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Author: Subject: Bad days in the lab or with glassware?
Arthur Dent
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[*] posted on 6-6-2011 at 04:31


Outch. a vigreux is always a painful sight to see shattered...

An odd breakage happened this weekend as I was heating a solution of copper sulphate in a beaker. I usually put a sheet of aluminum paper over the element of my outdoors electric heater. As the solution was boiling gently, it suddenly overheated and upon cooling, I noticed that some of the aluminum paper had become stuck on the bottom of the beaker, after washing thoroughly the beaker, and dipping it in cleaning solution to remove the aluminum stains, there were several small cross-shaped cracks where the beaker had contacted the aluminum-covered element. Sigh.

So no more direct contact with glassware anymore, from now on, sand-bath all the way.

Almost had another breakage, I have this nice 600 ml widemouth erlenmeyer that rolled off my table and landed loudly on my hardwood floor. Didn't break! Phew. I inspected it for cracks and it appears to be ok. I use that flask for my gold-dissolving experiments, because you can easily drop a Pentium broken in half in it.

Robert




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[*] posted on 6-6-2011 at 12:33


Quote: Originally posted by Arthur Dent  
So no more direct contact with glassware anymore, from now on, sand-bath all the way.


If you're simply heating a beaker, you can just use a piece of wire gauze. I use them to heat beakers over flames, and I've never had a breakage!
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[*] posted on 10-6-2011 at 12:27


Today I was in the middle of a synthesis of SO3 from NaHSO4. I don't turn the hood fan until T=550C. I was just about ready to do that when I looked out the window. Who did I see but the neighbor's son who occasionally visits for a day of chores on Fridays. This caused me to shut down this day-long synthesis. Said son is a millwright and would instantly recognize the sound of my blower. He knows me and would very possibly start asking questions. I have to chalk this one up to "failure to adequately plan." But looking on the positive side, I did see him in time to take corrective action.



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[*] posted on 10-6-2011 at 12:50


Some gunk from a chemical cold pack crystallized in the bottom of my only beaker. It was moderately hard but was still like an extremely viscous liquid. I was starting to pry it up with my knife when I punched a little hole in the bottom of the beaker. :mad: I also burnt sulfur and ascorbic acid in separate test tubes and tried to scrape them out--same result as above.



hibernating...
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[*] posted on 21-6-2011 at 18:14


Quote: Originally posted by LanthanumK  
I was starting to pry it up with my knife when I punched a little hole in the bottom of the beaker. :mad:


I do this also! I lightly dropped a metal spatula into a 25 mL graduated cylinder, and it just fell right through the cylinder. :(
Granted, it was a very cheap cylinder, it was my only one of that size.




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Newest video: Synthesis of Chloroform

The difference between chemists and chemical engineers: Chemists use test tubes, chemical engineers use buckets.
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The WiZard is In
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[*] posted on 22-6-2011 at 06:22
A bucket of sand .. my Kingdom for a bucket of sand!


Found on the depths of my hard drive.

From: herodotus <paiuteNOpaSPAM@my-deja.com.invalid>
Subject: Anecdote from 1st year grad school
Date: Monday, June 05, 2000 9:49 AM

Down the hall, outside the undergraduate lab was a 5 gallon drum
of sand, the D-type fire extinguisher for quenching metal fires
and such. It had apparently never been needed and was covered
with a scattering of butts and papers. One humid summer day we
decide to clean out our THF still. The 5L pot was about a
third-full of the whitish-blue crust of sodium benzophenone ketyl
debris entraining God knows how much unreacted sodium. We remove
the THF in a hood and carefully begin to quench the residue with
alcohol. Sure as shit, it bursts into flames pretty soon as we
get bored with being cautious and pour the alcohol in too
quickly. I am prepared. I hose the pot down with a CO2
extinguisher and put the fire out. We relax. But then I notice
that the CO2 has cooled down the flask, and it is condensing
quite a bit of moisture from the room air. It builds up and
trickles down into the pot. FOOM! I hose it down again and the
fire goes out. But the glass is cold again. FOOM! I realize that
this cycle will repeat until I run out of CO2, so I scream at a
labmate to run down the hall and grab the bucket of sand. I go to
the door in time to see him carrying the bucket back with great
difficulty. It turns out to weigh close to a hundred pounds, and
he is a skinny guy. He manages to drag and hump the thing into
our lab with his adrenaline-enhanced strength. He puts it down by
the hood, and I plunge my hand in to gather up some sand, as the
flask has just FOOMed! again. Crack! My fingers bend back
unnaturally. The contents of the bucket have seized up over time
into an inpenetrable mass, the sand cemented together by years of
spit, dregs of sodas, and other things I do not want to know
about. We can't dig enough sand from the bucket to put atop a
silica gel column, let alone put out a fire. By now we know that
fate is against us, so we let the flask burn for a while. The
fire is small. Eventually we scrounge up a real D-type from
another lab and smother the thing.

As we later realized, this is the type of valuable educational
experience we would never have gotten at Harvard.


djh
----
The people of those foreign countries are very,
very ignorant. They looked curiously at the costumes
we had brought from the wilds of America. They
observed that we talked loudly at table sometimes.
They noticed that we looked out for expenses and
got what we conveniently could out of a Franc, and
wondered where in the mischief we came from. In
Paris they simply opened their eyes and stared
when we spoke to them in French! We never did
succeed in making them understand their own
language.

Mark Twain
20 November 1867


[Edited on 22-6-2011 by The WiZard is In]
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Arthur Dent
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[*] posted on 22-6-2011 at 08:02
Sand or kitty litter?


Quote: Originally posted by The WiZard is In  
The contents of the bucket have seized up over time
into an inpenetrable mass, the sand cemented together ...


I had a bag of sand for emergencies, which is kept outside in my shed. but I realized that moist, heavy sand is much less efficient and easy to manipulate than clean, free-flowing dry sand, so I bought several 2l plastic containers with a hermetic lid and I filled them with sand that I thoroughly washed and dried in the oven.

I also keep similar containers filled with cat litter, if I ever have an emergency, i'll probably see very quickly which product is more efficient/less reactive in case of a tenacious fire.

Robert




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[*] posted on 1-7-2011 at 08:47
Performic acid


Chem. Eng. News, 1952, 30 (29), p 3041
DOI: 10.1021/cen-v030n029.p3041
Publication Date: July 21, 1952

Abstract

Chemist Loses Hand in Performic Acid Explosion

Five milliliters of performic acid exploded recently at Laval
University, Quebec, Canada, tearing off the right hand of a
graduate student and smashing all glassware in a radius of two
to three feet. Numerous glass slivers were driven into his skin
and into one of his eyes.

According to information from the student, A. Weingartshofer-
Olmos, and Paul A. Giguère, professor of physical chemistry at
Laval, a small receiving flask containing the 5 ml. of
approximately 90% performic acid was being removed from the
still when it detonated for no apparent reason. The acid had
been prepared by the addition of 25 grams of 99% hydrogen
peroxide to 20 grams of 99% formic acid in the presence of 6.5
grams of concentrated sulfuric acid as catalyst. After two hours
for reaching equilibrium, the mixture was distilled under
reduced pressure (5 to 10 mm. Hg) at 30° to 35° ... [$$$$]


----
Unless perfomic acid has a phenomenal density - 5ml ain't much
weight. A lesson for the assorted fools here who dismiss all
safety information on primary explosives.


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Arthur Dent
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[*] posted on 1-7-2011 at 09:24


Quote: Originally posted by The WiZard is In  
Unless perfomic acid has a phenomenal density...


One could say that it "performs" admirably well as an explosive...
...podom bom...

As for defunct glassware, my favorite "drying dish" (a 10x10" Pyrex baking dish) literally split in half because of a dumb mistake of mine. I was gently heating some solution to dessicate it and instead of leaving the dish on the heater element, I put it on the concrete floor of the balcony to cool down. The temperature difference was too great and it just went "klink... KLANK!!!" and was effectively split into two perfect halves. Thankfully, there wasn't any liquid left, just a dry salt. Oh well, I paid $1 for it at a thrift shop... ;)

Robert

[Edited on 1-7-2011 by Arthur Dent]




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[*] posted on 1-7-2011 at 10:30


I discovered that my first erlenmeyer flask ever from four years ago has a 5mm crack! Must have been from the time where I put dry ice and ethanol in it... Oh well, it was only $4 and I have others now.
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[*] posted on 6-7-2011 at 12:24


This has been such a shitty day for chemistry. The week started out nicely with a trouble-free nitrobenzene synthesis. But today wouldn't turn out to be that nice. First I cough my ass of trying to transfer 15 ml of bromine to an addition funnel. Then I break my only 50 ml measuring cylinder. :(

Then, while doing a bromobenzene synthesis, I first realize that I haven't greased the joints: bromine vapour and HBr leaks all over the place, and I have to evacuate the lab and let the fan do its job for a while. Then, after sealing it up and making sure all the joints are actually in place (there was a relatively large gap between the liebig and three-neck adapter) everything proceeds nicely...Until I leave the setup for ten minutes (tops). When I return the liquid in the round bottom flask appears to be refluxing vigorously. "Hm. Vogel says the solution needs to be warmed. Makes no sense that it's refluxing from the reaction heat then?" Turns out it wasnt - the liquid from the HBr absorber had sucked back and poured through the condenser, ruining my reaction! :( I did put in a checkvalve, but I didn't realize at the time that it wouldn't react to such a slow sucking (sometimes I'm so stupid and short-sighted I amaze even myself). Then, while sealing the apparatus up, I break one of my three yellow NS14 keck clips to top it all off... So, summary: wasted a bit of bromine and benzene (my two most valued reagents), got a bad cough and broke a keck clip. At least I got some invaluable experience.


TO DO-LIST:

* Build a fumehood efficient enough to safely boil a liter of cyanogen bromide in it
* Buy a coiled or double surface condenser, a 200 mm 19/26 liebig just isn't suitable for anything involving bromine
* Buy some washbottles
* Buy sodium thiosulfate
* Buy some metal keck clips for use with high temperatures and hydrogen halides
* Hang up a poster in my lab saying "GREASE ALL JOINTS / ADD BOILING CHIPS / PREVENT SUCK-BACK" or something along those lines.


Now I'm just looking forward to monday, when I will pick up some exclusive glassware at the glassblower. Can't wait! :)




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[*] posted on 9-7-2011 at 00:56


Yesterday i was trying to make a concentrated ammonia solution by bubbling ammonia gas through water. I did this using a simple setup that consisted of a stoppered 100ml flask that had pvc tubing leading into cold water. I used ammonium chloride and sodium hydroxide to produce the ammonia, about 2 minutes into the reaction the water that i was passing the ammonia gas through got sucked back into the flask containing the NaOH and NH4Cl :o, at this point i knew something was going to go wrong so i ran out the room slamming the door behind me when all of a sudden . . . BANG!, the rubber bung gets blown off the flask and sodium hydroxide and ammonium chloride went everywhere, not to mention the amount of ammonia gas that was flooding my room, cleanup took at least 2 hours :(. At least next time i know not to do this experiment inside and to use another flask to lead the ammonia gas into the water so that incase another suckback does occur it won't get out of hand again!

Also does anyone know why this suckback occured ? I was thinking maybe due to the dissociation of sodium hydroxide being exothermic it heated the air/nh3 inside the flask and when it cooled down a little a partial vacuum was created ?
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barley81
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[*] posted on 9-7-2011 at 03:55


Well, next time you do this, you should:
Not be doing it in your room.
Use a suckback trap.

Ammonia gas is very soluble in water. See this experiment, the ammonia fountain:
http://www.youtube.com/watch?v=sLpITPAqdUI&feature=relat...
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[*] posted on 9-7-2011 at 05:18


i always thought it was caused by absence of oxygen and the void tries to grab it from the atmosphere but its probably the other way around. the oxygen tries to go into the void or maybe i am about to learn something new about this occurence that broke my favorite vessel. at the moment i am waiting on the gentlemen going back and forth on the ammonia and aluminum thread to come up with something concrete because i want to make an ammonia generator using an aluminum joggers bottle and i dont want to blow up. i can sacrify aluminum but glass is priceless almost.i dont want to waste my hydroxide so i am using baking soda and ammonium nitrate and heat. oh! you already know about the oxygen thing and you want to know how it happens.

[Edited on 9-7-2011 by cyanureeves]
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[*] posted on 9-7-2011 at 05:30


Its not about a specific element, its the pressure of the gas (or gas mixture) that determines if the vessel will explode or implode.
The air around us puts a very strong pressure on every object, the only thing that keeps objects, say glass, from imploding is the inner force applied by the pressure. For instance an erlenmeyer got the same mix of gases inside and outside of the vessel, but when you close it, and some reaction that produces heat/gases occurs, the inner pressure grows and can apply enough force that the vessel will explode (overcoming the force applied by the outer pressure and the glass strength). If the reaction takes up heat or uses gases from the air (without releasing any other gases) then the inner pressure and the strength (molecular bonds) of the glass may not be enough to equal to the force applied by the outer pressure and the vessel will implode.
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[*] posted on 4-8-2011 at 13:44
Boy Hurt In Chemical Blast .Packed Rocket Pipe Lets Go


http://tinyurl.com/3cgzenv
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[*] posted on 5-8-2011 at 06:30
Later we will make an even stronger [rocket] fuel....!


Darwin never sleeps.

Teacher Killed In Explosion Of Pipe Rocket .‎

Ocala Star-Banner - Dec 5, 1957
FLOYDADA, Tex. A rocket made from a piece of pipe blew up during a school ...
a member of the class who was only a few feet from the explosion but escaped ...

http://tinyurl.com/4x83o86

If the teacher previously worked at an AEC Research Center I assume he swept its floors.

Several more reports from Google.com/news
http://tinyurl.com/4xv4vpm


[Edited on 5-8-2011 by The WiZard is In]
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[*] posted on 5-8-2011 at 08:24


Personally speaking - I would like to thank W.I.N. for his posts and offer a small bit of history to clarify my thinking.

I have been reading material for this gentleman for quite a bit over a decade now. He had been posting some difficult to procure items [to find] back in the days of UseNet (news groups) well back into the 1990's. Some of the material was extremely difficult to find back then.
We face a situation where our collective interests are being restricted in a variety of ways. As tragedies from disturbed individuals result in a knee-jerk fear reaction from the public. More and more of this information will become much more difficult to obtain. Even well back before these horrors, were perpetrated on the public, the difficulty in finding some of this material was obvious to hobbyists and interested persons. Often it had been remarked that his sourcing was of great value as some of the material simply became frozen out of university libraries as well as the US Library of Congress (for common reading).

One of the the MOST valuable items in any collective interest or hobby is the knowledge regarding it's idiosyncrasies. Without it, there is limited means to move forward no matter what level of expertise weighs in the individual's background. The amount of background material available had been uncommon & with more and more politics entering this subject simply the pursuit of background material, it will become much more rare in it's availability.

Very realistically; we may not have another chance at some of this. The Governments of some nations have almost (& in some cases, fully) restricted certain books and papers. Some many years back the Government Printing Office of the US was the method to obtain the full hard-bound PATR. This is no longer so. In fact I could list several sources which have totally dried up. The collections of Urbanski and Federoff (when available) sell for $250 per individual copy, with collections (depending upon condition) meeting rare book prices.

SEVERAL individuals have made available scanned copies of various publications & I would like to thank them all as they preserve an aspect of knowledge that may be eliminated in the not too distant future!
This is not simply opinion. Collecting material on various aspect of subjects such as energetic chemistry has entered the "rare book" arena; check for yourselves on titles that are not part of modern industrial usage. You may be very surprised. Please keep an open mind. Contributions to a knowledge base should be appreciated as some may not be available in the future.




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[*] posted on 5-8-2011 at 08:26


Quote: Originally posted by The WiZard is In  
Teacher Killed In Explosion Of Pipe Rocket .‎
From the article:"when he struck a match to the opening at one end of the rocket".

Well, that explains that.
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[*] posted on 5-8-2011 at 08:37


Quote: Originally posted by quicksilver  
Personally speaking - I would like to thank W.I.N. for his posts and offer a small bit of history to clarify my thinking.

Very realistically; we may not have another chance at some of this. The Governments of some nations have almost (& in some cases, fully) restricted certain books and papers. Some many years back the Government Printing Office of the US was the method to obtain the full hard-bound PATR. This is no longer so. In fact I could list several sources which have totally dried up. The collections of Urbanski and Federoff (when available) sell for $250 per individual copy, with collections (depending upon condition) meeting rare book prices.


W.I.N. steps to the podium — bows to the applause of the audience.
Notes that PATR-2700 ("Federoff") can be DL's
from www.dtic.mil. Exit's stage left.

Urbanski has been reprinted. however, even these copies
dobe $$$$$!
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[*] posted on 7-8-2011 at 11:14
Hydrogen and Fluorine


Erying and Kassel(Cf. Ref. 35) describe experiments in which
the reaction between hydrogen and fluorine was inhibited…..
In one experiment, they admitted the hydrogen and then a
quantity of fluorine much larger than usual, but there was a
very violent explosion. The flask was shattered, a towel which
had enclosed the flask was cut into shreds, and a protective
screen made from glass containing wire was cracked in many
places. The experimenters presume that the explosion was
started by sulfur, talc, or other catalytic material from the
rubber tubing of the nitrogen supply line. They point out that
for ½ hour before the explosion, there must had existed a
mixture of hydrogen and fluorine varying in composition
between 100 per cent hydrogen and 100 per cent fluorine
without appreciable reaction.

35. Erying, H. and Kassel, L.
The Homogeneous Reaction Between Hydrogen and Fluorine.
Journal of the American Chemical Society,
55:2796-2797, 1933.

In:—
Accession Number : ADA800192
Title : The Properties of Fluorine, Oxygen Bifluoride, and
Chlorine Trifluoride
Descriptive Note : Memorandum rept.
Corporate Author : CALIFORNIA INST OF TECHNOLOGY PASADENA JET PROPULSION LAB
Personal Author(s) : Doescher, Russell N.
Handle / proxy Url : http://handle.dtic.mil/100.2/ADA800192
Report Date : 06 SEP 1949
Pagination or Media Count : 73
Descriptors : *LIQUID PROPELLANTS, FLUORINE, CHLORINE
TRIFLUORIDE, LUBRICANTS, FLUORINE COMPOUNDS, FUELS
Subject Categories : LIQUID ROCKET PROPELLANTS


djh
----
Todays factoid —

Quartz burns with
a brilliant light in
oxygen bifluoride.



[Edited on 7-8-2011 by The WiZard is In]
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[*] posted on 10-8-2011 at 09:56


Broke a buchner funnel the other day. I set it down inside of a quart mason jar so it was held up-right and the contents wouldn't spill. It tapped and I mean tapped, the inside of the jar. *clunk* the bottom part is inside the jar and the top remains. Nothing major, but another small impedance.

edit - next time I will use a steel ring extension on a clamp.

[Edited on 10-8-2011 by smaerd]




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Arthur Dent
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[*] posted on 10-8-2011 at 12:41


Quote: Originally posted by smaerd  
Broke a buchner funnel the other day.


Was it one of them fancy fritted glass ones or the large white ceramic type?

Mine rolled off the table a while ago and the trash basket broke its fall thankfully. Yeah I was lucky because these puppies are expensive!

Robert




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[*] posted on 10-8-2011 at 12:52


I broke 2L Beaker :(
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[*] posted on 10-8-2011 at 13:22


thankfully it was ceramic. It served it's worth, I think I got it for 5$ and it was used probably hundred plus times. Although it is always a let down when something breaks.



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