All matter is composed of particles which are in constant random motion. What is the effect of temperature on the speed of these particles? To answer this question, you will need to use some common materials and do an experiment. You will use food coloring and different temperatures of water to test a hypothesis.

Problem:

How will differences in temperature change the rate at which food coloring spreads throughout water?

Materials:

• Two beakers or drinking glasses
• Warm water
• Cold water (suggestion - add ice to water before using it)
• Food color with dropper
• Watch, clock, or stop watch

Procedure:

1. Fill one beaker or glass with a measured volume of warm water.
2. Fill the second beaker or glass with an equal measure of cold water.
3. Make sure that the water in both containers has seemed to stop moving after the container was filled.
4. Carefully put one drop of food coloring in each container.
5. Use the watch, clock, or stop watch to determine how long it takes for the food coloring to diffuse (spread equally) throughout both containers.

Instead of doing the activity, you may choose to use this link to view a QuickTime movie comparing food coloring put into hot and cold water.

Analysis:

1. Which container did you expect the food coloroing would diffuse fastest in?
2. How much longer did the food coloring take to diffuse in the slower container compared to the one it dissolved fastest in?
3. How do you suggest that you can vary the water temperature and see if you get the same results as this experiment?
4. How do your experiment results explain the differences between the phases of matter?