The „benign” isopropanol can also be a risky one. In 2011 I've bought for myself (mostly for cleaning electronics) a 5 dm³ plastic canister of IPA. A couple of years ago it started to smell bad, a very noxious irritating smell. So I've tested it with GC-MS, and here's what I've found: acetone, diacetone peroxide, triacetone peroxide, and some other minor products. Yesterday I've finally titrated it for peroxides, it turned out, that it contains about 2,3% of peroxides determined as H2O2, and since the titration was performed with a cold solution, that may in fact be only the hydrogen peroxide, organic peroxides require higher temperature to be determined properly. What happened is as follows: HDPE, from which the container was made is permeable to oxygen. Oxygen oxidizes IPA to acetone, and a molecule of H2O2 is formed as a side-product (which once was an industrial method for the production of H2O2, before the antraquinone process). H2O2 oxidizes acetone to acetone peroxides. There are some reports of accidents involving isopropanol distillation.
Non-chemist that stumbled on this channel by the magic of the YT algorithm - I realized my domestic 70% IPA was actually expired by about 3 years. I compared it to a fresh container I had yet to open and wow I can tell the difference by the smell. Definitely filing that away under "that expiration date is super important".
Some thoughts from someone obsessed with safety after seeing far too many dangerous situations with peroxides: If you're working with sodium amide (and KNH2), the stuff has to be as close to white or grey as possible. YELLOW or brown samples are extremely dangerous! Grey is usually alright, might have slightly decreased activity. Destroying bad amide is a rough one and not to be taken lightly, as far as I recall it's done in toluene excess with very slow addition of t-Butanol. Don't even think of trying to recrystallize bad samples. In general for Classes B and C ethers you can *usually* recover them if it's a large amount by reacting off any peroxide with a mild reducing agent (iron II or titanium in low ox states I believe), followed by pre-drying with alumina, then in a still (over drying reagent of choice). Make sure to test peroxide strips, I've had cases of a good 15% of a packet of them giving false negatives! Taking your time with destroying peroxides is extremely important, you make mistakes if you rush. Oh yeah and if you're being stupid and doing an oxidation...don't dump in ethers unless you know what you're doing, if you're working with ether + nitric acid and see oils or whitish flakes forming, that's when you run.
Excellent job getting this information out. At my last employer we developed a general rule for peroxide formers: test every 3 months after opening and discard if peroxides are present or after a total of 12 months. Peroxide formers were stored in their own cabinet and checked during monthly lab inspections to see if they required testing or disposal according to our general rule. The only exceptions were for peroxide formers stored in strictly anaerobic conditions (glove-box or stainless steel tanks under inert gas pressure). Fortunately, the only bad experience I have had with peroxides was a vicarious one. Two of my college classmates had some trouble with their senior research project and traced it to some bad diethyl ether. Being somewhat ignorant, they pulled a half liter of ether from the ancient 55 gallon drum in the stockroom and rotevapped it down to about 50 mL of clear oil, which they transferred to a beaker. The oil tested as being heavily contaminated with peroxides. Having read that ferrous sulfate could be used to decompose peroxides, they tossed in a spatula tip's worth. This produced a relatively slow deflagration, which left the beaker intact, but produced a fairly large fire-ball. Figure we all dodged a bullet that day.
When I worked at AMRI in Albany, a colleague was synthesizing a tertiary amine N-oxide using hydrogen peroxide. Some sort of mistake happened during the workup and she used methanol in some way, and the reaction formed dimethylperoxide, which concentrated during workup and shortly after placing the flask on a cork ring, exploded. The hood was demolished and she was seriously injured, ending up in the hospital. It was really terrible. Peroxides are serious business.
Great video! It makes me realize that I need to test several reagents that we have in nearly every group that we've had for a couple months now. We generally don't keep peroxide forming compounds that can be a hazard for more than a couple months, so we don't really have a lot to worry about. But, that said, better safe than sorry. Very much so. Again, thanks for the reminder! Your channel has turned into a great resource for both professionals and amateurs alike. Keep up the great work!
Most peroxides are scary enough, let alone holding the explosive when having to dispose of those unstable compounds. I'd prefer to test it in small amount, which is generally safe to handle if you know what you are doing, to test for presence of chemical KA-BOOM, so that way you know if your reagents are fresh enough to be safely handled, preferably with the bottle under Nitrogen or Argon gas atmosphere to keep it from reacting any further.
Most monomers used for radical polymerization (acrylate, methacrylate, styrene, ect.) are stored under air (or some oxygen) in industrial settings with inhibitor. I would suggest this should be done whenever possible. Oxygen is a potent radical polymerization inhibitor. This can prevent autopolymerizatons, huge exotherms, ect. It is a little counterintuitive.
Wow. I've been using quite old bottles of isopropyl ether during my PhD - it's a nice crystallization/precipitation solvent - well aware of the peroxide award, but not to the extent of it. I'll spread the word, although my current institution is way more modern when it comes to resources and procedures.
Thanks for the tips. I feel people around me underrated the danger of peroxide. For me, I've never thought about it before while opening an old bottle of ether.
I remember when in the NileRed discord server, one kid asked "Hey, I mixed hydrogen peroxide and acetone. What happens?" Me and a few dudes started explaining to him, that he accidentally made an extrmely sensitive explosive. Luckily one phd chemist came and instructed him how to neutralize it with chemicals that the kid had. That's why you do research before mixing two chemicals!
If you just mix the two, almost nothing happens as long as you don't put acid in. The reaction is far too slow. After about two days (at RT, unstirred) I started seeing some barely visible white flakes forming, so the reaction does happen, but if you just mix the two you're not in any immediate danger (still shouldn't do it ofc). With H2SO4 the reaction is quite rapid tho, it goes to completion in about 15 minutes.
When I got into chemistry, before I knew anything, I kind of wanted to know in theory at least how to make explosives and propellants. I never actually did, but I've had plenty of things go boom or poot or whatever and now I'm actively interested in trying to avoid making things that could explode. I didn't know about most of these things, especially 1,4-dioxane, which I have a bunch of and it was annoying enough to make that I redistill it to recover it rather than just disposing of it. Please keep making the videos and maybe I won't die of something stupid.
Can you do a video of misused vocab in org chem? Examples are byproduct vs side product and configuration/conformation being interchanged in articles but clearly mean diff things
We were doing home chem with rubbing alcohol, bleach and 3 percent h2O2. We did a flame test in an outside test. This was 25 years ago. My chem teacher said the alcohol got chlorinated with oxygen. It formed a green-blue-yellow 7 foot flame.
I'm an immunobiochemist who woefully needs a refresher in inorganic and organic chemistry basics, since, more often than not, you end up becoming ridiculously specialized on minutiae that pertains to your career, but kinda forget the 101/102 versions of a given field. majority of my chemical reactions are done with kits, cz capitalism (in the industry people don't create their own in-house reagents and raw materials if they kitted and can be bought. especially if the brand name's synonymous with the reaction itself. looking at you Fischersci BSA assay). your videos make my day. thank you. also, if you don't mind, do you know where I can get a lesson on the reaction of slime, aka polyvinyl acetate + sodium borate? I need the molecular formula, cz ppl sell the idea of eye drops + baking soda as a Borax-free activation method, even tho, eye drops are buffered boric acid and in the presence of baking soda, aka base, it produces a borate salt (tho not sodium borate). I posit that the rxn of borate salt + PVA glue is not that different from sodium borate, aka Borax.
When my lab moved out of our former lab space and into a new space we found a bottle that predated our lab being in that space. It was about 20 years old and was completely covered in a thick layer of cyclopentadiene peroxide crystals. It was very scary.
@@That_Chemist I doubt it was crystals of peroxide. Pure dicyclopentadiene melts at 32-33 C. I've seen plenty of bottles of DiCp that were masses of crystals.
Sometimes even freshly purchased, unopened reagents can be scary. Long ago, a lab in my dept. received an order (as small order fortunately) of some alkyl ether. The P.I. unpacked the bottle before it was opened and noticed that it was only 1/2 full. He called the bomb squad, who took it to a nearby construction site and blew it up. I don't think anybody wanted to handle it enough to test it for peroxides. Now that it's a zillion pieces of brown glass and gases, we'll never know if it was contaminated or not. Point being that reagents aren't always stored as if they had a limited shelf life, and a reagent you just bought isn't necessarily a 'fresh' reagent.
Iirc ther was one guy on the E&F discord server who was borrowing 20-year old bottles of ether from his grandfather. Tested it and it was pretty badly contaminated. Ended up calling the bomb squad as per the strong recommendation of many people, pretty crazy day for everyone on the server.
While I was in college, a grad' student in biochemistry was gently evaporating diethyl ether from an extraction. The flask exploded in her face -- due to peroxide.
Halfway through the video I had to open up EHS inventory and see if we had diisopropyl ether. Thankfully we don't, but I just had to check, otherwise I may have been a bit uneasy in the lab tomorrow...
Peroxide test strips normally work in an aqueous phase as they use a peroxidase enzyme. So testing can be tricky. I once was in the unfortunate situation of having to dispose of old THF with no budget for professional help. Using special chemical and cut resistant gloves and a blast shield, I very carefully opened the bottle and added in enough Iron (II) sulfate to render the material safe for conventional disposal. A bit of a hair-raising experience.
Yeah I heard a story of people who poured ethers down the drain and they formed explosive compounds - presumably peroxides. The day they exploded was an exciting day to go on the toilet.
someone in our department once accidentally made shit tones of acetone peroxide, the bomb squad had to be called and it was taken to a local park and detonated.
Hi! I've a question: when I draw a series of resonance structures I should use single arrow like this or can I use double arrows like equilibrium? Usually I use double arrows (equilibrium) if there is a proton transfer (like tautomerism enol-ketone), I'm wrong? Thanks!!
preferably as these are resonance arrows and indicate that the forms are NOT interchanging rapidly, which would be implied (wrongly) if you used ⇌. ⇌ is fine for proton transfers as they are indeed reversible reactions.
When in org chem many years ago a German-American professor put the fear of the Chem gods in me and my lab partner by telling us about a time when he was a student in Germany and a fellow student had an old bottle of diethylether with which he effed around and found out...supposedly, along with his friend, several nearby lab rooms in the building were also destroyed Whether or not the story was *actually* true or just "based on true events", it worked on me lol...Since then I have always had a latent fear of mistreating any ether
@@Firerider5 agreed, with what I know now I find the story to be sus - likely embellished, possibly completely fabricated - however 15 years ago I believed it and that story put the fear of the Chem gods in me...so, really, the prof accomplished his goal of teaching me to forever respect ethers even if he had to take some creative liberties to do so
You might be able to displace oxygen this way, but hydrogen will leak out of almost anything so it isn’t a good passivation atmosphere. Also, flammable.
I have a 6 year old sample of dioxane (about 30mL) that has been sitting over some sodium hydroxide during all that time. Any chance that some peroxide could have been formed?
Absolutely - almost certainly. A 1-year old bottle of 1,4-dioxane will usually have an uncomfortable amount of peroxides. However, since it is such a small amount, it would probably be safe to dispose of, but you could do a quick test with some iodide solution.
@@That_Chemist The problem is, Alumina filtration doesn't always work for every single peroxides, as some simply stay a liquid, without changing the physical properties. So that's kinda tough to get rid of it, so some compatible chemicals that doesn't combust upon contact but does do the job destroying the peroxides may be preferred in some scenarios.
And I personally recommend to fill the glovebox with neutral gas like Argon and / or Nitrogen gas before drawing any Ether, to guarantee that it won't react with air especially if you want the pure, unadulterated reagent, as preventative actions is occasionally preferably rather than having to worry about the situation where the bottle of Ether would suddenly spontaneously combust. It's a bit easier if you have a vial with the rubber top which the sharp needle syringe is required as it's easier to maintain the atmosphere where there's absolutely no Oxygen, and some Ethers indeed come in such bottle for good reasons.
R-H + O2 -> R(radical) + HOO(radical) R(radical) + O2 -> R-OO(radical) R-OO(radical) + R-H -> R-OOH + R(radical) -> that R(radical) continues the cycle the HOO(radical) is low in concentration, so it doesnt need to participate in the mechanism, but it can react with RH or R(radical) directly, but the concentration is so low that it isn't a significant operating mechanism
@@That_Chemist I'm reading do not store over 6 months, test after 3 months. I use it more often than 3 months and distill to dryness each time. Would that destroy or concentrate the peroxides?
@@leeroy144 if it is older than 3 months, it will concentrate the peroxides when you distill it, but you could do a titration with iodide to be sure if you don't have a test kit
@@That_Chemist but can it be used to destroy them? Because I've been hearing about ether distillation over sodium to destroy peroxides. Seems to have worked for nurdrage, since the guy distilled to dryness and didn't blow up. (Also he's a PhD chemist, so I figured that he'd check if the information was true before doing whatever).
It's compatible with SOME reagents, the trick is that Iron loves Oxygen, so it's one way to prevent the formation of peroxides - well, I mentioned "some" as couple of reagents will still form peroxides as they can chemically attack the Iron the nail is made of, taking Oxygen from it (the surface rust), so I'd suggest to check MSDS or ask the chemical supplier that question. There's no such thing as dumb question in science field.
@@That_Chemist I noticed the iodine test you mentioned how accurate is it? I've been distilling my own from engine starter, purity definitely suffers, unknown. I could attempt a test, two samples, 5ml each , on ice , under a Mercury lamp(o3 producing) for a day , one with a small nail , then test. I just wish I had a quartz curvet. Sound good?
@@petevenuti7355 It's usually pretty pure for all intended purpose, especially when you fractionally distill it by temperature reading (you can actually control the purity when you do it that way - Nigel over at RedNile channel have some videos on high purity distilling process), and why not? Just be careful when doing the experiment, though.
Also, potassium metal is a good peroxide and radical scavenger. Keeping it in air is foolish, but a chunk left under ether will decrease the peroxide formation.
The radicals that form will react with oxygen in its ground state, where as initiation occurs from oxygen in its excited state. As long as there is more oxygen present, the formation of peroxides will continue accelerating.
@@That_Chemist Yes. The initiation step is ¹ΔgO₂ + R-O-CR'R''H → HO₂· + R-O-CR'R''·. The hydrogen abstractions and combination of ³Σ¯gO₂ with the ether radical don't increase the free radical count. As such, we do not have an exponentially accelerating rate of peroxide formation.
The „benign” isopropanol can also be a risky one. In 2011 I've bought for myself (mostly for cleaning electronics) a 5 dm³ plastic canister of IPA. A couple of years ago it started to smell bad, a very noxious irritating smell. So I've tested it with GC-MS, and here's what I've found: acetone, diacetone peroxide, triacetone peroxide, and some other minor products. Yesterday I've finally titrated it for peroxides, it turned out, that it contains about 2,3% of peroxides determined as H2O2, and since the titration was performed with a cold solution, that may in fact be only the hydrogen peroxide, organic peroxides require higher temperature to be determined properly.
What happened is as follows:
HDPE, from which the container was made is permeable to oxygen.
Oxygen oxidizes IPA to acetone, and a molecule of H2O2 is formed as a side-product (which once was an industrial method for the production of H2O2, before the antraquinone process).
H2O2 oxidizes acetone to acetone peroxides.
There are some reports of accidents involving isopropanol distillation.
Yes! There was a paper published a couple days ago that highlighted this! It is scary to hear that the peroxide levels in your IPA were so high!
@@That_Chemist I was about to mention the same thing. Here's the paper if anyone else is interested. DOI: 10.1021/acs.oprd.2c00112
Non-chemist that stumbled on this channel by the magic of the YT algorithm - I realized my domestic 70% IPA was actually expired by about 3 years. I compared it to a fresh container I had yet to open and wow I can tell the difference by the smell. Definitely filing that away under "that expiration date is super important".
Some thoughts from someone obsessed with safety after seeing far too many dangerous situations with peroxides:
If you're working with sodium amide (and KNH2), the stuff has to be as close to white or grey as possible. YELLOW or brown samples are extremely dangerous! Grey is usually alright, might have slightly decreased activity. Destroying bad amide is a rough one and not to be taken lightly, as far as I recall it's done in toluene excess with very slow addition of t-Butanol. Don't even think of trying to recrystallize bad samples.
In general for Classes B and C ethers you can *usually* recover them if it's a large amount by reacting off any peroxide with a mild reducing agent (iron II or titanium in low ox states I believe), followed by pre-drying with alumina, then in a still (over drying reagent of choice). Make sure to test peroxide strips, I've had cases of a good 15% of a packet of them giving false negatives! Taking your time with destroying peroxides is extremely important, you make mistakes if you rush.
Oh yeah and if you're being stupid and doing an oxidation...don't dump in ethers unless you know what you're doing, if you're working with ether + nitric acid and see oils or whitish flakes forming, that's when you run.
Amen!
I gather yellow chemistry is always bad
@@treelineresearch3387 but...but my sulfur chemistry
@@jeremymcadams7743 One of the kings! 🤣
@@MadScientist267 *slips elemental sulfur into the flask and whispers* "enjoy the best element on the periodic table besides aluminum"
Excellent job getting this information out. At my last employer we developed a general rule for peroxide formers: test every 3 months after opening and discard if peroxides are present or after a total of 12 months. Peroxide formers were stored in their own cabinet and checked during monthly lab inspections to see if they required testing or disposal according to our general rule. The only exceptions were for peroxide formers stored in strictly anaerobic conditions (glove-box or stainless steel tanks under inert gas pressure).
Fortunately, the only bad experience I have had with peroxides was a vicarious one. Two of my college classmates had some trouble with their senior research project and traced it to some bad diethyl ether. Being somewhat ignorant, they pulled a half liter of ether from the ancient 55 gallon drum in the stockroom and rotevapped it down to about 50 mL of clear oil, which they transferred to a beaker. The oil tested as being heavily contaminated with peroxides. Having read that ferrous sulfate could be used to decompose peroxides, they tossed in a spatula tip's worth. This produced a relatively slow deflagration, which left the beaker intact, but produced a fairly large fire-ball. Figure we all dodged a bullet that day.
When I worked at AMRI in Albany, a colleague was synthesizing a tertiary amine N-oxide using hydrogen peroxide. Some sort of mistake happened during the workup and she used methanol in some way, and the reaction formed dimethylperoxide, which concentrated during workup and shortly after placing the flask on a cork ring, exploded. The hood was demolished and she was seriously injured, ending up in the hospital. It was really terrible.
Peroxides are serious business.
Oh my gosh, I’m so sorry to hear that!
Great video! It makes me realize that I need to test several reagents that we have in nearly every group that we've had for a couple months now. We generally don't keep peroxide forming compounds that can be a hazard for more than a couple months, so we don't really have a lot to worry about. But, that said, better safe than sorry. Very much so. Again, thanks for the reminder! Your channel has turned into a great resource for both professionals and amateurs alike. Keep up the great work!
Thanks!
Most peroxides are scary enough, let alone holding the explosive when having to dispose of those unstable compounds. I'd prefer to test it in small amount, which is generally safe to handle if you know what you are doing, to test for presence of chemical KA-BOOM, so that way you know if your reagents are fresh enough to be safely handled, preferably with the bottle under Nitrogen or Argon gas atmosphere to keep it from reacting any further.
Most monomers used for radical polymerization (acrylate, methacrylate, styrene, ect.) are stored under air (or some oxygen) in industrial settings with inhibitor. I would suggest this should be done whenever possible. Oxygen is a potent radical polymerization inhibitor. This can prevent autopolymerizatons, huge exotherms, ect. It is a little counterintuitive.
this is true!
Wow. I've been using quite old bottles of isopropyl ether during my PhD - it's a nice crystallization/precipitation solvent - well aware of the peroxide award, but not to the extent of it. I'll spread the word, although my current institution is way more modern when it comes to resources and procedures.
I will never not be amazed hearing stories of the old school chemist and the crazy shit they did 😂
Thanks for the tips. I feel people around me underrated the danger of peroxide. For me, I've never thought about it before while opening an old bottle of ether.
I remember when in the NileRed discord server, one kid asked "Hey, I mixed hydrogen peroxide and acetone. What happens?" Me and a few dudes started explaining to him, that he accidentally made an extrmely sensitive explosive. Luckily one phd chemist came and instructed him how to neutralize it with chemicals that the kid had. That's why you do research before mixing two chemicals!
If you just mix the two, almost nothing happens as long as you don't put acid in. The reaction is far too slow. After about two days (at RT, unstirred) I started seeing some barely visible white flakes forming, so the reaction does happen, but if you just mix the two you're not in any immediate danger (still shouldn't do it ofc). With H2SO4 the reaction is quite rapid tho, it goes to completion in about 15 minutes.
When I got into chemistry, before I knew anything, I kind of wanted to know in theory at least how to make explosives and propellants. I never actually did, but I've had plenty of things go boom or poot or whatever and now I'm actively interested in trying to avoid making things that could explode. I didn't know about most of these things, especially 1,4-dioxane, which I have a bunch of and it was annoying enough to make that I redistill it to recover it rather than just disposing of it.
Please keep making the videos and maybe I won't die of something stupid.
Can we just appreciate those absolute chads who took an explosive hazard out into the wild and threw rocks at it until it exploded.
Can you do a video of misused vocab in org chem? Examples are byproduct vs side product and configuration/conformation being interchanged in articles but clearly mean diff things
maybe yeah - Vittig vs wittig
I will add it to my list - this is a solid maybe
We were doing home chem with rubbing alcohol, bleach and 3 percent h2O2. We did a flame test in an outside test. This was 25 years ago. My chem teacher said the alcohol got chlorinated with oxygen. It formed a green-blue-yellow 7 foot flame.
Read the manual of the peroxide test kit.
They might need preparation, e.g. add some water to the sample.
I once missed that, luckily nothing happen.
I'm an immunobiochemist who woefully needs a refresher in inorganic and organic chemistry basics, since, more often than not, you end up becoming ridiculously specialized on minutiae that pertains to your career, but kinda forget the 101/102 versions of a given field. majority of my chemical reactions are done with kits, cz capitalism (in the industry people don't create their own in-house reagents and raw materials if they kitted and can be bought. especially if the brand name's synonymous with the reaction itself. looking at you Fischersci BSA assay).
your videos make my day. thank you.
also, if you don't mind, do you know where I can get a lesson on the reaction of slime, aka polyvinyl acetate + sodium borate? I need the molecular formula, cz ppl sell the idea of eye drops + baking soda as a Borax-free activation method, even tho, eye drops are buffered boric acid and in the presence of baking soda, aka base, it produces a borate salt (tho not sodium borate).
I posit that the rxn of borate salt + PVA glue is not that different from sodium borate, aka Borax.
you could ask ppl in the discord but idk
When my lab moved out of our former lab space and into a new space we found a bottle that predated our lab being in that space. It was about 20 years old and was completely covered in a thick layer of cyclopentadiene peroxide crystals. It was very scary.
its crazy because I didn't even know that it was a peroxide former - I've cracked dimer before from a super old bottle before
@@That_Chemist I doubt it was crystals of peroxide. Pure dicyclopentadiene melts at 32-33 C. I've seen plenty of bottles of DiCp that were masses of crystals.
Sometimes even freshly purchased, unopened reagents can be scary. Long ago, a lab in my dept. received an order (as small order fortunately) of some alkyl ether. The P.I. unpacked the bottle before it was opened and noticed that it was only 1/2 full. He called the bomb squad, who took it to a nearby construction site and blew it up. I don't think anybody wanted to handle it enough to test it for peroxides. Now that it's a zillion pieces of brown glass and gases, we'll never know if it was contaminated or not. Point being that reagents aren't always stored as if they had a limited shelf life, and a reagent you just bought isn't necessarily a 'fresh' reagent.
Iirc ther was one guy on the E&F discord server who was borrowing 20-year old bottles of ether from his grandfather. Tested it and it was pretty badly contaminated. Ended up calling the bomb squad as per the strong recommendation of many people, pretty crazy day for everyone on the server.
wow
I love chemistry and I hope some day I will come back with enough knowledge to understand this
I would love to see some videos on your experience with technique and technical errors that can decrease yield, lead to reaction failures, etc.
The only time that I will use a chemical with a peroxide in the name is when on my flesh wounds or I want to explode
Really Outstanding!! Thank you.
While I was in college, a grad' student in biochemistry was gently evaporating diethyl ether from an extraction. The flask exploded in her face -- due to peroxide.
F
oh good to know this. This makes sense why i couldnt use diisopropylether XD
Great video!!
Thanks!
How hazardous are the various glycol ethers? For that matter, is PEG susceptible to peroxide formation?
Halfway through the video I had to open up EHS inventory and see if we had diisopropyl ether. Thankfully we don't, but I just had to check, otherwise I may have been a bit uneasy in the lab tomorrow...
Understandable!
Peroxide test strips normally work in an aqueous phase as they use a peroxidase enzyme. So testing can be tricky.
I once was in the unfortunate situation of having to dispose of old THF with no budget for professional help. Using special chemical and cut resistant gloves and a blast shield, I very carefully opened the bottle and added in enough Iron (II) sulfate to render the material safe for conventional disposal. A bit of a hair-raising experience.
Yikes!
Yeah I heard a story of people who poured ethers down the drain and they formed explosive compounds - presumably peroxides. The day they exploded was an exciting day to go on the toilet.
yes tBME I had too
That is *peak* 1960s safety.
I work with ITX (isopropyl thioxanthenone, a proton abstracting photoinitiator) a lot and always worried about it making peroxide in acetone.
someone in our department once accidentally made shit tones of acetone peroxide, the bomb squad had to be called and it was taken to a local park and detonated.
I'm not sure acrylonitrile is a precursor to cyanoacrylate.. At least I've never heard it as such.
acrylonitrile*
Hi! I've a question: when I draw a series of resonance structures I should use single arrow like this or can I use double arrows like equilibrium?
Usually I use double arrows (equilibrium) if there is a proton transfer (like tautomerism enol-ketone), I'm wrong? Thanks!!
preferably as these are resonance arrows and indicate that the forms are NOT interchanging rapidly, which would be implied (wrongly) if you used ⇌. ⇌ is fine for proton transfers as they are indeed reversible reactions.
When in org chem many years ago a German-American professor put the fear of the Chem gods in me and my lab partner by telling us about a time when he was a student in Germany and a fellow student had an old bottle of diethylether with which he effed around and found out...supposedly, along with his friend, several nearby lab rooms in the building were also destroyed
Whether or not the story was *actually* true or just "based on true events", it worked on me lol...Since then I have always had a latent fear of mistreating any ether
i am not sure that the amount of peroxides forming would be enough to destory a few labs, that should be to much force for such an explosive
@@Firerider5 agreed, with what I know now I find the story to be sus - likely embellished, possibly completely fabricated - however 15 years ago I believed it and that story put the fear of the Chem gods in me...so, really, the prof accomplished his goal of teaching me to forever respect ethers even if he had to take some creative liberties to do so
@@pe4958 Yeah i understand that. I mean, not even a kg of a high explosive would be enough to destroy a few labs, 1-2 at best
Can hydrogen be used to flush a container?
I wouldn't recommend this
You might be able to displace oxygen this way, but hydrogen will leak out of almost anything so it isn’t a good passivation atmosphere. Also, flammable.
I have a 6 year old sample of dioxane (about 30mL) that has been sitting over some sodium hydroxide during all that time. Any chance that some peroxide could have been formed?
Absolutely - almost certainly. A 1-year old bottle of 1,4-dioxane will usually have an uncomfortable amount of peroxides. However, since it is such a small amount, it would probably be safe to dispose of, but you could do a quick test with some iodide solution.
@@That_Chemist ok, thanks. I will check it for peroxides first.
Are there any reliable ways to *destroy* unwanted peroxides that won’t permanently contaminate ethers? Or at least methods that are easy to separate?
I’ve heard about people filtering through Alumina, but I don’t know if this is legit - you should ask people in the discord
@@That_Chemist The problem is, Alumina filtration doesn't always work for every single peroxides, as some simply stay a liquid, without changing the physical properties. So that's kinda tough to get rid of it, so some compatible chemicals that doesn't combust upon contact but does do the job destroying the peroxides may be preferred in some scenarios.
And I personally recommend to fill the glovebox with neutral gas like Argon and / or Nitrogen gas before drawing any Ether, to guarantee that it won't react with air especially if you want the pure, unadulterated reagent, as preventative actions is occasionally preferably rather than having to worry about the situation where the bottle of Ether would suddenly spontaneously combust. It's a bit easier if you have a vial with the rubber top which the sharp needle syringe is required as it's easier to maintain the atmosphere where there's absolutely no Oxygen, and some Ethers indeed come in such bottle for good reasons.
I want the reaction mechanism of ethers with O2 to form peroxide
R-H + O2 -> R(radical) + HOO(radical)
R(radical) + O2 -> R-OO(radical)
R-OO(radical) + R-H -> R-OOH + R(radical)
-> that R(radical) continues the cycle
the HOO(radical) is low in concentration, so it doesnt need to participate in the mechanism, but it can react with RH or R(radical) directly, but the concentration is so low that it isn't a significant operating mechanism
@@That_Chemist Sir please make a proper video,I want it as its important for my JEE exam.Please make a video sir🙏
is storing dioxane over sodium enough to prevent dangerous levels of peroxides from forming?
sodium doesn't prevent the formation of peroxides as far as I know
@@That_Chemist I'm reading do not store over 6 months, test after 3 months. I use it more often than 3 months and distill to dryness each time. Would that destroy or concentrate the peroxides?
@@leeroy144 if it is older than 3 months, it will concentrate the peroxides when you distill it, but you could do a titration with iodide to be sure if you don't have a test kit
@@That_Chemist but can it be used to destroy them? Because I've been hearing about ether distillation over sodium to destroy peroxides. Seems to have worked for nurdrage, since the guy distilled to dryness and didn't blow up. (Also he's a PhD chemist, so I figured that he'd check if the information was true before doing whatever).
the nail in the container ????
Idk how good this is, and I would be concerned about adding iron impurities unless you are distilling it
It's compatible with SOME reagents, the trick is that Iron loves Oxygen, so it's one way to prevent the formation of peroxides - well, I mentioned "some" as couple of reagents will still form peroxides as they can chemically attack the Iron the nail is made of, taking Oxygen from it (the surface rust), so I'd suggest to check MSDS or ask the chemical supplier that question. There's no such thing as dumb question in science field.
@@That_Chemist I noticed the iodine test you mentioned how accurate is it?
I've been distilling my own from engine starter, purity definitely suffers, unknown.
I could attempt a test, two samples, 5ml each , on ice , under a Mercury lamp(o3 producing) for a day , one with a small nail , then test.
I just wish I had a quartz curvet. Sound good?
@@petevenuti7355 It's usually pretty pure for all intended purpose, especially when you fractionally distill it by temperature reading (you can actually control the purity when you do it that way - Nigel over at RedNile channel have some videos on high purity distilling process), and why not? Just be careful when doing the experiment, though.
Can IPA form peroxides ?
I mean in principle they could - I would assume that if they did, it would form acetone and hydrogen peroxide
Fortunately, peroxide forming is not exponential growth. Apart from the initiation step, the quantity of radicals does not increase.
Also, potassium metal is a good peroxide and radical scavenger. Keeping it in air is foolish, but a chunk left under ether will decrease the peroxide formation.
The radicals that form will react with oxygen in its ground state, where as initiation occurs from oxygen in its excited state. As long as there is more oxygen present, the formation of peroxides will continue accelerating.
@@That_Chemist Yes. The initiation step is ¹ΔgO₂ + R-O-CR'R''H → HO₂· + R-O-CR'R''·. The hydrogen abstractions and combination of ³Σ¯gO₂ with the ether radical don't increase the free radical count. As such, we do not have an exponentially accelerating rate of peroxide formation.
Hmm, I think there might be an Australian bloke who might be inclined to make these on purpose
Not sure, i think he is smart enough not to do things that stupid (at least unless it involves electronics or power tools)
@@semifavorableuncircle6952 He made liquid ozone. And ozonated 95% peroxide, to try for H2O3.
I am finding these comment humorous. I work at a chemical plant and we produce.........organic peroxides.....in the hundreds of kilos........
Yikes!!!
I am suddenly terrified of my potassium metal sample...
damn