Cody'sLab - 2020-07-17
I accidentally stumble across an interesting property of heavy gasses. applied science video: https://www.youtube.com/watch?v=TjiP8QIPews Help me make videos by donating here: https://www.patreon.com/CodysLab Follow me on Facebook: https://www.facebook.com/codydonreeder SubReddit: https://www.reddit.com/r/codyslab/ Twitter: https://twitter.com/CodysLab
Funny, how Cody always "discovers" these scientific concepts, pretty much the same way some bored nobles did in the 18th century
I think he just likes educating people on youtube that don't know about it.
@Psalms 118:8 I need someone to do this.
@Adam Wade bro what. How can you not be bored regardless of the time period
So cody is nobility. Cool.
Conclusion: Cody is a noble.
Gas permeation is a nasty buisness. I spent almost a month trying to solve Oxygen contamination in a pure Nitrogen stream flowing in a gas reactor. Turned out it was permation through the Teflon tubing carrying the Nitrogen, 1 mm wall was causing a 200-300 ppm of O2 permeation per meter of tube. Metal tubing solved the issue, but I was very surprised as well.
@Tom Mackellar You forgot about those 80 N2 molecules outside. You'll have to conclude that diffusion of N2 through barrier is slower than the one for O2. Given that two molecules are comparable in size, and N2 being lighter, purely ballistic transport is less probable.
@Darko Simonovic I wouldn't conclude that without data. You're forgetting that in the Teflon tube the N2 concentration gradient developes in an opposite direction to that of the O2. Also, as the point at higher concentration is inside the tube, which is flowing at 1 L/min from a liquid nitrogen tank while O2 is at atmospheric temperature (laboratory air-conditioned at 18-20°C) in a low perturbated system very likely Brownian and kinetic effects are in place.
@Andrea Gallo My comment was intended to be a reply to the Tom Mackellar comment and refers only to the case of Cody's balloons, 100% O2 inside. My hypothesis is that balloon membrane act as a molecular sieve of sorts.
@Darko Simonovic sorry, I wrongly assumed you were referring to the case I mentioned. Your suggestion of ballistik effects is very interesting, also considering the difference in the concentration gradients between O2 and N2
Well there is a saying for those looking to preserve food too... Plastic is not an oxygen barrier, they swear to metal.
Either sealed foil or canned goods to keep the oxygen out.
Actually, some diving beetles use air bubbles to breathe under water. The bubble sticks to their body and they can breathe out of and into it. As they lower the oxygen content inside the bubble, oxygen dissolved in the water starts diffusing into the bubble, thus multiplying the possible duration of a dive.
hermanni1989 - as water pressure increases and you go deeper underwater, the amount of dissolved oxygen and other gasses decreases... dissolved oxygen is primarily a surface effect similar to evaporation
DJ Scottdog - lots of tiny bubbles
pdorism - then you would encounter significant buoyant forces and would stay at the surface
they did that in harry potter
Oh wow that beetle is dope as fuck
That relatable moment when you don't have any weights so you have to use your can of radioactive matirals
When you need something heavy, reach for your heavy metals.
For me it's massive transformers and chokes lol.
Cody “We need something heavy to hold down the lid.”
casually puts a pin of radioactive materials on top of it
Hey Cody: could you put a small amount of SF6 in an upturned glass that's underwater? (But not sealed to the bottom of the tank). Curious if it will pull O2 out of the water.
Very interesting idea! I suspect this would be very slow.
I would suggest filling the glass about 2/3 with water, the rest SF6, close it, put it underwater and open it again. My guess is the gas volume will eventually double, although that is assuming no SF6 will escape the container. No idea how well it dissolves in water.
And maybe note how much water vapour would diffuse (osmose?) into the balloon, too.
Using a reagent that changes color with exposure to oxygen would let you quantify the relative levels present in the water over time. Just take a sample and add equal amounts of reagent.
Youtubers: jump cut
Cody: time travel
Laughs in photoShOp 🤣 Cody out here swingin' fists, maybe slaps I don't wanna assume.
I never thought that putting a gas in a balloon would eventually result in the balloon being popped or left with just Air inside. It's good to know that balloons are not a good way to store gas for a while.
A Car Wheel Innertube Would Be Better
@רותם שלו Even then the oxygen was diffusing in and out of the balloon, just at equal rates
@רותם שלו yeah but theres really no point because then you're essentially just storing a balloon in a tank of whatever gas you were trying to store
Imagine if every time you farted your ball sack would inflate a little
@VoxNerdula Imagine if the composition of gasses in your ball sack determined your child's natural body odor at conception
Cody: So it has been, gosh over a year since I first put these ballons here.
I: Wot? Thats real devotion to science right there :)
Yea the got me too.
CKinfall when did he jump two years in plants in a tank 2? I don’t remember that
@Cody'sLab Oh you science tease!
Cody does that a lot I think the carbonated honey one lasted 3 years
@nitehawk86 It has taken a lifetime already. Fascinating though, and more interesting than watching paint dry and then flake.
Great to see the "old style Cody" experiments. 👍
That was great experimentation! 👍
Using the radioactive bucket as a paper weight.... nice
@Sibula definitely.
but so will be a craker box......
The old rad can.
@david blarstron Lol hell no. A cracker box will stop alpha and beta radiation but doesn't do shit to gamma. It's a maximum of 0.5mm of steel, usually not even that much, and steel only blocks about a third of the amount of gamma radiation compared to lead. I doubt it would reduce the radiation intensity even 10%. Why don't you just go see the video where he made it? He shows a geiger counter next to the yellow cake he made and when it's in the can...
@Sibula cody dosent have anything thats even remotely dangerous.
@david blarstron Not so much anymore after most of it was taken from him, but I'd still feel much safer storing the reminder in the rad can if I was him. I'm not sure what he still has, but while yellowcake is pretty safe because of the extremely long half-life, I wouldn't be surprised if he had something a little more dangerous there as well.
“I’ll have to bury less charcoal to offset my greenhouse potential” what a guy. Love you Cody!
That's funny, I was just thinking how sad it is that smart people are usually more susceptible to indoctrination.
I love it when Cody does science at pure random. It it always a joy to hear him break down the scientific method.
I disagree ,he pretty much follows it ,i was thinking about how he is a really scientist because the way he founds an answer to a unknown phenomena.
Excellent discovery! I would have guessed that the SF6 was actually increasing in pressure due to breaking down while interacting with the latex in the balloon. Would it be possible to attempt a SF6 in something like a mylar balloon to see if the same results appear? It isn't that I disagree with you, I just think it would be a good proof of concept. If there were a way to see the gas interaction inside the balloon I would have suggested that too, but without some type of spectrometer, I had to think of a different possibility. Thanks for the content and excellent experiments! Keep up the great work!
Mylar has a different structure, so we wouldn't know what was causing it. You could possibly put some SF6 in a sealed box with a lot of balloons, and then see if it is still SF6 at the end.
SF6 is pretty much the model of an inert compound. It takes really extreme conditions for it to break down.
The amount of projects you must have going at once is amazing. A YEAR later, that's some dedication, really interesting experiment and results.
and he said its not even on the top ten longest experiment he had. lmao
i was taught that helium escaped because the atoms were so small. I was taught wrong
@nagualdesign What, the bit about metal cylinders leaking H and He? That's fact.
@Cody'sLab Partial pressures are more important than many people realise.
@nagualdesign I worked at a place where Hydrogen (the capital letter is correct) was stored in canisters. It leaked from everywhere, including the gas bottle walls, albeit very slowly. More of it leaked from valves, connectors and metal tubing (which has a thinner wall than the gas canisters.. The gas had to be stored outdoors to prevent the possibility of escaped gas building up to an explosive partial pressure.
Fun Fact, I just did the perfectly fitting exercise for exam prep... How long does a 20cm diameter, 2mm wall thickness glass bulb filled with 4 bar He need to get down to 3 bar pressure? Spoiler alert, approximately 14.000 years..... So yes, it works, but very very slowly is literally not an understatement...
@Myke Prior Brilliant remark, this is very easily forgotten. In fact the difference in size between He and H is by a factor of 4 !!! Thats half a magnitude...
“Just playing with sulphur hexafluoride”
Best quote from Cody ever
this is so nice. when you said sulfur hexaflouride, I immediately thought that air must have diffused in, but yeah, one doesn't really think about osmosis in terms of gas to gas. I certainly never heard about it before.
Good stuff, I'm amazed this experiment was a year long.
I didn’t expect that. but I think of all the other experiments that must be run also such long.
I mean, the majority of the video was probably done in a month, maybe two. Then he might have forgotten about it etc, and then came back to it recently to finish it off.
That's my take at least.
Hell yeah, like I might have expected half year...dunno?
Awesome video to Cody because, I got to know SF6 through electrical engineering, sulfur hexa fluoride is a really good electrical insulator. We used it contained at high pressure in the mobile high voltage disconnects. Weell mobile meaning fork it onto a flat bed buuut...ya know.
Is this a property of fluids, or all matter? Looking forward to your video on osmosis in solids...
Yes? Most crystal lattices have space for impurities to get through. Molecular air is simply too large at standard temperature. Ironically cooling it down to decrease any bond lengths would allow more permeation (as the solid lattice doesn't change as greatly as the repulsion of gases would)
Applied Science did an interesting video on supercritical CO2 in which he found that the pressurized CO2 would in fact diffuse into acrylic, which was really mindblowing.
Fascinating, my first guess would have been that the SF_6 had decayed and never would have thought of this sort of experiment.
Prank idea: fill a baloon with enough SF₆ so it will pop in a few days, and leave it at a “friend's” house in a rarely-used closet or hidden somewhere.
Calculate so it goes off when they’re awake, but not doing anything
That's how you get idiots running around saying their house is haunted.
8:27 >>
You could say that some of the atoms...
Argon.
You gave me cancer.
@Krisematics
I a-door your kindness but I'll pass.
Olaf Gołąb your noble attitude is rad.
@Olaf Gołąb bro you're lit XD
Arrr , You Be Walking The Planck .
Accusing of "stealing ideas" of science videos is very stupid by itself. The whole point of scientific approach is to replicate results over and over to confirm facts and test hypotheses. Multiple science channels doing same stuff is a good thing, not a bad worth complaining or accusing of copycatting.
I agree with you, but copying others repeatedly would make the whole community less diverse of ideas and topics, and therefore less likely to grab the attention of new comers, which is the primary goal of most YouTube channels, as that's how you sustain a channel.
When it's you're livelihood you give a shit. Applied Science actually imparts value, not highschool science fair projects.
@Myke Prior lmao you confirmed my suspicion that you're a hater of the channel. Why are you even watching his videos if they're so beneath you? Do something with your superior intellect other than commenting on YouTube about how stupid everyone else is
Myke Prior no, science is like 90% doing what other people have already done. No good scientist would care if someone makes a video about the same topic as someone else.
Hey Cody! I was always hoping you'd make a video on this topic. I mentioned a pure-nitrogen balloon in a comment to another video, to which you correctly replied that it would pop! I work with gases, and had some opportunity to try this phenomenon before. My method was a little simpler, and did not require a vacuum pump: I simply inserted one balloon into another, then filled and closed the inner one with one gas, then the outer with another (or the same gas, for control).
So there's a couple different things going on here:
Molecule size vs. weight: With these balloons, it's mostly molecule size that makes a difference. All the noble gases have very small molecules (being monatomic) leak very quickly and I see no difference between helium and xenon, even though the xenon is heavier than SF6.
Chemical effects: For these latex balloons, chemical reactions make a difference. This is a common science fair project, just try some propane/butane in a balloon. It can dissolve through the membrane faster. I suspect this is the main difference between oxygen and nitrogen diffusion (oxygen leaks faster in my experience).
Partial pressures: The partial pressures of each gas species want to equalize across the membrane. If you have SF6 in a balloon, then the oxygen and nitrogen from the atmosphere essentially "see" empty space inside it (zero partial pressure of oxygen and nitrogen). So they will leak in relatively quickly. This even works when the balloon is filled with pure nitrogen, because oxygen will leak in faster than the nitrogen can leak out. The difference in partial pressures is also higher (the balloon starts with about 1.05bar of N2 inside. Outside is 0.2bar O2 and 0.8bar N2. The balloon probably pops at about 1.1bar).
Before I knew this, I tried storing some leftover xenon in zip-lock bags, thinking that these would not have overpressure and therefore not leak. I then put it in the freezer to slow the gas down. When I took the bag out some time later, it was still inflated. However, inhaling it did not have any effect on my voice... Air had filled the entire volume of the bag and the xenon had left it, without deflating the bag.
Lastly: I mentioned my own experiments above. What really convinced me of the fact that gas can leak into a balloon across a total pressure differential, was having a small nitrogen-filled balloon inside a larger helium-filled balloon. Of course the outer balloon leaked a lot to the outside, but also into the inner balloon. Not only did that balloon get bigger, inhaling it affected my voice.
Oh, and let's not forget that one gas is often left out when discussing atmospheric composition: Water vapor! If you have 100% humidity in standard conditions, about 3% of the air is water! Would be interesting to see what a balloon filled with dry air does in a humid atmosphere! 3% increase could be enough to pop an already full balloon.
@foogoid going by that paper, water seems to diffuse quite strongly/quickly through rubber, so maybe harder to tell
"That's cool! I didn't know that. Now I do and so do you" -That sentence sums up the appeal of this channel quite well
I've heard that "party store grade helium" is mixed with a little oxygen so that it's less likely to asphyxiate people accidentally... But it seems much more likely that they're just cheating you out of some valuable helium by padding it out with cheap oxygen, which also requires you to use more of the helium mix to lift the balloon. I think this may have been part of why your helium balloon had some gas remaining after a long time to diffuse out.
I'm an automotive mechanic and I've experienced this with converting older vehicles from R-12 to R-134a refrigerant as the R-134a is a smaller molecule the hoses need to be changed to a different type to keep the gas from escaping through the rubber. This is still a very eye opening science experiment.
There must be another explaination for it on the energetic level. A bigger volume under overpressur stores more energy than bevore. So in a way the high SF6 concentration has some hidden energy in it that is transformed.
The energy you are looking for is hiding in it's low entropy.
The gradient is what drives the permeation and the gradient is basically potential energy on a molecular scale, aka entropy.
Pure separated gasses are lower entropy than mixed gasses. I think there are a few different ways to turn that into useable energy. Though i don't know of any practical uses for it
I've read a few articles about electrical generation methods that work using this principle. One of them is a type of electrolytic carbonic acid cell that generates electricity from the diffusion of pure CO2 into air, and there's another one that does this with freshwater diffusing into seawater.
So the interesting question is, why is the entropic gradient here is bigger than the pressure gradient?
@Daniel Katz Watch cody's vid on partial pressures
Once I was doing some stuff with hydrogen balloons and I left one out for a long time and when I tried to burn it nothing happened. I guess it was just a air balloon by then.
Cool
This is like water moving due to a differential in osmotic pressure through a membrane, it never crossed my mind gasses would do something similar.
what a great scientific surprise! I love those type.
lol
@Cody'sLab shame as you're the one doing the hard work most of the time and not being paid much for it.
@Cody'sLab Why would someone patent this idea? I'm not seeing any marketable or industrial uses for a non rigid container that very slowly expands.
@The White Dragon It looks good on a resume.
@The White Dragon These are the jokes, folks.
Ok just gloss over the fact that you let those balloons sit there for a whole year
what do you mean?
wait he was serious? xD
Seriously, I had to do a double take there.
Oh wow I just got to that part lol
2:10 I think the rubber matrix is damaged by the constant bombardment of heavy molecules and the ftalates are leaking out just like old rubber bands 'melt' before they dry out
Incredible content Cody! You keep me learning new things all the time. I'm impressed with the large timescale of so many of your experiments, you are very dedicated. Keep up the great work man!
i always love the part when you explain the science with stuff around you and you really explain it real easy something that could be very complex
When you think about it, osmosis is just selective diffusion: Some molecules pass through and equalize in partial pressure, while others don't.
Yeah, pretty nice! I also like to think of the bigger molecules just "blocking the holes" on one side of the porous material, making it semi-permeable. A bit like a rubber valve in piping :-)
@The Cheaterman I think you can also think of it as that SF6 slams into the balloon plastic and is repelled. Thus that increases the pressure without leaving the balloon. Other gas molecules get in and raise the pressure until there is enough of them such that leaving and entering molecules numbers are at a balance.
@The Cheaterman like a ball check valve
@Andrew Stambaugh yes exactly!
I love stuff like this, this is exactly how some of the most exciting scientific discoveries are made; completely by accident! :D
Thanks Cody. It would have been very interesting to weigh the balloon at various stages, whilst calculating the volume (and surface area, if possible). Volume is easy to measure by immersing the balloon in water. You could also have inflated several balloons with SF6, and done gas analysis on each of them at timed intervals, if you have a suitable analysis tool.
Nice video Cody. It reminds me how interesting it was for me to find out in one of my classes that no polymers are actually impermeable. Makes sense of course, especially how you explained it, just surprising since we tend to think of polymers (especially elastomers used for sealing gaskets and such) as being totally impermeable. Nice!
Amazing video cody!! I really like those fun projects you just stumble upon by accident. Really makes you feel like there is so much in this world left to learn!!
I remember watching a video from Applied Science about sulfur hexafluoride in tennis balls, and even though that was never actually done, he explained how that could have helped the balls stay inflated for longer by having the right concentration of air and SF6, where air enters at the same rate as the FS6 exists, keeping the pressure more or less constant
Hmm. Loved this but got me thinking. The sound of a popping balloon: is it dominated by the gas around the balloon or the gas in the balloon? If you fill to popping with air, helium, SF6, do they sound notably different? The sound is still traveling to your ear via air, but does the density inside affect the pitch of the pop?
This is a great video! Such a simple idea, you decided to use the scientific method to come to your conclusion by doing all the necessary steps, textbook like. You're great Cody :)
This is very interesting! It reminds me a lot of cells in hyper/hypotonic solutions.
Your explanations were excellent too!
I remember doing an experiment like this way back in middle school but it was using water and salt water, It was a way to understand how our cells in our body absorb water using osmosis. I always thought it would work with gasses but I never knew what gas’s would work.
I'm always perplexed by his opening statement "Welcome back..."
We never left planet CodysLab.
This is a really awesome video, keep it up. It's always insightful, to have you teach me something the textbook doesn't. Keep doing what you're doing, you rock! ;-)
NightHawkInLight - 2020-07-17
Whaaat. What a cool thing to discover at random. Almost as surprising as back when you did vials of supercritical gasses, how the liquid needed a certain amount of headspace or it would crack the vial. I still don't understand the goings on of that one.
sumduma55 - 2020-07-19
@NightHawkInLight Could the Ballon wrinkles just be an effect of the surface tension of the balloon overcoming the elesticity because the gasses are released slow enough that it doesn't automatically overcome it? If so, then disturbing the balloon should or could allow the surface tension to release triggering the normal elasticity to return to a normal condition.
I guess it would be an effect of inertia. The amount of energy input isn't high enough at a single time to overcome the inertia of an object at rest when the gasses are released slowly enough. When you touch it, energy is added to the system and the inertia is overcome.
Carlos Leon - 2020-07-20
Freezing water in a bottle.
Eskir - 2020-07-21
@Richard Smith I can confirm that animal fat does not work as a plasticizer for latex, and by extension PVC/Vinyl. I know this from observation because I spend a lot of time around those materials for personal reasons. That, and fat/grease/oils are known to damage latex condoms.
It is, infact, the heat that causes this. You can observe this by simply inflating a balloon, deflating it a while later and then blasting it with a hairdryer. Or poke it with, say, a spoon - it will not contract in that case provided the spoon is colder/same temperature.
GRBTutorials - 2020-07-21
NightHawkInLight I always assumed it was just the rubber decomposing and becoming sticky... maybe there’s another explanation?
RWBHere - 2020-08-09
@fredlllll Warm rubber contracts.