This experiment will grab your students attention.
Place a small amount of water (about 1 cm) in the bottom of the can and heat to boiling without the cap until steam starts to rise out of the top. Remove the can from the heat and quickly put the cap on. Watch students amazement as the can is crushed as it cools. As the can cools a vacuum is formed inside that can cause over 1800 pounds of force to be exerted on the walls of the can. 1 gallon tin can comes with lid and has no labeling on it.