A Sodium Bromate Cell

[@ScrapScience]

Back into the practical stuff. I apologise if the audio in this video has a bit of an echo - I hadn't fully transitioned to using my new microphone when filming this one. Also, if you missed it last time, Scrap Science now has a Discord server! You should join us and chat about electrochemistry and projects here: discord.gg/m76mHpvdGW

[@mcwolfbeast]

The animations explaining the reaction were nice and clear. Thanks for that! *POW!*

[@bedlaskybedla6361]

Nice video as always! You could just put jar with sodium bromide into beaker with hot water from kettle, that should be enough heat to dissolve it. It's nice and easy setup for some simple heating when you don't have hot plate. I use it for heating test tubes all the time, it's faster than waiting for water to start boiling on the hot plate. And test tubes don't need much heating. Add some KCl solution into your leftover cell solution, KBrO3 is much less soluble than NaBrO3, so you should recover most of your bromate pretty easily. I've read that Na2MoO4 or K2MoO4 can be used instead of dichromate. Never tried that though.

[@nugget4814]

Here is something that I've been obsessed the past few years: cheap energy-dense inter-seasonal energy storage. I spent months of research and still didn't find something simple and reliable enough. I am basically trying to find an electrochemical plant that can store energy in a much more efficient way than natural plants do (unicellular algae being the most efficient but difficult to harvest and requiring large ponds) Great video and animations!

[@thedarkestlotus2086]

I appreciate your time to show that electrolysis is an applicable and underused form. Thank you.

[@Cs13762]

there are a lot more experaments you can do with electrolysis lol one thing in particular i would love to see you do something with is those ion exchange membranes you can get. would love to see you do some continuous electrodeionization or separation of different ions with dialysis type things!

[@ScrapScience]

As a matter of fact, I've got a cell running that uses a Nafion membrane right now as I'm typing. There'll be a video soon (though I have a backlog of about 4 videos to get through before it's uploaded).

[@0Arcoverde]

​@@ScrapScience maybe doing them with both to show difference

[@varshil_Pandav]

@@ScrapScience Yeah , i can definitely expect Backlogs by the Person from Science XD

[@RiehlScience]

I built a bromate cell using graphite rods from a battery and it worked surprisingly well. There was very little erosion.

[@SerumCRM114]

I really liked the animation of the reaction mechanism. It is a good visualization of what is happening in the cell. Is your next project going to be the production of the illusive perbromate ion?

[@ScrapScience]

Good to hear! It may be in the works... As I may have mentioned a couple of videos ago, I now have a certain electrode material that can do some very impressive things...

[@Hyo9000]

The explanation was amazing as always ❤

[@Chemixtrea]

Hmm, yes that was very similar to a chlorate cell. Just for an idea, i'm thinking about a catalyst to convert formic acid into hydrogen and CO2... You know, to run hydrogen cells off. Anyway, love your work, keep it going.

[@ElectraFlarefire]

The new animations/etc work really well! I still don't understand the why(EE brain, not chemistry brain), but it shows how the atoms move around and where it all goes.

[@olimp231]

I like the animations. It is much easier to understand what is going on.

[@alllove1754]

Hi there ❤❤ I love watching your stuff, especially since I've had interest in electrolysis for some time. I've not put anything into practice otherwise I'd be filming it on my own channel. Perhaps in time... anyways.. since you said you want to do everything electrolysis it is actually possible to synthesize nitroethane and perhaps nitromethane using a propionate salt and a nitrite salt. The electrodes may be expensive, but it appears you've got the necessary precious metal electrodes for anything. There is a channel on here where the guy actually had a success. I thought that was pretty cool. Bromate salts are very useful even in organic Chem for oxidizing substrates. ❤❤keep em coming❤❤

[@michaelzumpano7318]

Beautifully done!

[@_cindy_sherman_7714]

animation and explanation were excellent. This is the first time I've watched your channel, so I might be a little rusty, but it would be nice to see a review of the oxidation states of the ions and their names.

[@ScrapScience]

I'll jot it down as something to possibly cover in a future theory video, thanks!

[@haraldclark6206]

Great work! And excellent explanation!

[@CryptoFrenzyX]

Yes he is back

[@user-pr6ed3ri2k]

I love the animation! This video taught me a lot about electrolysis

[@user-pr6ed3ri2k]

Although I do wonder whether or not the radical intermediates actually do stick to the cathodes and anodes like that

[@ScrapScience]

As a matter of fact, the intermediates certainly do bond to the electrode surfaces! The reaction pathways of the hydrogen evolution reaction are great things to look up if you want to see more of an explanation.

[@user-pr6ed3ri2k]

@@ScrapScience I see. If I understand correctly, the reason the platinum anode isn't corroded despite the bromine bonded to it is because any formed bromide is instantly oxidized again. A question I have is why aren't all anodes resistant to halogens or persulfate despite this protection at the anode?

[@user-pr6ed3ri2k]

What happens to titanium at the cathode too? There is an oxide layer afaik, which should(?) stop anything from bonding to it. Assuming the oxide layer isn't a problem, titanium hydride is unusually stable at room temperature, and unlike the case with bromide, hydrogen is actually reduced to hydride. Why doesn't it form on the surface? (I have only seen diagrams about the hydrogen evolution reaction, and it seems to me that the animation in the video is of the Volmer-Heyrovsky mechanism)

[@ScrapScience]

Ah, don't consider these bonds to be chemical bonds in the sense that they form new compounds like platinum bromide or titanium hydride. They are adsorption bonds - as in, they are physically bonded, not chemically (or at least, not in a 'true' chemical bonding sense). The reason the platinum anode is not corroded is because the platinum atoms don't get oxidised themselves in the whole process. Adsorption can still occur on titanium if the oxide layer is thin enough. The hydrogen evolution reaction I've animated follows the lines of the Volmer-Tafel mechanism, but the animated chlorine and bromine evolution reactions follow the Volmer-Heyrovsky mechanisms instead.

Those animations are really cool and helpful.

[@FireAndFumes]

Hi! I saw your potassium chlorate cell and I have a few questions. Firstly, how long did you let it run in total? Mines been on for a bit over a day and there a few tiny crystals of potassium chlorate but barely any. I also made a bit of a mistake and put the electrodes quite far apart (I don't think it matters too much as nurdrage did it) so maybe that may be making it slower then normal? Also I'm curious why you only used 3 amps, are there downsides to using more such as 4-5?

[@Nesveller8976]

How many amps are you running at? I'm not exactly sure why he used 3 but probably to reduce excess heating. But at the same time it's good to have some heat in this cell so I'm not sure.

[@FireAndFumes]

@@Nesveller8976 I'm running at the same as him pretty much. 3 amps 4.1 volts

[@ScrapScience]

I had it running for 16 days all up. It's a pretty slow process sadly... The only reason I limited my current to 3 amps is because of my alligator clip connections. In general, I don't like pushing more than 2 amps through a single alligator clip. The contact resistance can lead to excessive heating on the connections. If you've got multiple alligator clips or a proper bolted connection, there's no reason to limit the current to such a low value.

[@FireAndFumes]

@@ScrapScience What's bad about excessive heating?

[@ScrapScience]

It would damage the electrodes (at least on the connection points), lead to excessive oxidation of the clips, likely damage the lid of the cell, and pose a fire risk. I’ve genuinely seen some bad connections locally heat up above 350 C. Obviously, this is dangerous to touch since you generally don’t know if a surface is hot before you grab it, and its combination with a flammable gas like hydrogen is… worrying.

[@GeraldBlack1]

Just glad we don't burn the trash anymore, just the good stuff lol.

[@AradijePresveti]

Yeah, that looks healthy

[@Dan-vq4pz]

This man driving electrons into everything he can; hardest working power supply in the amateur chemist circle 🤣

[@Ma_X64]

Try electrolysis in liquid CO2 and NH3.

[@ScrapScience]

Liquid ammonia is a plan for the future. Liquid CO2 is not something I can do...

[@Uldarr]

Would you expect your product to significantly be polluted with dichromate, or should the recrystallisation have dealt with most of it?

[@ScrapScience]

I performed two successive recrystallisations to get the stuff really pure, so I expect there to be no leftover dichromate. Either way, there was only ever 100 mg of dichromate in the cell, so that's the extent of the possible contamination.

[@snoowbrigade]

we're so back

[@mackdog3270]

Neat stuff 👍

[@Scrogan]

Great animations! I was wondering, if your cathode was above the anode at the very top of the solution, and you never mixed the solution, would the separation due to gravity prevent it from reversing the anode’s reaction? At least if your aim was the production of elemental bromine. What do you do with bromate and chlorate anyhow? And where do you learn about the different electrochemical additives?

[@ScrapScience]

In theory, yes, that's possible. However, whilst the bromine/tribromide is perfectly happy to sit at the bottom of the cell without mixing or diffusing, the hydroxide ions from the cathode diffuse much more readily and will eventually make their way down there. With a good electrode arrangement to slow this down, you might be able to make some elemental bromine, I'm not sure. If you want bromine by electrolysis, it's much easier to use a divided cell, or to just electrolyse hydrobromic acid to avoid the hydroxide ion issue. I have almost no use for chlorates and bromates. The main reason I made these videos is just because they're interesting procedures that people seem to really like. Ultimately, the only thing my sodium chlorate will ever be used for is a sodium perchlorate cell. The only plan I have for the sodium bromate is... also very similar... Anyway, other people like these things for pyrotechnics I guess, which I'm not really into myself. The additives are just things I've found recommended on old forums. They're also used in the industrial versions of these cells.

[@hantrio4327]

There is procedure from woelen.homescience where NaBr is electrolysed for some time and then acidified which causes NaBr, NaBrO and NaBrO3 to comproportionate to Br2. You can also use the isolated NaBrO3 to make Br2

[@lautaromorales2903]

How the dichromate helps to increase efficiency?

[@ScrapScience]

When dichromate in in the solution, a thin film of chromium hydroxide is formed by reductive deposition on the cathode. This film is only a few nanometres thick, but it effectively acts to selectively allow water to traverse to the cathode surface, while slowing the transfer of active bromine species.

[@lautaromorales2903]

@ScrapScience thank! nice animations, i love reaction mechanisms

[@rylanpeepee]

0:37 Bromate go weeeeeeee!!!

[@ioeter5]

I think you should convert the 50g of bromate remaining in solution to Potassium Bromate, as it's a lot less soluable you will be able to extract it more easily.

[@ScrapScience]

Thanks for the idea! I'll hang on to the solution in case I ever need the potassium salt.

[@hantrio4327]

The electrolysis also works when using KBr

[@izzybarwick1521]

lab tour??

[@Tyresio12]

Would it be possible to make a bromine solution this way? Like, the generated Br2 would sink to the bottom layer of nonpolar solvent like CH2Cl2 or CHCl3 and that way "secured" from further oxidation? I wonder what concentration of bromine would be achievable.

[@ScrapScience]

Yes, but if you want a bromine solution, you might as well do this under acidic conditions. Without hydroxide ions hanging around, it's possible to electrolyse fast enough to get liquid elemental bromine to form on the bottom of the vessel. I've actually done this in the past in a very old video, though I'll warn you that I probably wasn't very good at talking to the camera or trying to keep the footage stable: kzbin.info/www/bejne/Y6umh4OwhrRjpc0si=6-15E4NV6UsS-56Z

[@mackdog3270]

Why electrolysis? Is it a particular interest?

[@ScrapScience]

Of mine? Yes, definitely. I’ve been pretty much obsessed with it since I was sixteen - to the point where I’m now also getting a degree in electrochemistry.

[@dimaminiailo3723]

Can sodium bromate be prepared from Br2 and acidified solution of NaClO3 like the iodate? Chlorates are not hard to prepare in bulk even without a platinum anode

[@ScrapScience]

It's quite likely, but I'm not sure. You don't really need platinum for this though - even graphite electrodes will do fine.

[@dimaminiailo3723]

@ScrapScience I'm afraid that bromides are less abundant than chlorides and small scale electrolysis is a nightmare so it's best to avoid it

[@ScrapScience]

But for the bromine and chlorate route, you'd still be needing to synthesise elemental bromine on a small scale too, correct? Is that not equally difficult (at least in terms of yield and practicality)? I'm not asking because I hold a strong opinion on this, by the way - I'm genuinely unsure how difficult the small scale synthesis of bromine is.

[@AnMar13]

Can it produce chlorate aswell?

[@ScrapScience]

Yes, but I have two other whole videos about cells that are more suited to chlorate production.

[@emilalmberg1096]

Found your channel today, and you don't seem that active anymore, sad!

[@ScrapScience]

I took a break a few months ago to move lab spaces, but I’m now back to my regular uploading pace.

[@dav1dbone]

Suppose you had a supply of hydrogen, any ideas for a cheap and simple way to turn it into electricity, possibly some sort of fuel cell?

[@ScrapScience]

Cheap? No. Simple? Yes. I think you can buy commercial fuel cells online for about $10-20 per watt. This is much cheaper than anything that could be built at home. If you're super interested in building the setup yourself, you can also get kits to build the cell stack. Doing it completely from scratch is... borderline impossible without a lab equipped to manufacture the necessary electrode catalysts.

[@dav1dbone]

@ScrapScience I had thought of buying a kit. That is the problem, catalysts, palladium etc, what about running at a higher temperature, does that mean solid oxide fuel cell, that could be even more complicated?

[@ScrapScience]

How high of a temperature are you talking? Solid oxide fuel cells operate at over 500 C! They're not something I have any experience with.

[@slimani373]

Why don't you try making chlorates using a graphite anode and explain how to separate chlorates from chlorides?

[@ScrapScience]

I've got other videos on the production of chlorates. Using graphite anodes doesn't meaningfully change the overall procedure.

[@atari7001]

Potassium chlorate is insoluble. Easy to separate.

[@dimaminiailo3723]

@@slimani373 Perform electrolysis of conc NaCl the usual way until x3 of necessary current has been passed, filter it, add some pure KCl, filter, recryst, dry, enjoy

[@till2911]

Can you try to turn an old car battery into an sulfuric acid production machine? Just fill it up with an epsom salt solution and charge it with a car battery charger.

[@ScrapScience]

I don't really see how that works. What happens to the magnesium ions in that case?

[@till2911]

@@ScrapScience Magnesiumhydroxide or sth else. I just thought it should be possible because some guys repair their old car battery that way

[@الديركي]

The poles you use are always expensive ):

[@ScrapScience]

You can use graphite electrodes if necessary here. I've debated whether to use cheaper electrodes in my videos to make things more accessible, but I don't see the point in having platinum and MMO if I'm never going to use them. I'll always try to make it clear whenever cheaper alternatives can be substituted.

[@الديركي]

​ Thank you I lost hope when I saw the platinum shine

[@snomnoom2741]

Kmart jar

[@ThylineTheGay]

Na Bro

[@Whatisuswold]

It cool but the cell has problem

[@michaelcaprio5269]

Na, bro... na

[@inquaanate2393]

Na Bro 😂

[@gsestream]

na bro.

[@Flesh_Wizard]

NaBrO

[@Ang3lUki]

Nah bro

[@samfisherkiller]

Sweet, love the video! When are we going to see that diamond anode used :P

[@ScrapScience]

As a matter of fact, I've got a cell running that's using it right now as I'm typing. The video will be here soon, though I do have a backlog of other videos to upload first...

[@samfisherkiller]

Awesome. Love the videos. Your channel got me into the electrochemistry of pyrotechnics. Thank you

[@sahiltakalkar7512]

Na Bro