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G430: Pressure and Temperature – The Collapsing Can

Introduction

A small amount of water is added to an aluminum soda can and brought to boiling on a hot plate or with a Bunsen burner.  The water gas molecules will occupy all the space inside the can since the air molecules have been pushed out. The hot gas molecules are the same pressure as the air outside the can. When the can is placed in cold water upside down, the hot gas water molecules are cooled very rapidly. Some of the gas molecules are condensed back into liquid water so there are less molecules of water in the gas phase inside the can. The cold water will also cool any remaining gas molecules, decreasing their kinetic energy and therefore decreases the number of collisions with the walls of the can. This decreases the pressure inside the can.  Since the air pressure outside the can is stronger than that inside the can, it causes the can to collapse.

H2O(g)   à   H2O(l)

To Conduct Demonstration

• Place the can containing water on a hot plate (turned to high) or a ring stand with a Bunsen burner underneath.
• Allow several minutes for the water to come to a full boil.
• Steam must displace the air inside the can; wait until you see a steady flow of steam exiting the spout, then immediately remove                   the can from the heat and place in the ice water bath.
• As the hot steam cools and condenses to water, a vacuum is created inside the can and atmospheric pressure will crush it.
• 250 ml water to a 5 gallon can
• 20 min to boil, 1 or 2 min to collapse.  Collapsing will take longer if the can is left     to heat longer and   it itself gets hot.
• Requires a large hotplate.

If using a large can do not continue heating the can after inserting the rubber stopper as pressure will increase. 

• G410: Gases – Boyle’s Law
• G430: Prep Notes
• G440: Evaporation and Expansion – The Drinking Bird
• G450: Effusion – Relative Effusion Rates of H2, He, and O2
• G460: Charle's Law
• G420: Graham’s Law of Diffusion – NH3 and HCl Diffusion

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Level of Education

Post Secondary

Recommended Age

Time Required

• ~10 minutes
• ~20 minutes
• ~30 minutes
• ~45 minutes
• 1 day or more

Number of people

• 100 – 200 €

Supervision

Collapsing Metal Can  WIP

Meta Description

Learning Objectives

To investigate the effects of change in pressure.

To understand how a vacuum is created when water vapour condenses in a confined space.

Vacuum A space void of matter.

Atmospheric pressure The pressure caused by the weight of the atmosphere.

Condensation The change of state from gas to liquid, commonly used to denote the formation of water from water vapour.

Step 1 Pour some water in the metal can.

Step 2 Place the metal can on the fire stove and start heating.

Step 3 Wait a couple of minutes until the water starts boiling and water vapour is seen coming out of the can.

Step 4 Use safety gloves to seal the can using the rubber stopper and place the metal can in a tray of cold water.

Step 5 Pour more cold water on the metal can, to cool all the surfaces.

Step 16 Wait until the metal can implodes.

• Wear safety gloves when handling the hot metal can.
• Make sure the water is boiling before sealing the can with a rubber stopper.
• The metal can must be thoroughly cooled by placing it in a tray of cold water and also pouring water on it.

Sometimes it might feel like the weight of the world is pressing down on your shoulders, but it turns out this is only partly true. You may not notice it, but the air around you and above your head is pressing down on you all the time. It’s actually pretty heavy! So why are we not crushed by the weight of it all? Well, it turns out, we have the same pressure in our bodies, applying an equal and opposite force against the air pressure. Things only get dangerous when these pressures are different. When the pressure inside you is greater than that of the air around you, you explode! If the pressure in your body is less than the air pressure, you implode! Either way, not a great way to go.

For safety sake we are going to use a metal can instead of your body to demonstrate the crushing power of the tonnes of air above your head.

What is happening to the water as it boils? The water turns from a liquid to a gas, taking up more space.

What happens upon cooling the can with water? The vapour inside condenses back to water, creating a vacuum.

Why does the can collapse? The vacuum creates a change in pressure causing atmospheric pressure to crush the can.

When water is boiling in the metal can, water vapour occupies most of the volume within the can. As soon as the can is sealed with a rubber stopper no gases can escape. When the metal can start to cool the vapour inside condenses back to liquid which occupies much less volume, resulting in a rapid fall in internal pressure.

Standard atmospheric pressure exerts 101.3 kilopascals, which is more than sufficient to crush the metal can as shown in the demonstration. ( http://www.abc.net.au/science/articles/2011/07/13/3268575.htm )

The ideal gas law describes the relationship between pressure, volume, and temperature within a system, it is described by the following equation:

where P is the pressure, V is the volume, n the number of moles, R is the universal gas constant and T is the temperature in Kelvin.

Assuming that the temperature is just above the boiling point of water, i.e. 100°C , for one mole of water we have:

P = 101325 Pascals T = 373 K R = 8.314 J K-1 mol-1 n = 1 mol

V = 0.0306 m3.

Meaning that one mole of water converted into steam occupies 0.0306 m3 of volume.

The mass of one mole of water is 0.018 kg and thus the density of one mole of water at atmospheric pressure is

density (steam)=0.018/0.0306

0.588 kg m-3

Now, the density of liquid water at room temperature is 1000 kg m-3, so the relative density of liquid water to steam at atmospheric pressure is:

density (water)/density (steam)=1000/0.588

Thus, the volume of steam occupies 1700-times less volume when converted back to water. This explains why when the hot can, filled with water vapour is cooled, a pressure difference is created large enough for the external atmospheric pressure to completely crush the can. Notice that when the can is crushed the volume inside is minimized such that the external and internal pressure are equilised.

( http://www.abc.net.au/science/articles/2011/07/13/3268575.htm )

Applications

In meteorology, the change in atmospheric pressure is used to forecast weather. Changes in atmospheric pressure cause mass air movement and thus changes in pressure can be a good indication of the upcoming weather conditions. ( http://www.theweatherprediction.com/habyhints/18/ )

Research In Ireland, research has been carried out on a hull design optimisation of a service vessel used in an offshore wind farm. The main objective of the research was in making better designs that can withstand high pressures. ( https://www.researchgate.net/publication/312174757_Offshore_Wind_Farm_Service_Vessel_Hull_Design_Optimisation )

• Cool the metal can with different water temperatures and investigate the time it takes for the can to collapse.
• Investigate how different geometries of the metal container used can resist pressure differently.

Preparation: 15 mins

Conducting: 20 mins

Clean Up: 15 min

Number of People

2 participants

Tray Metal can or drum Gas stove Water Beaker Rubber stopper Safety specs Safety gloves

Contributors

Imploding drum

Offshore Wind Farm Service Vessel, Hull Design Optimisation/span>

CHANGES IN ATMOSPHERIC PRESSURE

Imploding Drum

Additional Content

Imploding Drum  (Beginner)

Imploding Drum  (Moderate)

Offshore Wind Farm Service Vessel, Hull Design Optimisation  (Advanced)

Cite this Experiment

Vella, R., & Styles, C. (2019, November 12). Collapsing Metal Can. Retrieved from http://steamexperiments.com/experiment/collapsing-metal-can/

First published: November 12, 2019 Last modified: July 28, 2020

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Collapsing a Can

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Did you know that air has weight? In fact, a large amount of air can be very heavy. Here’s a way to demonstrate the weight of air. You should do this with the help of an adult so you don’t burn yourself.

What you need:

• Empty soda can
• Hot plate or stove
• An adult to supervise
• Get an empty soft drink can. Put about a quarter inch of water in the can.
• Put several inches of water in a sink or large pan. Set the can on the burner of a stove and bring the water to a full boil. Let it boil for about a minute, but be careful not to let all the water boil away.
• With a large pair of tongs or hot pads, remove the can from the stove. Don’t touch the can; it’s very hot! Place the can upside down in the sink or pan of cold water. The can should be instantly crushed!

What’s going on?

When the water boils, the steam forces the air out of the can. When the can is placed in the cold water, the steam changes back into liquid water. This leaves a vacuum in the can. The can crushes because of the weight of the air outside the can. The total weight of the air can be as large as 700 pounds!

The weight is so large because we live at the bottom of an atmosphere that goes up many miles. All that air isvery heavy and presses down on us all the time. Why aren’t we crushed just like the can? Why does a balloon filled with helium rise?

Have you ever gone down deep in a swimming pool and felt the pressure? That’s because of the weight of the water above you. Do you think a fish notices the weight of the water?

ScienceDemo.org

Collapsing Can

The collapsing can demo is one I loved seeing for the first time when I was at school, although my teacher used a tin with a screwed down lid which took a little more time to cool down. In some ways I prefer the version using a can with a screw lid because the additional waiting time makes for an even more dramatic “collapse”. Doing the demo with a drink can is of course far cheaper (and I think, more reliable as it doesn’t depend on the lid being screwed down properly) and I suspect this is why the approach we use in our video has become far more widespread in schools.

I like the demo a lot but, as I hope we’ve managed to convey in the video, I think we need to be careful how and why we use it in our lessons. This is a really fantastic demo for using the Predict, Observe, Explain (POE) approach as the explanation of what’s going on is not entirely straightforward – there are a couple of things relating to the behaviour of particles and the action of forces that need to be considered and this can lead to some really interesting discussion with students, providing they’re familiar with the relevant concepts.

We’ve suggested in our video that the collapsing can demo can be used in conjunction with another demo, as a way of “ scaffolding ” (I really hope I’ve used that term correctly – I think this may be the first time I’ve used it in writing in this context).

Once you’ve done the demo live in class, you’ve got the perfect justification for showing your students this video of a rather more spectacular demonstration of the same physics at work:

6 thoughts on “Collapsing Can”

I always like the collapsing can demo – it challenges even the most able kids to use the particle models they already know to come up with an explanation. I’ll try it with the vacuum fountain in future too – that’s a handy extra tool to help with the particle theory models.

Beautifully presented and shot. Thank you. FYI pressure using a rotary pump like that in that small volume after 15 seconds is likely to be ‘a few’ millibar – i.e. less than 1% of atmospheric pressure.

For a few years now I’ve been using the collapsing can as one of five ‘amazing pressure demos’ that A2 students have to explain in terms of kinetic theory. They like it (it goes bang), they can show their friends (beer cans and a camping stove at a festival), and if they’re really good they can explain it too in terms of the kinetic theory! Good point about it being a long chain of argument, I’ll definitely include the water fountain next year as its a more obvious demo. BTW, the other demos I use are (1) the inverted tumbler of water with a piece of card over the top (very difficult to explain using kinetic theory, I do it as an example) (2) the poor man’s magdeburg hemispheres (one student pushes together a pair of rubber sink plungers, then attempts to pull them apart) (3) a small sealed balloon inside a bell jar connected to a vacuum pump and (4) the ‘boiled egg into the bottle’ trick, done with a conical flask and nothing more than a trough of ice water and a trough of very hot water. My favourite for sheer theatricality (and ease of explanation) is the egg into the bottle. There’s no sudden bang, but a long hard squeeze instead.

Do you plan to make more of these? I often feel that non specialists struggle out of their subject area and would benefit from this sort of resource. Written instructions are great but a video helps so much more. What would be good to see is video accompanying the practical physics website so that each experiment had an accompanying video – a massive project!

Pupils do experience the effect outside of the classroom, every time they use a straw they create a region of low pressure and form their own internal water fountain but very few will think of it being to do with difference in pressure, just a suck.

• Pingback: I'll show you impact | ScienceDemo.org

Hi Alom, Great video and nicely explained demonstration. I really like the addition of the YuoTube video at the bottom with the imploding tank. I think it really shows how the same principle works on a much bigger scale. Kids can crush a can with their hand, but crushing a whole tank of those dimensions is another story 🙂 Very nice, thanks! Alessio.

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Crushed Can Experiment

Love exploding experiments? YES!! Well here’s another one the kids are sure to love except this one is an imploding or collapsing experiment! All you need are a coke can and water. Learn about atmospheric pressure with this incredible can crusher experiment. We love easy science experiments for kids !

How to Crush a Can with Air Pressure

This simple science experiment has been on our to-do list for a while now because we wanted to know if air pressure can really crush a can! This soda can experiment is a great way to get your kiddos excited about science! Who doesn’t love something that implodes?

Check out our chemistry experiments and physics experiments !

Grab an empty soda can (Suggestion – use the soda for our pop rocks and soda experiment ) and find out what happens when you put a hot can in cold water! Make sure to have an adult involved with heating the can!

F ree printable STEM activities pack!

Can Crusher Experiment

Also check out how changes in pressure can suck an egg into a bottle.

• Empty aluminum can
• Heat source Eg stove burner
• Bowl of ice water

INSTRUCTIONS:

STEP 1. Prepare a bowl with ice and water,

STEP 2: Put about two tablespoons of water in an empty aluminum can.

STEP 3: Set the can on a stove burner or over a flame until the the water in the can turns to steam.

THIS STEP SHOULD ONLY BE DONE BY AN ADULT!

STEP 4: Use an oven mitt or tongs to carefully remove the steaming can from the heat source and immediately turn the can upside down into a bowl of cold water.

Prepare for a loud POP as the can implodes!

Why Does a Hot Can Crush in Cold Water

Here’s how the collapsing can experiment works. As the water in the can gets hot, it changes to steam. The steam or water vapor is a gas and so it spreads out and fills the inside of the can. This a great example of states of matter phase change, and a physical change !

When you flip the can and put it in cold water, the steam condenses quickly or cools and changes to a liquid state. This reduces the number of gaseous molecules in the can, and so the air pressure inside becomes lower.

Air pressure is the the force exerted onto a surface by the weight of the air. The difference between the low air pressure inside and the pressure of the air outside creates an inward force on the walls of the can, causing it to implode!

What does implode mean? Implode refers to exploding violently inwards rather than outwards.

MORE FUN EXPLODING EXPERIMENTS

Why not try one of these science experiments below!

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Solution to Chemical Mystery #6: The Case of the Collapsing Can

In Chemical Mystery #6, I used chemistry to crush a metal can. To do so, concentrated sodium hydroxide solution (about 35% NaOH by weight) was added to a can that was almost completely filled with carbon dioxide gas. The can was then sealed. The carbon dioxide gas in the can reacted with the added sodium hydroxide:

2 NaOH(aq) + CO 2 (g) --> Na 2 CO 3 (aq) + H 2 O(l)        Equation 1

This chemical reaction removed the gas from the can. Of course this lowered the gas pressure inside the can. Once the pressure inside the can became low enough, the surrounding air pressure was able to push on the can, causing it to implode. The same effect was not observed in a can simply filled with air, because air contains very little carbon dioxide. The video below shows one way you can carry out this experiment.

So that’s how you can crush a can using chemistry, and also present a neat chemical trick! 

Congratulations to Andres Tretiakov and Bob Worley who both figured out how this experiment works. Bob likes to use plastic soda pop bottles as a less expensive alternative for this experiment, but I happen to think it’s a bit more impressive to use metal cans. For those interested, Flinn Scientific has published a procedure on how to carry out this experiment using plastic bottles 1 .

There are a surprising number of concepts that can be taught while using this demonstration. Certainly one can discuss the gas laws and composition of the atmosphere when using this demonstration. Students could be challenged to identify reactions that might allow one to crush a can filled with air. This demonstration can also provide a reference point for one way chemistry is being used to combat climate change: sodium hydroxide, though application of Equation 1, is used as a reagent to remove carbon dioxide from the atmosphere 2-4 . Finally, this experiment provides an example of a spontaneous reaction for which both the enthalpy and entropy changes are negative. Although I didn’t mention it in the video, the can becomes quite warm as a result of the reaction (negative enthalpy )and a gas is consumed (negative entropy). 

Are there any other concepts you think might relate to this particular experiment? I'd love to hear your thoughts in the comments below.

References: 1.     https://www.flinnsci.com/media/621027/91423.pdf 2.     http://scholar.harvard.edu/files/davidkeith/files/97.stolaroff.aircaptur... 3.     http://wordpress.ei.columbia.edu/lenfest/files/2012/11/ZEMAN_LACKNER_200... 4.     http://www.popsci.com/molika-ashford/article/2008-10/better-co2-scrubber

Chemistry: Charles's Law: The Incredible Imploding Can

• Charles's Law: The Incredible Imploding Can
• Boyle's Law: Why Compressed Gas Is Small
• Gay-Lussac's Law: Spray Paint + Campfire = Bad News
• The Combined Gas Law
• Avogadro's Law and the Ideal Gas Law
• Dalton's Law of Partial Pressures

Let's do another demonstration. You'll need a brand new, never used, metal can with a screw-on cap. Remove the cap, place the can on the stove, and turn it to "high." After the can has been heated for about two minutes, take it off the stove with metal salad tongs and tightly screw on the cap.

Because I know that none of you actually did the demonstration (shame on you!), I'll just tell you what you would have seen—over a period of two or three minutes, the can would shrink until the sides caved in.

Way back in 1787, the French scientist Jacques Charles did exactly the same experiment while sitting around the house on a rainy day. (Editor's note: Historians believe that only the year in the preceding statement is correct.) When he observed the can imploding, he devised the following law to explain his findings:

• V 1 ⁄ T 1 = V 2 ⁄ T 2

V 1 is the initial volume of the can, T 1 is the initial temperature of the air in Kelvin, V 2 is the final volume of the can, and T 2 is the final temperature of the air (in Kelvin). We will assume that the pressure and number of moles of the air are constant. If the can has an initial volume of 5.00 liters, the temperature of the air before you took the can off of the stove was 250º C (523 K), and the temperature of the air after the can cooled was 25º C (298 K), we can use this equation to find the final volume of the can:

Bad Reactions

When working with gases, remember to always convert temperatures from degrees Celsius to Kelvin (K = ºC + 273). If you don't, your answer will be wrong!

• 5 L ⁄ 523 K = V 2
• V 2 = 2.85 L

What this equation means is that when the air inside the can cooled, the volume decreased, causing the can to implode. The kinetic molecular theory would explain this by saying that the air molecules had less kinetic energy at the lowered temperature, causing them to strike the sides of the can with less energy than they did before. Because the energy of the molecules hitting the sides of the can decreased, the pressure inside the can also decreased. When the pressure inside the can decreased, the much higher air pressure outside the can pushed in the sides of the can, causing it to implode.

Figure 16.1 The air molecules in the can hit the inside walls with less energy at low temperature, causing the can to implode as the air temperature decreases.

Excerpted from The Complete Idiot's Guide to Chemistry © 2003 by Ian Guch. All rights reserved including the right of reproduction in whole or in part in any form. Used by arrangement with Alpha Books , a member of Penguin Group (USA) Inc.

To order this book direct from the publisher, visit the Penguin USA website or call 1-800-253-6476. You can also purchase this book at Amazon.com and Barnes & Noble .

• Chemistry: Gay-Lussac's Law: Spray Paint + Campfire = Bad News

Here are the facts and trivia that people are buzzing about.

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Instructional Resources and Lecture Demonstrations

2b30.15 - crush the soda can.

Put 20 ml of water into a pop can and put onto the hot plate. Let the water come to a boil and continue for 2 minutes. Quickly take the can off the hot plate with the tongs and invert into the cold water. The can should collapse dramatically. 1 gallon and 5 gallon cans can also be collapsed in this manner.

• Hewitt, "Figuring Physics, TPT, Vol. 60, #2, Feb. 2022, p. 136.
• Hewitt, "Figuring Physics", TPT, Vol. 51, # 1, Jan. 2013, p. 8.
• Anonymous, "Figuring Physics-Whopped Can", TPT, Vol. 49, # 2, Feb. 2011, p. 70.
• Pirooz Mohazzabi, "The Physics of the Imploding Can Experiment", TPT, Vol. 48, # 5, May 2010, p. 289.
• Mike Shaw, "'A Golden Oldie': Canned Again", TPT, Vol. 44, # 3, March 2006, p. 184.
• L. M. Gratton and S. Oss, "An Extension of the Imploding Can Demonstration", TPT, Vol. 44, # 5, May 2006, p. 269.
• Ronald Bryan,  "Avogadro's Number and the Kinetic Theory of Gases",  TPT, Vol.  38, # 2, p. 106, Feb. 2000.
• Mario Iona, "Thermodynamics of Cans", TPT, Vol. 35, # 8, Nov. 1997, p. 452.
• Brian W. Holmes, "Save Those Soda Cans", TPT, Vol.  35, # 5, p. 281, May 1997.
• James E. Stewart,  "The Collapsing Can Revisited",  TPT, Vol. 29, # 3, p.  144, March 1999. 
• James McGahan,  "Collapsing Soda Cans and Efficiency",  TPT, Vol. 28, # 8, p. 550, November 1990.
• Ron Edge, "Strength and Shape", TPT, Vol. 25, # 1, Jan. 1987, p. 50.
• John G. McCaslin, "Barrels are More Fun Than Beer Cans", TPT, Vol. 21, # 8, Nov. 1983, p. 520.
• Tim Taylor, "The Imploding Beer Can", TPT, Vol. 20, # 7, Oct. 1982, p. 458.
• E. Scott Barr, "Comments On the October Issue", TPT, Vol. 20, # 9, Dec. 1982, p. 578.
• P. B. Visscher, "Simple Student-Repeatable Atmospheric Pressure Demonstration", AJP, Vol. 47, #11, Nov. 1979, p. 1015.
• F- 025:  "Collapsing Cans and Drums",  DICK and RAE Physics Demo Notebook.
• H- 068:  "Balloon in Flask - Collapse Can",  DICK and RAE Physics Demo Notebook.
• M - 855:  "Stand on Pepsi Can", DICK and RAE Physics Demo Notebook. 
• Julien Clinton Sprott, Physics Demonstrations,  "2.4, Collapsing Can",  p. 74, ISBN 0-299-21580-6.
• "Experiment with a Vacuum", The Boy Scientist, p. 170.
• Shar Levine, Leslie Johnstone, "Pumping Aluminum", Silly Science, Chapter 4, p. 12.
• Bobby Mercer, "Can Crusher", Junk Drawer Chemistry, 2016, p. 191.
• Tik L. Liem, "The Crushing Pop Can", Invitations to Science Inquiry - Supplement to 1st and 2nd Ed. p. 26.
• Borislaw Bilash II, “Crush the Can“, A Demo A Day – A Year of Physical Science Demonstrations, p. 88.

Disclaimer: These demonstrations are provided only for illustrative use by persons affiliated with The University of Iowa and only under the direction of a trained instructor or physicist.  The University of Iowa is not responsible for demonstrations performed by those using their own equipment or who choose to use this reference material for their own purpose.  The demonstrations included here are within the public domain and can be found in materials contained in libraries, bookstores, and through electronic sources.  Performing all or any portion of any of these demonstrations, with or without revisions not depicted here entails inherent risks.  These risks include, without limitation, bodily injury (and possibly death), including risks to health that may be temporary or permanent and that may exacerbate a pre-existing medical condition; and property loss or damage.  Anyone performing any part of these demonstrations, even with revisions, knowingly and voluntarily assumes all risks associated with them.

Crushing Can Experiment : Effect of Atmospheric Pressure

• December 3, 2020
• 7-9 Year Olds , Physics , Rainy Day Science

You may be used to crushing can using foot or hand. Have you crushed it using an implosion?

Today were are going to explore effect of Atmospheric Pressure with ‘Crushing Can Experiment’.

Air Pressure Can Crusher Experiment

The pressure created in the air surrounding us plays an important role while doing this activity.

Objective: To crush the empty soda can and explore simple science concepts like air pressure, equilibrium, water vapor, condensation, and unbalanced forces.

Hypothesis: If water in a can heated to reach its boiling point and then dipped by inverting in a cold bowl of water, this would create vacuum and result in decreased vapor pressure resulting in crushing of the can (implosion).

Safety Measures: Of course, the activity looks simple and easy while offering a lot of fun! But this experiment is in need of a burner or any other heat source and implosion happens suddenly. So, this experiment is not to be done by kids. However, under adult supervision, the activity can be explored.

Materials Mandatory to Gather:

• A Glass Bowl
• Empty Cans (we chose 3 empty soda cans)
• Burner or Stove or any other heating source

Simple Guide to the procedure of the Crushing Can Experiment

Let us step into the simple instructions guide!

Step-1: Clean all the Necessary Containers

Cleaning is the foremost and important step to do before we start any experiment. Because the remnants attached to the glass bowls and other containers may change the final results of the experiment.

So, in the process of cleaning, pick the empty soda cans and glass bowls. And rinse them thoroughly with clean water. Make sure they are clean and perfect for using in the experiment.

Step-2: Pour Cold Water into the glass bowl

Take the cleaned glass bowl and fill it with fresh ice cubes to its half. Then pour some normal water into the bowl. Such that we are making sure the water in the bowl are cold for longer time.

Or else you can use cold or chilled water directly from the freezer and pour it in the glass bowl.

Step-3: Fill the Empty Cans

Now it is time to fill the cleaned empty soda cans with a little amount of water. 2-3 table spoons of water is more than enough to pour into the cans.

Normal and regular water is preferred to use. But make sure the water you are using is fresh and clean.

Step-4: Heat the Cans

The next step is the precautionary step as we are bringing burner into the picture. Yes, switch on the burner and take the water filled cans on to the burner. You can see the videos or pictures attached to get an idea.

We took three empty cans and filled with 2 table spoons of normal water. Then, we brought all these three water filled cans on to the burner and set the right temperature to make it boil.

Wait for some time until the water inside the cans are boiled enough. It just takes a couple of minutes to do the job.

Note: If your child is performing this experiment on his/her own, then this is the step where adult supervision is compulsory to avoid unnecessary accidents that happen with the heat. So, adults please supervise your children to heat the cans on the burner.

Step-5: Take out the Heated Can

Once you feel the sounds of water bubbles formed due to enough heat supplied to the water inside the cans, wait for one more minute.

And then observe the water vapor fumes coming out of the cans. That is the time, you need to switch off the burner and take out the cans from the burner.

Do not forget to use the tongs in order to handle the heated cans.

Step-6: Place over the heated can upside down into the Glass Bowl

This is another important step to do with extra care!

Yes, to see the positive results, you need to perform this step with utmost care.

Soon after you remove the cans from the burner, using tongs place the cans over the glass bowl filled with cold water.

The trick here is you need to place the cans upside down into the glass bowl. That’s it! You can see and hear a loud noise of popping out sound from the can.

Can you guess why we hear that sound? That’s the sound of the crushing can!

As soon as the heated cans brought in to the glass bowl filled with cold water upside down, the cans get crushed and collapses on their own.

Crushing Can Experiment Calculations

In this modern world, we generally come in touch with 12oz drink cans like soda or beverages can.

Mostly, we find them in aluminum material. The approximate measures of these cans are like: 4.75 inches or 12cm in height and 2.5 inches or 6.5cm in diameter which in total makes the whole area of this cylindrical can to 49.5 square inches or 315 square cm.

The dimensions of the cans are also designed specially in order to withstand the outside pressures. A square inch of a soda can bears 80-90 pounds of force from outside.

One atmosphere pressure force is equals to 720lbs or 3200newtons. So, in order to crush a soda can, you need to give nearly 50 pounds of force.

Do you want to know what the science behind Crushed Can?

An empty aluminum soda can is full of air molecules. When you apply enough force or pressure on the can from outside, there happens an imbalance between the pressures outside and inside the can.

In fact, the pressure outside the can is stronger and more than the pressure inside the can.

At the time, the can from outside experiences enough pressure, it collapses and gets crushed immediately. This is how air pressure plays important role in crushing an aluminum can in our hands.

Let us know what is air pressure? Air pressure is the pressure or force created by the surrounding air on the surfaces within the atmosphere as gravity pulls. Hence, it is otherwise known as atmospheric pressure.

Science behind Crushing Can Experiment

As I already told you, the empty can is not really empty instead filled with air molecules.

When the can filled with little water and arranged for heating on the burner, the water inside the can starts boiling.

Once the water starts boiling, there happens the transformation of liquid state to gaseous state.

This means we can observe water vapors coming out of the can through the fumes. Evaporation is the process of converting liquids into gases, which is the result of heating cans on the burner.

Eventually, the can is filling with vapors replacing the air molecules. Soon after you remove the cans from the burner and bring it over the chilled water in a bowl, the water vapor condenses.

You can see the condensation process clearly when there is formation of a few drops of liquid back on the can inside.

Unfortunately, these little liquid droplets are not strong enough to produce enough pressure inside the can. That is the reason the pressure outside the can is much more and stronger than the pressure inside the can.

Hence, the strong pressure developed outside the can is good enough to crush the can from outside.

Here, we need to talk about “Implosion”. Implosion is nothing but a sudden process of something collapsing themselves towards inside violently.

Implosions happen when there is heavy pressure from outside an object rather inside and finally destroys the object inwards. Explosion is quite opposite to implosion.

Matter and energy plays important role in causing explosions and implosions.

In this experiment, due to imbalance of pressures between outside and inside surroundings of can, implosions happens.

Because to maintain and bring the balance between outside and inside pressures of can.

 What happens after Implosion?

After implosion, just observe the inside of the can, you can observe water filled inside the can. This is the water dragged from the glass bowl due to stronger pressure build outside the can.

This high pressure created pulls the water from the glass bowl into the can where there is less pressure.

What is Gas Law and How it works?

Gas laws are the laws which establishes the association among pressure, volume, temperature, and the quantity of gas. In simple words, gas laws were designed around 16th-17 th century to learn the amazing properties of matters of gas regarding amount, volume, pressure, and temperature.

Generally, there are different types of gases available and all these gases behave differently while showing their chemical properties but strictly follow gas laws in the same way.

P= Pressure

n= Amount of Substance

R= Ideal Gas Constant

T= Temperature

The three principal and basic laws of gas includes: 1) Boyle’s Law

                                                                                           2) Charles Law

                                                                                           3) Avogadro’s Law

These three gas laws states different equations and properties but at the end they all come under Ideal Gas Law and General Gas Equation. Well, let us the three main gas laws in detail:

Boyle’s Law

Robert Boyle put Boyle’s Law into words in 1662 stating that the pressure of a gas is inversely proportional to volume of a gas. To keep it simple, if there is less volume of gas then there is more pressure on the gas at constant temperature. This law is otherwise known as Boyle–Mariotte law or Pressure-Volume Law.

V is inversely proportional to 1/P

Charles Law

Jacques Charlesformulated Charles Law that states that when pressure remains constant, the volume of stable amount of gas is directly proportional to temperature. In simple words, the rise in the volume of gas tends to increase the temperature as well. This law is otherwise known as Temperature-Volume Law.

Avogadro’s Law

Amedeo Avogadro established the Avogadro’s Law which states that volume of a gas is directly proportional to amount of gas at constant temperature and pressure. Modern Avogadro’s Law states that equal amount of volume of gas consists of equal amount of molecules at constant temperature and pressure. This law is otherwise known as Volume-Amount Law.

All these experimental gas laws are a part of Ideal Gas or General Gas Equation Law. Let us see what ideal or general gas equation law is.

Ideal Gas Law

Ideal Gas Law is also known as General Gas Equation Law. It states that it is a combination of all three gas laws and finally proves that pressure, volume, temperature, and amount of a gas relate each other. The gases that are fit to establish perfect relation between volume, temperature, pressure, and amount of gases are referred as ideal gases. The equation says:

When the aluminium can is hot, the pressure outside and inside the hot can are same. And when it is flipped upside down over the glass bowl containing cold water, immediately you can see sudden drop in temperature. Hence, the water molecules get cool rapidly causing imbalance in the outside and inside pressures around the can. The pressure outside the can is stronger and more compared to the pressure inside and hence the can pops out and collapses itself towards inside.

Crushing Can Experiment proves the Boyle’s Law, which is one of the major fundamental and experimental gas law of ideal gas equation law. Boyle’s law states that the volume of certain amount of gas is inversely proportional to pressure of a gas.

According to the sources and research studies, 10-20 pounds of force is necessary to crush an aluminium can. If you just want to open the mouth of the aluminium can, you need 1-2 pounds of force. Whereas nearly 50 pounds of force is necessary for crushing a steel beverage can. Remember that these numbers are just an estimated ones.

Take an empty aluminium soda can and pour two table spoons of normal fresh water. Now bring the can on to the burner and heat it until you hear the boiling water sound. When you observe the steam coming out of the can, switch off the burner. And pick the hot can using tongs and carefully flip it upside down over the glass bowl containing chilled water. That’s it, you can see the hot can crushing with a pop sound.

Jacques Charles formulated Charles Law that states that when pressure remains constant, the volume of stable amount of gas is directly proportional to temperature. In simple words, the rise in the volume of gas tends to increase the temperature as well. This law is otherwise known as Temperature-Volume Law. V T

Soda cans are generally encompasses of aluminium to keep its structure solid and strong enough to withhold the outside pressures. A regular soda can bears 80 pounds-90 pounds of pressure per every square inch. According to the research studies, 1pound-2pound force is necessary to open the mouth of the soda can whereas to crush it completely, nearly 50 pounds of force is necessary.

We have so many real life examples to discover Charles law around us but we just ignore to observe. Here is a classic example: the tyres of vehicles get deflated during chilled winter season whereas the same gets inflated during summer months: this phenomenon is due to Charles Law. During winter days, because of chilled temperature, the gas inside tyres get more cool and starts shrinking as well. While during summer months, due to hot temperature the sir inside tyres gets hot and starts expanding. This is the reason why tyres of some vehicles expand during summer and deflate during winter months.

Charles law does show its impact on human body but it is not much. You all might have observed shortened breath during winters and normal breathing during summer months. This is because of Charles law. Yes, during winter months, the chilled temperature outside causes the change in inside temperature of lungs. The inhaled cold air when passes through sinuses, gets warmed and expands in its volume. When the volume increases, you need to take shorter breaths in order to balance the increased volume. In this way, Charles law affects human body.

A: In real life, we can observe a lot of things happening around us which are actually related to ideal gas laws. Let us see a few of commonly happening things: 1) An inflated football shrinks when left aside during winter months—Proves Charles Law 2)  Leave the slightly inflated rubber life raft under sun light for some hours and observe the swelling of the raft– Proves Charles Law 3) Increase in number of bubbles blowing out by a scuba diver especially when approaching the surface or river banks—Proves Boyle’s Law 4) Death of deep sea fish when brought to the surface or land– Proves Boyle’s Law 5) Expansion of lungs when filled with air and shrinks when air released—Proves Avogadro’s Law 6) Humid air is more thick than damp air—Proves Avogadro’s Law

Gases have low densities than solids and liquids because in solids and liquids the molecules are tightly and narrowly filled. Whereas gaseous molecules do not pack up closely and occupy more volumes because these molecules fall apart. This is the reason why gases have low densities.

Before heating, the air pressure outside and inside the open soda can measures equal. Because the open can is not really empty instead occupied with air molecules.

When you pour two table spoons of water inside can and kept on the burner, the water reaches its boiling point and leaves steam. This steam occupies the rest portion of the can inside and substitutes all the air molecules.

The process of conversion of a gas into a liquid is known as condensation. The reverse process of conversion of a liquid turning in to gas is known as evaporation. Evaporation and condensation are the nature’s fundamental phenomenon and goes hand in hand.  

Crushing Can Experiment Worksheets

Simple worksheet for Class room : https://www.wlwv.k12.or.us/cms/lib/OR01001812/Centricity/Domain/2114/Can%20Crush%20Key.pdf

https://www.csub.edu/chemistry/_files/The%20Can%20CrusherAO.pdf

Explanation with method to do the experiment in large setup : https://www.flinnsci.com/api/library/Download/12267d76eaf04431b63a82777bb16195

Interesting Air Pressure Experiments

Balloon in a Bottle

Tornado In a Bottle

Drip Drop Water Bottle

Candle Rising Water Experiment

DIY Balloon Rocket

One comment

How is the can crushed if it is not sealed? Surely it would simply suck up the cold water you mention that is used for condensing the steam.

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The Physics of the Imploding Can Experiment

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Pirooz Mohazzabi; The Physics of the Imploding Can Experiment. Phys. Teach. 1 May 2010; 48 (5): 289–291. https://doi.org/10.1119/1.3393054

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One of the popular demonstrations of atmospheric pressure in introductory physics courses is the “crushing can” or “imploding can” experiment. 1–4 In this demonstration, which has also been extensively discussed on the Internet, a small amount of water is placed in a soda can and heated until it boils and water vapor almost entirely fills the can. The can is then quickly inverted and its opening is allowed to touch the surface of cold water in a container. Upon touching the cold water surface, the can implodes in a fraction of a second as the water vapor in the can condenses.

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Project Weather School: Crushing Can Experiment -- How Temps Affect Air Pressure

Pressure: How Temperature Differences Affect Pressure

ORLANDO, Fla. --  Pressure means everything when it comes to forecasting weather and learning about global patterns. High pressure gives us sunny weather and low pressure gives us stormy weather. This lesson will be broken into two parts over the next two weeks. This week will focus on the relationship between temperature and pressure. Next week we will learn about how pressure controls our weather patterns. 

First, let’s start off by defining air pressure. It is the weight (force) of the Earth’s atmosphere pressing down on any object on the Earth’s surface. There are many units to describe air pressure. The two most common metric units meteorologist use are “Inches of Mercury (Hg)” or “millibars (mb).” You may hear meteorologist refer to these units when describing the strength of a hurricane. There is a cool tool used to measure air pressure and it is called a barometer. 

BELOW: Take Nick's Weather Quiz!

Here’s a fun fact! The average atmospheric pressure is 1013.25 mb or 29.92”Hg. What does this mean? It translates down to 14.7 lbs per square inch! Think about that. Take out your pencil and let’s do some quick math. Let’s calculate the approximate weight of the atmosphere over a standard piece of paper with the dimensions of 8.5” x 11”?  

Find the area of the piece of paper which equals 93.5 square inches. Multiply that value by 14.7 lbs per square inch and you get a weight of 1,374 pounds of air over that sheet of paper. Now that is a lot of weight!

Did you know more than 2,000 pounds of air is resting on our heads every day? So why aren’t we crushed by it? Thank goodness for a strong vertebrae! Our bodies exert pressure too and these forces are balanced. Equilibrium is a great thing! 

Now that you understand the standard pressure of our atmosphere and what it means, let’s talk about how this influences weather. We know that pressure varies greatly around our planet and the pressure difference generates wind and storms. 

Why do we have a change in pressure around the planet? This has to do with temperature and the heating of the planet from the sun. The tilt of our planet causes the globe to heat up at different rates. Some areas like the equator are warmer than others, especially the poles. Cold air is more dense, therefore it has a higher pressure. Warm air is less dense and has a lower pressure associated with it. 

As the sun heats the ground, the air near the ground warms. Remember, heat is less dense than cold air so the warm air will rise. This rising motion creates a natural vacuum lowering the air pressure at the Earth’s surface. 

Think of a hot air balloon. When you heat the air inside the balloon, it causes the balloon to rise because the heated air is less dense than the colder air around it. 

Cold air on the other hand can create large areas of high pressure because cold air is more dense and hovers near the ground. Think back to last week’s lesson when we demonstrated how cold fronts work. The sinking air can create areas of high pressure at the Earth’s surface. 

When high pressure is in control, the air sinks. Sinking air compresses the atmosphere and inhibits clouds to form. Sinking air also pushes down toward the ground so the weight above you is greater than on a standard day. 

The opposite is true with a low pressure system. With low pressure, air rises, cools, and condenses into storm clouds, which may lead to a rainy day. Since the rising column of air weighs less, the air pressure is lower. Think back to our water cycle lesson. Water vapor rises, cools, condenses into a cloud, and later produces rain. 

Let’s demonstrate how temperature pressure relate to one another in this crushing experiment. 

Experiment: A collapsing can

Purpose: To demonstrate how pressure changes with temperature

What you need:

- ADULT SUPERVISION

- Empty soda can 

- Stove top of burner

- Large metal or glass bowl filled with ice water

- Kitchen Tongs

- Goggles, gloves, and apron (protective gear)

Procedure: 

1. Fill the empty metal or glass bowl with ice water

2. Turn the stove top to a medium heat

3. Fill the empty soda can with 2 inches of water

4. Place the soda can on the stove top

5. Let the water boil. This is when you will see steam escaping the top of the can

6. With an adult, turn the stove off and use the tongs to take the hot soda can and swiftly flip it over into the bowl filled with ice cold water. 

7. Observe your findings

Results: The can crushed immediately after placing it in the bowl of ice cold water. 

Conclusion: The heating of the can turned some of the water into water vapor. The warm water vapor was less dense than the surrounding environment causing it to rise out of the can. It was visible as steam. Heating the can causes the water particles to expand and therefore the total volume of water inside the can decreased as much of it was lost due to the water vapor escaping through the top. 

When the can was flipped into a pool of ice cold water, the can collapsed on itself. The water vapor that was left inside the can quickly cooled and condensed into water droplets, creating a vacuum. Suddenly the pressure outside the can is greater than inside the can, causing it to collapse on itself!

Next week, we will learn how pressure differences causes the wind to blow. 

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