4C30.34: LIQUID NITROGEN - EXPANSION OF GAS FROM LIQUID

PURPOSE: This demo shows the increase in volume which accompanies the transition from liquid to gaseous nitrogen.

DESCRIPTION: Pour some liquid nitrogen into a coffee can or a film canister and install the plastic lid. The liquid nitrogen heats up, changes to a gas, and blows the lid. Repeat for students who blinked.

SUGGESTIONS: Wear gloves and safety glasses, always be cautious when using liquid nitrogen. Placing the demo in the front of the classroom will reduce the chances of contact between liquid nitrogen and students. Film canisters will explode if the lid is on too tight or if the plastic becomes brittle due to cold.

EQUIPMENT: Liquid nitrogen, can with plastic lid or a empty film container.

SETUP TIME: 10 min.

KEYWORDS: change of state