States of Matter Experiment: Show Relationship of Temperature and Changing State
About 2 min read
(updated 21 November 2022)
When you lower the temperature of water to 0°C (32°F), the liquid water freezes to become a solid ice. Likewise, when you raise the temperature of water to 100°C (212°F), the water changes its state to steam.
Questions you may have include:
- What happens when water is at the freezing point or boiling point?
- Does the liquid suddenly change states exactly at that point?
- How does the temperature change during that change in state?
This experiment will answer those questions.
Purpose of experiment
The purpose of this experiment is to determine what happens to the temperature of water when it reaches the freezing point and the boiling point.
Freezing water
Put a thermometer in your refrigerator freezer and measure the temperature.
Put the thermometer in a container of water, wait until the thermometer settles, and measure the temperature of the water.
Put the thermometer and container of water in the freezer. Check the temperature of the water periodically until the water starts freezing.
Caution: Once the water completely freezes, it expands and can damage the container and/or the thermometer.
How does the temperature vary, once the water starts freezing? Does it slowly get colder, stay the same or increase?
Once the water is frozen and kept it in the refrigerator freezer, it will continue to get colder until it reaches the temperature of the freezer.
Boiling water
You can do a similar experiment with boiling water. Put a cooking thermometer into a pot of water. A cooking thermometer is one that will go over 100°C (212°F). Often they are used in ovens.
Heat the water and record the temperature at intervals. Once the water starts to boil, what happens to the temperature? Does it go up, go down or stay the same?
Stop the experiment before all the water boils away, so that you do not damage the pot. If the steam was in a container it could be heated beyond the boiling point of water. But that is very difficult to show and beyond the scope of this experiment.
Outcome
Document your findings and determine an outcome for the experiment.
Summary
You can find out how temperature varies at the freezing point of water and at its boiling point with this experiment.
Think clearly