Air Pressure Can Crusher Science Experiment

How to explain to your kids that we are surrounded by the air. I think our Air Pressure Can Crusher is a good idea. It is super simple to demonstrate it and the required material can be found in almost every home.

Age: 6+           Time: <20min

 Safety 

1. Be careful with the hot soda can.
2. Adult supervision.
3. Wear protective gloves.

 Materials List 

• Soda cans
• Alcohol lamp
• Water
• Clamp
• Lighter
• Glass bowl (any container)
• Protective gloves

 Instruction 

Step 1/4 – Pour about 300ml water in the glass bowl and about 10ml water into the soda can.

Step 2/4 – Light the alcohol lamp, put on your protective gloves, hold the soda can with the clamp, and heat the bottom of the soda can. 

Step 3/4 – Heat the soda can until there is some white smoke coming out of the can mouth. 

Step 4/4 – Put the soda can upside down right in the water. The soda can will be rushed. (Be prepared for a loud noise as the can is rapidly crushed.) 

 Troubleshooting 

Why my soda can was not crushed?

— You need to increase the heating time and the soda can mouth should be completely immersed in water. If after this, that still does not work, replace the water with more cooler water.

 Question to Ask 

1. What makes the cans deform?

2. Can you have such an effect without pouring a small amount of water into the can in advance?

 Scientific Description  

This happens because of the different air pressure between outside and inside of the can. Under normal circumstances, the air pressure in the can is equal to the atmospheric pressure outside the can, so the can will not be crushed.  The can is filled with air. We boil the water in the soda can and the water changes its states from a liquid to a gas. The water-gas pushes out the air that was originally in the can. When put the can upside down in the water, the water in the bowl forms an airtight seal to separate the air outside and inside of the can. When you put the very hot can in the cool water, the water-gas condensed into drops of liquid which reduce the air pressure inside. Thus, the atmospheric pressure outside is a lot larger than the air inside and the atmosphere push from the outside of the can, which is great enough to crush it. When you drink from a straw than is using the atmospheric pressure. You suck in the air to reduce the air pressure inside your mouth so the outside air pressure pushes your drink into your mouth.

 Extensions 

Our Drinking Candle experiment happens because of the air pressure too. 

 Disposal 

The crushed soda can is sharp, wrapped it with some cloth or paper before you throw it into the trash can.