Rookie Mistakes in Chemistry
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- Опубліковано 2 лип 2024
- In this video, I discuss some of the common mistakes that people make when they are doing labwork.
/ thatchemist
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NotVoodooX - www.chem.rochester.edu/notvood...
I once mocked a warning in the procedures for a test i was doing which said "CAUTION: Hot things are hot!". I then proceeded to burn myself with extremely hot glassware.
In hope someone else can learn from this in a less painful way…
In my High School chemistry class, I was making about 500 ml of a supersaturated solution (maybe ammonium chloride?) for no good reason.
A while after I had turned off the burner, I touched the top of the liquid to see if it was still hot. This works fine - in a kitchen, with ramen. You get a quick sensation of the temperature, then enough water evaporates to cool any remaining liquid in less than a second. It works poorly with a supersaturated solution well above the boiling point of water. The hot liquid stuck to my fingertip and STAYED hot, despite desperately fanning my hand. It stayed hot until I ran water over it in the lab sink. The only other thing that I remember about the outcome is the solution was saturated enough when it cooled to become entirely solid.
A professional or cautious student would never do this, but for anyone else - leave kitchen habits outside of the lab!
@@firstmkb it’s such a common kitchen habit to touch things that are hot to test if they are ready to use. I once saw a cooking UA-camr touch an empty hot pan with his fingers and he proceeded to burn fingerprints from every finger onto the pan, and had to get bandages on each one.
I've heard it since middle school when we first started using Bunsens and hot plates: "Hot glass looks like cold glass" despite taking chem in four different schools in 2 different cities
@@LemurG I've always just let some water on my hand and then dropped a droplet onto the pan to figure out if it's getting hot, I'm a bit concerned people are touching pans out there
freaking pansexuals
starting a reaction and not finding enough reactant happens more than it's supposed to xD
yeah :(
I ended up optimizing a procedure once because of that mistake. I was supposed to use a huge excess but the bottle was empty after 1.2 eq. Ended up with a higher yield😂
I think I got burned once in a very unusual fashion. I synthesized some compound, I can't recall what it was, except that it was some complex ketone. The batch was quite big, something around 50 ml. That ketone had a m.p. of about 115 degrees Celsius. I did a shortpath distillation with air cooling to purify it and used a heat gun to melt the crystals that stuck to the walls. I thus got it in liquid form and after the system had cooIed down the ketone was still liquid. I disconnected the recieving flask and while I held it in my hand everything inside suddenly became solid. =) The flask became extremely hot in a matter of seconds. I could drop it, but I needed that damn ketone! So while I looked where to put it safely I got myself a first degree burn. Never underestimate the enthalpy of crystallization! Cold liquids can sometimes instantly become hot solids. 😁
damn I don't think I've ever even considered that possibility happening. I mean, it makes perfect sense when you think about it, but sill
that is.... a crystal burn. yaaaa!
@@mechadrake 😁
guess enthalpy really doesnt care about preconceptions
Also runaway polymerization etc yeilding almost impossible to clean gunk stuck in the flask. 😵
Actually, I think one of the dumbest things I've ever done was use the crusty, 10-years-out-in-the-open bottle of KOtBu for a sensitive reaction, TWICE, and being surprised that the yield was an unsalvageable brown gunk. I doubted my technique more than the reagent
Haha, that’s brutal
I confused acetic anhydride for acetic acid few times because they were stored next to each other and I just glimpsed on the name and were satisfied with seeing "Acetic" 😁
_That's_ why my fish and chips tasted so terrible!
That's ought to hurt with the price difference.
When we worked with acetic anhydride, my professor said "It's not tear gas, but it's not far off."
A few more that either have happened to me, or I've seen happen around me:
- Trying to catch falling glassware. Just don't.
- Not recording the empty weight of a vial/flask/whatever
- Not removing the stopper from a sep funnel...
- Not labelling your flasks or vials
- Forgetting to add a stir bar
- One time I was working up a Friedel-Crafts acylation and had the reaction mixture in a sep funnel. Turns out there was some excess AlCl3 in there still and the second I shook the funnel it blew the stopper out, covering myself (and the roof!!) in my reaction mixture and a memorable cloud of chlorine gas. It was at that point I decided "that's enough lab work for today".
F rip
During a lab cleanup, I found a bottle in a fridge that had a solid brick of tosyl azide, probably 50 grams or more. EH&S wanted me to try to quench the thing myself. I told them I would do no such thing, and eventually they got the bomb squad to dispose of it.
Lmao - worst EH&S department
Proper disposal technique. Take to a shooting range and use it for target practice 😁😅
@@christopherleubner6633 I totally would have, but the idea of driving around with that shock-sensitive abomination in my car was a non-starter 😆
we shared a lab with the microbiologists so we shared a lot of their safety procedures, negative air pressure working environment etc, one rule was that anything brought into the lab could only leave again if it had been autoclaved, a lot of first years had no idea what an autoclave was and so apparently there were a few cases of peoples phones/wallets getting autoclaved
Haha
My usual rookie mistake is to run an experiment with 'X' difference between the two samples, run it for 6 hours and then realized that I didn't label them and finding I can't distinguish which is which and have to start over.
F
During 5th grade, we went on a field trip to do a science experiment in the neighboring middle school's science classroom. This was also the first time I learned about how crazy powerful the sinks are in classroom labs.
While cleaning a beaker, I cranked the water on to max and the beaker shot right out of my hand and crashed in to the sink and destroyed it...
yikes!
Oh yeah I have had so many glassware that was broken by doing this…Thoughts and prayers to them…🤣🤣🤣
Absolute classic for undergrad chemists. Luckily the 1 L measuring cylinder I was using bounced rather than breaking ^.^
@@SocialDownclimber shivers in hailine cracks
Ayy I did this last week to the first vial I started cleaning. Then proceeded to clean the next 200 vials without issue.
One time, I mistakenly used a water bath instead of an oil bath for my reaction (which ran at 130 C). I finally realized it after 20 minutes of wondering why the silicon boiled so vigorously
I was in the fumehood preparing some samples for acid digestion, I asked my partner (the kind we delegate simple tasks to so they don't get expelled from the group for inactivity) to pour a little bit of sulfuric acid in a small beaker for me. I expected him to give me like 10 mL on a 25 mL beaker, like I showed him the week before, but he showed up with a 250 mL beaker filled to the brim. I gave him a dissapointed look and thought to myself "watch him spill that shit". I was right on the money, and in the acid. A whole half second after putting the beaker inside the fumehood he turned and toppled it over, the wave of acid splashed all over me and my precious samples. I wanted to facepalm so hard but stopped myself because my gloves were melting and/or on fire. After getting rid of them and taking off the remains of my labcoat I just casually go get ye olde box of sand whilst the partner and a few bystanders are on the verge of unnecessary panic. After I cleaned everything up the teacher arrives and I for some reason decided to take on the blame. I didn't get punished, but commended for acting calmly and properly dealing with the emergency. Little did they know, I was moments away from facepalming myself with a hand full of acid and on fire.
Moral of the story: trust no one, not even yourself.
Oh my gosh!
Not a rookie mistake, and I did not witness it but I heard of a male PhD student a few years before me in the lab where I did my PhD who weighed some benzyl bromide (lachrymator) without gloves (early 90's, H&S in France was bad) then went to the toilets. He quickly had to rush back to the toilets and was found by a lecturer with his gentleman's bits in the sink being rinsed with a copious amount of water to ease the burning sensation.
Please don’t alkylate your Johnson
@@That_Chemistthis should be a warning sign in any bathroom of a chemistry department.
My industrial testing lab fired its metal testing manager and his underling took over. He found a pretty coin with a pretty logo and put it in his pocket. It was the Nuclear Regulatory Commission logo. The "coin" was a Sodium22 radiation "Source". In the 3 days he carried it hevrecieved a "lifetime dose" of radiation.
what the heck!!!
holy shit wtf. Why was it made like that? I've seen different radioactive sources of different elements, sorta coin-shaped too. But you would never mistake them for a coin, because... like obviously? It's a dangerous thing and should be made readily apparent that it is what it is.
sodium 22 is a beta emitter too, probably the worst option. At least with alpha most of it would get absorbed by the fabric of his pants and outer layers of (dead) skin. And gammas would mostly just pass through him anyway. Beta emitters are probably the worst to be in such close proximity to.
a Teledyne zirconium sample I can see, but a test source? wow.
Guess that coin did not have "drop and run" in nice font going around it :)
Remember seeing that on the sources posted last year
@@mechadrake TBH unless one is a nuclear worker, the "lifetime dose" is still quite small with little risk...
I used to put an empty beaker below the separatory funnel before pouring anything to sep funnel. Always. It saved my ass for a few times. Also everytime I can (I mean if there is enough glass) I keep all fractions from any extractions, clearly labelled to mitigate a risk of discarding the wrong phase
if you fail to plan, you plan to fail
That’s a nice precaution and we always need to be aware of which layer is the phase that we want. I made a big mistake a few weeks ago about seperation but not discarding wrong layer. I was trying to make a TLC from the sample which is in a seperation funnel with a capillary tube stupidly. As you can guess it spilled everywhere and I lost almost half of the sample which was already in low amounts. Long story short, always be careful when using sf and make sure it is fasten to holder. If not you may end it up with a disaster.
Yes and due to experience I’ve learned to save all the layers of the extraction until I’ve taken and nmr to confirm I indeed collected my product.
I was tought to do that in university as well. Its really good practice! I still managed to spill organic phase anyway because one time I thought its unnecessary and that was the first time where I had left the separatory funnel open. Havent doubted it since!
I think my worst rookie mistake was not double checking the stoichiometry for an organic chem lab project (synthesis of tetraphenylphthalic anhydride from phenylacetic acid, benzil and maleic anhydride). The prep was known (to the instructors) to be wrong, but being naive, I used the weights from the original paper. I guess this was meant as an intelligence test, which I failed miserably. The result was that what should have been barium phenylacetate also contained excess phenylacetic acid, so instead of pyrolyzing smoothly to 1,3-diphenylacetone and barium carbonate, the acid clogged the distillation column, pressure built up and the flask popped off, gushing forth super-heated phenylacetic acid (which smells a little like butyric acid, but with more than a hint of fermented slaughter house dumpster). The lab, and I, stunk for the next week (several showers a day did not really help, just had to wait for my contaminated epidermis to flake off). Just because a procedure is published does not mean it is correct.
that's a really clever use of alkaline-earth decarboxylative ketone synthesis! I hadn't heard of it being done with barium before - if you have a write up, you should post it in the discord :D
When I took inorganic in my undergrad, we were required to go glass blowing as part of our lab section as well as synthesis of some inorganic compounds. I burnt my fingers more times than I can count doing that. I eventually just turned in some half baked glassware and took my B.
F
A couple years ago I was handling a 2L sep funnel and somehow I hot potato’ed it and dropped it on my workbench. A colleague heard it, came to check on me, and promptly informed me that I was bleeding out from my right wrist. I didn’t even feel it. Thankfully the glass was empty and clean, but still scared the shit out of me.
yikes!
@@00bean00 it was probably somewhere in between. There was a lot of blood but not enough to get me lightheaded or anything. I did have to get stitches for it, the scar is about 3 inches long
Imagine if that had DCM in it, ever heard about the DCM finger accident?
@@leothecrafter4808 I haven’t, but I looked it up thanks to you. Holy shit that looks so bad, and to think that the amount of DCM that entered his finger was in the low microliter range, man that’s absolutely insane. Having knowledge of this incident should make anyone have more respect and carefulness for all chemicals and common solvents
Another story from my B.Sc: someone from the physical chem dept did an experiment using one of the NMR machines in our school. The last part of the experiment was to cool it waaaaay down, I don't remember why exactly (there's a standard procedure that uses this iirc). So far ok, but they forgot to tell the machine to re-heat itself and just left. This should have resulted in a Heilium depletion and then runaway heating of the super-conducting magnet and then, well, kaboom. Say bye-bye to several tens of thousands of dollars worth of equipment (at least). Luckily for that student, me and another friend booked the NMR for 23:00 (11 PM), to finish something, so we managed to catch the error on time (thanks to a big red blinking error massage on the computer screen), call the supervisor and woke her up so she could guide us on how to prevent the runaway heating. We managed, and all was well. She thanked me the next day saying that we literally saved the faculty A LOT of money (never got an official thank you from anyone else in the faculty though ¯\_(ツ)_/¯).
You are literally a hero
@@That_Chemist or just lazy students who preferred pushing the deadline to the extreme 😉
@@pelegsap double hero then ;)
I’d go with hero too. A lot of people would have seen the red error blinking on the machine, and just gone home without making a call about it.
I hope that Pchem guy got reamed out later
I remember in my undergrad organic chem lab we were told over and over again about not putting paper towels, filter paper or weighing paper in the fume hood for the explicit reason being that they will get sucked into the fans at the top of the fume hood. Cut to me doing a reflux with an aluminum foil over the flask and, when done, taking the foil off and leaving it in the fume hood for 5 seconds too long just to see it soar to the top of the hood. Thankfully it was a fume hood where there was another fume hood opposite to it and when the lab duo across from me closed their sash, something about the pressure must have changed within the fume hood to make the aluminum foil drop back down and I was able to snag it! Definitely went from extreme embarrassment walking up to my professor and explaining to them my potentially costly mistake, to extreme relief (and I'm sure to the nearby lab tech's relief as well) when I somehow got the aluminum foil back.
We definitely had the fumehood suck up many paper towels and Kim wipes
I think my dumbest "rookie mistake" is that in a low stakes situation (non-lab environment, just handling cleaning chemicals), I think to myself "I don't feel like putting on eye protection, I'll be fine" and then splashing acid in my eye. No significant damage because it wasn't very hazardous, but I still had to leave to go rinse my eye and I felt dumb for ignoring one of the biggest rules of safety
This is probably a good reminder for me to go try to implement making sure people have eye protection at my work because nobody really bothers despite it being in the policy
the worst part about a broken NMR tube is never the potential stitches; its always the potential lost product
true
I love this channel. So many people out there acting like they've never made mistakes and yet here this man is detailing all of the times he has screwed up and inviting others to do the same so that people watching can learn what not to do.
Thanks :)
When setting up a reaction in a 3-neck flask, I had to repeatedly pull a vacuum and flush it with nitrogen. I opened the nitrogen to quickly, and the addition funnel went flying and shattered, sending glass all over my fume cupboard. Was really embarrassing (and probably expensive), and since then I use clips on every single joint of every piece whenever I add gas to the system. Never again
F
@@That_Chemist I felt like Max Payne bullet time, seeing that thing sail across the bench, and my reaction was to head-desk myself on the fume door. RIP
@@FarragoTheFox f
Someone was lazy and tried to pipette a pyrophoric reagent instead of using a syringe under N2. They burned their hand and stained part of the fume hood coal black.
Another fun story:
We were doing some sort of experiment in HS with Copper Sulfate, and in a class prior to mine a student was adamant that the Copper Sulfate was just pop rocks.
So adamant in fact that she decided to eat a few of the crystals... She was promptly sent to the hospital to pump her stomach and was then suspended.
I don't think there was anything necessarily toxic about the Copper Sulfate, but more of the school saving it's ass in case it was poisonous.
oh my gosh!
Yea it's pretty toxic... Cu (II) is carcinogenic
"Heavy metals" bind to neuro and immuno protein Sulfydryl groups. I worked in a plating shop with Sulfuric-CopperSulfate mist, we wore polyester clothing from the company but cotton underwear became holy. Noone died of Copper poisoning.
Copper sulfate absolutely is toxic...en.m.wikipedia.org/wiki/Copper(II)_sulfate#Toxicological_effects
Generally speaking copper salts are not very significant poisoning hazard, because any significant amount causes violent vomiting.
I had an excellent old Swedish book about basic lab work, glassware, and a lot of info that was second nature to the old professors that they never were teaching us. Lost it and I am really sad about it now. It had a chapter on lab safety and stated that the most common accidents were with glass and mostly damaged glassware and that caused the most injuries. So it said that the riskiest parts were not chemicals but glassware and I believe that. We all know to be careful with chemicals but we often have less respect for glass. So we all should be more careful about glass, discard damaged or give it to someone to melt the edges that can give cuts. AND NEVER throw away broken glass in the bin for general lab trashbin or chemicals. waste Always in a special bin for sharp and cutting objects.
Yeah, I was always the one flaming the sharp edges so that people didn’t get cut
This was fascinating - I didn't know all these details about lab work (I got as far as college chem 101, which they gave as an advanced class in high school. We filled Christmas tree ornaments - the kind made of very thin blown glass - with a mixture of powdered red phosphorus and potassium chlorate, and threw them out the third story window onto the concrete pavement of the quad. This annoyed the school principal, who changed policy to keep the red phosphorus in his safe.
The heating a sealed vial reminds me of a story from undergrad ochem lab. We were doing a dials alder in diethyl ether, and we were instructed to use a warm water bath to gently heat the ether to dissolve everything. A few students instead decided to use boiling water, and sealed the vials. TA sees this and tells student to take it off heat and unscrew the cap, student does. this in opposite order, ether boils immediately and the vapors ignite on the hot plate.
F
During my studies in the organic lab course, a labmate decided to wash out his bromination flask with acetone (not quenched beforehand) and put it in the drying oven. Vietnam flashbacks by all the tear gas fumes
It’s such an exothermic reaction too
I think it is really interesting: I am doing my PhD in inorganig chemistry (Phosphorous centered biradicals bound to transition metals of Group 4)
And all my products are way to sensitive to run a column since it would readily react with silica... Or air
And many of your "mistakes" deal with workup like columns or seperatory funnels, whereas my mistakes are mainly letting some air into my systems in any way
A couple of weeks ago I was making an organometallic precursor which required a *lot* of Grignard. Fortunately, we had a nice big straus of said Grignard from ~1y ago. Sure, it was running a little low, but I can just scale down the synthesis based on how much Grignard is left, i thought. I get everything set up, and as I cannula in the solution to the graduated addition funnel, my heart sinks. I'm like 5mmol short. The partially alkylated side product is nigh impossible to separate without several, low-yielding recrysts, so I did what anybody would do on a Sunday morning. I whipped up the laziest Grignard I possibly could, dumped it in the reaction, and went home.
Fortunately, the yields were still decent, and the side product was nowhere to be seen
Awesome, glad to hear that it worked still :)
What Grignard were you using?
In my first year of grad school (biochem), I was preparing a bright orange dye solution (I forget which dye) to stain the coat protein of tobacco mosaic virus. I left the glass-stoppered 1L erlenmeyer on a warm plate and went to lunch, not thinking to add a pressure release. Upon return, the flask was nearly empty, the stopper nowhere to be found, and the ceiling of the lab was bright orange. It was a brand new lab in a brand new building, so I guess I christened it!
Haha
Was working at a lab where all the fume hoods need to be turned on manually, but turn off *automatically* at various points during the day. One day I came early because I had a lot to get done, and the first thing I did was turn on the fumehood, then get everything ready for a bromination reaction. While setting up the reaction and adding the bromine to the dropping funnel, I noticed that I could smell something awful, and I got an unpleasant feeling in my throat. I thought "crap, these vapors must be too heavy", closed the lid of the hood further. Did not help.
...then I notice that it is unusually quiet. I look to the side, and see that the hood's green LED was not lit up. Evidently, I had been in the lab so early that, while I was setting up the reaction, the hood had turned off. So I was rewarded for my early arrival with a nice healthy dose of inhaled bromine. Lovely.
Always make sure your hood is turned on, folks. Even if you already turned it on earlier that same day.
That’s a really poor safety choice for the fumehood manufacturer
@@That_Chemistwell at the very least it should give a warning before turning off...
I have spilled my product before. The problem is that my product in this case was a suspension of an insoluble polymer (highly crosslinked one), so unfortunately the bench top extraction was not applicable.
Also, "mise en place" works both in the kitchen and in the research laboratory.
When I was doing an extraction the product did not go into the organic layer. While the solvent was evaporating, I happily discarded the aqueous layer and the product with it. After that I have learned to TLCs after extraction.
I have also learned that nitrating with concentrated nitric and sulfuric acids at 180 C will produce nitrogen dioxide
a libation to the chemistry gods
I have a few stories.
One old one (first year of grad school) being setting up a grignard rxn on the schlenk line. I had everything connected, everything is dry and air free. I have my THF and Mg and this chlorosilane stirring, and I am going to start adding bromoform. Mistake #1: forgetting to dilute the bromoform with THF, Mistake #2: forgetting to open my reaction to my inert line to prevent pressure build up lol. Was adding the bromoform and the reflux got out of control, pressure built up, and the rxn literally exploded the glassware at the neck of the condenser and rbf covering me in chlorosilane, THF, and bromoform and making a mess of my hood.
One more recently (i.e like 3 weeks ago), I was attempting to quench a hydroalumination reaction with O2 to give alcohols/ketones (this is known), so me being ignorant and over-confident used PURE O2 from a cylinder by flushing it over the product in a septa'd test tube while holding it in my hand. Not even 5 seconds later, BOOM! It was like a gun was fired and there were no remnants of that test tube to be found. Luckily no injuries.
I still to this day hold a record in my AP chem lab for most pieces of glassware broken- averaged around one beaker/Erlenmeyer per lab lmao. Got it all out then and only broke a sep funnel stopper in all my undergrad labs lmao
One thing I learned when scaling things up to pilot plant scale is large amounts of disagreeable substances such as sodium hydroxide or liquid bromine are a lot more disagreeable than small amounts.
In my undergrad OC lab we did vacuum distillation. End of day, turn off the pumps, remove the traps from LN2. The pumps had a vent button so I put it on vent and left the bench. I assumed it would just open a valve and create an open system. What happened instead was a loud BANG about 1 minute later as the cold trap got pushed out from the overpressure, shattered and imploded the dewar underneath.
And of course there was that one time where I sucked my product in the rotovap. (one of many) We made dye compounds visible in what must have been ng concentrations and so despite dozens of washes from every angle and hours of distilling pure solvent through the condenser every product from that rotovap turned out slightly blue for like a week. But you couldn't detect it at all. There was zero impurity in the NMRs. On the other hand...blue is the opposite of yellow so I probably made the compounds better.
Not exactly a rookie mistake but more of a general fun situation: one guy in the training lab broke a mercury thermometer and for some reason the supervisors freaked out, evacuated the entire lab and took like 30 minutes to clean that one drop of mercury. Shows you that even PhDs working with dangrous chemicals all day long can have completely irrational fears.
At least my benchtop extractions always turned out amazing since I've made it a policy very early to always thoroughly wipe my workspace after a finished reaction or at least once a week if I keep things clean. I just can't stand dirty benches and fumehoods.
it is a wise idea - the only time you can brag about doing a benchtop extraction is when you had a clean benchtop :)
Thank you so much for this content. I'm a chem undergrad going into my senior year, going to be doing research for my OChem II professor in the fall. The content definitely helps me stay sharp this summer, I feel more confident and prepared for the fall!
:)
In [the equivalent of] Highschool, we had some sort of worksheet, and i put it in the fumehood. We were doing a Fischer Esterification, and using 98% H2SO4. I accidentally spilled the beaker with the acid, and the worksheet went completely black. Everyone was amused, even our chem teacher.
You don’t even need conc h2so4 for fiscer
@@alexwang982catalyst
Nice Video! I would add another topic: "impatience"
A) putting the solution from the NMR tube back to the flask (not one you can hang on the rotational evaporator) of your substance library, and instead of leaving it to evaporate, get it in the exicator (because whatever, it is not even 1mL, right?) Even with cap on the flask and carefully reducing the pressure on the vacuum line by hand, the solvent will pop out and spread your product all over the exicator.
B) Opening the exicator too fast, very classic one, spreading your product all over the walls inside like a snow globe.
C) Adding to much solvent for recrystallisation because you could not wait a single minute for the solid to get dissolved in less amount of solvent.
D) Putting to much heat on a flask with a slurry of product and water hanging on the vacuum line, leading to an "explosion" inside, once again a snow globe with product in the flask, adapter and most likely in the hose as well. Instead of just waiting over lunch and the line will do the job by itself.
E) at the vacuum line: trying to flush a big reaction gadget under high vacuum and a solid, powdery substrate already in, with argon... you know what will happen: snow globe!
Just one question regarding the MeOH and KOH on the basebath: Are you commonly using methanol/KOH as a basebath (why not iPrOH) to get your glasses clean or did I just get that story wrong?
And just on that NMR without spinner story: If this would happen when our old supervisor for NMR was still there, you better run for dear life and take like one week off :D
I prefer isopropanol, but I’ve used methanol as well
I had a postdoc in my lab that would initiate conversation while they were running their columns and without fail, every single time, they would forget to switch the test tube and it would overflow. I had to start saying "hey look at your test tube" while they were talking multiple times a day.
at least now they are a post-post doc
Haven't done anything stupid in uni yet but back in highschool, oh boy. The best one I remember is from a fiber test.
We had to heat up the solvents in test tubes on a bunsen burner (off to a bad start, I know, but textile analytical procedures haven't been updated for quite a long time and are still very 1960's, if you know what I mean).
The procedure called for dissolving the fiber in boiling benzyl alcohol, adding cold ethanol, and if polymer crashed out heating up again to boiling.
So I started out with the benzyl alcohol, test tube far away from the flame, and moving it very slowly towards it. I got the solvent to boil without a problem, but since it's so high boiling (205°C) I had to basically put the test tube on the flame. Then I let it cool a bit, added cold ethanol and moved on to heating up again. The problem was, I forgot that I had ethanol besides benzyl alcohol in my test tube this time. So, confident in the high-boilingness of my liquid, I proceeded to put the test tube right on the flame. *FHWOOMP.* I shot out a 1.5m long stream of flaming ethanol and benzyl alcohol on my bench. Luckily noone got injured, but the whole bench was on fire.
Bunsen burners are super useful if you have stuff to heat up quickly, but let's just say I understand why they have been banned from labs.
I snapped a thermometer in half trying to force it into a stopper and got myself good
yeah I forgot about that - I have also had that happen :(
Ooo, mercury/ alcohol flavoured pain
@@FarragoTheFox thankfully not of the mercury type
Idk if this counts as a rookie mistake but in 8th grade some of my classmates went into the chemical storage because a teacher forgot to lock it and just started setting random stuff on fire (luckily nothing serious happened tho)
O.o
This could have ended very very badly.
One thing I learned to do during my study of chemistry was I should do everything they can to discharge all potential static electricity before handling dry reagent. One time I forgot to do so, toxic inorganic reagent I was measuring on the laboratory scale decided to defy gravity and stay afloat above the beaker I was transferring the reagent to, then proceeded to spread all over the place.
I don't know what curse was inflicted upon me, but that seemed to happen almost every time whenever I didn't do at least two discharge procedures prior to handling them.
Just finished my MSci chemistry degree, can definitely relate to a few of these already.
Of mistakes not mentioned, most embarrassing was dropping two pipettes into a flash column when trying to wash down compound with eluent. Especially as these two pipettes fell into the same column. Either that or adding dry ice to the solvent trap full of water (thinking it was acetone) which of course then froze and I had to let it thaw out - didn't crack the glass thankfully.
It's refreshing to know that even the more advanced chemists make the same silly mistakes sometimes!
Oh yes, dropping pipettes into columns is definitely also a thing I have done many times
Worst mistake I've made recently, I had obtained the mass on a product, was getting ready to combine it with more from another batch, and had it waiting on the counter on a folded piece of weigh paper. I turned too quickly, and the breeze caught the paper, dumping the entire thing on the floor. Worse still, it was a yellow dye, so when I tried to wipe it up with damp paper towels, I managed to dye the floor yellow.
The reaction was quick and easy, so I just made more, but it always sucks when you essentially have a giant neon sign that says "I screwed up!!!"
Sorry to hear that haha
@@That_Chemist I had a few terrifying minutes when I thought I might have dyed the floor wax permanently, but I was eventually able to get it cleaned up.
In Germany it’s required for any lab accident to be documented for insurance purposes. At my former workplace, there was still a booklet for this with the first aid materials (now it’s usually done differently for data protection purposes) and we once looked through it. Almost all of the incidents were related to broken glass.
Definitely guilty of overfilling waste jugs, but there's one episode in particular that stands out. Finished a synthesis of some organometallic complex, and the glassware is stained with some particularly stubborn gunk. Water/Acetone doesn't work, weak HCl doesn't work, weak peroxide doesn't work, but conc. peroxide finally does something and we start using that in substantial quantities. This all goes into the waste bucket with the normal waste from the synthesis. Cut to a few seconds later, and we've got a waste jug overflowing with coloured foam that is spilling into the entire fume hood.
We got to test out the absorbent towels, which turned out to be very effective.
Haha, that sounds awful
I am working in a organometallic synthesis lab too. After using glasswares, we wash them with solvents first and then put them in base bath. After atleast few days of sitting in base, we take them off and run with solvent again. But after this we put them in acid bath and repeat the process. After several washings with solvent it is ready to put in stove. As I can say collecting chemicals in waste bin is not a good idea because they always react with each other if not neutralized.
U got me at ‘concentrated peroxide into waste bucket’
Great idea for a video and many interesting comments!
Many been there done that moments...
NMR tube glass is very thin and very sharp when broken... Always have a slight fear when putting the lids on or off now after cutting myself once
I once worked on N2 atmosphere using needles and a septum. Overpressure caused it to jump out and stab my hand (luckily no puncture, but I washed my hands pretty thoroughly afterwards!)
yeah this is definitely a thing that happens :(
Obligatory not a chemistry incident;this in an advanced biology class and we were testing isotonic,hypertonic and hypotonic solutions with eggs,on the last day of the lab I took the egg out of a jar of vinegar and was writing something down and I didn't click my pen close and accidentally pierced the egg and it went everywhere. Definitely a fun cleanup at 7:45 am.
After a couple of times I overfilled a waste jug, I decided to put some deep plate under it, so if I overfill it again at least I wouldn't clean everything up. Definitely it's my piece of advice about it.
smart!
some guy in basic course thought it was a great idea to remove a stuck glass stopper from his 3-neck flask by adding some water, clamping the flask and the other two stoppers down and heating the whole contraption. He also told noone he did this. He just set it up and left it to explode several minutes later :O RIP third stopper, only very small shards remained
haha
violates not making bombs rule. again :D
sounds like a success tbh he managed to get the stopper out
My lab partner was using an oil bath to heat a flask in first year, unfortunately the oil bath had a puddle of water sat at the bottom, which started to boil quite violently and bubbled hot oil all of the fume hood, neither of us were hurt because i managed to turn the heat off pretty quickly but that could have gone pretty badly.
lucky you for not getting it to flash boil and "explode" the bath onto you :)
My favorite was when my lab partner, after getting the admonition about how to "waft", stuck his nose in a beaker of chloroform.
"I have a whole nose, I'm gonna use my whole nose"
"hey, does this rag smell like chloroform to you?"
Stopper on a reflux/cooler smoothly popped out with an elegant sharp small parabola to flat fall trajectory, landing perfectly in the silicon oil bath beneath and shattering the glass container.
Scrubbing out a ~2L silicon oil spill in my fume hood took me 2 hours, first time I've had to use pentane as a cleaning agent.
I now exclusively use metal containers for oil baths...
In my first year of engineering during some basic classes where we make simple glassware, we were heating glass tubes to bend them. Mine didn't bend the way I liked it, so I decided on reflex to place my thumb closer to the bend right on the glowing red glass.
Dumb accidents happen so fast but that was 1 giant blister.
I finished chemical engineering but I long left the field because I'm too freaking clumsy to work in labs :D
During my second year we did a massive Organic Chemistry lab course and one of my synthesis was an epoxidation of styrene using a Prilezhaev-Reaction involving concentrated formic acid and hydrogen peroxide. After distilling over my product from the crude reaction mixture I went to disassemble my apparatus and accidentally touched the condenser on a contaminated part and pulled a big streak of remaining peroxo carbonic acid across my skin - that stuff really has some kick to it and hurts the second you touch it. Later I did a deprotonation with n-BuLi and had a leaky stamp in my syringe that caused the base to spill all across my glove - luckily I realized it really quickly and discarded it
I haven't overfilled a waste jug yet, but I'm only in my second semester so I still have a lot of time to do it
But in the month we've been in the lab this semester the wast jug has been hopelessly overfilled at least two times, eventhough it has a clear maximum mark which is still about 2/3 of a litre away from the top of the container........ Both times it was overflowing
It’s always someone else’s job to empty the trash!
- Shattered a glass cassette while pouring an acrylamide gel multiple times
- serial thrower awayer. i've thrown out entire finished experiments and very expensive equipment. cue me sifting through the glass waste container to retrieve what ive thrown away
- definitely microwaved things that should not have been microwaved because i was too impatient to wait for reagents to heat up in the water bath
- sat down, missed chair, fell hard on my ass while holding full canister of 81 degree formamide. of course in front of a mechanic trying to fix a broken fumehood
- forgot to remove supernatant. add next reagent. wonder why tube is overflowing
- phenol centrifuge incident
- cross contaminated tubes countless times because i lost track of what i was pipetting and where. ive since learned that i should never multitask
sometimes i wonder how i was allowed to be in a lab
Yeah stuff happens :(
When performing reaction (I dont exactly remember what reaction it was), I used 100 mL round bottomed flask. It needed to be heated in an oil bath to quite a temperature, so I used glass stopper - but one made of solid glass (not hollow), and doing some unrelated stuff in lab when hearing loud POP and milisecond after BANG. Somewhat, pressure build up in the flask and sent the heavy solid glass stopper flying to the top of the hood and cracking plexiglass on the lights inside :) it was like 5 years ago. Nobody was injured, just the poor light and stopper - which didn´t make it.
I've had a lovely cut right across my palm from shearing off the screw-thread fitting on a B45 condenser while screwing the fittings onto it before. It left a small jagged piece which my hand went straight over. Somehow avoided a scar with that one. I've also managed to spray toluene up myself due to a syphon slipping out of a measuring cylinder while I was measuring it out, Tyvek saved my body and safety specs saved my right eye!
yikes!
Just like the open separatory funnel thing, i've done that in an addition flask. Except i was quenching a reaction containing AlCl3 with some water. A whole bunch of water went in with me realizing too late, and the whole thing started boiling, sending stoppers flying and benzene spraying all over the place.
Recryled glass maybe budget boiling chips?
Big fan of the floor extraction. Chuck everything broken in a big beaker , then add solvent then pray you can save some product.
Getting salts stuck in a ground glass joint (sept funnel etc.) resulting in two pieces of seized glasswre that are suprisingly hard to seperate.
Fascinating stories! Thanks. Duly subbed to your channel.
Just a few I encountered as a lab techie (mainly inorganic)
You have to remember that this happened a long time ago. Safety has tightened up a lot here in the UK. COSHH and all that.
Went to prepare some bromine water, picked up a 3ml ampoule of bromine which broke in my hand, more like exploded which I couldn't understand giving the BP of bromine it 59C, Mu h higher than hand temperature. Quick dip in sodium thio solution but my hand felt like it had an accident with a blowtorch. The lab floor was never the same after. I know... should have used gloves but I'd done it tons of times and just got cocky.
Transferring ETOH from a big bottle into a flask. Spilled some on my hand, didn't notice my hand had caught fire from a nearby bunsen. (I know!) Went to put the lid on the big bottle and the ETOH/air mixture ignited and turned iinto a rocket exhaust. Long time with my hand under the cold water tap.
Managed to spill some solid phenol on my arm... still got the scars.
Various sheets of flame from heavy solvent vapours catching fire.
Mercury spills... so many mercury spills. For some reason the students couldn't resist measuring the temperature of a bunsen flame with a mercury thermometer. Which makes me wonder exactly how much mercury is still lurking in the cracks in floorboards of old physics labs in the days before mercury was hazardous.
Student was dissolving iron filings in H2SO4 in a test tube over a flame. The liquid bumped and shot the hot mixture into his face and eyes. Grabbed the kid by his hair and dragged him to a sink, forced his eyes open and flooded them with water from a rubber tube attached to a tap for this very purpose. (before eyewash stations were mandatory) Student didn't suffer any permanent harm but had sore eyes cor a while.
Not exactly as exciting as your tales but fun to look back on now I'm happily retired.
yikes!!
My teacher once decided it was a good idea to tell us to reduce the volume of the heavy metal waste, which was mostly a 0,1 M Copper-(II)-sulfate solution with some CuCl2 thrown in there, by boiling it down a bit. In an aluminium pan.
In university, I was asked to do a reaction with 5 mL of some concentration of HCl. I was only given a 10 mL volumetric pipette, and being rather shy, I decided to just eyeball it as half full instead of asking for proper equipment. I was told that we're not doing such things in chemistry.
One of my first assignments working in organic synthesis was to do a synthesis that the guy working there before me wrote up extremely sloppily. His procedure called for "repeatedly boiling the solid in Hexane and decanting from the insoluble residue". I was doing solubility tests and kind of knew that only about 1/10 th of the product would be soluble, so I carefully asked my colleagues if I should maybe do that in portions. They said that this would waste some time, and that the other guy would have written that down.
We wasted 2 months and multiple 2 L flasks to violently polymerizing product before I had the guts to ask for his previous versions of the synthesis. In 1 out of 3, it was clearly stated to do that in portions. Got a raise after 3 months working there afterwards.
The lesson here is: While you should usually listen to people with a lot more experience then you have, sometimes, you should grow some balls or ovaries and recognize when they are making you do stupid shit.
True - you do need to develop your own competence and do procedures the way you know they should be done
Hot glass looks very, very slightly clearer than cold glass. I found this out during my first course in lamp working.
I love that your cursor is like a laser pointer, that's adorable 🤣
its a setting in powerpoint - just right click and bam
So true. I like your videos as I'm also a organic chemist I can totally understand the challenge in organic lab and mentanence.
100%
the reason i now always carry an infrared thermometer in my lab coat is because i was sick of constantly getting burned from people leaving hot glassware on hotplates that are turned off
Wise
i had an amateur chemistry set when i was about 5 years old tried to insert a capillary tube into a holed bung it snapped and inserted about an inch into my wrist, i pulled it out straight away but i felt no pain at all, would have to wait for the time i stapled my thumb to experience proper pain for the first time, ive never tried shoving a glass capillary into a bung since
I still consider the worst mistake I ever made personally to be crashing a turbopump while alone in the lab. I didn't open a throttle valve all the way and so a little bit too much back pressure built up. It started to squeeze the grease out of the bearings and the pump made the screeching squeal of death. I shut it down, realized what I'd done and my heart sank. Then I tried bringing it back up to high vacuum over the course of several minutes, at this point just hoping it was actually magically fine. Nope. Turbomolecular pump screeched for a moment when it was turned on then shut off on its own. I was so stressed at that point and operating on so little sleep that I just broke down crying. I ended up practically hiding behind a lab bench with my laptop hoping nobody walked in as I tried to write an email to the lab supervisor while barely able to see past my own tears.
Awe I’m so sorry to hear that :(
I once dropped a flask with compound and DCM in the rotavap bath. Looked actually pretty impressive, because all the DCM instantly evaporated, without making a big mess, but the compound was lost.
F
Borosillicate cuts are the worst. Very deep. I once had a cut I didn't even notice until some dilute NaOH solution managed to reach it when I was switching gloves or something, I don't really remember. What I do remember is the feeling of a hundred knives stabbing me at that area. nope/10 would not recommend.
*relabels NaOH bottle to "cut finder", thows out disinfectant bottle labeled that way
;)
Ooh I have a few good ones.
Once I was putting s flask under argon , and I tried to spin the gas adapter which lead to my schenk line. My flask was under vacuum, the gas adapter broke really easily and I got a big cut on my thumb.
We have a puriflash MPLC in our lab, which most people bring thier own distilled solvents for. Once someone in our lab grabbed their brine bottle instead of thier hexane bottle, and put brine through the MPLC and wondered why they didn't get good separation on thier suppose hexane:ethyl acetate column.
In our lab, we redry and reuse sieves where we can. Once, someone put some "wet" sieves in the drying oven. The sieves had still some pyridine on them and the exhaust fan from the oven leads right into my workspace.
Oh no!!
Funny home lab mistake: I was boiling a solution of acetic acid with some MgSO4 as drying agent. The first time, this worked perfectly, the MgSO4 served as boiling stones. I then added some other (also dry) solution and let it react at room temp for some time, and afterwards wanted to boil it again. I was starting to get surprised why it takes so long to boil, at this moment it bumped violently and shot half the reaction mixture everywhere, leading to a benchtop extraction. I totally didn't realize that the MgSO4 may have absorbed water and may not act as boiling stones nicely anymore. Duh. Next time, I will for sure not trust in the MgSO4 as boiling stones.
Yep, base bath fires are a common incident, especially in organometallic research labs, where you often have residues of something pyrophoric in your schlenk tubes. Though usually you can just slam the lid on to starve the flames of oxygen, which puts it out straight away. When I needed to make up a fresh base bath, I would dissolve up the KOH in a small amount of water first and then dilute that down with IMS.
A problem I sometimes encountered was that we also used IMS for making cold baths with dry ice, and some people would just dump the spent cold bath into the base bath to avoid tipping the IMS down the sink. Which is fine to do if most of the dry ice has gone already, but if there is still some in the cold bath, it has a tendency to convert some of the KOH in your base bath into potassium carbonate - which is far less soluble in alcohols so crystallizes out on the sides and bottom of the container.
Worse though was when someone did the same with a cold bath they had made with acetone. Dumping a load of acetone into a base bath converts it to a porridge-like sludge after a few hours, containing a stinky mixture of condensation reaction products - essentially a bunch of organic waste which is useless for cleaning glassware.
So refreshing to find such honesty. Now if doctors would do the same.
To err is human, to survive divine.
To help with breaking or hot glassware I think I've been regularly saved by using rubberized work gloves. Either under or over disposable nitrile depending on reagents used.
Yeah - a little grip goes a long way!
Carbon disulfide molten sodium story please!
Also superheated acetonitrile at 160 °C in a pressure tube is fine as long as you dont question what the pressure tube is rated for...
The benchtop extraction got me ;)
Accidentally used concentrated sulfuric acid instead of dilute to neutralize NaOH waste. Luckily, it wasn't that much of a base left, but reaction vessel still went pretty hot.
I've dropped the magnetic stir rod in the waste beaker not once but twice in the same semester 😅
I used regular-ass oven mitts to handle hot (640 C) quartz glass because I thought they were 'good enough', forgetting that oven readings are in F in Canada for some reason. I managed to calmly put the glass tube down where I wanted to put it, while my gloves were on fire.
In my institution we have barrels with a pumping mechanism for technical grade solvents. So that you can bring a can from the lab and fill it up there. I place my can for THF under the tap of the barrel and gave it a cuple pumps. When nothing came out my colleague came over and wanted to try suddenly the THF shoot out so violently it hit the funnel went vertically up in the air and showered me with THF.
I was once doing a colum (a really big one for like 20 g of prodcut) just minding my own collection the fractions. Out of nowhere I heard the sound of glass cracking and I looked up and see this rapidly growing crack going vertically down the coloumn. The solvent started pouring out through the crack. So I grabbed the first thing I could find which was a large bucket and dumped the entierty of the coloumn into it right when I was done the column broke apart into multiple pieces.
The worst accident I have seen was when a PhD student in my lab was working with liquid nitrogen and had nitrile gloves on. The Dewar fell over and all the nitrogen poured over her hand. She took the glove of and with it she ripped of most of the skin on her hand. It took a couple months to fully grow back.
oh my gosh those are both crazy stories!
I would love to hear about the CS2 and the Molten Na Story
I'd love to see a column chromatography tips and tricks video! Particularly for when you have to column something and the crude mixture is just very insoluble and makes loading the column difficult. :)
ua-cam.com/video/fF1gXUvyGb4/v-deo.html
something i was told to do once is to mix it with the silica directly so you include the crude mixture in the silica gel suspension rather than dissolve it. lt did work, but no clue if that's universally, applicable.
Ah, the benchtop extraction reminds me if the time i broke a separatory funnel by slamming it against the table after shake #243 that day, i had to do a floor extraction after that one. Luckily after cleaning everything up i still had a few mg of tge required products (or at least one with the same color and melting point haha)
Haha
Once, I had finished, solid product from the column that I rotavap'd and after turning off the pump, refilling with air, taking of the flask I looked for a yellow cap to close it. Didn't find one in the drawer (which is right in front of the rotavap) and my brain just turned off: i let the flask drop in the nasty rotavap bath, ruining my clean product. It was a very worky week I guess.
Glass cuts to the hand are part of the job. The scar is called the "Mark of the Chemist".
During my first year of undergrad we were determining melting points with a Thiele tube, unfortunately I didn't seal the cappilary containing my compound well enough and oil seeped in. So by the time I had prepared a new capillary with compound, my Thiele tube cooled off and had to be reheated. I wouldn't think reheating a Thiele tube would require supervision, so I went to clean up some glassware. However, the wire of my digital thermocouple had shifted slightly into the flame of the bunsen burner and unfortunately the supervisor had noticed it before me and yelled at me. But by the time I got to my setup it had burnt through the plastic coating and all that was left was a metal wire
On a side note, I have never overfilled a waste jug though. Overfilled many fraction tubes during column chromatography, but not a waste jar yet.
The biggest fuckup I've done involved bukkakeing a huge amount of fluorescent material all across a fume hood - basically, the flask overpressurized because I'd set up a thermocouple totally wrong (and heated past the BP of the solvent) and the joint on the flask that decided to give was the one that was at a 45 degree angle from vertical. Literally like one of those physics problems where they ask you how to aim a cannon for the maximum distance. The whole fume hood got splattered in fluorescent particulate and cleaning out the fume hood so that it was mostly clean enough to use took like a few days. I think it glowed for at least a few years afterwards if you shined UV on it.
On that note, something to add to this video - thermocouples can pop out really easily (or not be properly immersed due to stirring shifting liquid level). Controllers have a loop break error trip (of course, only after heating the living shit out of your material first) but hot plates don't come with such luxuries (or, at least, ours don't... maybe newer ones?). Vials can easily explode (or force themselves to loosen) this way.
Dont stab your finger with a syringe filled with GC-MS toluene.
The chlorine photochemical cleaning is actually a genius move, your only mistake was doing an exotherm in a sealed flask.
The base bath is mild. I have witnessed large glass fritted filters cleaned with a perchloric acid + cc. nitric acid bath. Not sure about the concentrations, but might have been 70% perchloric mixed with RFNA.
How else he could contain all that chlorine in the flask?
@@quint3ssent1a A hose adapter with a long tube? There are many ways to have a semi-sealed system that does not ventilate on its own too much, but also cannot build up any pressure.
@@TheBackyardChemist hose adapter and reverse funnel is exactly what i was thinking. it’s… not an elegant solution but a lot of genius is borne from wanting to get shit done quickly.
@@milesmccollough5507 Eh, i am not sure if i would have bothered with the funnel trap if I wanted it done quickly, its all going to be done in in the fume hood anyways. If some chlorine escapes, oh well that is what the airflow is for.
@@TheBackyardChemist yeah, the atmosphere can have a little bit of chlorine, no big deal 😏
I've had the water inlet pop off my reflux condenser twice, both times landing straight into my oil bath that was set to 120 degrees. A huge mess of boiling water and hot oil spraying everywhere, covering my stir plate and spilling over half my fumehood. I never trust leaving any water tubing unsecured anymore!
I had a glass pipette break in my hand once. Left a decent scar on my thumb. The burn from the sulfuric acid was the icing on the cake.
during some class this year, which was the first thing in the morning and it was also just after a party that was organized by the college, someone had to put a pipette into the propipetter, he held the pipette from the tip, so what would happen happened, and it broke off, and due to him forcing it in, he stabbed it in his hand, where he just started leaking a lot, a classmate went to the teacher with what the teacher later described as "the funniest face of dread i have ever seen" to announce that he was over there leaking out from his hand after stabbing himself, which then the teacher called the college's doctor or nurse, who said to go to the hospital (which is like 1km away so it's not that bad), teacher asked for someone to drive him there, he ended up having some stitches and missed by like 5mm a tendon.
cool thing was that his group for another class had something they didn't finished and got awarded extra time since they said he had the documents.
Surprise injury saved the day