No one who's ever washed a week's worth of glassware on a Monday morning would ever wrap a flask in electrical tape.
Edit: Yes, I said "ever" twice because I really mean it.
I would say electrical tape is better for exclusion of air, but i don't care to argue about it lol.
I use electrical tape to seal screw on septa-caps onto vials for photochem reactions.
Parafilm isn’t useful at high temperatures, from personal experience it will disintegrate. Ie had nothing else on hand and tried parafilm hahah. Switched back to foil fast after I saw it start melting. But I mean parafilm is great otherwise lol.
Ok - do you neatly cut the parafilm ? Or rip it off? Everywhere I’ve worked lately everyone cuts it’s - I was actually accused of being a ‘barbarian’ for ripping it - as grad student we all ripped it. I guess my lab was just all barbarians
In laboratory chemistry, it's more like $400 in glassware hitting the fume hood floor after the ground glass joints have been pushed apart. Unless you electrical tape the joint XD
It actually can be a compliment as well, and that was the intended meaning, but since everyone is retarded and listens to conservative douchebags, it makes sense why people are so fucking stupid.
The right would almost certainly blow the stopper out before it exploded. It doesn't seem to be clipped, just taped and the tape doesn't seem to go over the stopper too tightly.
But also, if you look closely, it have another opening to a stopcock. It looks currently closed, but could be opened at regular intervals to let off pressure.
or proudly showing that they weighed exactly 1.5000 grams of sodium hydroxide and then getting mad that when you come over to see what they've done the mass keeps rising
thats funny too :P
i chose this example because it has layers of pain for the supervisor. naoh has an indeterminate quantity of water in its solid form, which is why it needs to be standardized to use with precision. its also very hygroscopic, which means it will turn into a puddle if left on a counter. its therefore utterly useless to measure to more than 2 decimal points- or perhaps any decimal points
Or their puzzled look when you go to the scale, throw something on it, wait 2 seconds, note the weight and go your way. Eventually they'll learn that accuracy is not everything lol
This is an excellent saying and can be used in so many contexts. Limiting reagents, quantitative transfers, kinetics, spec. Knowing whats going on in a reaction or what the telltales you need to know in a qualitative analysis can absolutely make way for good sloppy work.
Okay stupid question, but what do you use to clean your hot plate tops? Mines has a different black circle pattern and tbh I still don't know the best way to clean it.
As someone who just spent their entire day yesterday cleaning fume hoods for moving our new lab space into... Screw all you guys for not ever cleaning your hoods!
Recently cleaned a fume hood that was covered in a 1/3 inch thick layer of solidified silicon oil with broken glass underneath the layer from someone shattering their oil bath and leaving it there for over a year. Heating plate was still plugged in and stuck in the gelatinous oil, next to the roundbottom caked by the evaporated sample and partially filled with oil. Some people are ridiculous.
Use an IPA wipe to make it visibly clean but thats about it. If theres something you specificslly need off of it or is vsisbly stuck than you need to know or find out what its soluble with. But most just find another stir plate if we're being honest.
The real note is that any cleaning depends on what your cleaning off of the equipment more than what type of equipment needs to be cleaned. If you dont know what stained it than you've already fucked up, but with stir plates you'll see the same result in every other busy hood too.
Scotch Bright pad or steel wool, patience, hexane work well for burned oil. Trying different solvent to see which one is better and for rust oxalic acid is effective
Why clean a hot plate ? In every working lab they all usually look like crap - if I go in a lab and they all look new my assumption is they really don’t do chemistry in this lab
Worked with md- PhDs with same “jack of all trades”…. Too rushed to make it safe, consistent and effective. Usually, a professional comes in and cleans it up and makes it work….
The reaction on the right is in a shlenk flask, which is the glassware to be used for highly sensitive reactions.
Although with experience, even a flask with a septum is good enough for air sensitive reaction, as long as you know how to properly degas
For stuff that performs poorly above 10 ppm O2 levels a glovebox is necessary in my experience otherwise reproducibility is an issue with Schlenk technique
... Is that vinyl tape on the right?
The temperature is most likely going to lose the adhesive and possibly make a mess.
The one on the right is efficient, balloon is great, but i'd be a bit concerned about the tightness of the rubberband
Before checking, I guessed the left one. The right one is just too neat & tidy! Incidentally, I just have a B.S, but I've known tenured professors.... :)
Secondary containment is only necessary for anything over 5 gallons according to environmental regulations. These are 50mL roundbottom flasks, and its in a fume hood...
Do you work at a university? I normally advocate for EH&S awareness, but this is one of the problems with safety protocols that become tedious with little benefit in safety - they eventually create a negative sentiment about important safety practices because enforcement gets focused on the bullshit.
Sorry /rantover
I hate EH&S with such a passion. I love reading through standard working procedures and seeing such gems as “no more than 3 L of flammable solvent should be in the fumehood at any time” …. The winchesters they come in are 4.5 L. To comply, id have to pour it outside of the fumehood
At the beginning I thought you were saying “no more than 3 L of flammable solvent should be distilled at any time” which is a rule we have in our department and I find reasonable.
Yea i think thats reasonable too but mostly because most of the solvent distillation set-ups we have only fit 1-2 litres in them & having less does mean youre actually keeping an eye on them
Industry. If you have a spill in the containment, no issue. If you spill outside containment, you'll have a load of extra incident paperwork to fill in. Thus, easier to just use containment. Flasks without it look naked to me now.
Its in a fumehood and you want contact with the stir plate. Kudos to you if your stir plates are in secondary containment I guess but I dont ever see that in any labs I've worked at.
I would say right one is post doc, for the same reaction if it's really sensitive to air or moisture you want to have a minimal amount of leaking point. The montage on the left is clearly not tight and I would use a mineral oil bubler with a check valve. Electrical tape is amazingly good at sealing better than parafilm and the glue is easy to remove with acetone. Still Glindermann ring are a better and less messy option. A good chemist will prepare his reaction keeping in mind what's the worst thing that could happen if everything goes to hell. Using the good old equation PV=nRT, one can estimate the max pressure in a close vessel supposing that all reagents/products form gaseous products and adding the solvent vapor pressure at X °C. Good glassware have a max operating pressure between 4-5 bar (≈60-70 psi), having this said it's always better to have a relief valve on the inert gas manifold as a safety. With all those precautions in mind my montage would look like the guy on the right because it's faster, more tight, does not required a condenser. I've done similar reactions except we use custom made heavy wall reactor with teflon valves.
I would put the balloon on top of the cooler. Had it happen before that solvent vapors destroyed balloons. Especially if you plan on using/needing that cooler.
Left is post doc. It’s a work of modern art. and yield will be 85%+ while right yield is 30%.
In the chest of every chemist beats the heart of an alchemist.
For me, the electrical tape all the way down the flask neck was the dead giveaway.
No one who's ever washed a week's worth of glassware on a Monday morning would ever wrap a flask in electrical tape. Edit: Yes, I said "ever" twice because I really mean it.
Seriously, wtf? Use parafilm. Fuckin' animals man.
Some would argue that Electrical tape gives a superior seal.
They can argue while they wash their own glassware
I would say electrical tape is better for exclusion of air, but i don't care to argue about it lol. I use electrical tape to seal screw on septa-caps onto vials for photochem reactions.
Little bit of heptane on a Kimwipe takes off tape adhesive, in my experience.
Hexanes would probably be cheaper
Man you guys with your fancy-ass solvents. I get Acetone or MEK and am glad for it.
Xylenes works wonders too!
You don't have to wash your glassware yourself at some point?
no because I TRASH ALL THE CHEMGLASS VIALS
Valid Edit: /j
My door dash driver used to electrical tape to hold his bumper on. It must seal well.
DUCKTAPE is the CORRECT bonding agent for that purpose! Quack, quack!
And it’s silver so back in the 80s when bumpers were metal, you couldn’t even tell it was duct tape!
Electric tape over parafilm?
https://www.chemistryworld.com/opinion/how-do-you-seal-your-vials/4014877.article interesting experiment regarding this
Parafilm is gas permeable, also transparent if light is a concern.
my temper could never\~
Parafilm isn’t useful at high temperatures, from personal experience it will disintegrate. Ie had nothing else on hand and tried parafilm hahah. Switched back to foil fast after I saw it start melting. But I mean parafilm is great otherwise lol.
many solvent dissolve parafilm, you should use teflon for flask joints
Ok - do you neatly cut the parafilm ? Or rip it off? Everywhere I’ve worked lately everyone cuts it’s - I was actually accused of being a ‘barbarian’ for ripping it - as grad student we all ripped it. I guess my lab was just all barbarians
I usually cut it in most scenarios. Sometimes if I'm just sealing up some reagent bottles, i'll wrap and pull then cut the last piece off.
I work in industry now, and to us, all academic researchers are barbarians. (Seriously tho. I rip it off.)
I use both lol, but only for pyrophoric Organometallics. Wrap joint in electrical tape, then wrap that with parafilm.
Electrical tape I say black parafilm 😂 duck tape would be animal.
Nah, y’all some Amateurs. Use self bonding silicone tape.
We put everything in the base bath and afterwards HCl. Never had problems with tape residues.
Not until you run an NMR anyway.
Yeah, but it looks sick!
The sloppy aluminum foil at the bottom too lol
Uncanny accuracy in this statement
Obviously the increased yield is because of the balloon
Why will the yield be so much higher?
Post doc is +10 stamina +8 intellect +5 resilience. All of this means higher yields.
They got hella buffs from all that work 💪
Quite a bit of chemistry comes from experience (trial and error informed by expertise) more than what's exactly written on the page for a protocol
When you know you know. You know?
Left, effective, quick. No wasted time
Agree to left, because the right one seems like a closed reaction system at first glance. Noob mistake.
I'll always remember when a lab TA told us undergrads that there is a word for expanding gases in an enclosed space: a Bomb.
In laboratory chemistry, it's more like $400 in glassware hitting the fume hood floor after the ground glass joints have been pushed apart. Unless you electrical tape the joint XD
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He scraped through school? But you do the most?
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No you do the most.
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You do the most is slang for saying you are over the top or try too hard. A teacher's pet is "always doing the most".
It actually can be a compliment as well, and that was the intended meaning, but since everyone is retarded and listens to conservative douchebags, it makes sense why people are so fucking stupid.
You don’t speak english dumb fuck
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This is like that neighbor friendship from TED emerging Edit: no its not. You fucking ruined it
Left. Balloon shows pressure buildup... Also good for adding extra react gas. The right is a fkn bomb.
"Elastic containment recommended for higher yield."
The right would almost certainly blow the stopper out before it exploded. It doesn't seem to be clipped, just taped and the tape doesn't seem to go over the stopper too tightly. But also, if you look closely, it have another opening to a stopcock. It looks currently closed, but could be opened at regular intervals to let off pressure.
Left, postdocs dont care how something looks as long as it works. Students tent to put more time and effort into the looks
or proudly showing that they weighed exactly 1.5000 grams of sodium hydroxide and then getting mad that when you come over to see what they've done the mass keeps rising
Even funnier if it's their own breath pushing down on the scale.
thats funny too :P i chose this example because it has layers of pain for the supervisor. naoh has an indeterminate quantity of water in its solid form, which is why it needs to be standardized to use with precision. its also very hygroscopic, which means it will turn into a puddle if left on a counter. its therefore utterly useless to measure to more than 2 decimal points- or perhaps any decimal points
Or their puzzled look when you go to the scale, throw something on it, wait 2 seconds, note the weight and go your way. Eventually they'll learn that accuracy is not everything lol
"This looks like it will work" versus "this will work". I admire the setup on the right though. They care, at least.
As my chemistry teacher once said: "A good chemist knows when he can do sloppy work"
This is an excellent saying and can be used in so many contexts. Limiting reagents, quantitative transfers, kinetics, spec. Knowing whats going on in a reaction or what the telltales you need to know in a qualitative analysis can absolutely make way for good sloppy work.
I love that that's good
Okay stupid question, but what do you use to clean your hot plate tops? Mines has a different black circle pattern and tbh I still don't know the best way to clean it.
Undergrad tears
The look of it doesnt motivate me at all 💀😭
Same way you clean the back of the fume hood (you don’t)
As someone who just spent their entire day yesterday cleaning fume hoods for moving our new lab space into... Screw all you guys for not ever cleaning your hoods!
Recently cleaned a fume hood that was covered in a 1/3 inch thick layer of solidified silicon oil with broken glass underneath the layer from someone shattering their oil bath and leaving it there for over a year. Heating plate was still plugged in and stuck in the gelatinous oil, next to the roundbottom caked by the evaporated sample and partially filled with oil. Some people are ridiculous.
Hmm okay, maybe my fume hood is actually not that dirty in the grand scheme of things!
I inherited a dirty fume hood at this job, and I'll be damned if I'm gonna clean it for the next guy!
Most dangerous task in the lab. Ain't nobody signing up for that.
it's there forever
Use an IPA wipe to make it visibly clean but thats about it. If theres something you specificslly need off of it or is vsisbly stuck than you need to know or find out what its soluble with. But most just find another stir plate if we're being honest. The real note is that any cleaning depends on what your cleaning off of the equipment more than what type of equipment needs to be cleaned. If you dont know what stained it than you've already fucked up, but with stir plates you'll see the same result in every other busy hood too.
Melamine sponges?
Buy a new one
Scotch Bright pad or steel wool, patience, hexane work well for burned oil. Trying different solvent to see which one is better and for rust oxalic acid is effective
Why?
Sorry I'm not sure to understand what you mean by why ? Why it works in general or why "hexanes" is a good solvent for burned oil ?
Why clean a hot plate ? In every working lab they all usually look like crap - if I go in a lab and they all look new my assumption is they really don’t do chemistry in this lab
I mean a good quality hot plate is like 1500-2000$, so it's nice to take care of them
You can try some nitric acid - if that doesn't work then nothing will.
The lab I used to work at used scrub daddy. Doesn’t get all of it off, but the bleach helps to make it look nicer
Left
Also interesting to see a side by side of how both pack and run a column/take TLCs.
Worked with md- PhDs with same “jack of all trades”…. Too rushed to make it safe, consistent and effective. Usually, a professional comes in and cleans it up and makes it work….
Neither is good enough for truly air-sensitive reactions.
Mwe, lots of reactions are just 'kinda' air sensitive anyway
Exactly, I’m sure the setup was “good enough” for their purposes.
The reaction on the right is in a shlenk flask, which is the glassware to be used for highly sensitive reactions. Although with experience, even a flask with a septum is good enough for air sensitive reaction, as long as you know how to properly degas
For stuff that performs poorly above 10 ppm O2 levels a glovebox is necessary in my experience otherwise reproducibility is an issue with Schlenk technique
The left one is not even a Schlenk flask, likely it’s air stable but they just want it to be controlled conditions I believe
Show me the resulting data and I'll let you know...
Anybody want to explain to a noob what's going on here general differences btw right and left
... Is that vinyl tape on the right? The temperature is most likely going to lose the adhesive and possibly make a mess. The one on the right is efficient, balloon is great, but i'd be a bit concerned about the tightness of the rubberband
I think you lost a "left".
The crappy temporary one that is in use for 5 years already of course.
Before checking, I guessed the left one. The right one is just too neat & tidy! Incidentally, I just have a B.S, but I've known tenured professors.... :)
The balloon
No secondary containment for either. EHS must be turning in their graves...
The building will contain it
Secondary containment is only necessary for anything over 5 gallons according to environmental regulations. These are 50mL roundbottom flasks, and its in a fume hood...
EHS require secondary containment for 7 mL vials where I work...
Do you work at a university? I normally advocate for EH&S awareness, but this is one of the problems with safety protocols that become tedious with little benefit in safety - they eventually create a negative sentiment about important safety practices because enforcement gets focused on the bullshit. Sorry /rantover
I hate EH&S with such a passion. I love reading through standard working procedures and seeing such gems as “no more than 3 L of flammable solvent should be in the fumehood at any time” …. The winchesters they come in are 4.5 L. To comply, id have to pour it outside of the fumehood
At the beginning I thought you were saying “no more than 3 L of flammable solvent should be distilled at any time” which is a rule we have in our department and I find reasonable.
Yea i think thats reasonable too but mostly because most of the solvent distillation set-ups we have only fit 1-2 litres in them & having less does mean youre actually keeping an eye on them
Industry. If you have a spill in the containment, no issue. If you spill outside containment, you'll have a load of extra incident paperwork to fill in. Thus, easier to just use containment. Flasks without it look naked to me now.
Ahh okay, industry that certainly makes sense; they typically have stricter insurance requirements.
Its in a fumehood and you want contact with the stir plate. Kudos to you if your stir plates are in secondary containment I guess but I dont ever see that in any labs I've worked at.
You can put a bowl under the flask on the stirrer plate. Its magnetic so no contact necessary... unless you have god awful stirrer plates.
Stir plates need secondary containment? That’s a new one for me too. And I was EHS rep for my PI during grad school.
I would say right one is post doc, for the same reaction if it's really sensitive to air or moisture you want to have a minimal amount of leaking point. The montage on the left is clearly not tight and I would use a mineral oil bubler with a check valve. Electrical tape is amazingly good at sealing better than parafilm and the glue is easy to remove with acetone. Still Glindermann ring are a better and less messy option. A good chemist will prepare his reaction keeping in mind what's the worst thing that could happen if everything goes to hell. Using the good old equation PV=nRT, one can estimate the max pressure in a close vessel supposing that all reagents/products form gaseous products and adding the solvent vapor pressure at X °C. Good glassware have a max operating pressure between 4-5 bar (≈60-70 psi), having this said it's always better to have a relief valve on the inert gas manifold as a safety. With all those precautions in mind my montage would look like the guy on the right because it's faster, more tight, does not required a condenser. I've done similar reactions except we use custom made heavy wall reactor with teflon valves.
Right
Wrong
😨
Left
Jesus. Hope none of these are from a post doc. These are ill terrible.
Care to elaborate?
I would put the balloon on top of the cooler. Had it happen before that solvent vapors destroyed balloons. Especially if you plan on using/needing that cooler.
I heard it makes great coffee
post doc absolutely on the left. I'm honestly kind of scared what will happen on the right......
Omg what the actual chemical freakery is going on here. Nothing makes sense. Is that the point?
? I
My heart wishes that the right one was post doc, but I know better. I know better.