DIY: Diffusion Science Experiment

Girl with static hair.

Have you ever stopped to notice the beauty of the swirls of color coming from a tea bag into a hot mug of water? Or had a magnificent smell of freshly baked goods waft its way over to your nose? You were experiencing diffusion. Here is a simple DIY experiment for you to try to demonstrate factors that affect diffusion.
Diffusion is the movement of a substance from an area of a high concentration to an area of low concentration. All you will need for this experiment are a few glasses of water and some food coloring. We will be looking at the diffusion of the food coloring in the water.
diffusion 1
Factor 1: Temperature
Temperature is a measure of the average kinetic (moving) energy of molecules. The hotter a substance is, the more kinetic energy it will have. If the water is hotter, it will have more energy, pushing the molecule of the food coloring more, therefore, diffusing it at a higher rate. The colder water will clearly take longer to diffuse all of the color.
Factor 2: Concentration
The rate of diffusion also depends on how concentrated the water is with food coloring. If you start off with plain water and add just a drop of color, it will take a long time to diffuse. However, if you add a bunch of food coloring, the concentration difference between the top of the glass and the bottom is much greater. This greater concentration difference will greatly increase the rate of diffusion.
Factor 3: Distance
Distance is one of the more obvious factors in diffusion rates. The shorter the distance that must be traveled, or the less volume there is, there will be a higher rate of diffusion.
Factor 4: Material
Material is another factor that might seem obvious. The lighter and small a substance is, the faster it will diffuse. On average, gases will be able to diffuse quicker than liquids which diffuse quicker than a solid. However, for our set of experiments, we are keeping the materials the same throughout.
Regardless of the factors that you manipulate, diffusion is truly beautiful to watch. So grab some food coloring and water to see it in action for yourself!

Written by: Mimi Garai