Recreating one of the weirdest reactions

about a year ago I came across this video and it was one of the weirdest reactions that I'd ever seen it's called the Bella Yousaf zhabotinsky reaction and it's one of the very few good examples that exists of an oscillating chemical reaction the moment I saw it I knew I had to repeat it myself and with a bit of searching I managed to find a decent recipe the main ingredients that it called for were sulfuric acid sodium bromide malonic acid and sodium bromide most of these are pretty easy to find online at places like eBay but the malonic acid tends to be a bit more elusive and if you do find it it's often pretty expensive I just managed to get Ridley lucky and one day when I looked it up on eBay somebody was selling a whole bunch of it for really cheap in any case there was still one final ingredient called phenanthroline ferrous sulfate or fara one for short and this was only available from chemical companies however I found that I was able to make it myself with just a couple things from eBay the first ingredient was ferrous sulfate heptahydrate which is often used to adjust soil pH and to increase plant iron levels I actually didn't need that much of it but for some reason I still ended up ordering a five-pound bag the other ingredient was 110 phenanthrene monohydrate and I managed to get 10 grams of it for about $40 so with that being said the basic goal for this video was to first make the farrowing and then to do the Bela Asaf sabot insky the ferrous sulfate was dirty garden store quality and before using it I needed to clean it up so into a beaker I added a hundred and sixty miles of water turned on the stirring and carefully poured in 8 mils of concentrated sulfuric acid I then dumped in 120 grams of the ferrous sulfate and turned on the heating I probably could have just added it all at once but I ended up doing it in several portions just to make sure that it didn't mess up the stirring I let it warm up to about 65 C and at this point all the ferrous sulfate should have dissolved the other stuff floating around were just impurities that needed to be separated off to do this it was pretty simple and I just passed it through a coffee filter the first filtration was still a bit cloudy so when it was done I put it through the same filter again it still wasn't completely clear but it was much better than before and I felt it was good enough when it was done I covered the top with plastic wrap to protect it from air I then place it on the side to cool and I waited for crystals of ferrous sulfate to start appearing instead though a white fluffy solid started precipitating out I think this was just ferric sulfate which formed as some of the ferrous sulfate was oxidized by air the ferric form is way less soluble than the ferrous one so it would make sense that it would be the first to be kicked out when he got to room temperature I filtered it again and almost immediately some small crystals started forming on the bottom of the beaker this time it was actually the ferrous sulfate and I just let it sit here undisturbed overnight for the crystals to grow I then left it for a couple more days but it didn't really seem like very much changed to get more to crystallize out I had to reduce the solubility and the easiest way to do this was to just put it in the fridge when I checked back on it about a week later it looked like I had about double the amount I poured off as much of the liquid as I could and at the bottom I was left with a nice chunk of crystals I tried getting it out as one solid piece but it didn't really seem to work so instead I just had to smash it into pieces which I first thought was gonna be really hard the crystals weren't nearly as strong as I expected them to be though and it was actually relatively easy to break everything apart I then poured it onto a coffee filter with some paper towel to try to soak up some of the liquid that might remain I uh left it there for a few minutes though because they didn't want the ferrous sulfate to start getting oxidized I put it all into a dish and then I placed it in a vacuum desiccator I pulled almost a full vacuum on it and I let it dry for about five hours over this time some of the crystals had become white and I think it's just because a small amount of the ferrous sulfate heptahydrate had become dehydrated and some of its less hydrated forms like the monohydrate and the in hydrous are white instead of the bluish green the final recovery was about 80 grams which meant that there was about 40 I'm still left in the water that I pour it off so this process here wasn't exactly super efficient but I still ended up recovering way more than I needed so it was good enough for me I was now ready to make the phenanthrene ferrous sulfate which from this point on I'll just be calling Ferro in in theory this should be done in volumetric glassware but it didn't really have to be super accurate so I settled for a grad cylinder instead I started by adding point seven grams of the ferrous sulfate that I just purified followed by 90 mils of distilled water I mixed it around until it all dissolved and then I added 1.5 grams of the 110 phenanthroline monohydrate it immediately reacted with the ferrous sulfate to form a complex which had a nice red color I then stirred it until it all dissolved which actually took quite a long time when it was done though I washed the glass rod with a bit of water and I topped it off to a hundred mils I poured the blood-red solution into a storage bottle and I was now ready to do the actual reaction I needed to make three solutions which I'll just refer to as a B and C for a the original recipe called for sodium bromide but at the last minute I realized that I accidentally ordered potassium bromate instead however I figured it wasn't really a problem because it's mostly the bromide part that matters potassium bromide has a slightly higher molar mass though so I couldn't just add five grams and I had to scale it appropriately this was pretty easy to do and I just divided the molar mass of potassium bromate by the molar mass of sodium bromide and multiplying that by five in any case to make a I added 67 mils of distilled water and dumped in 5.6 grams of potassium bromate I turned on the stirring and when most of it had disappeared I poured in two milliliters of concentrated sulfuric acid a few minutes later the solution was completely clear and I moved on to making solutions B and C both of which were much simpler for B I just added one gram of malonic acid and dissolved it in 10 mils of water and finally 4c I dissolved one gram of sodium bromide in 10 mils of water to run the reaction I just had to mix these solutions together along with the fair Owen for the first run I use six mils of a 1 mil of B and 0.5 mils of C there was no obvious reaction between a and B but the moment that C was added bromine started to be produced this turned the solution a yellow orange and I mixed it around until it became colorless again after doing this a few times though I found that mixing it doesn't actually do much and it can just be left there into this I then added 1 mil of the farrowing I swirled it around and it quickly went through a nice range of colors when it stopped changing and it stayed this brownish red color I let it sit there and I waited for the reaction to happen it did end up starting but I was honestly pretty disappointed because the spot that was forming wasn't really very nice to look at this happened because the solution was just too deep so I scrapped this run and I did another one this time though I took out some of the liquid using a pipette which allowed me to get it to the perfect amount one thing that I thought was cool is that sometimes when this solution is disturbed or mixed it can transiently go back to being blue in any case this run was a lot better and the first spot that formed had a nice blue ring around it this reaction isn't so slow that you can't just look at it and see it happening but it's also not very fast so I've gone ahead and sped it up this entire shot was taken over the course of about 35 minutes the process that's going on here is extremely complicated and it hasn't been a hundred percent fully explained yet it seems to be dominated though by nine major reactions and I'm gonna do my best to explain them before I do that though let's just have a recap on what was in each solution in a there were sulfuric acid and potassium bromate in B there was malonic acid and in C there was sodium bromide when Parts A B and C were mixed the concentration of the bromide ions from the sodium bromide was initially very high the bromide ions quickly reacted with bromate ions b ro 3 to form orange coloured bromine this is why the solution changed colors before when Part C was added the bromine then reacted with malonic acid to make bromo mala acid and it regenerated one bromide ion even though one bromide was recovered there was still a net overall loss of bromides from solution in another reaction the bromide ions react with the bro-mates in a different way to make bromas acid and hypo Brahmas acid these reactions caused the general depletion of bromide ions and because of this it can't make more bromine the malonic acid eventually consumes all the bromine and it's why after mixing the solutions the bromine slowly disappeared with little-to-no bromide ions left in solution another process is able to take over this reaction is between the bromide ions the farrowing and the Brahmas acid the major effect is the oxidation of the iron in the farrowing which brings it from its red two-plus form to its blue 3 plus form this reaction also produces more Brahmas acid which feeds back into its own reaction this creates a positive feedback loop and it causes this reaction to quickly take over however there's eventually a point where there's no more Farah when to oxidize so it ends up getting shut down the excess bromas acid that was made starts to dissociate into hypo Brahmas acid and it regenerates some of the bromide ions these last three processes then start to take over where the malonic acid and the bromo malonic acid reduced the farrowing back to its red two-plus state these reactions are much slower than the other ones though so they only take over after the other ones have shut themselves down the overall effect of them is the regeneration of some bromide ions which allows the cycle to repeat itself it's able to cycle many times but the reactants do slowly get depleted and when there's no malonic acid left the farrowing can't be reduced back to its red form so if it's left long enough all the farrowing gets stuck in its three plus state and the entire solution just stays blue anyway I hope that was a decent explanation and that it wasn't too confusing I think the basic idea to remember is just that it's a cycling between the oxidation and the reduction of the farrowing i still have to explain though why this reaction propagates as these waves I think it's a pretty complicated process and it's hard to explain it concisely but I'm gonna do my best the solution here isn't being mixed so the only way for ions to move around is by diffusion however the consumption of the bromide isn't perfectly even across the entire solution and some points will develop a slight bromide deficiency this creates a concentration gradient and it causes the bromide ions in the surrounding areas to diffuse towards it in doing so it resets the reaction at the center of the nucleation point but it decreases the bromide concentration in the surrounding areas this allows the competing reaction to take over and to oxidize the faroe into its blue form this makes a blue ring of solution that has a lowered bromide concentration and again the bromide from surrounding areas diffuses towards it this causes the wave to slowly move out and propagate until it hits the walls of the - the cycle can repeat itself many times and a lot of waves come out of the same nucleation point anyway this was only my second try at doing this and I was pretty happy with how it turned out I decided to try it again in a larger dish and I just scaled up everything by a factor of three so for this one I used 18 mils of a3 of be 1.5 of C and three of the farrowing I also pre-mixed it in a beaker so that I could control how much I added to the dish and somehow on my first try I poured in pretty much the perfect amount it initially seemed to be working well but a bunch of bubbles started to appear which interfered with the visuals at first it's honestly not that bad but as the reaction progresses it just gets worse and worse the reason they form is because of the reactions that I mentioned earlier that reset the cycle when the blue farrowing is reduced back to its red formed by the malonic and bromo malonic acid it produces carbon dioxide and carbon monoxide aside products this didn't really seem to be an issue with the previous run though so I thought that maybe it was just a problem with larger scales I tried it again with a smaller dish though and not only did it make a lot of bubbles its spots also didn't grow very nicely where the spots grow from and propagate seems to be somewhat random so it means that every run is gonna look different so I guess I just got lucky that my first one not only didn't make bubbles but it also was visually very nice I ended up trying this a few more times on both the small scale and the larger scale and it was never able to get it without bubbles I really wanted a nice clean large scale version though so I tried to figure something out for this run I tried it with a bit less malonic acid and a bit less sodium bromide to see if it would make fewer bubbles however it didn't really seem like there was much of a difference I didn't actually really think it would do much of anything but just for the sake of it I tried using less bromate what I did was instead of measuring out 18 mils of solution a I measured out 12 and then diluted it to 18 so the bromide ions are about 30% less than they were before it still kind of worked but there were some odd effects and it wasn't able to make the blue wave fronts in any case from a chemical perspective I think the only way to reduce the bubbles is to completely replace the malonic acid and to use something else instead of ferrah one with a quick search on Google I found a paper that talked about some bubble-free variations this is a pretty big topic though and I think it's something that I should maybe cover in a future video so for now I just tried coming up with another solution I didn't mention it yet but this reaction is able to do multiple cycles if it's shaken or mixed at any point you can just leave it there again and it will start over so my ideal was to let the first cycle go completely to the end and then to shake it to manually dislodge the bubbles this was my first attempt and it seemed to work by the third run there were no bubbles but the cycle was also way faster and looked really different I think this is just because at this point the amount of malonic acid that's present is much lower this means that it can't convert the farrowing back to its red color as quickly so the blue color slowly takes over with this result I just immediately jumped to trying it on a much larger scale I mixed together 90 mils of a 15 of B seven and a half of C and 15 mils of the farrowing and poured it all into a large cooking dish I spread it out as best I could and I also leveled the dish using a bit of paper the first cycle wasn't very good and I think it's because it was a little bit too deep with each subsequent cycle though the color seemed to improve in the end though the result was pretty much this a smaller scale and by the third cycle there were no bubbles it had the same issue though where there were no ripples and it was just these growing solid blue spots I still thought that it kind of looked cool but it wasn't exactly what I wanted I ended up trying several different things and I think that this was the run that turned out the best the first major change was instead of using 15 mils of the fair one I used nine I also found that I could add less liquid than necessary and just let it sit there for the first cycle I'm not really sure why but afterwards when I mixed it to reset everything it would spread out properly although the first cycle is completely lost by doing this it's still pretty useful I found that one of the biggest issues when scaling up was just getting the liquid even across the dish and this really helped with things the third run still had some bubbles in it but it was relatively clean and the colors were nice and vibrant it did have random flashes of blue in the background though which was kind of weird the first blue flash also seemed to change the appearance of the waves and make them a bit sloppier in general the waves in this third cycle were a lot thicker than the previous runs and at first I thought this was a downside however after going over a lot of footage I realized that it was actually a good thing because as the scale gets bigger it becomes harder and harder to see the thin waves so for large scales to work and for them not to look like a jumbled mess the waves need to be thickened anyway with that being said that brings us to the end of the project as I mentioned before in the future I might try to explore some of the other variations of this reaction there are some bubble-free ones which might be interesting and there's also the original recipe which uses cerium ions as well in the last video I did a giveaway and these were the winners I've already shipped everything out for Jack and David but unfortunately Audrey never got back to me so I did another drawing and replaced her and the new winner is Joshua from Belmar New York anyway with that being said here's a cool clip that I just posted to my Instagram if you haven't already you should definitely follow me there because I often post stuff that never makes it onto this channel as usual a big things goes out to all my supporters on patreon everyone who supports me can see my videos at least 24 hours before I post them to YouTube also everyone on patreon can directly message me and if you support me with $5 or more you'll get your name at the end like you see here [Music]

Channel: NileRed

Views: 3,244,421

Rating: 4.9640574 out of 5

Keywords: nile, red, science, chemistry, tutorial, belousov-zhabotinsky, belousov, zhabotinsky, organic, waves, hypnotic, malonic, oscillating, weird, phenanthroline, ferrous sulfate, ferroin, chemical, reaction, nilered

Id: LL3kVtc-4vY

Length: 19min 14sec (1154 seconds)

Published: Mon Jul 16 2018

Reddit Comments

[u/Ankari_]

The fluxing, vortical properties of space-light manifest in this video O:

[u/hanizen]

beautiful, as a chemistry graduate I give this guy major props for his knowledge

[u/Yahwings]

Fascinating stuff. Thank you for sharing.