Making Iodine

To make an addition to my halogen collection, I have a go at synthesising a small quantity of iodine from potassium iodide.
Due to the lack of cheap oxidisers available to me, I decide to oxidise the iodide ion by electrolysis, with pretty limited success. Electrolysing a solution of potassium iodide mixed with sodium bisulfate results in iodine forming (albeit quite slowly) on the anode, assuming the electrode is inert.
Running a cell like this for 20 hours at an average current of around 0.3 amps, I extract a couple of grams of elemental iodine. After purification by sublimation and then sealing in an ampoule, I'm left with close to one gram, not much.
It would definitely be possible to improve the yield of this process (probably by increasing run-time or current density), but it seems that oxidisers like concentrated sulfuric acid, peroxide, or chlorine are MUCH more efficient at extracting the element. If you decide to make iodine yourself, I'd recommend going with those options rather than this electrolytic process.
Links to my bromine videos:
Making Bromine - • Making Bromine
Ampouling Bromine - • Ampouling Bromine

[@ErgonBill]

All the other halogens end with the 'een' pronunciation. Enjoying your videos; you are very clear, concise and very well presented. You are a good teacher.

[@HwSystems]

I'm very interested in your peroxide production via gas diffusion electrode. If you succeed it will be awsome.

[@SciDOCMBC]

It doesn't matter if graphite contaminates the iodine. This can be solved by sublimating the iodine afterwards. Iodine in the gas phase is wonderful to look at.

[@geniusdude8975]

You could pass chlorine gas in KI solution. You could also make chlorine from your hydrogen generator by adding NaCl.

[@ScrapScience]

I did consider it, but generating chlorine seemed like more trouble than it was worth. My H2 generator actually can’t be used for chlorine either, the nickel electrodes wouldn’t hold up. I’ll build a chlorine generator in the future for these kinds of oxidations though, it’ll be useful.

[@geniusdude8975]

@@ScrapScience yeah, you can use Pb Or C electrodes

[@pavithrank1012]

You can generate Cl by adding harpic and bleach

[@MadScientist267]

@@ScrapScience I agree. It's easy once you have a dedicated cell set up for it. I just use carbon/carbon and HCl with a tube set up to catch it, just release the hydrogen. This works for hydrogen as well, just flip the polarity, although kinda a waste for just the hydrogen lol Probably wouldn't be a bad idea to make both rods trapped but if you're mostly after chlorine from it, not necessary. The presence and use of chlorine assumes adequate ventilation for such and implies the hydrogen present will not be problematic.

[@tomwatson9178]

By 14:47 I was expecting to read “even thIS quantity was misleading”

[@mohmad2822]

13:12 I suggest that you read an article entitled (Recovery and purification of iodine) to know that sublimation does not purify iodine so as to make iodine suitable for human use such as eating it, for example. and I would like a video of an application for the correct purification method in the best way!.

[@NormReitzel]

You might try oxidizing iodides to iodine using netutral persulfate (sodium or potassium, not ammonium). Works great - not super fast, but quite exothermic,

[@mrgreenswelding2853]

I live in Brisbane and can get both sulphuric acid and h2o2 both concentrated.

[@Enjoymentboy]

While i have absolutely zero need or use for it I've always wanted to make some iodine. I find the crystals and colour to be extremely pleasant to look at. This however has not been a good enough reason to go through the effort.

[@deathkeys1]

I suppose, chlorine gas would work as well, since it is a good oxidizer and would force a single displacement reaction.

[@ScrapScience]

Definitely yeah, I honestly just wanted to see how effective electrolysis would be (as it turns out, not very). Chlorine or peroxide is definitely the go though.

[@markshort9098]

For peroxide check hydroponics stores and for sulfuric acid check plumbing supplies.. in Australia mo flo drain cleaner is 98 percent and cost 48 bucks per litre at plumbing supplies and 65 bucks at hardware stores

[@ScrapScience]

I’ve been planning on checking with my local hydroponics store for peroxide, that definitely seems to be the way to go if they sell it. As for mo flo, I’ve been looking in various plumbing/hardware stores for years and have never found any of it, I’m starting to doubt they even sell it in my state, but I’ll keep looking.

[@markshort9098]

@@ScrapScience eagles plumbing supplies have it in nsw

[@lisawilliams8312]

It’s not sitting in plain sight. You just need to ask the salesperson and you Shall receive

[@ErgonBill]

@@ScrapScience They sell acid drain cleaner, but only to registered plumbers in Tas. Battery stores maybe?

[@loganbrown9553]

I prefer the pronunciation of iodine as io-deen becase: Fluorine Chlorine Bromine Iodine Astatine

[@MadScientist267]

It's funny you mention it in this way... Was thinking the same thing. It should just follow the others but because I learned it "dyne", "deen" sounds strange to me lol

[@experimentalaquimica]

Povidone iodine contains 1% iodine in molecular state I2 in addition to excipients. The method I have used is reduction with sodium bisulfite and precipitation with calcium hydroxide to remove excipients and povidone.

[@-r-495]

Have you ever experienced the copper cable acting like a wick and sucking out your reaction mix?

[@ScrapScience]

Occasionally, yes. But never to a large extent. It occasionally drips out the other end, but I've never lost more than a few millilitres that way.

[@michaelfischer6984]

Why were both solutions brown from the start? They should be clear.

[@ScrapScience]

Under acidic conditions, some of the iodide ions are oxidised (by oxygen gas in the air) to make triiodide, which gives the solution a very brown colour. It just happened quite quickly in this case.

[@ivanfaye3041]

Will you try to do helium 3or is it to complicated

[@ScrapScience]

Are you talking about regular elemental helium gas or the isotope helium-3?

[@heathwilliams1489]

sublimated in the early morning? must be VERY hot there.

[@ScrapScience]

Iodine sublimation can easily occur at (or below) room temperature.

[@kryel2614]

I just closed iodine in the amuple, why after time Iodine vaporizing into brown color-violet, and make dirty, brown glass that I cant see iodine anymore :( I tried with the argon gas but no helping..

[@thomasfranks8598]

Assuming you did have Hydrogen peroxide and Sulfuric acid, how would your procedure differ?

[@ScrapScience]

In that case, I'd just use one of these methods: kzbin.info/www/bejne/aHfCnIOOl85lepo kzbin.info/www/bejne/kHezaJmPfNd5iKs

[@SkynetT800]

Thanks for the lesson.👍 I was wondering how I can check a product four traces of fluorine?

[@hubari7867]

Hey, nice video :) Which buck converter are you using?

[@ScrapScience]

Thanks! I pretty much just searched on ebay for the cheapest 'ten amp' buck converter I could find: www.ebay.com.au/itm/192007593319 Turns out it actually works very well, but whether or not it can actually handle 10A is not something I really want to test.

[@kreynolds1123]

@@ScrapScience probably most every computer power supplies can put out well over 10 amps at 3.3v and several 10's of amps at 5 volts, without needing a separate buck converter from 12v. But maybe it's nice to have the extra control over the amp draw through controlling the applied voltage. Incidently, one can also limit the current by controlling the submergef surface area of the electrode.

[@MadScientist267]

So if you were intent on drying the iodine completely, what method would you use? Everything I can think of would either result in reactions taking place or non trivial ad/absorption loss

[@ScrapScience]

It's a very tricky thing to purify without loss. I honestly don't know any good methods here. I'd imagine a series of repeated sublimation process would probably be the best way to get minimal loss.

[@ngochuy6250]

ok good

[@markselten4985]

Local chemists, Woolworths store or hairdressers sell peroxide. Shouldn't be too hard to access?

[@ErgonBill]

It's only 3% and too expensive to concentrate.

[@kayakMike1000]

Polar pure!

[@canadafelixproductions4036]

哇，是不是碘化钾吗？

[@tek4]

I'm very new to your channel. Like found you today. I like the way you make vids bro. I appreciate the knowledge, and if you check my channel you will see I'm a different feild then chemistry. But it's wonderful science that bonds us

[@lisawilliams8312]

Where r u located?

[@elyesgrati]

I think Australia

[@ScrapScience]

Yep, Australia’s correct

[@dangriff12]

So Australians are on the fence with pronunciation of iodine. I think it's the case that we (The British use the een sound and the Americans use the eyne sound.)

[@AndreLuizaet]

I really like your videos and wanted to know if you have any emails to contact, I want some tips on a project of mine.

[@ScrapScience]

Hi, sorry for the late reply. I'm afraid at this stage I don't have the time to answer full email inquiries. If your questions can fit in the comments here, I'd be more than happy to help. Either way, I hope your project works out.