in both regions i.e. equal concentration of the molecule.

In this question, a drop of red food coloring was released in the center of a plate containing water until the water becomes faintly red. The water gradually changes to red because molecules of the dye are moving from high concentration areas to lesser concentration areas. However, when an equal concentration is attained i.e. equilibrium, the MOLECULES WILL STOP MOVING.