Physics Demo Number: 098				Approximate Run Time: 5 minutes
Soda Can Crushed by Steam Condensation
Demo Description An opened and empty soda can is filled with steam by boiling some water in its bottom. The can is then turned over and its top quickly submerged in a container of water. The abrupt cooling of the effectively resealed can reduces its internal pressure. The internal pressure reduction allows the atmosphere to crush the can.					Â	Scientific Principles ·Â Â Â Â Â Â Â Â  Pressure Balance Consequences
Equipment ·         Soda can ·         Propane Torch ·         Tongs ·         Open-Topped Vessel of Water	Â	Equipment Location ·         Kit ((098),(125),(149)) on row [D-3-5] houses the first three items. ·         [D-3-6] has a plastic drink pitcher with handle which will serve as water vessel.
1			2
Instructions Photo 1 shows a soda can being held by a set of tongs. The piece of duct tape on the tongs is for purposes of the photo only. The can is being heated from the bottom by a flame from the propane torch. A small amount of water (¼ inch or so) was placed in the bottom of the can. The heat had caused boiling of the water for a minute or so prior to the instant photo 1 was snapped. This boiling is evidenced by by the darkish looking mixing cloud coming out of the top of the can, commonly referred to as “steam” boiling out of the can. After a minute or so of vigorous boiling , steam has replaced most of the air in the can. The steam-filled can is removed from the flame and quickly flipped over so that its top is downwards. The top of the can is rapidly thrust into the room temperature water in the big beaker in photo 2. The resulting sudden condensation of the steam in the water-sealed can causes the can's internal pressure to drop so low that atmospheric pressure implodes the can. The resulting state of the can is seen in photo 2.   Writeup created by David A. Burba Copyright © 2013, Vanderbilt University.   All Rights Reserved.