Sciencemadness Discussion Board - When Chemistry Goes Wrong

Share a mistake or actual experience battoussai114 or i shall share my beer-breath while you are trying to eat.

Experimental chemistry lab: Student on the other table forgets that the cold bench-top is really cold in comparison to the beaker he just took of the heating. Blam, shattered beaker and a mess to clean.

My home lab: I'm rushing the preparing of potassium manganate and try to add water before letting it cool properly. A lot of manganese dioxide, potassium hydroxide and potassium manganate spills on my electric stove as the glass broke in an almost perfect line were the cold water/reaction products interface once was.

aga - 15-9-2015 at 15:12

Similar gdflp, similar.

[Edited on 15-9-2015 by aga]

aga - 15-9-2015 at 15:15

That's the kinda stuff i'm talking about battoussai114.

What Actually Happens when it goes bad.

Edit:

Maybe how people dealt with it to get a synthesis back on track, or even escape the lab alive ?

Practical stuff about What Can Happen and how to deal with it instead of just 'I got 95 % yield and it was all fine' or 'it gave 20% due to unexpected lizard alien contamination'.

Actual 'it went bad Here when i saw This, so i did This, and got 93% instead on 95 %' - that kind of thing.

Education by actual experience is what i guess i'm looking for.

[Edited on 15-9-2015 by aga]

Magpie - 15-9-2015 at 15:25

For starters: forget to add boiling chips to the boiling pot when distilling Phenol under vacuum.

When doing a vacuum distillation boiling chips will often not prevent bumping. An ebulliator is usually used instead.

An ebulliator is easy to make using a glass tube (~5mm dia) drawn to a fine tip. Then break off the fine tip to achieve an opening ~0.2mm or so.

Cou - 15-9-2015 at 15:30

Let's not forget that chemistry goes beyond purely mechanical knowledge.

Forgetting to convert gas volumes from room temperature to STP BEFORE using the 22.4 liters/1 mole ratio.

aga - 15-9-2015 at 15:31

Simple exaple, not documented before, is twice (yes twice) getting carried away with the Proceess and not thinking about the consequences of each step.

One was to neutralise a strong NaOH solution with HCl.

I just dumped the HCl in the pot.

It exploded (both times) which is one reason why my fume hood is a bit stained.

Stupid, yes, however it happened.

I learned from this: the idea of this thread is that Others can do so too, without the inherrernt danger of making that same silly mistake.

[Edited on 15-9-2015 by aga]

aga - 15-9-2015 at 15:34

Real life example Cou or 38 Mol of aga breath will bathe you as you sleep.

Hawkguy - 15-9-2015 at 15:34

How much Chemistry fucks up clothing

aga - 15-9-2015 at 15:42

Recount your own experiences or get some agaBreath when you go to kiss your partner.

Repeat offenders get an agaFart, Full Face, just as you're inhaling.

[Edited on 15-9-2015 by aga]

Little_Ghost_again - 15-9-2015 at 15:53

30% nitric acid with copper wire in, nothing much happening so decide to heat it up a little on the hotplate. Nothing for a couple of mins then brown gas!!! Not in the fume hood and only around 250ml in a 2ltr flask, so I decide to equickly end the brown gas by grabbing the nearest alkali (magnesium carbonate powder). I dump small amount of powder in flask (didnt get a chance to dump much!!) and woosh foaming nitric acid and magnesium carbonate powder spew from the top and cover by beloved hotplate.
It still stirs but the heater dosnt work anymore

, not to mention the agro of cleaning up.

Dont play with thing without thinking the whole thing through and have what if's in place! I did none of that and lost my heidolph hot plate because of it, I was also lucky with the gas and should have at least expected that!

Oh and two sep funnel mishaps, first check the valve is off when filling

and secondly I shook one intending to vent but forgot to hold the stopper on as it was tight, splish spalsh splosh chloroform everywhere

[Edited on 15-9-2015 by Little_Ghost_again]

j_sum1 - 15-9-2015 at 16:08

I have enjoyed reading the mishaps thread that gdflp cited. (bad days in the lab and with glassware.) But mishaps and "bad" days are not the only thing -- or not even the main thing.

"When things go wrong" covers situations like lysander's where it is a case of "I am following the procedure and I still can't get the #%$# thing to work." In other words, something other than a mishap and something less than a disaster -- something where the application of bit of specialised knowledge might pay dividends.

"When things go wrong" probably does not include gaseous emissions from aga. From what I understand, that is inevitable. The consequences are largely a matter of proximity: diffusion and the inverse square law being what they are. I am close to antipodal and so feel reasonably secure.

My contribution -- alas, as a beginner it is all pretty lame; but here goes.
My first attempt at purifying battery gunk involved reacting the MnO2 with acid to separate from the carbon powder. The only strong acid I had available was HCl. Of course I had overlooked the fact that the reaction is a redox reaction: the Mn goes from +4 state to +2 and so chlorine gas was going to be liberated. I was kind of expecting a bit of a whiff of Cl2 but I had not thought it through or done any calculations. Anyway, I was working at 20gram scale and it did not take long for me to realise that 3.6 litres of chlorine released into my shed was going to render the air unbreathable for some time. Evacuation procedures worked though. (Hold breath. Run for door. Assess damage in a couple of hours.)

kadriver - 15-9-2015 at 16:58

I use a 5% dilute sulfuric acid bath, about 400 ml, to remove flux from cast pure silver bars. I turned on heat to medium low to preheat the dilute sulfuric acid bath then went outside to do something and forgot about the solution on the heat.

About an hour later I went back in and the entire interior of the building was engulfed in a thick sulfuric fog because the water and the acid boiled dry. I've actually done this twice in my 5 year amateur chemistry experience.

kadriver

BromicAcid - 15-9-2015 at 18:07

My early mistakes can be found here:

http://bromicacid.com/mistakes.htm

For those just looking for the high-points here is a list of the titles:

Neutralization of Sulfuric Acid
Acetone Peroxide
H2SO4 / HNO3
What's In a match head?
Silver Thermite
Phosphorus!
Caustic Nightmare
Chlorinated

KesterDraconis - 15-9-2015 at 18:43

^That acetone peroxide story is really scary. EDIT: I just read all the stories...you are very lucky indeed.

The worst I have (I think anyways) is when I grabbed a glass thermometer, dipped it in a solution containing some compound (can't remember which_, and stuck it in an alcohol flame to see the color. I think my line of thought was "well, I'll pull it out before the temp goes to high, just for a brief moment." or if it was "hey its a glass rod there is no problem with this lolz"

It exploded just a couple moments after being put in the flame. Is not the reason I always remember to wear safety goggles or face shield, because I wasn't, and I felt that glass shard fly far to close for comfort.

[Edited on 16-9-2015 by KesterDraconis]

sbreheny - 15-9-2015 at 20:41

I did some basic garage chemistry as a kid and only got back into it 2 years ago at age 33 but boy do I already have my share of mistakes made:

- Attempting to neutralize ~30% sulfuric acid solution by "slowly" adding 50% NaOH solution. The problem is that it was so viscous and dense that it didn't mix until it sank to the bottom and then bubbled explosively. The fume hood front glass saved my eyes
- Breaking open an ampoule of Bromine using pliers and no gloves, thinking that my hands would be far enough away from the Bromine - not realizing that I was tipping the ampoule horizontal as I did this so about 1mL of Bromine spilled out onto my ungloved hand. I felt a burning sensation immediately but quick dousing with water saved my skin from real damage.
- Drawing Bromine up into a glass pipette with a rubber bulb at the top. Bromine went into bulb and immediately reacted exothermically with bulb, making it too hot to hold and shooting Bromine out the other end. Thank God this was in the hood.
- Boiling a sulfuric acid solution dry in an attempt to recover dissolved solids and ending up with plenty of SO3 gas.
- Testing out about 1 gram of silver nitrate+magnesium flash powder in my kitchen sink - I could not see for about 10 seconds after the flash.
- Having a cheap (but supposedly borosilicate glass) bottle crack when I added approximately 100C sulfuric acid to it. I was wearing gloves but what really saved me is that the bottom didn't fall out until I got it over the sink.
- Storing white phosphorus in a glass bottle of water in an unheated room. Water froze, glass broke. I didn't notice for a week. What I did right was that I had a secondary container so the humidity inside never got low enough (and the temperature was not high enough) for spontaneous ignition of the WP. This was on a shelf next to a bottle of diethyl ether. I don't store the WP near anything flammable now!

woelen - 15-9-2015 at 22:35

I wanted to demonstrate that sunlight can be used to ignite things very easily when it is concentrated with a magnifying glass. In order to make it look spectacular I took appr. 500 mg of KClO3 and half of that of red P. Outside, I put the KClO3 on a concrete tile in a small pile. Next, I put the red P on it. I took a dry little twig from a tree (10 cm length or so) and intended to use that for coarsely mixing the two powders. I stick the little twig in the mix and nearly instantly I have a bright flash and have many tiny droplets of molten stuff sprayed around, also on my hand. This was painful!!! The magnifying glass was not needed in this "demo"

ave369 - 15-9-2015 at 23:15

Using the wrong vessel as the crucible when calcining bisulfates. Yesterday, I was calcining a big yield of bisulfate and chose a thoroughly washed cat food tin can as the crucible. It turned out that the can still had a lot of trace organics or, possibly, some kind of polymer coating on the inside, resulting in much carbonization of the melt. And part of the can reacted with the melted acid salt, contaminating it with blue-green crap insoluble in sulfuric acid.

Forgetting to empty the waste jar, and forgetting what's there. I had a case when the waste jar contained hypochlorite, and I discarded an HCl-containing solution there. World War I chlorine attack!

[Edited on 16-9-2015 by ave369]

Bert - 16-9-2015 at 04:16

About 12 years back, attempted to duplicate Rosco Bodine's work with Lead azo clathrates. First attempt did not control the (carefully specified!) extremely slow liquid reactants addition rate sufficiently well, failure.

Second attempt with VERY slow addition rate, watched it like a hawk- It took HOURS to do the synthesis/ crystalization... finished well after midnight and done drying product at 03:00. Did a test. FAILED AGAIN! Darn. Just a sad little "poof", NO EARTH SHATTERING KABOOM! THERE WAS SUPPOSED TO BE AN EARTH SHATTERING KABOOM!!!

Next morning before breakfast, and before taking the sad, failed little pile of product out to destroy it... I took a small chunk (half size of a pea! Perhaps 100mg?) off the filter paper and set it on one of the nifty little ceramic glazed cast Iron plates that covered the tops of the burners on my brand new (expensive!) gas stove. Turned burner on low while I made coffee on counter a few feet from stove, range hood was on to handle the Lead fumes. Knew it would just flash and poof like the night before.

Ear (and stove component) shattering KRAAACK!

Ceramic covered cast Iron is quite brittle. The shards from that little plate flew at high speeds, impacted Aluminum burner parts and embedded themselves therein... Cost some $'s to fix that dammage. Cleanup was a bitch. Did NOT get to eat the breakfast I was making, glass and Iron "sand" scattered over all the kitchen surfaces.

Lessons learned:

1: A kitchen is not a chemistry lab- OR a materials testing lab.

Don't EVER do tests of energetics in living spaces, MOST particularly, in food prep areas. Even when you "know" it's not going to be spectacular.

2: Don't work with HE chemistry when tired and unobservant/uncoordinated/brain dead from fatigue. 4 hours of sleep after a 20 hour day... Not safe.

3: Don't be in a hurry. The drying time sitting on the filter paper overnight allowed the stuff to show its true nature... I still have the witness plate on which I re-created that impromptu stove top test.

Cou - 16-9-2015 at 15:34

Real life example Cou or 38 Mol of aga breath will bathe you as you sleep.

Do not have only a mechanical knowledge of chemistry, for that is the biggest symptom of kewlery.

Everyone knows that distillation works by boiling and then condensing in a cold tube. But what about distillation curves?

Everyone knows that you can make cool bubbles by mixing vinegar and baking soda. Can you do the stoichometry?

annaandherdad - 16-9-2015 at 18:49

Bromic, those stories are really frightening, all of them.

Bert - 16-9-2015 at 19:05

I thought that I had a surprisingly unsupervised childhood of experimentation- Bromic puts my little chemistry, fire and explosion related issues as a kid to shame.

ave369 - 18-9-2015 at 14:10

A particularly minor blunder, but still: preparing a chemical that loves to form colloidal solutions, then feeling all butthurt because it does not want to be filtered out. Happened today with sulfur. In my country, an "ersatz solder" is commonly sold, which is made by melting sulfur with powdered aluminium. It is cast into sticks and used by setting the stick on fire and sticking the burning stick into a hole, which makes the melted mass of sulfur, aluminium and aluminium sulfide to fill the hole with a metallic glossy mass.

What did I do? I ground this ersatz solder with a mortar and pestle and dissolved it in KOH. Aluminium dissolved, and sulfur formed a colloidal solution, which I failed to filter out.

tommy claisen - 6-10-2015 at 18:14

today decarboxyating in a 50L glass reactor at 180c. glass/PTFE tap underneath decided to crack, we were only a few feet away when this happened and bolted out of there. we were lucky that the contents were essentially chemically innocuous, although the resultant thick white aerosol that quickly filled the room appeared somewhat disturbing. thankful for no burns or fire. tomorrow will be a better lab day.

karlos³ - 6-11-2015 at 06:59

Oh I have a nice example!
Once, in the lab, whole class being there, a girl put a beaker full with diethyl ether on the magnetic stirrer, turned on the heating... thinking it was the stir control...
She turned around to the teacher and claimed her stirrer didn´t work...
Just in this moment the beaker had started to boil vigorously and splashed on the heating plate (which was indeed turned to nearly full heat)...
It was not very loud, a "whoosh" sound, as the fireball was nearly at the (very high, around 3 and a half meters) ceiling!
No one got hurt, well, except the teacher was angry at her so you could say he was butt hurt

We made fun of her being that stupid for a whole year.

Edit: Damned, I´ve just read Bromic´s stories!
Some of them caused me to hold my breath, for having situations nearly that worse... on a much lesser scale, but anyway...
Phew! Luckily you didn´t loose an eye or else...

Once got a splash of lye in my eye, reading your lye story reminded me much of it.
Had to get ascorbic acid solution dropped in my eye every half an hour for two days... even at night(This is the treatment for lye burns in the eyes).
Lost a good portion of my sight on that eye because of this.

[Edited on 6-11-2015 by karlos³]

hyfalcon - 6-11-2015 at 07:11

Was she blond? I can legally ask that being a male version. Thank God I don't all take after that trait, though I have run across a couple male iterations.

[Edited on 6-11-2015 by hyfalcon]

Schleimsäure - 6-11-2015 at 13:55

I just ruined my 1l chrystallising dish as I cleaned 500g of sodium and got a nice fire in the bathroom sink.

Because I needed to heat the sodium in 3 batches after the first one I emptied the dish and on the bottom some very small beads of sodium were left in the dirty slurry (the sodium was very dirty). After collecting the somewhat bigger beads out of the slurry the remaining sodium crumbs were very small, below 1 mm in diameter.
I wanted to go on with rest of the uncleaned sodium and therefore wanted to use the dish again. So I put in some ethanol into the slurry and waited half an hour for the sodium crumbs to react and neutralize. Of course much to little. As I thought there is no more hizzing from H2 production I went to the bathroom with the dish and wanted to free it from the brown mess in order to go on with cleaning of the remaining 300g of sodium afterwards.

But just after the water contacted the slurry in the sink - poof. And the ethanol was burning. The flame was firstly like 20 cm high and grilled my water tap of the sink

I deceided not to use my CO2 extinguisher and let it burn down - like 10-15 min. A fair bit of smoke and stinking in the bathroom and after 2 min or so the boro dish cracked. The watertap was unharmed.

Lesson learned: Even with smallest amounts of sodium one should wait a day or so after adding ethanol and before adding water.

[Edited on 6-11-2015 by Schleimsäure]

Deathunter88 - 6-11-2015 at 23:42

Quote: Originally posted by Schleimsäure

Lesson learned: Even with smallest amounts of sodium one should wait a day or so after adding ethanol and before adding water.
[Edited on 6-11-2015 by Schleimsäure]

Another lesson, get a fire blanket. Your crystallising dish would have been saved had you draped a fire blanket over it. (MAKE SURE YOU GET ONE WITHOUT ASBESTOS)

JJay - 7-11-2015 at 16:07

I just dropped a fairly expensive assembly composed of an addition funnel, a 3-neck flask, and a drying tube onto a test tube rack and came away no more damage than with 2 broken test tubes, neither of which contained anything at the time. They were cheap flint glass tubes I bought locally at a craft store. I consider myself lucky.

JJay - 8-11-2015 at 03:27

Oh and just now I was removing solvent from an oil that wouldn't crystalize... I tried applying gentle warming and a high vacuum and realized that there was a leak in the apparatus. So I sealed it, and the solvent flashed, turning the oil into a foam that fortunately instantly crystalized almost entirely inside the boiling flask (my Claisen got a little bit of product in it).

Schleimsäure - 8-11-2015 at 15:43

Quote: Originally posted by Deathunter88

Quote: Originally posted by Schleimsäure

Lesson learned: Even with smallest amounts of sodium one should wait a day or so after adding ethanol and before adding water.
[Edited on 6-11-2015 by Schleimsäure]

Another lesson, get a fire blanket. Your crystallising dish would have been saved had you draped a fire blanket over it. (MAKE SURE YOU GET ONE WITHOUT ASBESTOS)

Yes, with a 6l CO2 extinguisher I just thougt about the "big incidences". Good hint, will aquire one.

j_sum1 - 8-11-2015 at 16:19

I have a fire extinguisher -- powder type. I feel inspired to also get a fire blanket and possibly a CO2 extinguisher as well.
Thanks arky for sharing.

Twospoons - 8-11-2015 at 17:56

I built an electrolyser with a gas separator and NaOH as the electrolyte. I was using it to fill two balloons (one with hydrogen, one with oxygen). After a while one balloon slipped off the gas exit tube, resulting in a fountain of hot NaOH solution thanks to the pressure from the other balloon. This fountain covered both my lab, and me. Fast disrobe, and jumped in the shower - no damage to me thankfully. But boy did i feel like a twit.
Lesson: secure all fittings in a pressurised situation.

Same electrolyser, new game: making exploding foam by bubbling the mixed gas through soapy water. This time we (had some mates around) thought we'd be cautious and try a lighting a small amount of foam before going large. The resulting bang left my ears ringing for two minutes. Acquired hearing protection for the rest of the festivities.
Lesson: sometimes you can't be careful enough! We should have had ear protection right from the start .

My biggest mistake involves power electronics - not chemistry I know, but I'm sure a few of you play with electricity too. I was running a prototype electric fence energiser, which stored about 50J at 900VDC. I then turned it off, and went to so something else. Half an hour later I came back and picked the PCB up. Blam! 900V, 25J, DC shock from arm to arm (only got half the juice as the energy was split into two banks internally). I think I was lucky to survive that one, took me an hour to stop shaking, and left holes burnt in my fingers.
Lesson : capacitors storing lethal charge should have bleed resistors and a tell-tale (neon or LED) to let you know when they're charged.

[Edited on 9-11-2015 by Twospoons]

TheIdeanator - 8-11-2015 at 20:24

When I was young I mixed some bleach and nailpolish remover (acetone) to see what would happen. Having no clue what I was doing, I poured them both some of each into a solo cup. It started getting warm and the top of the cup started tipping over. Not wanting it to spill, I put it into another plastic container. That didn't end up helping. I'm not sure what else I did but I ended up with stringy bits of solo cup all over. I mixed rubbing alcohol and bleach at the same time with similar results. I found out that I made chloroform. That was my first foray into chemistry.

I was screwing around with Bi, trying to grow crystals on the stove and generally screw around with molten metal. I put some back in the pot to re-melt. Usually the re-melting was a trivial process, the water flashed off on the surface except for one time. I put the metal back in the pot and a second or two later there was a pop and molten metal went all over. One droplet got my glasses and some others are still embedded in the cabinet. I think what happened is that when I cooled the metal with water, a bit got trapped subsurface that couldn't flash off when I re-introduced it to the melt. I couldn't repeat the accident, even dropping water directly on the molten metal. Nobody was hurt.

Steam explosions are no joke and are also require special conditions in order to happen.

[Edited on 9-11-2015 by TheIdeanator]

JJay - 8-11-2015 at 21:48

I just started dehydrating some 3A seives that had been used to dry ethanol. I let the seives air dry overnight to remove ethanol and then put them in an oven at around 300 C. They burst into flames! I watched the seives burn for a couple of minutes and then realized that the top of my oven was turning red hot, so I removed them. The flames refused to be blown out; blowing on them made things much worse. I finally just suffocated the flames with a metal lid.

Some of the sieves have lost their wet look, probably due to the high temperatures from the ethanol flames. I'm now drying the sieves at a low temperature and slowly increasing it to avoid any unwanted fires.

ave369 - 16-11-2015 at 15:56

Today is a bad night in my lab: I received a sneaky bite from my nitric acid. That polyethylene stopper that I close the bottle with, it was always somewhat fishy: it sits tightly in the bottle, requiring some fingernail action to pull it out, and it is always wet with nitric acid. But before this day, I always managed to pull off the finger acrobatics to pull this bung out safely, relying on my long fingernails: the worst thing I got was yellow fingernails.

Today I completely forgot that I broke a nail on my right middle finger, and started to open the nitric acid bottle the usual way. And got nitric acid on my fingertip, mostly right under the nail.

JJay - 16-11-2015 at 16:04

Quote: Originally posted by ave369

Today is a bad night in my lab: I received a sneaky bite from my nitric acid. That polyethylene stopper that I close the bottle with, it was always somewhat fishy: it sits tightly in the bottle, requiring some fingernail action to pull it out, and it is always wet with nitric acid. But before this day, I always managed to pull off the finger acrobatics to pull this bung out safely, relying on my long fingernails: the worst thing I got was yellow fingernails.

Today I completely forgot that I broke a nail on my right middle finger, and started to open the nitric acid bottle the usual way. And got nitric acid on my fingertip, mostly right under the nail.

Ow.

Yesterday I dropped my 105 degree vacuum takeoff adapter on the floor. D'oh.

I temporarily substituted an assembly constructed from a Claisen adapter and gas inlet adapter... it's not an ideal setup, but it will work until I get a new vacuum takeoff adapter.

Texium - 16-11-2015 at 16:10

I just started dehydrating some 3A seives that had been used to dry ethanol. I let the seives air dry overnight to remove ethanol and then put them in an oven at around 300 C. They burst into flames! I watched the seives burn for a couple of minutes and then realized that the top of my oven was turning red hot, so I removed them. The flames refused to be blown out; blowing on them made things much worse. I finally just suffocated the flames with a metal lid.

Some of the sieves have lost their wet look, probably due to the high temperatures from the ethanol flames. I'm now drying the sieves at a low temperature and slowly increasing it to avoid any unwanted fires.

Now imagine doing that but with ether instead of ethanol...

ave369 - 16-11-2015 at 16:31

Yesterday I dropped my 105 degree vacuum takeoff adapter on the floor. D'oh.

Also today my Vigreux column broke in half out of the blue. Damn Chinese glass.

James Ikanov - 18-11-2015 at 11:12

A number of months ago (at least 8), before I had the money for proper glassware, I collected a sample of MnO2 from a fairly large oldschool battery I was taking apart for the carbon rods inside. I simply chucked it in a jar and forgot about it.

It was very wet when I stored it so about 4 months ago, at least, I decided I was going to dry it out. I opted to just put the jar on my hotplate and run it gently. What's the worst that could happen? I left the room for a moment to check on something else, and when I came back I noted that there was a small "leak" near the base of the jar.

I tried to grab it and quickly move it into an un-compromised container.
Imagine my surprise when the bottom section of the jar shears clean off, and my arms are covered in a mixture of hot MnO2 and near boiling water!

I sure learned my lesson after that. Jars are for storage, NOT heating.

One of many of my various poor decisions with experimentation in the past, but at least it was a learning experience, even if there are still MnO2 stains everywhere.....

JJay - 21-11-2015 at 07:26

Well, I just averted disaster....

Last time I tried drying out 3A molecular sieves, they caught fire. I was heating them in a glass beaker in an oven, and they were moist with ethanol (they had been air dried, but they looked wet). The flames were alarming and could have caused damage to the oven but weren't that serious.

Today I spread out a much larger quantity of molecular sieves in a pan and allowed them to air dry until they lost their wet look before putting them in the oven at 300 C. To my surprise, the entire pan caught fire, and when I opened the oven I was greeted with a large blue fireball followed by shooting flames. I immediately closed the oven. The flames weren't extinguishing themselves, and I'd prefer not to destroy the oven or catch anything else on fire, so I grabbed a spray bottle full of water that I had been using on my terrariums and misted the flames until they went out.

I'm not sure why so much ethanol is adsorbed into the sieves, but I guess I'll try heating them gently before hitting them with high temperatures.

[Edited on 21-11-2015 by JJay]

JJay - 21-11-2015 at 07:50

Quote: Originally posted by zts16

Now imagine doing that but with ether instead of ethanol...

I'm guessing it could blow the door off of the oven... scary stuff.

JJay - 21-11-2015 at 07:56

Quote: Originally posted by ave369

Yesterday I dropped my 105 degree vacuum takeoff adapter on the floor. D'oh.

Also today my Vigreux column broke in half out of the blue. Damn Chinese glass.

That sucks!

My Chinese kit appears to be a mix of low quality and high quality components. The sep/addition funnel appears to be high quality; the flasks appear to be high quality; the condenser appears to be high quality; and everything else looks like it was picked out of the reject pile. The vacuum takeoff adapter was pretty low quality but I have a good one now, and I figure I'll just replace components as they fail with American counterparts. Vigreux columns aren't cheap....

Magpie - 21-11-2015 at 16:37

I just started dehydrating some 3A seives that had been used to dry ethanol....

I'm guessing it could blow the door off of the oven... scary stuff.

From an earlier post of mine:

I had been using 3A mole sieves to dry some 95% ethanol. Wanting to re-activate them I poured them into a 9"x9" glass cake dish and set them on the kitchen counter to dry. They were already mostly dry after sitting in a large beaker overnight. After about an hour on the counter they looked dry so I set the kitchen oven for 500°F (260°C) and placed the sieves in the oven. Some time after the oven had reached temperature I hear a loud bang while sitting in our family room watching TV. I looked in the kitchen expecting to see some heavy object laying on the floor; but there was nothing amiss. I then surmised that the noise must have come from the oven - an explosion of ethanol/air pushed the spring loaded oven door open and then it closed itself with a bang! So I just continued the heating until the time (2 hrs) was up then turned off the oven. A short time later I opened the oven and retrieved the sieves, after assuring myself that the oven temperature was below the auto-ignition point of ethanol.

The Volatile Chemist - 22-11-2015 at 16:17

Bromic Acid tells great stories...

I once (mind you, before I know how chemistry worked) thought sparklers *must* contain some sort of oxidizer to work. Since I had sublimed sulfur powder, I thought I could make some pseudo-gunpowder. I ground up approximately 10 sparklers, and added all the sulfur I had. I placed this on a very large piece of copper sheet metal I had acquired. Well, thank God it wasn't actually gunpowder, there was a lot of this stuff... I lit a sparkler with a magnifying glass, and carefully placed it on the mix. It flared up with the most intense heat and light I'd ever seen at the time. Great spectacle for a pre-teen. It stayed lit, spewing 'sparks' for a while. The sulfur was obviously reacting with the copper sheet, forming nice blue-green splotches on the metal (in retrospect, it could've been an iron sulfur-oxyanion too). I realized, though, that the flying pieces of metal and molten mix flowing on the copper sheet were a bit of a fire hazard, given the fact the whole thing was sitting on dry grass in our back yard. Trying to stay calm (but still feeling ridiculously cool for figuring out how to do this), I picked up the sheet by its corners with my pointer wingers and thumbs, each corner on a finger or thumb. Now, this plate was approximately 12 inches long and 3 inches wide. And it had been allowing a thermite reaction to continue on its surface for a little while now. So it slid out of my fingers and thumbs, melting four lines down them, one for each corner, one on each finger. It took a bit to feel the pain, but of course it didn't last too long, since I now had to stamp out the fire caused by the fallen sheet and dripping metal. Parents never did hear much about it, though it made a good story at school...
Lesson: 1. Don't be Stoopidd.
2. Know what your reaction is doing, d3on't assume what's in something.
3. Adding sulfur just makes it smell bad. And make clouds of suspicious gas/smoke.
4. Don't be rash, and don't do chemistry if you're just doing it for bragging rights.
Not that chemistry's bragging rights anymore. Heck, the girls in my chemistry class last year probably thought I made drugs due to my 'friends' in the class making loud jokes and statements. This year, I get asked for help by a few, but I've been ostracized from the general social world anyways. If I'd stayed in band I'd at least've had those friends... :/
Chemistry stories, man. They're great. Max Gergel's first novel is my favorite biography, story, almost favorite book.

ave369 - 1-12-2015 at 06:23

Today, in a break between playing Fallout 4, I decided to test my brand spanking new distillation setup. When I ran it on water, it all did handy-dandy. But then I've run it on Glauber's nitric acid synthesis, and totally forgot about that rubber bung sitting on the top of my Wurtz flask...

Poor, poor bung. It weeps some black liquid into the flask...

[Edited on 1-12-2015 by ave369]

MrHomeScientist - 1-12-2015 at 10:49

Just scrap a tire wall and some Nuka-Cola bottles and you'll have a new chemistry station in no time!

JJay - 1-12-2015 at 13:54

Quote: Originally posted by ave369

Today, in a break between playing Fallout 4, I decided to test my brand spanking new distillation setup. When I ran it on water, it all did handy-dandy. But then I've run it on Glauber's nitric acid synthesis, and totally forgot about that rubber bung sitting on the top of my Wurtz flask...

Poor, poor bung. It weeps some black liquid into the flask...

[Edited on 1-12-2015 by ave369]

I know not everything in my lab is not exactly state of the art [yet], but I am glad I don't have to use such primitive equipment!

aga - 1-12-2015 at 13:59

Rubber is one of the most advanced materials we have !

In Engineering terms, imagine your Car Tyre.

Temperatures from -40 to +50 and it works fine.

Immense pressure changes, high speed rotation etc etc.

Rubber is an Outstanding material.

Just that HNO₃ is nasty to it.

JJay - 1-12-2015 at 15:47

I don't like using rubber anything... I'd use ground glass test tubes and Erlenmeyers if I could afford them.

ave369 - 1-12-2015 at 23:30

By the way, the bung is basically okay. It merely has some bubble-like deformations in the bottom. But the flask, the flask! Now I need a 125g of perhydrol to make piranha and remove that black carbony stains it wept!

ave369 - 1-12-2015 at 23:32

Quote: Originally posted by MrHomeScientist

Just scrap a tire wall and some Nuka-Cola bottles and you'll have a new chemistry station in no time!

That's basically where I got equipment not so long ago. Now I have an additional source: discount deprecated glassware from China.

The Volatile Chemist - 2-12-2015 at 12:37

What do you mean by 'bung'? Are you referring to a rubber 'stopper'? I guess my terminology isn't up to date...
I've ran a few HCl distillations with a rubber stopper, and was thinking about doing an acetone one. Glad I happened to ruin another stopper prior to doing that one...

phlogiston - 2-12-2015 at 13:45

3 liter erlenmeyer on a hot plate. 68% nitric acid + excess of lead. Reaction proceeded nicely at first, but slowed down after a while despite heating almost to boiling. When I realized the lead nitrate precipitate was inhibiting the reaction I added distilled water.
Good idea, but way too much at once.
The reaction suddenly became extremely vigorous and the gas evolution was enough to launch nearly half the contents of boiling hot nitric acid saturated with lead nitrate out of the erlenmeyer. Fortunately, it was contained well because I had a basin placed underneath the hot plate and the fume hood caught the little splashes that escaped it. But it was a toxic mess to clean up nevertheless.

aga - 2-12-2015 at 14:21

What do you mean by 'bung'?

Bung is a more ancient word for a Stopper.

Being English, i'd say 'rubber bung' or simply 'cork' if it was made of cork.

Probably a Nautical term in origin.

aga - 2-12-2015 at 14:27

Ouch !

Could have been a Nasty accident phlogiston.

Great idea to have some sort of Containment system for liquids in case of accidents.

My own is simply that the bottom of the fume hood is a glass tray made from glass pieces and silicone sealant.

Saved liquid escaping the area a couple of times (accidents do happen !)

phlogiston - 2-12-2015 at 14:40

Yes, it is definitely a good idea to have a little raised edge on the fume hood bottom to contain liquid.
During a practical course a fellow student once had a large round bottom flask break that was filled with a large quantity (liters) of an acetone/ether mixture that was boiling under vacuum.
The quantity of the mixture was so much and it was released to suddenly that it a lot of it splashed out of the fume hood all over his trousers and shoes.
Amusingly, his pants and shoes both quickly dissolved which left him barefoot with just his underwear for the rest of the day, when a friend fetched him a new pair from home.
He was very fortunate that it didn't catch fire. The students in the adjoining fume hood were using a burning bunsen burner.

aga - 2-12-2015 at 14:58

Hmm.

Better to do Chemistry in a group or alone ?

Pros and cons both ways.

ave369 - 4-12-2015 at 08:58

Generally, being on the meds makes me a total klutz. Casualties in my lab yesterday: funnel, drip tube, small Erlenmeyer flask, measuring cylinder, balance (I spilled conc sulfuric on it, and it ate some of the electronics inside), and once again an already glued Buchner funnel.

Addendum: I'm losing Erlenmeyers one after another! Just found out that the other one, the favourite 100 ml Erlenmeyer cracked!

[Edited on 4-12-2015 by ave369]

eanardi - 8-12-2015 at 17:42

[rquote=428227&tid=63645&author=Jars are for storage, NOT heating.

[ Thats true, and I learned it when I was cleaning up the jar I used to carry out exotermic solutions (in this case I had used it to react calcium carbide with water). Fortunately the calcium hydroxide that sticked to my coat didn't even react with it! /rquote]

The Volatile Chemist - 12-12-2015 at 15:06

Hmm.

Better to do Chemistry in a group or alone ?

Pros and cons both ways.

Alone, or with a lab partner of the opposite gender (kidding...).
I talked to my uncle, once a member of the US Navy, who was an electrician and rubber and plastics technician. Bung is a term used for rubber plugs, even those not like a so-called 'stopper'. Probably nautical.
Not really an accident, but today I tried to make copper(II) borate from basic copper(II) carbonate and boric acid. After much heating, a total waste...

aga - 12-12-2015 at 15:12

Heigh Ho.
Shit happens

Things (good or bad) only Happen when people have the Will to actually Do things, and then actually Do things.

Your Experience quotient just went Up TVC.

As a post-experimental dissection, what did you expect the product to be ?

The Volatile Chemist - 12-12-2015 at 15:46

Haha, Copper(II) borate. ...Are metal borates even reasonably possible from boric acid? (My practical knowledge is very low...)

chemrox - 12-12-2015 at 18:01

jsum_1 made an incredibly good point today : what Can go wrong is rarely documented, just the Successes are publicised.

I suggest we share the knowledge of what actually happens when chemistry is done wrong/badly.

For starters: forget to add boiling chips to the boiling pot when distilling Phenol under vacuum.

What happens is that it boils nicely for a while, then the liquid goes still for a few seconds, then explodes up the column and pukes all over the place before boiling nicely again for a few seconds, then goes silent again etc.

Edit:

We should learn by our mistakes, and that means sharing them.

[Edited on 15-9-2015 by aga]

Boiling chips don't serve in vacuum. What you need is very fine bubble inlet. Or use a vigeraux to minimize the bumping consequences.

Having made the rant; I think publishing errors is not too bad an idea. Most of us do that by raising questions. The latter approach makes us research the issue prior to posting. Otherwise the risk is getting a lot of random posting with no real chemistry.

[Edited on 13-12-2015 by chemrox]

The Volatile Chemist - 14-12-2015 at 15:11

Indeed, they're useful. Perhaps our SM Wiki should include more of such.

KesterDraconis - 14-12-2015 at 15:18

I spilled quite a bit of acid all over a glove the other day. It ruined the glove, but I am fine. I had placed it on wrong/insecurely, and it came off in an unexpected manner.

Just a friendly reminder to respect the chemicals (even when is seems safe, like in a bottle) and wear your protective equipment, it will save you from a lot of pain!

The Volatile Chemist - 14-12-2015 at 15:45

Today at school, we did gel electrophoresis in my AP Bio class. I was the only one who wanted to fill the gels (the holes are tiny, of course). We ran them in boxes that fit two, and my group of four was the second to fill ours (we filled them after they were in the fluid). I filled the first one, and in filling the second one, my hand started shaking a bit, and got pretty shaky by the end of filling. One of the guys in the group said I looked like I had Parkinson's, and that I was more shaky than his grandpa...well...
At least I got samples of the DNA we were using, Lambda Phage DNA.

tommy claisen - 15-12-2015 at 05:28

Another unfortunate event occurred while extracting the product of an ester hydrolysis. 30l of aqueous were being dropped from the wash tank in the walk-in hood. The MTBE fumes from what was dissolved in the water layer ignited, causing a brief but rather startling fire. It's a miracle that the organic layer in the tank was not ignited by this event. The product was then stripped of solvent and vacuum distilled as normal.

chemrox - 15-12-2015 at 18:20

Rubber belongs on when chem goes wrong

JJay - 16-12-2015 at 03:25

I was just boiling some copper (II) chloride solution to dryness in a dish in a small oven, and after the solution became saturated, it started bumping badly, splashing concentrated copper (II) chloride solution all over the inside of the oven. Fortunately, the oven is mostly stainless steel.

The Volatile Chemist - 16-12-2015 at 18:15

I was just boiling some copper (II) chloride solution to dryness in a dish in a small oven, and after the solution became saturated, it started bumping badly, splashing concentrated copper (II) chloride solution all over the inside of the oven. Fortunately, the oven is mostly stainless steel.

This has happened to me, too. I think it's a given for making the dry salt.

I accidentally forgot to read the graduated cylinder before titrating today at home...

Wasted 2g KH - Phthalate...
Also got ~0.25mL ~2M NaOH on my pointer finger and thumb, found out how that felt...
But at least I found a method of producing Copper(II) Phthalate (If this compound doesn't exist, please tell me, otherwise I'm fairly sure I've produced it).

Heavy Walter - 17-12-2015 at 08:18

Hi
Here are my old bad experiences:
-When working at the university, I needed to protect some carbides from ambient humidity, so I picked up a large 5 lt vacuum desiccator on heavy glass, looked for a cover with stopcock and started evacuating the desiccator, which after some minutes, I left on a table.
After walking out ONE step outside the lab a large explosion brought me back into: the lab was full of small glass pieces...
That way I learned that covers and desiccators are matched, grinded and polished to couple exactly. Using a different one subjected the cover to excessive stresses by deformation.
-When needed to cool a trap with liquid nitrogen, I employed a home plastic food flask. After using it, at pouring the excess into a large industrial dewar the flask suffered stresses so extreme that the flask exploded, ejecting liquid nitrogen, plastic and glass by its bottom.
Here are my two cents...

Hawkguy - 17-12-2015 at 19:56

HOLY FUCK Like 5 minutes ago things went to shit. So I was recrystallizing Urea, I had about 800ml of half dissolved Urea solution bubbling, when the glass broke, and it went everywhere. The hot burner vaporized a lot of the stuff, so now it looks like a smoke bomb went off in the kitchen (I only use the kitchen for somewhat harmless stuff, plus it was really damn cold today). Fuck. Now I need a new giant beaker, and more Urea, which was hard enough to come by in the first place. At least its not as bad as when a pan full of gunpowder/ firework comp ignited. (Outside, but still scary)

Heavy Walter - 18-12-2015 at 03:25

Hi
By the way, did you use heat spreader?

j_sum1 - 8-1-2016 at 04:29

Today's episode comes to you from the files of "things I should know but didn't think all the way through."
And supported by "sometimes you just don't know how significant a phenomenon is until you see it for yourself".
With an encore by, "If you are a real idiot you make the same mistake twice in quick succession."

No real accident I am pleased to say but a bit of wastage of some cheap chemicals and some tidying up to do.

It was time to make some ammonia solution -- difficult to obtain anything but cloudy ammonia floor cleaner in Oz and I have been making do for too long. However, not something I have had to make before.

Procedure involved ammonium sulfate and sodium hydroxide powders in a three neck reaction vessel with water being added via addition funnel. NH3 evolved was bubbled through chilled water in a measuring cylinder. I was aiming for a 25% solution and decided on about 60% excess ammonia production to make sure I got there. Excess gas from the cylinder was passed into a shallow bowl of water via an inverted funnel to prevent suckback.

My main mistake was overlooking how much cooling the reaction would need. I didn't have any ice easily available to chill the measuring cylinder and foolishly decided it wouldn't matter too much.

A few minutes into production and the measuring cylinder had heated up so much that no more ammonia could be absorbed. The solution was bubbling and boiling so much that it was in danger of squirting all over the place. I quickly switched to a new cylinder: a bit concerned because there was still a lot of gas being produced. Of course in my haste to fix the situation I did nothing to prevent suckback. All went well for another few minutes. The reaction slowed a bit and I decided to increase the water drip rate from the addition funnel. Next thing I knew and 250mL of solution was sucked out of the cylinder and into the reaction flask: of course greatly accelerating the reaction. Now, I have seen videos of an ammonia fountain before but really was not prepared for how swift and suddenly it could happen.

I now had a slightly overfull three-neck still spitting out ammonia gas. I figured that I may as well refill the cylinder with chilled water and get the rest of the ammonia if I could. I'd watch it carefully this time. It seemed to work. A bit of gentle heating and I was again collecting some nice solution. When that one started to warm up I swapped again.

It doesn't pay to be too confident. I left the lab for a few minutes and came back to the results of another ammonia fountain. The cylinder was again empty and this time my reaction flask was completely full right up into the addition funnel.

Things to learn.
This is one that must be kept cool.
60% extra ammonia was too much.
Ammonia sucks at water like a camel in a salt mine. You have to plan for that.

The yield? Density measurement on my first collection revealed a concentration of 23.5% -- close to what I was aiming for. I also got 250mL of some more dilute solution. I haven't measured it but guess around 10%.

So, by no means a disaster. But definitely not the way that I want to be working. It would not have been a good day to have been working with anything really hazardous.

Texium - 8-1-2016 at 15:17

I've been quite frustrated for the past few days about a Jones oxidation of n-butanol to butyric acid that I've been working on. The oxidation went fine. Then I decided to neutralize the mixture and precipitate the Cr(III) with bicarbonate and filter it. It worked fine for neutralizing it, but most of the Cr refused to precipitate, even with excess bicarbonate added. To make matters worse, whenever the slurry is heated or put under reduced pressure, it foams like mad in an uncontrollable way. I tried adding ammonia to some, and this seemed to cause the rest of the Cr(III) to precipitate, but there was still too much dissolved gas to vacuum filter it, so I gravity filtered some. I found that the filtered solution was yellow, and turns orange when acid is added. This seems to indicate that there is still Cr(VI) present, which is strange since I used an excess of butanol. However, I did notice a fruity smell throughout the course of the oxidation and handling afterwards. I'm not sure if it's butyraldehyde or butyl butyrate as I have not smelled either of them, but I've narrowed it down to those two compounds since I don't know what else it could be. The presence of either could explain the apparent Cr(VI) in the solution.

The whole situation goes to show how a supposedly simple procedure can have so much unexpected stuff go wrong with it...

aga - 8-1-2016 at 15:30

Paragraphing should be made a Rule

What's the puke smell stuff for zts ?

I noticed butyric acid a while back, although saw no use for it at the time.

blogfast25 - 8-1-2016 at 16:02

I noticed butyric acid a while back, although saw no use for it at the time.

It stinks like rancid butter (which contains some of it) but makes really nice smelling esters. pine-apply, IIRW...

JJay - 8-1-2016 at 20:06

I haven't done any chemistry in a week (building a new lab - today I got delayed by CNC router table wiring issues), but I have been lucky lately - I haven't broken any glass in the past month and a half except when I torched a department store test tube to red hot and dunked it in water to check its quality. Of course tomorrow I will probably drop an addition funnel on concrete or spill sulfuric acid in my vacuum pump.

KesterDraconis - 8-1-2016 at 22:16

I broke a round bottom flask recently. What out were you have even the slightest water. The thing was hot and I had to put it somewhere that it wouldn't fall over/roll somewhere, and I saw this pot sitting on the table nearby. I placed it in said pot. The pot had a tiny layer of water on the bottom.

I admit, it was cheap glassware, and I probably shouldn't have been using it anyways, but dang it annoyed me to find it cracked!

The Volatile Chemist - 12-1-2016 at 13:49

In AP chem we did a lab on equilibrium reactions, and we had to go from table to table with a test tube rack filled with various glassware needed for our group at each station. A partner had put all the needed glassware into the rack, and I only felt the need to check that everything was there. In pouring some KSCN - Fe(NO₃)₃ solution into a rather long test tube, I was immediately made aware it was lacking a bottom...Thankfully the teacher wasn't nearby, and only a few chuckles were made about 'Nathan's bad chemistry skills'. These were countered with comparing the parties voicing such thoughts with garbage.

Etaoin Shrdlu - 13-1-2016 at 10:29

These were countered with comparing the parties voicing such thoughts with garbage.

Unprofessional. Just laugh. It was funny.

The Volatile Chemist - 13-1-2016 at 14:18

Quote: Originally posted by Etaoin Shrdlu

These were countered with comparing the parties voicing such thoughts with garbage.

Unprofessional. Just laugh. It was funny.

Well, the garbage part was actually the result of one of such parties noting that a beaker labeled 'waste' was reminiscent of me. I then retaliated by stating after the lab I would show him an evolutionary tree showing he was closer-related to garbage. Perhaps unprofessional.

Texium - 13-1-2016 at 15:47

Quote: Originally posted by Etaoin Shrdlu

These were countered with comparing the parties voicing such thoughts with garbage.

Unprofessional. Just laugh. It was funny.

Yes, and also a better comeback in theory than in practice, I'd think. :/
Try not to take that sort of stuff to heart. When you do it makes them want to say stuff like that more in the future.

JJay - 14-1-2016 at 09:47

Just ask if they'd like a glass of warm prussic acid

But seriously, it's best to avoid referring to people has human refuse or discussing how there are a lot of eels in their part of the gene pool and so forth....

Double Whammy

aga - 14-1-2016 at 15:02

Tried chlorinating ethanol again.
Didn't work, yet it did last time, easily.

The Cl₂ cannot be different to last time (same chemicals from same containers) so tested the latest batch of 'super dry ethanol' with a potassium permanganate crystal and it turned all purple.

Damnit ! It's still got a significant amount of water in it.

Gas mask off, brief sniff of the result of the chlorination.
Smells like chloroform to me.

Appears that EtOH + Cl₂ goes all Haloform if there's any water around.

Previous ethanol batch was treated with homemade tripotassium phosphate to get the last few % water out.

This ethanol batch was treated with purchased K₂CO₃.

OK.

Make some more K₃PO₄ to rip the water out of a fresh batch of ethanol before trying the chlorination again.

200ml of 76% (green farm-feed grade) H₃PO₄ in a 500 ml comical flask.

Start lobbing in KOH.

Some flakes heat, splutter, react like mad, others do nothing !

Damned KOH is as impure as hell too !

During cleanup a small ammount of TCCA got on my blue lumber jacket, which now has a white spot.

Oh the horror. The horror. The horror ...

blogfast25 - 14-1-2016 at 15:37

Oh the horror. The horror. The horror ...

Hmmm... sounds a little bit like:

'Oh the haste. The haste. The haste... That maketh the Waste (?)'

How do you check the anhydrousness of your EtOH (what that KMnO4 trick really consist of)?

Refractometry on 1:1 diluted sample gone out of fashion?

[Edited on 15-1-2016 by blogfast25]

aga - 14-1-2016 at 15:47

The worst bit is the jacket.

I can no longer hide under copper sulphate crystals.

Where the hell am i going to find a place to sleep tonight ?

[Edited on 14-1-2016 by aga]

The Volatile Chemist - 20-1-2016 at 16:41

Quote: Originally posted by zts16

Quote: Originally posted by Etaoin Shrdlu