Supercooling is a phenomenon in which a cold liquid stays liquid past its freezing point. This is possible under conditions that reduce or eliminate the nucleation points that normally facilitate ice formation; nucleation points include things such as air bubbles, impurities, or a container with a rough surface. You can demonstrate supercooling and rapid freezing with a plastic bottle of drinking water. The smooth plastic surface inside a water bottle helps retard ice formation.
Things You'll Need
- Plastic bottle of drinking water
Obtain a fresh, unopened bottle of drinking water. If the bottle is completely full, pour a few milliliters out. Emptying some of the water out leaves an air gap in the bottle that helps agitate the water for the demonstration.
Tape a thermometer to the bottle so it makes good contact and place it inside a freezer.
Monitor the temperature carefully without touching the bottle -- if you move the water too much it may freeze. When the temperature has reached -1 to -3 degrees Celsius (30.2 to 26.6 degrees Fahrenheit), the water is ready. Remove the water from the freezer carefully after it has cooled below freezing.
Pour the super-cooled water out of the bottle and observe the water freeze instantly. You can also shake it to see it turn from liquid to solid ice.
Tips & Warnings
- Do not drink super-cooled water. It can turn to ice within your body, causing serious injury .
- Avoid the use of glass bottles, as the freezing water may shatter the glass.
- Be careful when handling super-cooled water and avoid contact with your skin or eyes. It could cause freezing burns.
- Photo Credit water bottle image by Radu Razvan from Fotolia.com