An average can of soda at room temperature measures 55 psi before you ever crack it open. (In comparison, most car tires run on 35 psi, so that gives you an idea how much pressure there is inside the can!)
If you heat a can of soda, you’ll run the pressure over 80 psi before the can ruptures, soaking the interior of your house with its sugary contents. Still, you will have learned something worthwhile: adding energy (heat) to a system (can of soda) causes a pressure increase. It also causes a volume increase (kaboom!).
How about trying a safer variation of this experiment using water, an open can, and implosion instead of explosion?
Materials – An empty soda can, water, a pan, a bowl, tongs, and a grown-up assistant.
NOTE: If you can get a hold of one, use a beer can – they tend to work better for this experiment. But you can also do this with a regular old soda can. And no, I am not suggesting that kids should be drinking alcohol! Go ask a parent to find you one – and check the recycling bin.
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Grocery stores or drug stores will carry these. You don’t have to use a portable one – I did just to make the video easier to shoot.
where do you get a portable stove
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I can’t watch the video because it did not appear. How am I going to make that video appear?
Good observation! It sucks up water because there’s less pressure inside the can, so the pressure outside the can (atmosphereic pressure) pushes on the water level which gets pushed up inside the can. Keep trying – I know you can get it to work!
We just tried this experiment and the can did not squish, but sucked up the water. We are going to try again, this time adding more ice water to the bowl and letting the can heat longer. I hope it works as described, but the water sucking up was cool too! Why is it sucking up the water?
Tip: Do this experiment first, as it calls for 2 unsquashed cans:
https://www.sciencelearningspace2.com/2010/05/soda-can-trick/
Actually, this way you can get away with only 2 cans instead of the three on the shopping list.
It worked this morning for us. We tried twice because we only had two soda cans. Our kids were so thrilled and
we even videotaped it. We put 2 Tbsp of water for both of them and waited for the steam coming out lasting
for 3 min and 2 min respectively. Both of the cans squished and had a big “bombing” sound. :)(That’s what the
kids described) I think this time we just put the cans directly on the electric stove. Last time, we put it on the
watered pan and heated the pan. That made the experiment a little bit difficult because we couldn’t tell the
steam was from the pan or the can. And you mentioned a good point. That is, the can has to be full of the steam,
expelling all the air out. So this time, we just waited for a bit longer. Our ice bath is no problem.
Thank you for helping us out. 🙂
Science is like that sometimes… and yes, do keep trying this experiment, and vary the amount of water in the can as well as how long you leave it on the stove before inverting it. Try 1, 2, and 3 tablespoons of water and also try 1, 2, 3, and 4 minutes leaving it on the stove (that’s 12 trials!) so see which works best for your particular can. Make sure your ice bath is ice cold, too, or it will suck up the water and not crush at all. Let me know how it goes!
;(
We tried many times today but they all failed or not as good as we expected. I read some of the comments above.
We had simliar situations, too. We found that when we inverted the can into the ice bath, it didn’t crash but quickly
sucked the water all up. Could you also tell us how long we should keep on the stove to make sure that all the air
is out and the soda can is full of water steam? Thanks a lot. We will keep trying…… 😉
My kids loved it! It worked the first time we tried it! Thanks
Yea! So glad you got it to work… and you know, science is like that sometimes, which can be both frustrating and rewarding. Great job hanging in there til you figured it out! ::)
Okay – here’s the deal with the can: When you heated up the water inside, the small liquid water turned into a expanded cloud of steam, which filled the can (and shoved the air out the top). The superheated steam in the can is full of molecules that dance and jiggle all over the place. When you stick it in the ice bath, you are quickly cooling the volume of gas down (which is why it’s important not to have any leaks, or the can won’t crush because it draws in air as it cools and condenses).
The cooled steam takes a lot less space when it’s cooled than when it’s hot (the molecules slow down their jiggling motion when you decrease the temperature). This creates a lower pressure inside the can. Since higher pressure always pushes, the surrounding air is now at a higher pressure than the stuff inside the can, so the can gets crushed.
You basically created a vacuum inside the can by heating up the inside gas, sealing it off, and cooling the interior gas quickly. When temperature drops, pressure also drops – that’s one of the fundamental principles in thermodynamics (which we’ll cover in eScience Unit 13).
And since the Flight Lab is all about watching what happens when you have a difference in pressure, this experiment is perfect for observing what happens when one of the pressures is lower than the other (higher pressure always pushes)! Which means that if you don’t completely seal off the can, air rushes back in also because it’s at a higher pressure than the inside of the can.
Does that make sense?
We got it to work today! The can also sucked up all the water out of the ice bath. Is this because as the air pressue in the can decreased, the water was sucked in as a result?
It usually takes families a few tries to get this one to work right. Here are a few tips that might help: you need to get all the air out of the can and fill it with steam from the water inside the can. That means leaving it sit on your stove for longer than you think (especially if it’s not working), you can increase the amount of water int he can, but not by much.
The other place folks have trouble is that they don’t get a good seal between the can and the ice water. When you flip it into the ice bath, plunge the whole top section underwater so that there’s no chance for air to get sucked back into the can as it cools. Keep trying!
We cannot get this one to work. We have a gas stove and I followed the directions and put water in a sauce pan and then the soda can in. We cannot get steam out of the can. We tried both 1 tbsp and 2 tbsp in the soda can. Any suggestions?
A lot of fun! The kids wanted to do it over and over…and we just didn’t have that many soda cans around. They saved one for when Dad got home to show him and had fun explaining why it collapsed. Thanks for making this concept so fun!