Ingredients:
2 cups Heavy Whipping Cream
1/2 cup sugar
1/2 tsp. Vanilla
Materials:
1 lb Empty, clean coffee can with lid
3 lb Empty, clean coffee can with lid
1 bag crushed ice
About 2-3 cups Rock salt
Instructions (6 steps followed by scientific facts):
Step 1: Measure and pour the cream, sugar and vanilla into the 1 lb. coffee can and secure the lid with duct tape.
Step 2: Place the cream filled can inside the 3 lb. coffee can. Pack the remainder of the large can with ice and rock salt, and secure with lid and duct tape.
Step 3: Students shake, roll and kick the can back and forth on the ground for about 10 minutes. (The can will be cold to the touch and develop frost.)
Step 4: Remove the cream filled can from the 3 lb. can. Make observations of the rock salt and ice mixture. The ice portion changed from solid to liquid matter.
Step 5: Remove the lid from the 1 lb. coffee can. Notice the liquid cream mixture changed to solid matter, making ice cream!
Step 6: Enjoy!
Science behind the fun:
Solid matter: maintains fixed shape.
Liquid matter: takes shape of container.
As we roll, shake and kick the coffee cans the solid matter (ice) will change to liquid
matter and the liquid matter (cream mixture) will change to solid matter.
Rock Salt: Melts ice on the roads and sidewalks. When the salt comes into proximity with ice, the freezing point of the ice drops. Water freezes at 32 degrees F. The rock salt lowers the temperature to 20 degrees F. By dropping the temperature we are able to produce a domain in which the cream will freeze at a temperature below 32 degrees F into ice cream.
