Making Carcinogenic Potassium Chromate

[@user-eb3nm8cr7i]

The red color the melt takes on is actually from potassium chromate itself. It's a little known fact, but the salt is thermochromic, changing towards orange or even red at high enough temperatures.

[@THYZOID]

That’s interesting. Thanks for letting me know!

[@LiborTinka]

I found it more convenient starting from chromium hydroxide or chromium metal - the metal is very hard but can be shattered to small pieces by hammering in a covered steel mortar. It is then dissolved in acid and oxidized. Dichromate of sodium is valuable due to it's high solubility while that of potassium as a standard. I found one patent on preparation of sodium dichromate using sulfuric acid, the excess acid being removed as sodium sulfate and the excess sodium as bicarbonate (by bubbling CO2 through the mother liquor). I've look up preparing sodium dichromate from potassium dichromate - this might be done by removing potassium as iodate (the potassium iodate is even less soluble than potassium dichromate). However once we have the potassium salt, it's cumbersome to get the sodium salt as most potassium salts are too soluble and we would have to go through chromium trioxide, back through chromium hydroxide or oxide or maybe even through chromyl chloride.

[@EdwardTriesToScience]

Love the burner design, it's like a larger version of a blowgun, the furnace seems easy to make too, I might make a small one

[@chemistryofquestionablequa6252]

Extracting the nitrite from this synthesis could be interesting too, it's hard to get in some parts of the world. I guess they don't want us making tetrazoles, or GHB.

[@THYZOID]

I´ll turn it all to NO2 but a video on making nitrites should follow in the future!

[@midwestchem368]

Great video man! I dig the furnace that's really cool to have sort of a hybrid style there.

[@THYZOID]

Thank you!

[@hanleypc]

'I don't want to risk getting my beaker contaminated so i'll use this mixing bullet.....' A bit of chromium smoothie never hurt anyone lol

[@kalrbaum]

Isn't Chromic acid recommended for cleaning glasware in 60s Lab Manuals?

[@chemistryofquestionablequa6252]

@@kalrbaum yeah, it's badass for organic residue!

[@BalticLab]

Finally! Been waiting on this video since you posted pics on Instagram. Gonna watch it now and compare to my own experiment.

[@BalticLab]

Okay, looks like you had the same filtering issues that I had. I even tried a glas fritted (40 micrometer) Buchner funnel with filter Paper in it but even that pulled through some chromium oxide at first. I regret using that glas fritted Buchner because it's permanently green now. Even after leaving it in H2SO4 + H2O2 over a week.

[@FullModernAlchemist]

You may want to consider using Celite in your vacuum filtration setup it will catch those first very small particles that got through the filter paper.

[@alllove1754]

This reminded me of the kmno4 make on chemplayer. Thank you for the nitrate method.. makes me wonder is there is a nitrite method...

[@LabCoatz_Science]

Great video! Have you considered the very similar permanganate synthesis? I know manganese dioxide is pretty widely available (I purify mine from alkaline batteries), and permanganates don't seem to be nearly as toxic as chromates and dichromates, so it might be worth a shot!

[@EdwardTriesToScience]

NurdRage has a video on it, there still is no good breakthrough in making potassium permanganate in lab scale though. The main problem is that you can't easily get it to crystalize as any organic impurities whether that be fibers from your filterpaper or the oil droplets that are naturally in the air

[@THYZOID]

The permanganate synthesis is another great idea! I also might try to make ferrate too.

[@chemistryofquestionablequa6252]

Check out water filter stores, I bought ten pounds of potassium permanganate at one ten years ago for $60. Needless to say, I still have at least three quarters of it still. It's super useful, but you rarely need much.

[@dexterflodstrom9975]

Awesome video as always

[@ChemTalk]

Nice job!

[@WeebRemover4500]

interesting, a hotplate should do well for this with some aluminium oxide insulation, and the Cr2O3 may be recycled.

[@LiborTinka]

Also be aware of the airborne droplets! Always cover the reaction vessel with e.g. glass wool.

[@joeylo2302]

Wash the yellow crystals with ethanol to get rid of the potassium nitrite.

[@hegedusmarton8485]

Potassium dichromate have a lot lower solubility than potassium chromate, so if you acidified the (COLD) filterate with acetic acid, collect the dichromate crystals, redissolve it and basify the solution, then let it evaporate, the yield would be a bit higher i guess. That's how I'm making mine, I just don't basify the solution just but recrystallize it, because I use dichromate. Btw good video! New sub!

[@THYZOID]

If you acidified this solution you would get a lot of nitrogen dioxide.

[@noodlesoup2281]

Awesome furnace!! ❤️ What did you coat the inside with? Also I have wanted to ask when using the gas cylinder is there any chance of suck back when using it like that?

[@THYZOID]

The inner layer is called schamott. Suck back? You mean if the flame can go inside?

[@SodiumInteresting]

How do you make and print your labels, do you create an image in an app and load onto a handheld sticker printer? I was thinking of getting one of those

[@THYZOID]

this one was made using microsoft word and a piece of clear scotch tape

[@lborate3543]

Can we have a moment of silence for the Buchner filer?

[@chemicalmaster3267]

@ THYZOID LABORATORIES Quite funny, I actually thought you would do a video on extracting chromium in the form of a chromate or dichromate salt from stainless steel. That could also be quite interesting. And by the way, if you want to make potassium dichromate from that potassium chromate and potassium nitrite, you will have to deal with the latter somehow, otherwise you won´t get potassium dichromate and instead you will reduce the Cr(VI) into Cr(III) when you acidify the solution.

[@THYZOID]

That one is still planned! Don’t have a lot of stainless steel flying around rn though.

[@chemicalmaster3267]

@@THYZOID No worries! And another thing, if want a much better and cleaner way to make potassium nitrite, you can melt a mixture of potassium nitrate and potassium hydroxide and then carefully add little bits of sulfur at a time. 3 KNO3 + 2 KOH + S = 3 KNO2 + K2SO4 + H2O

[@chemistryofquestionablequa6252]

@@THYZOID You can get cheap stainless steel cutlery at second hand stores for really cheap. I'm sure you could buy enough for the synthesis for less than twenty dollars.

[@chanheosican6636]

Interesting but what does the potassium nitrate exactly do?

[@THYZOID]

We need it to oxidize chromium(III) to hexavalent chromium. Any other oxidizer, even air, would work.

[@rainwater397]

Can this reaction be performed in aqueous solution instead of a molten salt?

[@THYZOID]

no

[@karolus28]

cool

[@JustinKoenigSilica]

hell yeah, cancer, let's goooo what happened to the silica nanoparticles? any update on that?

[@THYZOID]

I honestly forget about that one but this is something I must definitely try! Just took a screenshot of your comment as a reminder.

[@kenbrady119]

Can some chemicals be dried in a microwave oven?

[@THYZOID]

Very few chemicals. Not chromates though and definitely nothing in the kitchen microwave

[@MichaelLapore-lk9jz]

Did you go out of your way to find the most pain in the ass way to synthesize potassium chromate?

[@THYZOID]

This way is acceptable. From stainless steel is much worse

[@galaxymyt4834]

Make potassium citrate

[@Cristi0986]

Your potassiun chromate shouldn't be yelow?

[@THYZOID]

Shouldn’t be green

[@Cristi0986]

@@THYZOID here ar yelow kzbin.info/www/bejne/fXO4Y5Ksf7N1laM

[@roman091000]

nice one

[@roman091000]

is it a long process of making the same thing from a chrom powder (actual metall)?

[@THYZOID]

the process from Cr metal is easier and faster

[@roman091000]

@@THYZOID i would like to see the whole process of it

[@THYZOID]

@@roman091000 i won´t try it. I have more chromate than i´d ever need and videos of this process already exist

[@roman091000]

@@THYZOID ok, thanks. what do you planning to do in your next making video?

[@ruchishinde8875]

TV

[@galaxymyt4834]

M