Question Video: Determining the Position of Red Dye in a Beaker of Water Science • First Year of Preparatory School

Video Transcript

A few drops of a water-based dye are added to a beaker of water. The beaker is then left for 10 minutes. What will the beaker of water look like after this time?

Molecules of a substance are in constant motion. So, the dye particles in the dropper and the water molecules in the beaker are constantly moving about and colliding with one another and the walls of the container. So, what happens when the dye is added to the water? When the dye is added, all of the dye particles and water molecules continue to move, colliding with one another. The interactions with surrounding water molecules are essentially equivalent. So, the dye particles should spread out similarly in all directions.

So, after 10 minutes, the beaker should look like the figure shown in answer choice (B).