Sciencemadness Discussion Board

When Chemistry Goes Wrong

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NeonPulse - 12-4-2017 at 04:11

so i made an attempt at making potassium dichromate via heating Cr2O3 with KOH and KClO3. went fairly well during the initial 10 mins heating but at one point it got too hot and the whole thing ended in a spectacular runaway which was bubbling very violently and ended up ejected much of the red hot molten mixture up like a volcano. it was relatively contained in the work area with a bit of paper on which my notes were written getting splashed and catching fire and some scorch marks on the sleeve of my labcoat the only damage.
I was able to retrieve much of the now rock hard mixture off the burner and sides of the crucible and the little balls of it on the board, to continue the synthesis. the rest of the synthesis was pretty un eventful. thats my excitement for yesterday. one screenshot shows the mixture left in the stainless steel crucible still glowing red hot.

IMG_2797.PNG - 2.5MBIMG_2798.PNG - 2.5MB

JJay - 12-4-2017 at 11:03

Oh wow, that doesn't sound like much fun to clean up! Did you get a decent product?

tsathoggua1 - 13-4-2017 at 13:03

Me, with the WP? not a clue. It might have been for a moment, but obviously not ALL of the argon backpurge before beginning to heat prior to sealing must have been purged, for the ampoule gave a CRACK! loud enough to wake my sleeping old man, and afterwards, only a few tiny fragments of glass, coated in phosphorus, were ever discovered, the rest of it, ampoule and all, ended up atomized in a fine cloud of glass dust from the obsservation of said event, and as for the phosphorus, part of it obviously burnt to a huge cloud of smoke instantly, being dispersed finely, and the rest, well some of it rebounded off my face shield and coveralls to splatter across a wooden cabinet, leaving a trail of burn marks an inch or two or three in circumference. And a little caught my hair (this is not because of inadequate protective gear, rather, due to the great length of my hair. Its a face shield that goes down below my shoulders, not a 'near-to-stomach shield' :P and I ended up with some hair burnt extra-crispy and the stink of burning proteins, but other than that no harm done (to me) whatsoever, can't say the same for the cabinet, that took a trail of burning splatters.

Was more hacked off about the loss of the ampoule I'd made, and the loss of a few grams of white phosphorus and having to go reset the fire alarm set off by the P2O5. No damage to the face-upper torso shield, the WP seems to have rebounded off of it and gone on to toast that cabinet. Only a few g of WP, a few thousandths of my supply of red P went into its creation, other than that, not a problem, just an irritation.

What else....annoyingly, a NaOH/KOH melt, producing NaK alloy electrolytically brutally attacked the nickel alloy electrodes (guitar fret wire pieces, and the end of it that started out blunt, used as anode ended up being corroded so badly it was a razor sharp point when withdrawn from the ~200 'C melt. The point on it was as sharp as any hypodermic needle tip and the end at least as fine as one of the 28 gauge needle sometimes used for my pain medication, and I imagine lengths of such electrolytically sharpened fretwire, being triangular rougly, would make, for those who wished to do so, fantastic ammunition for a shotgun cartridge, that would autostabilize in flight due to the T-like profile of the remainder of the fret wire other than the sharpened tip. Like a beehive flechette round fired from tanks etc.

I'd rather have had the wire undamaged though since it was the only long piece I have, but still, will come in handy for poking blocked condensers open.

JJay - 13-4-2017 at 13:46

I'm not seeing what went wrong exactly; what is another chemist to learn from these experiences with white phosphorus and NaK? To use PPE when handling dangerous substances? I mean, it's not quite, "Today I accidentally killed my dog while distilling some prussic acid in my grandmother's basement :( Good thing I was wearing a gas mask." I am interested in phosphorus chemistry, but I don't have any phosphorus, so I'm not *that* interested in it. But if you have exciting stories about phosphorus and NaK, I am sure people are interested in them.

I was thinking about actually trying a similar potassium dichromate synthesis but with potassium nitrate, so I am really quite interested in the synthesis with potassium chlorate. Chromium chemistry seems to be a popular topic right now, and it's plenty dangerous enough if you like that sort of thing.


[Edited on 13-4-2017 by JJay]

NeonPulse - 13-4-2017 at 18:44

the synthesis was fairly straight forward and the yield is 14g- i attribute this lowered figure to the obvious losses in the first stage. this was the second time around attempting this synthesis.
The first try was using sodium nitrate as the oxidiser and it did seem to be inferior and the reduced yellow solution released quite some NO2 upon acidification which suggests that NaNO2 was formed as well. there was also quite a lot of un reacted Cr2O3 on my filter so it probably needed longer heating even though it was heated full blast for about an hour. i had a problem with the workup so i had to ditch that attempt.
i did not have any KNO3 around to use this instead. i would say the chlorate method is probably better but i think slow and steady heating is the way to go. also use a large crucible! i only had a smallish batch 25g Cr2O3/ 28g KCLO3/30g KOH and thought that the size would easily handle the mixture but obviously i was wrong.

tsathoggua1 - 15-4-2017 at 03:24

The moral of the tale is to (probably) heat the OPEN ampoule a bit, to drive out the inert gas until P vapor is slightly exiting the amp, covering the end with a jet of inert gas and fusing with a secondary torch. Perhaps using one of those micro torches to expel the air and then seal it before suckback of air occurs. The ampoule was small, made from a 2ml (bulb size) pipette, the phosphorus being introduced as a suspension via cannula as in a volatile solvent, not quite sure what, but an inert for contact cleaning, rapid drying spray, kept mildly warm for a while to expel the solvent (it boils off in moments) by keeping the UNfused ampoule in the oven for a little while, away from direct flame.

On sealing it, then heating, the change occured from red to white unusually quickly. I noticed an odd change in appearance of the red phosphorus, it changed from its usual color to a dark color, like that of mercury sulfide, before transition to white P, and then all of a sudden the amp went off with a bang, loud enough to wake my sleeping father. Really glad of that face shield, since it got peppered with glass, as the amp ended up atomized, not much left of it, the resultant crack when it went off was sufficient to reduce it to dust, only a few small fragments left.

I'm curious about the change in the red phosphorus observed shortly before the disintegration of the ampoule. It darkened very significantly. Could this perhaps have been the beginnings of a transition to violet phosphorus?

This is afterall a thread for chemistry going wrong. It was chemistry. It went wrong. Scratch one ampoule, spend the rest of the night scratchING the jet-trail of burn marks off one of the nearby wooden carbinets. Personally I think it sort of decorative, in a way only a mad scientist could appreciate :D

As for chromium chemistry, I do have a synthesis of chromyl chloride planned actually, since I happen to have ended up with some very resistant bottles (the caps, that is) that seal well, especially wrapped in teflon tape.

The NaK is on hold for now. Well, probably. I do have a melt in a crucible to drill a hole in and see if there was any deposited under the surface of the melt, but it proved too reactive to isolate, forming large (about a half inch) bubble-like blobs which collapsed in on themselves in showers of sparks immediately. Unfortunately my power supply has blown something inside, and its beyond my ability to fix it. My old man is going to take a look at it, if its buggered, I'll buy myself a welding supply and use it to drive a constant-current DC source with variable yields. The lack of a power supply is driving me nuts:( I was spending all night, most nights, beavering away with it. Did get some sodium and sodium-calcium alloy out of it though.

NaK is, as well known, more reactive than Na or K, but bloody hell, just HOW reactive coming out of the melt is understated if anything. Small amounts spark and burn the second they touch air, larger bubbles of it can make quite a mess. Had to clean the walls after every experiment in NaK electrolysis due to the spatter of KOH and NaOH.

On to something a little tamer, until I get a power supply back up and running, got a manganese thermite planned for today. Zinc-plated one of my carbon crucibles as a temporary shield between the carbon and the manganese oxide hydroxide. Finishing drying off the oxide in preparation for reduction.

JJay - 15-4-2017 at 05:33

Quote: Originally posted by NeonPulse  
the synthesis was fairly straight forward and the yield is 14g- i attribute this lowered figure to the obvious losses in the first stage. this was the second time around attempting this synthesis.
The first try was using sodium nitrate as the oxidiser and it did seem to be inferior and the reduced yellow solution released quite some NO2 upon acidification which suggests that NaNO2 was formed as well. there was also quite a lot of un reacted Cr2O3 on my filter so it probably needed longer heating even though it was heated full blast for about an hour. i had a problem with the workup so i had to ditch that attempt.
i did not have any KNO3 around to use this instead. i would say the chlorate method is probably better but i think slow and steady heating is the way to go. also use a large crucible! i only had a smallish batch 25g Cr2O3/ 28g KCLO3/30g KOH and thought that the size would easily handle the mixture but obviously i was wrong.


Good to know. I figured that using a large crucible would help, but I didn't know it needed to be anywhere close to that large with that size batch.

I have been tossing around the idea of making a few mL of chromyl chloride for an ampule, but it wouldn't be my reagent of choice for any oxidation that I can think of, and I definitely don't want to be posting in this section about how I dropped a liter of chromyl chloride on concrete and ruined my new Asics.

tsathoggua1 - 16-4-2017 at 11:27

Trust me, thats really not pretty if it happens. Had just that occur once due to a flask failure, cracked right round the middle of the distillation flask and the bottom dropped out, and likewise the reaction mixture. Wasted a lot of dichromate and the best part of a liter of 98% sulfuric, plus scratch one desk. Nearly hit me too, thankfully I was quick enough to get out of the way. Not a mixture I'd like being covered with at ~120 'C:o

It is useful stuff though, the Etard reaction can selectively oxidize alcohols to aldehydes. Needs care in the choice of solvent though, chlorinated hydrocarbons, CH2Cl2 especially is a good choice.

[Edited on 16-4-2017 by tsathoggua1]

JJay - 16-4-2017 at 11:39

I'd probably use a different reagent for that. Pretty much any chromium based oxidizer can oxidize primary alcohols to aldehydes, but they also oxidize aldehydes to carboxylic acids in aqueous conditions.

tsathoggua1 - 16-4-2017 at 11:50

CrrO2Cl2 is NOT compatible with H2O. It fumes in air, releasing HCl, and best used in anhydrous DCM. There is no way of using CrO2Cl2 in aq. conditions. Don't let water get to the stuff, its messy and downright unpleasant.

JJay - 16-4-2017 at 15:02

Chromyl chloride hydrolyzes to hydrochloric acid and chromic acid in water. That combination can certainly oxidize alcohols to carboxylic acids.

Chromyl chloride isn't "compatible" with the things you would be oxidizing with it either, so I'm not sure what you are getting at. What do you clean up a liter of spilled chromyl chloride with anyway?

j_sum1 - 16-4-2017 at 15:40

Quote: Originally posted by JJay  
What do you clean up a liter of spilled chromyl chloride with anyway?


A litre!? Ouch!

I'd use plenty of PPE including a respirator and flood the scene with a solution of sodium sulfite.

tsathoggua1 - 17-4-2017 at 13:23

What do you clean it up with? you run like the devil himself were nipping at your heels.

And it was a liter of CrO2Cl2, plus a liter of sulfuric (98%), and the corresponding quantities of NaCl and dichromate, potassium dichromate IIRC. Was quite some years back. And I just got the hell out of the way and let it hydrolyse, sealed off the room for the next few days and vented it out. Couldn't have gotten close enough at the moment of flask failure. Its not pretty on that scale!!

Thankfully my receiving flask had stayed intact as had condenser. So I did get to keep some of my distilled chromyl chloride at least:D

[Edited on 17-4-2017 by tsathoggua1]

Rhodanide - 28-4-2017 at 11:12

Not a disaster, but...

Tried to filter excess Cu(OH)2 from concentrated Schweitzers reagent solution.

Used paper filter.

Filter dissolved.

Noticed incredibly obvious fuck-up.

Cried self to sleep.

j_sum1 - 29-4-2017 at 02:40

That cracked me up.
Well done, Tetra.

JJay - 7-5-2017 at 03:38

Today I managed to get sulfuric acid on several of my fingers.

The first time it was from picking up a rag I had used to wipe up a tiny amount of spilled sulfuric acid. I remember thinking, "Something tingles," and then realized what I was holding. I washed my fingers under water and then rubbed sodium carbonate on them and washed them some more. It left these big watery sulfuric acid blisters that were apparently full of dilute sulfuric acid. The second time I was holding a graduated cylinder (rather stupidly) with no gloves and pouring sulfuric acid and I noticed that my thumb was getting carbonized, although I didn't feel any pain. I put it under water for a while and got another sulfuric acid blister.

This was the first time I had ever gotten sulfuric acid on my hands, and I think I've handled quite a bit of sulfuric acid... and it happened twice within a period of about 10 minutes.

I was worried that I was going to have some nasty painful wounds, but after half an hour or so, the blisters dried up and my skin re-laminated itself. The skin on my fingers is still a little dry but other than that everything seems ok. I actually don't have particularly heavy-duty hands, but I sure am glad I didn't rub my eye or something.

NedsHead - 7-5-2017 at 04:17

Does this count? https://youtu.be/VRoYCpjMPyk?t=56s

gdflp - 7-5-2017 at 06:15

The viscosity of conc sulfuric acid can be a real pain sometimes. If you aren't careful, it's easy to get that one drop which clings to the pouring spout, then runs down the side of the container when you put it down. With good quality, clear acid, most of the time I don't notice unless I put it down on a piece of paper towel; a habit I've gotten into for that very reason.

Sulaiman - 7-5-2017 at 06:38

I have adopted the habit of rinsing the outside of my acid bottles after use,
I use self-adhesive paper labels but a quick rinse so far has not caused label damage,

and anything that comes into contact with conc. sulfuric acid
( stir rod, thermometer, funnel, measuring cylinder etc.)
I dunk under water then rinse, immediately after use.
... usually ...

JJay - 7-5-2017 at 15:41

It is easy to get lackadaisical around sulfuric acid if you handle it all the time. After all, it's not *that* dangerous compared to strong sodium hydroxide solutions or hydrogen peroxide. At the same time, it is one of the strongest commonly available acids and can cause extremely serious injuries. I wipe off the bottle, graduated cylinders, etc. after using them, but of course I should remember to put the rag used for doing so into water immediately rather than leaving it at arm's reach. It would also probably be a good idea to use a wet rag....

I sometimes do the paper towel trick also, and it is a good one.

tsathoggua1 - 10-5-2017 at 07:27

Excluding getting it in the eyes, I'm surprised that NaOH, concentrated or otherwise is rated as more hazardous than concentrated sulfuric. At least with NaOH there is a quick window within which to wash it off thoroughly, due to the greasy layer of saponified fats produced. The only time it gives me the willies a bit in terms of caution required is when not in solution but in the molten state,, fused NaOH at a few hundred degrees 'C is definitely rather nasty stuff. I'd still give concentrated H2SO4 my vote for the more dangerous substance however.

JJay - 10-5-2017 at 08:06

There's a window to wash off most mineral acids (note: no one should ever attempt to replicate anything in this video or conduct similar experiments with caustic substances): https://www.youtube.com/watch?v=XeVZQoJ5FdE

I have never personally gotten any sodium hydroxide on my skin other than a prill once or twice, but I have read that concentrated sodium hydroxide is extremely dangerous....

mayko - 15-5-2017 at 14:03

I usually put solutions in the microwave to get them up to boiling, even if I'm going to continue heating on a hotplate later. This is what I did the other day, when I put a 600 mL beaker in the microwave, containing ~250 mL of tribasic sodium citrate solution in excess sodium hydroxide, and a few inches of wooden dowel to act as a nucleation site for bubbles. I left the room for a few minutes (maybe 3 at the outside) as it heated.

When I returned, there was a charred, caramel smell in the air. Looking in the microwave, the liquid in the beaker was hot and brown, and the dowel was not at first visible. My first thought was that the very basic, boiling liquid had dissolved the wood. On closer inspection, though, I saw that the dowel had in fact been burnt into two pieces and fallen into the liquid. The burn mark looked to coincide with the level of the liquid.

Has anyone seen this sort of thing before? My (speculative) explanation is that a bit of solution landed on the wood, dried, and then the residual sodium hydroxide absorbed microwave energy until it melted, charring the wood. The carbon produced would then act as an accelerating energy sink. :o

j_sum1 - 15-5-2017 at 14:43

I dunno. But if it was me I would try to replicate this -- and watch it this time.

mayko - 16-5-2017 at 11:04

I tried recreating it on a small scale with concentrated NaOH; nothing happened with the stick but the beaker cracked, apparently from thermal stress, and I had to figure out how to move a cracked, liable to disintegrate container full of hot lye :( rescuing the TSC is probably my top priority right this second.

JJay - 16-5-2017 at 11:34

I am guessing that in some areas, like droplets on the side of the beaker, the water dried up. I am pretty sure that anhydrous lye can absorb microwaves... that would result in small, dry localized hot areas with no evaporating water. These could quickly become very hot.

I can think of a few ways to test this out, but you probably don't want to try melting lye in your microwave.

feacetech - 18-5-2017 at 14:03

Quote: Originally posted by tsathoggua1  
Excluding getting it in the eyes, I'm surprised that NaOH, concentrated or otherwise is rated as more hazardous than concentrated sulfuric. At least with NaOH there is a quick window within which to wash it off thoroughly, due to the greasy layer of saponified fats produced. The only time it gives me the willies a bit in terms of caution required is when not in solution but in the molten state,, fused NaOH at a few hundred degrees 'C is definitely rather nasty stuff. I'd still give concentrated H2SO4 my vote for the more dangerous substance however.


With conc sulphuric acid you have some time to remove it if your skin is dry, had a guy coverd in it (98.5%, face, chest wrists) and he cleaned up for 7 mins before he used a a chelating spay and got under the shower his skin looked a little like a water foul (white/yellow) but healed nicley like he had a chemical peel, he looked younger after he healed. He did have two small full thickness burns on a couple of spots but at least it wasnt his face.

NaOH soln (50%) can kill the nerves so you dont know its burning you.
A guy had some in his boot didnt notice until the end of shift when he took his boots off. massive burns to his foot.

Also fine granule (<0.5mm) NaOH burns quite fast,esp nasty if a fleck lands in the conrer of your mouth.

[Edited on 18-5-2017 by feacetech]

JJay - 19-5-2017 at 07:57

I made sure that one of my new lab needles was nice and tight on my glass syringe and tested it by taking up some water out of a beaker and then squirting it back. Then I tried to remove the needle, and it didn't want to come off. Being the clever sort that I am, I decided to remove it with a pair of pliers. I held the syringe firmly in one hand and tugged on the needle with the pliers in the other, grasping the needle by the hub. This worked so well that not only did the needle detach from the syringe, the luer lock nub did as well, remaining firmly lodged in the needle hub. The syringe was ruined, of course. So anyway, after about 45 more minutes of screwing around with with multiple sets of pliers, heat and cold, cutting myself twice on broken glass and nearly impaling myself numerous times, not to mention launching the two-inch long, surgically sharp needle across the room into an unknown and hidden location before hunting it down, the glass nub popped out of the needle hub, thus saving the $1 needle.

I've used lab needles don't remember having any problems, but removing the reusable ones from the syringe seems to be pretty dangerous unless they are capped... mine are threaded but didn't come with caps... I wonder if I could find caps for them at the veterinary store....



[Edited on 19-5-2017 by JJay]

tsathoggua1 - 21-5-2017 at 13:17

I've spilled saturated NaOH (aq) on myself plenty times (not deliberately), when its been steaming hot, and the only pain, as long as its washed off reasonably quickly tends to be from the heat. Never noticed any tissue damage caused by NaOH in any instance save one. An electrolytic sodium cell where a little piece formed when unexpected and shot out, taking some NaOH with it. Hit me in the face, wearing eye protection but at the time I was a fair bit younger and didn't have the blast shield I wear for most everything now. Problem was, it was dead on target, right up my right nostril. Fused caustic/caustic-Na intercalation grey-blue compound and Na blob. Shot like a bullet from a sniper's weapon, right up the one vulnerable place on my face. Fused caustic and molten sodium up the hooter ISN'T fun. Burnt/blasted/melted a hole in my septum that hurt pretty badly.

IMO the worst corrosive type accident Iv'e had, is coming so damnably close to having my balls melted off by that chromyl chloride distillation flask cracking. That, or either spilling SOCl2 on a leather gloved hand, and watching, horrified as it rotted my nice metal spiked leather gloves, steel and all and went on going to chew through the hand, down to bare muscle. The battery it came from ended up being thrown into a canal nearby as if a live grenade. Still got scars from that, plus with the same hand, same area, grasping a flask whos neck had an obviously considerable amount of concentrated perchloric wetting it. Its been 12 years or more since those happened to me, and my hand still looks like a piece of dried meat, and needs steroid cream and a blade applying sometimes to de-stiffen it enough to make movement easy again, after hacking off the scar tissue.

NaOH just doesn't seem to bother me. I've even had fused caustic spit on me in small amounts and all it does is sting. Caustic potash on the other hand I imagine would make quite a mess.

One thing I dislike about glass rigs, large capacity ones such as my 150ml one in particular is if held needle angled downwards, the vapor pressure of solvents can cause them to squirt out, along with anything else that might be in there. That and tendency of the plunger to want to back-slide outward and things to leak. Not a nice prospect when its full of GAA, or ICl.

cabal - 22-5-2017 at 00:49

I once made the mistake of buying a couple used glass beakers which were unlabelled, but sold as borosilicate. Sure enough, when I first used them to prepare some NaOH(aq), the heat blew the bottom of the beaker clean off, resulting in my workspace being drenched in lye. Since then I make sure to only buy beakers which are labelled when buying from a private seller.

AJKOER - 22-5-2017 at 09:23

Always research your on the moment ideas and test new procedures with incremental amounts!

For example, using Oxalic acid which I happen to have in supply, as the acid to be added all at once to NaOCl to make Chlorine gas!

Yes it works, but the exothermic reaction also forms HOCl which causes the H2C2O4 to breakdown creating some water vapor and a mole of CO2 for each mole of Oxalic acid.

Bottom line, unexpected massive toxic gas evolution!

One possible reaction sequence:

H2C2O4 + 2 NaOCl (aq) --> 2 HOCl + Na2C2O4 (s)

HOCl + H2C2O4 --> HCl + 2 CO2 (g) + H2O (Source: See Watts, p. 250, at https://books.google.com/books?id=PshJAQAAMAAJ&pg=PA250&... )

HCl + HOCl <---> Cl2 (g) + H2O

Net:

2 H2C2O4 + 2 NaOCl (aq) --> Na2C2O4 (s) + 2 H2O + 2 CO2 (g) + Cl2 (g)

Also, one must avoid an excess of H2C2O4 as it can drive the equilibrium chlorine water reaction above to the left as it reacts with the HOCl creating CO2 at the expense of free chlorine. In other words, Cl2 reacts with aqueous H2C2O4 (see Watts p. 250). Note: the presence of NaCl in the chlorine bleach could react with H2C2O4 forming HCl also. The observed system is a likely mix of competing reactions with products varying from the moles specified above as a result of mixing, presence of NaCl, temperature, ....

[Edited on 22-5-2017 by AJKOER]

mayko - 2-6-2017 at 07:36

Hey, at least no one has had a flaming barrel of possibly-chlorine fall from the sky yet! Keep up the good work, everyone!

https://www.youtube.com/watch?v=d2GNsjw07v0

Melgar - 4-6-2017 at 17:05

Quote: Originally posted by AJKOER  
One possible reaction sequence:

H2C2O4 + 2 NaOCl (aq) --> 2 HOCl + Na2C2O4 (s)

HOCl + H2C2O4 --> HCl + 2 CO2 (g) + H2O

In an aqueous solution it doesn't really make sense to think of the reactive species as whole molecules, since they split up as ions and are no longer attached to each other. If any acid will bring about a reaction, you can just write "H+" instead of the whole molecular form of the acid. The first reaction is just salt metathesis, and isn't needed because sodium oxalate is water-soluble, and stays in the reaction. The second can be written as:

OCl(-) + C2O4(-2) + 2 H(+) --> Cl(-) + 2 CO2(g) + H2O

You just need to make sure all the electrons are accounted for, like you would atoms.

[Edited on 6/5/17 by Melgar]

AJKOER - 7-6-2017 at 06:36

Quote: Originally posted by Melgar  

In an aqueous solution it doesn't really make sense to think of the reactive species as whole molecules, since they split up as ions and are no longer attached to each other. If any acid will bring about a reaction, you can just write "H+" instead of the whole molecular form of the acid. The first reaction is just salt metathesis, and isn't needed because sodium oxalate is water-soluble, and stays in the reaction. The second can be written as:

OCl(-) + C2O4(-2) + 2 H(+) --> Cl(-) + 2 CO2(g) + H2O

You just need to make sure all the electrons are accounted for, like you would atoms.

[Edited on 6/5/17 by Melgar]


Well yes and no. For example, HOCl is almost completely the molecule in practice. As an example, the reaction of chlorine and water in the presence of a metal oxide, followed by distlling, is a cited path, as I recall, to HOCl. Possible explanation:

Cl2 + H2O = H+ + Cl- + HOCl (See equation (3) at
http://pubs.acs.org/doi/abs/10.1021/es00015a014?journalCode=... )

And the metal oxide largely removes the H+ and the volatile HOCl/Cl2O is distilled off. Further details as to which metal oxides or a carbonate (best CaCO3), see Watts page 908 at https://books.google.com/books?id=2OJYAAAAYAAJ&pg=PA908&... .

[Edited on 7-6-2017 by AJKOER]

Velzee - 7-6-2017 at 18:10

A few weeks ago, for Memorial Day, and mostly to appease my friends' interests in pyrotechnics, I decided to attempt to make a small amount of TATP (yes, I know, and I've learned my lesson with this compound). I made two critical errors:

1) On my first attempt(after around a year since my last go at making TATP), I used HCl as a catalyst, and did not cool the reactants **BEFORE** mixing them together and putting the mixture in the fridge. I went to go check up on it around twenty minutes later, and noticed it was boiling, and the plastic wrap I had covered it with had developed a US quarter-sized hole. I noticed an odd, pleasant, chlorine-like aroma coming from the fridge. I closed it, and began to felt like I was going sneeze. The best way I could describe it, was imagine eating a spicy pepper, and the spice building up. Replace the spiciness with pain, multiply it by a few levels, and that's how my nose was feeling after ten seconds. Tears literally started pouring out of my eyes as the pain and burning sensation in both my nose, and my eyes, AND my throat was beginning to overwhelm me in a way I've never experienced in my life. Turns out I accidentally made chloroacetone, a tear gas. It had to be one of the most painful experiences I've ever had.

2) After the experience from above, I decided to make one more batch, making sure every single reactant was thoroughly cooled, I accidentally made WAY TOO MUCH TATP than I needed. I made almost 5-10 grams. Well Memorial Day came and the product wasn't dry enough yet, so I had to wait until a few days after to start using it. I took a small lump of product and used an incense stick (burning with a flame) to entertain myself and to slowly get rid of the product. It went off with a small poof, and so I attempted to proceed, but since the stick was burning too quickly, I blew out the flame and just decided to use the smoldering stick to ignite it. Mind you that I chose a lump probably the size of a small grape, and I placed it on my hotplate which was less than arm's length from me. I touched the incense to the TATP, and I watched as it disappeared with a very small flash, but immediately noticed that I couldn't hear anything from my left ear(which was facing directly towards the hot plate), and my right ear was badly ringing, like you see in the movies. Quickly, I could hear again, but my head was ringing the same way for about ten minutes, and didn't stop fully ringing until after about three or four days afterwards. Needless to say, I disposed of the rest of the TATP properly, and I don't think I'll touch that stuff ever again. There's a reason why it's frowned upon by most chemists with common sense. Unfortunately, I had to learn the hard way.

Melgar - 8-6-2017 at 03:58

Quote: Originally posted by AJKOER  
Well yes and no. For example, HOCl is almost completely the molecule in practice. As an example, the reaction of chlorine and water in the presence of a metal oxide, followed by distlling, is a cited path, as I recall, to HOCl.

Then all the more reason to write the formula with ions instead of molecules. You could make that fact clear in the formula by writing:

HOCl + C2O4(-2) + H(+) --> Cl(-) + 2 CO2(g) + H2O

The net charge is -1 on both sides, making it clear that the reaction is balanced. It also makes it clear that H+ ions are being used up, and thus the reaction will make it less acidic and slow over time.

tsathoggua1 - 11-6-2017 at 11:31

Somebody sent a fair sized quantity (lab scale, 1.5-2kg or 2.5, I forget, but enough to have nearly made a big pain in the ass mess) of ordered NaNO3 by just putting it in an unlabelled food wrap bag, thinner than a tobacco salesman's grasp of the moral high ground if it grew a kate moss-sized coke habit. This was wrapped in just a thin piece of cardboard taped together, by curling the cardboard around the bag, no packing or anything)

So, of course, the moment I slid a blade into the tape, the outer part sprang apart and the inner bag was slit open, spilling NaNO3 on my lap. Got it all recovered, thankfully, but the guy is a dick for choosing such lousy, stupid a way to pack the stuff. Didn't even have the courtesy to do anything but send an unlabelled sack of white powder, that if opened at customs could for obvious reasons attract unwelcome attention. Didn't actually LOSE any of the nitrate in the end bar a few grains scattered about on the carpet, but no more than a pinch or so. But only because there was somebody else present to go and grab me a sheet of paper to slide under where it had fallen, if I'd been alone about an average sized drinking mugs capacity would have gone everywhere since I'd have had no option but to move to get it myself.


JJay - 12-6-2017 at 20:32

I tried making some concentrated ammonia solution by producing ammonia gas with sodium hydroxide and ammonium sulfate and bubbling the gas through water, and there must have been a leak in the apparatus because the resulting solution is pretty weak and the neighborhood smelled like it was downwind from a leaking refrigeration plant. I've done this before with no problems, so I'm not really sure what the issue is, but I think I might try changing the hoses.

tsathoggua1 - 13-6-2017 at 12:57

Try the following:


Use dilute (or as strong as you have already) aq. NH3 rather than H2O.

Use a diffuser airstone as used in aquaculture to help bubble the NH3 through it.

Keep the NH3 and solutions as cold as possible without freezing to permit more and easier uptake.

JJay - 13-6-2017 at 14:21

I have gas drying bottles to use as bubblers, and the solution never got hot as it has in the past... there had to have been a leak somewhere; I just don't know.

Melgar - 27-6-2017 at 23:07

Forgot I had some benzaldehyde on my hands, then went to take a piss. Words cannot describe the agony. For such a pleasant-smelling chemical, it can be surprisingly evil.

[Edited on 6/28/17 by Melgar]

NeonPulse - 28-6-2017 at 17:44

Quote: Originally posted by Melgar  
Forgot I had some benzaldehyde on my hands, then went to take a piss. Words cannot describe the agony. For such a pleasant-smelling chemical, it can be surprisingly evil.

[Edited on 6/28/17 by Melgar]




A rather painful lesson on why we should wear gloves. Ouch.

Melgar - 29-6-2017 at 01:35

Quote: Originally posted by NeonPulse  
A rather painful lesson on why we should wear gloves. Ouch.

Not when taking a piss though! I actually did have them, but I think I took them off specifically to use the bathroom, and had to hurry to get back to the reaction I was monitoring. And of course, in the rush, got some benzaldehyde on my hands somehow and didn't realize it.

aqueous_solution - 5-7-2017 at 03:38

Quote: Originally posted by Melgar  
Forgot I had some benzaldehyde on my hands, then went to take a piss. Words cannot describe the agony. For such a pleasant-smelling chemical, it can be surprisingly evil.

[Edited on 6/28/17 by Melgar]


youch! The inverse is accidental numbing. I used to use lidocane / benzocaine mixture cream to deal with some topical nerve pain and onetime forgot to wash my hands before using the bathroom after application. Couldn't feel my shorts for about an hour and a half.. loll.

wayne_m - 8-7-2017 at 20:55

Quote:
Butyric acid isn't pleasant at any temperature, it just smells like puke threw up, ate its own vomit and washed it down with a cup of cold sick.


Such a way with words!

Where we work, we use some paints that I have described to my wife as smelling like one of The Walking Dead ate another dead guy, and then took a dump. It's awful. The smell clings, and the only thing you can do is rub some Vick's under your nose or sniff some H2S. (Not recommended.)

My latest (in a long line) of failures is in electrolyzing NaOH. The chinesium pot that I was using (it was stamped "stainless" but I have my doubts. Can you electroplate stainless? Would anyone be THAT cheap?) developed a 5mm hole right in the center and dumped a pound of molten NaOH right onto my hotplate. Thankfully, it wasn't expensive, but wouldn't you know it... The hotplate survived. The table under it suffered Unfortunate Circumstances.
When that much hot lye lets loose, there's only one thing you can do. Stand back, wait for it to cool, and chip it off of anything you want to keep.
So now I'm down one very inexpensive pot, a pound of NaOH, and a table, and up by a bucket where I dump aluminum scrap. Someday, I'll use it to make some new alumina catalyst beads or something. I can probably also use it to dump acidic waste, if it won't interfere with that.

As to cracked glassware: I have a 250ML 2 neck RBF that I particularly liked that just randomly got a star crack that spread into one of the necks. It was fine when I put it in its drawer, and when I opened it the next day, there it was. One: WTF? Two: Why couldn't it have happened BEFORE I spent fifteen minutes and several ounces of acetone washing out the tar from the last reaction?

tsathoggua1 - 11-7-2017 at 09:26

Benz-dick doesn't sound much fun.

But Tsath'll bet dollars to donuts that it isn't as bad as permanganate bollock. You all probably know its propensity for tiny little bits getting everywhere, that only show up when wetted? well gloves or no gloves, obviously got some on my hand or hands, and after going to the bog, having stripped off his gloves, err....long story short? that day he should have washed BEFORE he wiped. Had a MnO2-impregnated, brown-burnt speckled scrotum for roughly a week or so afterwards, right from nackers to chocolate starfish, which, for the same length of time burnt like the searing, raging fury of satan's own personal soul-barbecue during a heatwave in one of the more tropical regions of perdition, if Old Scratch decided to light the coals with a thermal lance in place of the more traditional petrochemicals and a match. Bird's eye chilli pepper residue on your fingers making it into an eye has NOTHING on pot perm nackers. Jesus bloody H, the searing fires of hell came to the mortal realm for a week that day. Fuck me diagonally with a sock full of rabid AIDS-infected mink...god fucking damn that HURT. Didn't realize it at first, it was only a little later, when it first began to sting and itch. So, of course what do you do when your balls itch? doesn't take a scientific genius to work that one out.

Nor, does it take one to realize that the usually appropriate course of action for itchy nuts was that day, merely the equivalent of slathering on more KMnO4. Felt like I was pissing SOCl2 and crapping phosphorus for the rest of the sodding week. Ended up getting desparate enough to get a tube of dental anaesthetic gel (benzocaine or lidocaine 20% and cover the afflicted nether regions with it frequently, and even apply it up the damn jap's eye) The one-eyed trouser-serpent got bit this time, rather than doing the biting.

Ever since then, Tsath' has been meticulously careful to the extremes to fully soak his hands in water before going to the bog after using permanganate.


JJay-if it gets in your eyes it certainly is. Been hit in the face twice over thus far into a lifetime with it. Once as a kid, and once, much worse, blasted in the face by a very forceful jet of a mixture of pretty much a catalog of the things in terms of alkaline entities you'd least like to have hit you in the face. Base slops, well, dry, so not sloppY as such, but the basic garbage bucket. It had been labelled, but LE tampered with it and removed the label. Instead of a little hydroxide and carbonate, as the UNlabelled base bottle had in there, which on adding water would have gotten warm and nothing worse, instead had alkali metal amides, alkoxides, NaOH, possibly KOH in there. Label taken off, bottle left there. Was wearing goggles, but added water, capped it, shook to dislodge what was believed to be a solidified chunk of hydroxide and carbonates/bicarbonates, only to see the bottle swell, and in a fraction of second go from room temperature to too hot to hold. Gripping onto it and ignoring the pain, because Tsath' knew full well what was about to happen, and the only thing that could be done was to hurl it as far off out of the back door into the garden as possible before the overpressure and heat burst the bottle and scattered the contents and plastic shrapnel everywhere, did so, but as it spun out of Tsath's hand, it chose just the precise moment during its turning arc of flight to melt/burst through the cap and as a result, hit him at an upward angle from fairly close range with a boiling, searing hot gout of ammoniacal steam from the decomposing alkali metal amides, boiling caustic soda/potash, decomposing alkoxides and the alcohols coming from them and bloody hell only knows what else, hard enough to near rip the goggles off his head, forcing the jet of boiling bases right into his eye. Was lucky not to lose the eye according to the eye specialist, unsurprisingly.

Probably only because of keeping focus and responding as near to instantaneously, within maybe 4-5 seconds at most, and irrigating the shit out of the eye under the cold tap, whilst at the same time, scrubbing clean the areas of neck and top of head it also doused, washing the caustics out of Tsath's hair (and that itself wasn't much fun, he has very long hair, down to about the solar plexus in length) before ringing for an ambulance, sticking some benzocaine in the eye, to enable him to hurriedly take apart the reaction he had going at the time (a Birch-Benkeser type reaction conducted in-situ in diisopropyl and diethyl ethers [note-not to be taken to mean he was doing the notorious methamphetamine synthesis known as 'shake and bake' but rather, employing a solvated electron type reduction employing an ethereal suspension of lithium metal on a freezing mixture bath at somewhere a little below -30, not enough to condense anhydrous ammonia, but no need to with the modification being used, which in short, employs inert gas coverage, strong stirring with very small bits of Li, in fact battery lithium is preferable due to its thinness and large surface area, pre-forming the blue-black of solvated electrons with a stream of anhydrous NH3 gas, generated from ammonium sulfate and base and led through a drying tube and precooler before being piped into the ether containing the Li or other alkali metal to be used through a diffuser stone, waiting until the stoichiometric quantity of Li has been reacted, before adding a solution of the compound to be reduced in an alcoholic thick slurry)

Rang for an ambulance, numbed my eye so I could see where I was going with the unhurt eye, added the pre-prepared alcoholic slurry of substrate, hurriedly, admittedly, but given the circumstances it was justified; then set up to vent the NH3 coming off as the setup warmed up to RT through a drying tube, disconnecting the gas source, and sticking it outside and stashing everything out of view should the medic crew enter the room in question without permission.

Had (not comfortably whatsoever) PH test strips poked in the affected eye, and the bloody surface of the eyeball that took the stream of chemical wastes was at PH >12 on arrival at the hospital.

Still haven't got good vision in that eye, although Tsath' is told that his eye, physically at least is healing as well as can be expected given what happened to it. Unbefuckinglievably painful though at the time. Still on an increased dose of strong pain meds (morphine and oxycodone) months after the accident (was already taking pain meds, have been for a long time, for an injury unrelated to chemistry that happened long ago, and is not going to get any better, plus some accompanying nerve damage that happened after having surgery to try and correct the problem, as well as bilateral trochanteric bursitis, which is no fun at all either, so was already on a fair dose of opioids, but taking another 80mg or so of oxy a day now. Sometimes a little more, sometimes a little less depending on quite how loudly various bits of me start to scream in protest at continuing to be attached to the rest of me.

That aside however, NaOH, even concentrated, as long as its washed off, never seems to bother me much, so long as its washed away without taking ages to do so, in solution or as prills/powder at least, the fused, molten variety is another kettle of fish entirely. Molten NaOH is wicked nasty stuff. Especially when it comes from molten Na metal flying up the nose out of a bath of fused hydroxide under electrolysis as mentioned earlier in the thread.

Cocaine habits are notorious for burning holes in septums. But at least had that been the cause of the crater blown out of Tsath's, there would have been some enjoyment before hand, instead of 'go straight to blasted, corroded septum, do not pass go, do however collect a glob of molten Na up your nose' like some manner of demoniacal monopoly board game.


Just recently had two awful lab fuckovers. First-a container of nitroalkene, in methanol, being treated with bisulfite solution, mistaken for dirty water by somebody else who promptly tipped the entire lot down the drain. Second-the replacement nitroalkene created to fill the empty void left by the stuff poured down the drain, having been reduced to a ketone and thence reacted with NH2OH/NaOAc in MeOH to give the ketoxime, after meticulous cleaning of the nitroalkene and vacuum distillation of the ketone, Tsath' was, finally, after working his arse off to get back where he started, making sure everything was clean and properly worked up, ketoxime in a large sep funnel. Couldn't sleep well the rest of that night, and was exhausted, and just as he got to sleep, what did he hear but a sickening crash and the sound of shattered glass, as some CUNTING MORON, the same piece of dog shit made incarnate responsible for tipping the original nitroalkene down the sink, knocked the funnel to the floor, smashing it to pieces and completely ruining all but maybe at most a gram or two of the ketoxime which had been isolated beforehand, the rest...all gone, all over the floor, and being woken by somebody bellowing in Tsath's face to clean up the mess they fucking made for them.

There are really no words which adequately describe the ice-cold fury and loathing Tsath' has for this worthless piece of trash individual now. Who not only didn't even bother to apologize, either time, but thinks they can refuse to replace the funnel. Cost over £100, saved up for over months it was. And with the work that Tsath' had spent day and night, over and over, without sleeping for many days, over the course of at least two weeks working it up to satisfactory purity, probably a bit longer. Gone in an instant. And being woken up abruptly at about 7am having just got to sleep and finally begun to get the much needed rest, rather than the occasional short cat-nap for half an hour here, an hour there once in a while, by a selfish, selfabsorbed, hypocritical fucking prick who expects everything from Tsath' but is completely unwilling to give what he demands and claims entitlement to when the tables be turned and something happens that (although shit for brains dogfucking toss-wad isn't a chemist) makes a mess, or breaks something, but won't show the same consideration to others. Acts like its one rule for himself, another for Tsath' and everybody else. Wants things doing for him, but won't do the same thing for the same reason in return.

Needless to say, he IS paying for that funnel. Whether he knows it or not, and whether he wants to or not. Even now, days later, that fury is seething and roiling, as if it were an ocean of virulent poison just under the surface. Can hardly look at the prick without wanting to cave his skull in and ram whats left of the funnel up his arse, sideways, after heating it with a blowtorch until just short of its softening and the sharp edges dulling. All that could be saved was the stopper, a metal keck clip and the stopcock.

JJay - 11-7-2017 at 09:50

Oh, I've been sprayed in the face and eyes with liquid ammonia a couple of times, miraculously with no injury. It's nasty stuff, but it's scarier than it is dangerous. It's best to wear a face shield around it, but that's more for comfort than safety unless the liquid ammonia is spraying like a garden hose, in which case you might get frostbite if it hits you in the face, and you'll want a gas mask and/or SCBA. Goggles are mandatory.

I've never had any accidents with alkali metals or hydroxides (or amides, alkoxides, etc.), but I'm sure they aren't fun.

Sounds like your lab partner is a major drag on your operation....

tsathoggua1 - 13-7-2017 at 09:51

Not a lab partner. Don't have one. Just a selfish relative who is not a chemist. And has no idea how close they came, after that to ending up seriously hurt. Not because of the oxime, that wasn't anything dangerous, but because being such a total fucking piece of dog shit can prove hazardous to health. He fucked off out of the house for the rest of the day and it was lucky he did, whilst I ended up taking a couple of 5mg nitrazepam tabs that I have a repeat rx for, a solid dose of chlormethiazole and a shot of maybe 700-something (I forget the exact quantity of the 'something' of morphine dipropionyl ester/morphine/oxycodone mixture [again, on RX, the dipropionyl ester aside, pretty sure it isn't used clinically in this country, although terminal patients, possibly some replacement therapy for addicts and cancer patients sometimes get diamorphine. Beats me why they don't use the propionate ester more frequently in medicine since it is actually vastly superior in all respects, its several times as potent by weight as diamorphine, it is faster acting, and rather than the 5-7 hours or so action from a single dose of diamorphine, with the dipropionate ester expect over double that. 8am dose lasting to about 10pm isn't unknown or uncommon, and it also produces less histamine release. Note that the above dose OR combination is NOT reccomended for anybody not used to chlormethiazole etc.-I have to take it, for seizure prophylaxis, although it isn't licensed here for that indication, I prefer it since I've been able to take it several times daily for years, and abruptly stop for a couple of days if I have to without a taper and experience no withdrawal effect, with a benzo, I'd be in big trouble doing anything like that unless having reached a steady-state plasma level/deposition in body fat of a potent, long acting one, I only use the stuff for a couple of days at most consecutively, 3 days max when its needed. And that dose of dipropionylmorphine is the equivalent of several grams of morphine sulfate, so really, don't try anything like that high if you want to wake up again!)


Since that incident with the getting hit in the face, bought a face shield and wear it when working with anything remotely toxic, irritant or corrosive unless it is a non-volatile, non-reactive entity that just sits there until something further be done with it. Goggles will do for things like non-glacial acetic, or conc. HCl (over the years, I've come to the conclusion that with HCl, that sans actually DRINKING it, administering it as an enema, eyewash or intravenous/intrathecal/IM/SC injection, I must have developed or been born with an immunity to HCl. Even hanging around for a while (not by choice, rather, whilst doing something which for safety reasons cannot be permitted to simply run itself unattended, like distilling CrO2Cl2 from hot 99%+ sulfuric, or running a Cl2 generator whilst distilling ICl at the same time, distilling bromine and the like, to walk away and clean off a soaking in some HCl was by far the greater evil than leaving the conc. HCl. Didn't do my clothing any good mind you but noticed no irritation either during the ICl distillation and synthesis of more of the same reagent to add to the still pot. In an open cut or graze etc. then yes, it hurts as expected, but was surprised to find out that the area where it had soaked into the clothing and stayed there throughout the distillation/synthesis/maintaining the chlorine generator and topping up the reactants within, which is where the HCl came from, oxidation of HCl by KMnO4 and to a degree by any MnO2 formed on its way to being converted to manganese chlorides, the area wasn't even pink, or at least, no pinker than my caucasian skin tone evolved to be, no irritation, except one small spot where an IM injection of my pain medication had previously been administered that day, which did sting and itch where HCl gained access to the puncture from the needle.

The assumed lab partner isn't, and would never be either (did allow him to hold a hand-drill steady once to manually stir some methanolic triethylenetetramine freebase whilst adding GAA to produce the tetraacetate salt for a knoevanagel catalyst [for which in Tsath's experience, btw, if ever doing a knoevanagel/henry condensation it seems, when using benzaldehyde at least, or 2,5-4-alkyl-benzaldehydes, then it works something amazing but that, and occasionally passing an empty pipette to be hend in the other hand when measuring out more GAA) is the absolute limit of what little trust I'd put in him. Maybe I'd allow him to measure out and hand me a plastic beaker of water and turn the cold or hot tap for himself, but otherwise, I wouldn't trust him so far as to have confidence he'd burn if I were to skin him alive, roll him in caustic potash flakes then drop him from a great height into an olympic swimming pool full of chlorine trifluoride. Which, to be quite honest, given the way I am going to have to extract the money for that funnel from him and the way he outright refused even to APOLOGIZE after both tipping Tsath's nitroalkene and unreacted benzaldehyde's bisulfite adduct down the sink, or after breaking the expensive separatory funnel with the valuable contents, made with, TETA-acetate aside, both valuable and difficult to purchase with safety nitroethane, plus the solvents, plus the hydroxylamine used to create an oxime, plus the reagents used to prepare the ketone (not valuable, or difficult to safely buy, but still neither are they things to be just trashed, nor are they things that, environmentally speaking ought to go down the drains) although the ketone in question, was one of considerable value.

And saying nothing of the weeks spent in preparation, relentlessly working days, and nights without more than at most a few hours rest every few days preparing, and purifying whilst worked-out to a point way, way well past exhaustion. And being woken up at 7-8am by having somebody bellowing in your ears...I'd very much take delight in skinning him, salting him with KOH and tossing him into that olympic swimming pool filled with ClF3. Preferably with an air supply and face protection so he'd last marginally longer before expiring in agony. Could have replaced it for my recent b/day even, but didn't even bother to do that (or anything else).

I'm not a hateful person generally, unless it comes to LE, after the abuse and harassment and illegal actions taken by them, theft of property (that had no relation to chemistry, things like an 8.5 carat precious gemstone and a second, smaller one went missing from their containers. And those were meant to be set into a silver ankh necklace Tsath' is making for somebody he likes, a lot. Those stones were there before the filth came, and after, they were gone, and containers opened. They don't just jump off shelves and out of closed containers by themselves and run away. There is only one explanation)

But in this case, family member or not by blood. He is a relative in terms of genetic material alone, and no family of Tsath's. Not anymore. Prick knows full well how much Tsath's lab is cared for, how it is his lifetimes work, that over time tens of thousands of GBP have been spent on it (twice, possibly thrice over having to restart from scratch) and that he works day and many, many many nights without a wink of sleep in there for days and nights on end, that his lab is his pride and joy treasured below nothing else he has ever owned and can't even be fucked to APOLOGIZE? and when the work in question was something for Tsath's birthday too since Tsath' was the only one did anything about that. Or tried to, at least. (although belated or not, he is determined that it must still happen, no matter how long it takes. Even though replacing the funnel means going without food for a week, once the last bits of his mostly-eaten piece of cheese are gone)

:(

Say, anybody have a few tens of thousands of liters of chlorine trifluoride they want to give away for free, by any chance? and maybe a spare olympic sized swimming pool in a soundproofed room?

Magpie - 13-7-2017 at 10:07

Quote: Originally posted by JJay  
Oh, I've been sprayed in the face and eyes with liquid ammonia a couple of times, miraculously with no injury. It's nasty stuff, but it's scarier than it is dangerous..


Member Tacho somehow got a face full of ammonia. Opening a bottle in his hot attic lab, IIRC. He quit home chemistry after that. Too bad, he was a gifted experimentalist.

JJay - 13-7-2017 at 10:36

People often think they need to be hospitalized from breathing less than 20 PPM. It's dangerous stuff, but it's nothing compared to sulfur dioxide, hydrogen sulfide, chlorine, hydrazine, bromine, phosgene, titanium tetrachloride, etc. Even sulfuric acid is arguably more dangerous.

ave369 - 13-7-2017 at 10:39

I had been getting facefuls of ammonia, like, ten times, but it didn't make me quit.

mayko - 13-7-2017 at 11:01

Squirted myself in the eye with 91% IPA the other day while cleaning the kitchen. Will definitely give up housekeeping now.

Who am I kidding? I gave up in spirit a long time ago.

tsathoggua1 - 15-7-2017 at 07:37

Bet an eyeful of isopropyl that concentrated stung a bit.

MeshPL - 15-7-2017 at 07:45

I was heating up a slurry of copper and nickel carbonates in a beaker with manual stirring. A thick slurry. So thick, that when I stopped stirring it instantly started violently boiling on the bottom and made the beaker jump so hard it broke! This was not a thermal stress. The beaker jumped a few times before it cracked and before I could resume stirring or take it off the hotplate.

I didn't even meant to boil the solution, just heat it and cool it a few times to increase particle size to ease up the filtering or decantation.

[Edited on 15-7-2017 by MeshPL]

JJay - 31-7-2017 at 12:32

I made the classic blunder of dumping a little too much water into a flask that was half full of sodium hydroxide and ammonium sulfate, resulting in a very stinky and caustic volcano. I managed to escape without any injury, but I am going to be wiping down my fume hood with cleaning vinegar later. Next time I make an ammonia generator, I'm going to use an addition funnel.

XeonTheMGPony - 31-7-2017 at 12:49

JJay: Use a 60Ml syringe, dissolve the Ammonium sulfate in minimal water then drip it in.

Thus no need for addition funnel if you lack one, bit more manual then addition funnel :)

or revers order sodium hydroxide dissolved in water and drip it in to ammonia sulfate slurry.

[Edited on 31-7-2017 by XeonTheMGPony]

JJay - 31-7-2017 at 13:29

I have addition funnels, but I wanted to minimize the number of pieces of glassware to reduce the likelihood of leaks.

Hypochlorite - 4-8-2017 at 20:06

Hi everyone, I have been reading on this site for at least a year now, and finally decided to create an account.
I've had one major incident in my lab.
Some Context: I had a chat with NurdRage on youtube about making P-Chlorophenylnitrile via the decarboxylation of Phenylalanine, followed by chlorinating on the Para position, rather than his very long synthesis starting from toluene. I told him I would try it out, and decided to buy my phenylalanine from a seller who marketed it as a ‘health supplement.’

I received a box labelled “Amino Acid” and when I started the decarboxylation (using pyridine and TCCA ), and after refluxing for around two hours, opened the condenser, I got a powerful, lingering, dying rat smell....the Horrific smell of Cadaverine. :(:(:mad:


[Edited on 5-8-2017 by Hypochlorite]

TheNerdyFarmer - 5-8-2017 at 12:52

Today while cleaning my 24/40 Buchner funnel I broke the little stem that goes in-between the jointed part of it. It will be missed dearly.

Melgar - 6-8-2017 at 23:39

Quote: Originally posted by Hypochlorite  
I received a box labelled “Amino Acid” and when I started the decarboxylation (using pyridine and TCCA ), and after refluxing for around two hours, opened the condenser, I got a powerful, lingering, dying rat smell....the Horrific smell of Cadaverine. :(:(:mad:

For amino acids, purebulk.com usually has very good prices. They're US-based but ship internationally.

XeonTheMGPony - 7-8-2017 at 07:44

When making sodium acetate from ethyl acetate the reflux got a bit energetic and launched the contents into the roof (Spackle) that is now dissolving slowly and I'm just letting it!run its course as I plan to do massive renos to the room (Walls, roof and so on)

karlos³ - 7-8-2017 at 09:12

Alright this happened quite some years ago, but I remember it everytime I put some water-sensitive reaction into an ice-salt bath again: So I was happening to prepare some EtONa, and the flask was already ready sitting in the cooling bath while I was cutting sodium... with very thick and clumsy gloves, my sodiumgloves... so I wanted to add a(luckily tiny) piece to flask, and one fell into the bath.... hurry, panic, a little sizzling and a wholeheartedly relieved chemists was the only outcome of this potential disaster :D
Since it´s been quite some time now, I can´t vouch for sure if the chemists underpants were richer in a drop of fluid or not afterwards :o :P

[Edited on 7-8-2017 by karlos³]

Melgar - 7-8-2017 at 13:43

I, for one, like ammonia. The smell of it tells me I'm not breathing phosgene or acid vapors or halogens, or any number of alkylating agents. With some ammonia vapor in the room, all those nasty gases are visible.

I've actually taken to using a mixture of ammonia and ammonium ascorbate in water as my go-to neutralization agent, like if I spill something and don't have time to figure out what it was.

JJay - 8-8-2017 at 20:29

A few weeks ago I dry distilled 70 grams of oven-dried calcium benzoate with 130 grams of oven dried calcium acetate. Both were oven dried at around 240 C, and the calcium benzoate did brown in the oven, which was not expected. I pulverized them together in a blender and placed the mixture in a steel can fitted with a copper tube leading to a glass condenser. I heated it strongly to a red heat with a propane flame, carefully venting the vapors. The distillate was a tan liquid that smelled like benzene and boiled at around 80 C, and it did not form a bisulfite adduct. It did not appear to contain any acetone. I am pretty sure it was substantially benzene.

It says on Wikipedia that heating calcium acetate to 160 C causes decomposition, but I haven't been able to verify that with actual references. Anyone know what might have gone wrong?

Melgar - 8-8-2017 at 21:23

Were you trying for acetophenone? I thought only a few ketones formed bisulfite adducts.

Quote: Originally posted by JJay  
A few weeks ago I dry distilled 70 grams of oven-dried calcium benzoate with 130 grams of oven dried calcium acetate. Both were oven dried at around 240 C, and the calcium benzoate did brown in the oven, which was not expected. I pulverized them together in a blender and placed the mixture in a steel can fitted with a copper tube leading to a glass condenser. I heated it strongly to a red heat with a propane flame, carefully venting the vapors. The distillate was a tan liquid that smelled like benzene and boiled at around 80 C, and it did not form a bisulfite adduct. It did not appear to contain any acetone. I am pretty sure it was substantially benzene.

It says on Wikipedia that heating calcium acetate to 160 C causes decomposition, but I haven't been able to verify that with actual references. Anyone know what might have gone wrong?


Okay, you just said you oven-dried your calcium acetate at 240˚C, when calcium acetate decomposes at 160˚C. Figure it out yet?

[Edited on 8/9/17 by Melgar]

JJay - 8-8-2017 at 23:39

This ACS reference says that no decomposition occurs at 160 C: http://pubs.acs.org/doi/abs/10.1021/je60012a040?journalCode=...

I've read that small amounts of calcium hydroxide can greatly influence the composition of the pyrolysis products, but I wouldn't expect that to be the case for calcium carbonate. All I can think of is that maybe there were some basic calcium salts present.

Melgar - 9-8-2017 at 00:19

Quote: Originally posted by JJay  
This ACS reference says that no decomposition occurs at 160 C: http://pubs.acs.org/doi/abs/10.1021/je60012a040?journalCode=...

I've read that small amounts of calcium hydroxide can greatly influence the composition of the pyrolysis products, but I wouldn't expect that to be the case for calcium carbonate. All I can think of is that maybe there were some basic calcium salts present.

At 240˚C, especially exposed to air in the oven, calcium acetate would decompose quite readily. Its decomposition temperature range is very broad as well, without a sharp line at any temperature where decomposition could be said to begin. CO2 can liberate acetic acid from wet calcium acetate too, forming the carbonate salt.

[Edited on 8/9/17 by Melgar]

JJay - 9-8-2017 at 00:39

I should also mention that in addition to failing tests for acetone, the product appeared to be quite buoyant in water. Yes, I was trying for acetophenone, which unlike most aldehydes and methyl ketones, doesn't form a bisulfite adduct. But acetone does, and it was the only expected product with a density lower than water.

JJay - 9-8-2017 at 00:42

Quote: Originally posted by Melgar  


At 240˚C, especially exposed to air in the oven, calcium acetate would decompose quite readily. Its decomposition temperature range is very broad as well, without a sharp line at any temperature where decomposition could be said to begin. CO2 can liberate acetic acid from wet calcium acetate too, forming the carbonate salt.



What is your source for this information?

Melgar - 9-8-2017 at 01:52

Quote: Originally posted by JJay  
What is your source for this information?

If your oven was hot enough to brown calcium benzoate, then it was definitely hot enough to decompose calcium acetate. In air, it wouldn't decompose into acetone anyway, it'd decompose into CO2, methyl acetate, methanol, etc. The references you have also appear to be anaerobic conditions, and the temperatures specified on Wikipedia and elsewhere (every MSDS for calcium acetate) are for aerobic conditions.

JJay - 9-8-2017 at 04:00

I think it's more likely that impurities caused the browning of the calcium benzoate, not an excessively high temperature. The first five SDS results for calcium acetate on Google do not mention decomposition in the manner that you suggested. It is of course possible to determine the exact temperature at which a reaction begins to proceed spontaneously using the thermodynamic properties of the substances involved in the reaction. And I don't think the paper above specifies anaerobic conditions, although they certainly wouldn't hurt.

The effect of calcium hydroxide on the pyrolysis of calcium salts of organic acids is well known: http://pubs.acs.org/doi/abs/10.1021/j150183a002

I used an excess of calcium carbonate to make my calcium salts, but I think it's reasonable to suppose that this could result in contamination with small amounts of basic calcium salts and that these had a similar effect to that of calcium hydroxide. Very little is known about basic calcium salts, but the theory is straightforward, and I think this is a sound hypothesis that could be verified or ruled out with further experimentation.

While I'm reluctant to rule it out at this point, I'm not seeing any theoretical basis or empirical results in the information you've provided, but I'll try doing the reaction with inert gas or a vacuum next time I get around to running it.




[Edited on 9-8-2017 by JJay]

Melgar - 9-8-2017 at 05:14

Quote: Originally posted by JJay  
And I don't think the paper above specifies anaerobic conditions, although they certainly wouldn't hurt.

It doesn't say strict anaerobic conditions, but it specifies putting the salt in an RBF with a slight vacuum. So there's a tiny amount of air that decomposes a little bit of the salt, but nothing like the convection cell that goes through a typical oven.

I did find a paper showing that decomposition for calcium acetate went first, endothermic dehydration. The second step was endothermic unless oxygen was present, in which case it was exothermic, meaning that it's two different reactions depending on the availability of oxygen. I have no idea where to find that paper, but I remember that much.

edit: you understand that I'm saying that I think you had calcium carbonate, not calcium acetate, when you took it out of the oven, correct?

[Edited on 8/9/17 by Melgar]

JJay - 9-8-2017 at 05:32

Yeah, but I'm saying that I don't think so. It still smelled like calcium acetate. I didn't notice any noxious fumes coming off of it while it was in the oven. And there seems to be a serious lack of good references suggesting that calcium acetate decomposes at low temperatures.

Also, that's just one small part of the paper, and it says *slight* vacuum. No vacuum is mentioned in the oven drying procedures. This is not the first time I've read a paper that discusses oven-drying calcium salts, and they generally don't mention a vacuum or inert gas for that step. In short, your assertion that they used anaerobic conditions is not supported even though they did use a slight vacuum at one point in the paper.

In addition, even if decomposition did occur, a small amount of calcium carbonate is unlikely to seriously interfere with the reaction.

nitro-genes - 9-8-2017 at 13:40

Also had an incident with an ammonia generator using diammoniumphosphate instead of ammoniumsulfate, which I normally use. The generator had been running fine for about 15-30 minutes or so, when suddenly a thick amorphous cake (mono/disodiumphosphate?) formed on top of the reaction mixture, which was pushed up by the ammonia still produced, clogging the neck and hose. Heard some loud hissing before the 250 ml erlenmeyer exploded from the overpressure, which was impressive to say the least...

Melgar - 9-8-2017 at 17:49

Quote: Originally posted by JJay  
Yeah, but I'm saying that I don't think so. It still smelled like calcium acetate. I didn't notice any noxious fumes coming off of it while it was in the oven.

Calcium acetate isn't volatile, you know, so any smells you associate with it are probably decomposition products.

You could know for sure by oven-drying calcium acetate, then reacting with acetic acid again. Fizzzing would imply decomposition.

JJay - 9-8-2017 at 18:44

@Melgar: Calcium acetate smells like vinegar. That you are not aware of this fact is surprising, but what is concerning is that you're making unwarranted assumptions about the nature of the decomposition products and also making speculation that would require me to waste excessive quantities of chemicals given the level of knowledge on display here.

Melgar - 9-8-2017 at 21:26

Quote: Originally posted by JJay  
@Melgar: Calcium acetate smells like vinegar. That you are not aware of this fact is surprising, but what is concerning is that you're making unwarranted assumptions about the nature of the decomposition products and also making speculation that would require me to waste excessive quantities of chemicals given the level of knowledge on display here.

First of all, my calcium acetate has no smell at all. The fact that yours did is what made me speculate. Second of all, virtually all the literature I could find gave the 160˚C decomposition point. For instance, here:

https://pubchem.ncbi.nlm.nih.gov/compound/Calcium_acetate#se...

These figures are for air atmospheres unless stated otherwise. To me, it seemed like a bad idea to heat your Ca(AcO)2 above that, just because you were able to find two different papers that claimed a higher decomposition temperature under very controlled conditions. The one paper went through a lot of trouble to only get the monohydrate in one form, which I doubt you did.

My thought here, is that proving literature wrong is kind of a big deal, and if you're somehow able to prove that it's wrong for amorphous calcium acetate at least, then it's actually something that's worth your time and effort and reagents. Of course, the other option is to assume that it's more or less correct, with some exceptions for certain pure crystalline forms, and dry your calcium acetate below that temperature.

JJay - 9-8-2017 at 22:13

That's not "literature" any more than a library card catalog is literature. It's a compilation. The only source that it cites with a 160 C decomposition temperature is an International Chemical Safety Card, and it gives no information on whether decomposition is production of acetone or simply dehydration. Taking it as gospel, Melgar, is a prime example of how Chemistry Goes Wrong.

In any event, I now have the actual literature that reported formation of traces of acetone at slightly above 160 C, and it concluded that production of acetone was very slight below 400 C.

I'm curious about the purity of your calcium acetate and whether it is the impure commercial form, hydrated, or actual anhydrous calcium acetate but this is not the place to discuss it unless you've had some failed reactions or something.

JJay - 9-8-2017 at 22:32

Quote: Originally posted by nitro-genes  
Also had an incident with an ammonia generator using diammoniumphosphate instead of ammoniumsulfate, which I normally use. The generator had been running fine for about 15-30 minutes or so, when suddenly a thick amorphous cake (mono/disodiumphosphate?) formed on top of the reaction mixture, which was pushed up by the ammonia still produced, clogging the neck and hose. Heard some loud hissing before the 250 ml erlenmeyer exploded from the overpressure, which was impressive to say the least...


Nothing like broken glass and sodium hydroxide flying all over the place :) I made an ammonia generator by a boiling strong ammonia solution through a column and running the vapors through a tube of sodium hydroxide and had no problems.

Geocachmaster - 12-8-2017 at 11:54

I was weighing out 30g of NaOH and a clump fell out of the bottle giving me about 20g too much. Trying to pour off the extra into a wide necked Erlenmeyer flask and the clump made a bunch spill everywhere. Most of it landed on my scale, getting on the top, under the keys, under the weighing surface, just making a terrible mess in general. Of course its quite humid and all of the beads stick instantly. I think my scale is lost. Oh well, I wanted to get a new one anyway...

wg48 - 12-8-2017 at 15:10

I recently ordered some gallium from china. 28g for £8 including delivery a nice price probably a to good to be true price.

It is supposed to be on its way but the listing has been removed so I was concerned in case its restricted. I could find no restrictions on its sale or possession in the uk but its not supposed to be transported by Royal Mail and probably not by air.

I guess I will have to wait (a long time if its by sea) and see if it arrives ok and hopefully I can not get in trouble. It should be the sellers responsibility to ship correctly.

Ok not really "When chemistry goes wrong" but sort of related

wg48 - 12-8-2017 at 16:39

I was experimenting with a microwave oven magnetron on my bench. I was careful to avoid significant microwave exposure. When I moved an earthed piece of metal the back of my little finger come too close to a wire connected to the transformer HT output.
.
Ouch zap, about 2kV between my little finger and my earthed index finger and thumb. I cannot say with certainty, as my brain was overload by the sensory input from my hand but it looked like a draw out an arc to several inches with my little finger as I pulled my hand away very very quickly. The were several burn spots on my little finger and big one on my index finger with a smaller one on my thumb. Initially no pain but the fingers where numb and my hand throbbed a lot. All the finger moved ok. Oh and the strange smell of burnt skin. Fortunately and painfully within an hour or so the sensation had returned to my hand and the burns hurt but not particularly so.

Sorry no pics I seem to have lost them or forgot to save them when I viewed them on my pc. It surprisingly how easy it was for me to forget to avoid that wire when I was preoccupied by the experiment. The outcome could have been much worse. I am getting a bit too elderly to chance shock testing my heart. I will not be experimenting with that set up again until the power supply and connections to the magnetron are fully enclosed.

Ok its a "When physics goes wrong" or perhaps a "call me stupid"

Hypochlorite - 13-8-2017 at 01:55

I had another incident regarding 'industrial grade' chemicals. I needed some benzophenone and decided to just buy some supposed ">95%" calcium benzoate powder for a thermal decomposition reaction to produce benzophenone. Instead of recrystallizing or purifying the "95%" Calcium benzoate, I felt lazy and decided to just do the decomposition reaction immediately.

I began to gently heat a flask loaded with around 100 grams of Calcium Benzoate and after around 10 minutes, steam began to come off at around 103 degrees, and then continued to gently heat until, after maybe 15 minutes, I heard a very loud "bang" and a very thick black smoke cloud rushed into my condenser, which smelt very strongly like petrol, and I immediately turned on my ventilation. I took the flask off heat and left the area for around 15 minutes.

When I returned, my condenser was coated with a thick layer of black soot that could only be removed by a mixture of Sulphuric acid and hydrogen peroxide, and I had to destroy the reaction flack. Then entire flask was basically filled with carbon foam that would not be removed, as was the glass adapter leading to the air condenser, despite me scrubbing both of them for a good half-hour.

The only 'good' thing is that I now have around 35 mL of Benzene that I don't know want to do with. I have done this reaction before with self-made Calcium benzoate and only got around 2-3 mL of benzene and side products distilling less than 300 degrees in the whole distillation. The moral of this story; Always purify your chemicals, and that I am an idiot for not checking to purity of 'Industrial grade' chemicals... :mad:

JJay - 13-8-2017 at 03:12

If I'd accidentally made benzene a couple of years ago I would have been overjoyed, but the same thing happened to me recently. Benzene tends to give off a lot of smoke when it burns.

There are lots of things you can do with benzene. I would wash it with water, dry it with a suitable desiccant, fractionate it and then store it in a suitable container. Benzene tends to degrade rubber stoppers.

JJay - 13-8-2017 at 03:34

Oh, and I was distilling some benzyl alcohol earlier and managed to melt a screw cap by heating the 14/10 flask directly on a hotplate with a foil skirt. Fortunately, I have two large bags of caps... I was wondering why they included so many in my kit. I managed to rescue the flask by carefully cutting into the cap with a razor knife. I guess next time I should use a heating bath or a vacuum.

It was my first time ever actually using a Hickman distillation head. They seem to work reasonably well.

Hypochlorite - 14-8-2017 at 01:40

The thing is, I honestly never use Benzene, or any well-known carcinogens if possible in my lab, so I really don't want the stuff just lying around. I normally destroy any benzene or other unwanted organic compounds by burning a mixture of the benzene and methanol in an old-fashioned spirit burner.

I prefer just burning it as I typically have around 10 mL of some non-dangerous organic compound lying around, so burning it is much, much easier than the ''dangerous waste disposal' as the fee for even small amounts of waste is a nightmare. However, I never incinerate any halogenated or nitrogen containing organic compounds due to the risk of forming small amounts of hydrogen cyanide and phosgene.


Where I live, you can buy liters of 98% Sulfuric acid and 38% HCl from your nearest hardware store, but buying any benzaldehyde or benzyl alcohol will get you a visit from the police.

JJay - 14-8-2017 at 01:53

Oh. Benzaldehyde is like that here (although they let some people get away with buying it). Benzyl alcohol, though, is very easy to obtain.

Geocachmaster - 20-8-2017 at 17:30

Unhooking the water lines to a condenser. Easy enough to do, except when you forget to turn off the flow of water first! I tried to clean up and grabbed a towl, but I forgot it was one that I had spilled methylene blue crystals on...

Sulaiman - 20-8-2017 at 21:31

You've got a good reason to feel blue now / you've entered your blue phase ?

This is what happens when you have a nice new shiny lab ! :P




If anyone asks - it's essence of smurf.

[Edited on 21-8-2017 by Sulaiman]

Melgar - 20-8-2017 at 23:20

Hey, at least it wasn't silver nitrate!

There are safe limits to benzene exposure, and its carcinogenic properties tend to be from occupational exposure. It's not in the same category as say, dimethyl sulfate. If it were up to me, the alarmists that study what causes cancer would have to rank everything on their list from most to least carcinogenic, just to give some perspective. And forcing mice to breathe 200 ppm of a chemical for their entire lives should not be enough evidence to label something as a carcinogen. Most carcinogens only cause cancer when they or their metabolites accumulate faster than your body can remove them or repair the damage they do.

Hypochlorite - 21-8-2017 at 00:44

I know, but I still don't want to work with any potential carcinogens in my garage lab, but I definitely agree that the current epidemic of Chemiphobia has gotten out of control. Anyways, I would just not work with dimethyl sulphate in my current lab, but I would see no problems working with Dimethyl carbonate.

In other news, I managed to spill around 10 mL of saturated K2MnO4 that I was trying to crystallize without decomposing to brown MnO2 muck, and it landed on the carpet. Now I have to deal with several holes in my carpet and a large brown stain to clean up.

Geocachmaster - 24-8-2017 at 17:38

I learned today that solutions of NaOH in alcohol are not compatible with HDPE. After two days I noticed that my 500 mL HDPE ethanol recovery bottle was cracking at the top and had warped and became soft at the bottom. I had poured ethanol which contained excess sodium hydroxide in and didn't think about it because HDPE is compatible with both of those chemicals. For now I placed the bottle in secondary containment and I will dispose of it tomorrow.

On another note I was trying to do a fractional distillation using a 1 meter packed column, it had massive flooding issues (I checked under the aluminum foil when I heard bad noises and more than 2/3 of the column was full :o). I will have to rethink my design. I'm thinking larger diameter column and slower heating rate.

wg48 - 26-8-2017 at 11:01

Quote: Originally posted by wg48  
I recently ordered some gallium from china. 28g for £8 including delivery a nice price probably a to good to be true price.

It is supposed to be on its way but the listing has been removed so I was concerned in case its restricted. I could find no restrictions on its sale or possession in the uk but its not supposed to be transported by Royal Mail and probably not by air.

I guess I will have to wait (a long time if its by sea) and see if it arrives ok and hopefully I can not get in trouble. It should be the sellers responsibility to ship correctly.

Ok not really "When chemistry goes wrong" but sort of related


I am pleased it arrived today via Royal Mail. Not packed very well. It had apparently melted and leaked from its container. The whole package weighed 36g so the weight of the gallium is about correct.



gallium-metal.jpg - 143kB

owie - 26-8-2017 at 17:21

Quote: Originally posted by BromicAcid  
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


LOL that phosphorus story is crazy. Had me laughing and made me realize this is something I never want to do.

TheNerdyFarmer - 5-11-2017 at 15:53

Yesterday I decided to generate some ammonia gas for a separate project of mine. I had the whole gas generating setup built and so I mixed the reactants and started gas generation. By the way I was making ammonia via ammonium halide salt + alkali metal hydroxide. Any way, the reaction started and a lot of gas was coming off. There was also a good deal of moisture coming with it. Little did I notice that some (a great deal) of ammonia gas was leaking from the tubing that I used to make the gas generating setup. Before I realized what was happening I lifted the sash of the fumehood up and got a huge whiff of ammonia gas. I had forgotten to turn my fume hood on. I quickly turned it on and ran to the other side of the lab. I walked over to the hood every few seconds and within 2 minutes there was no detection of ammonia gas.
This wasn't a super dangerous situation but it did give me somewhat of a scare considering that ammonia isnt the greatest stuff to inhale.

[Edited on 6-11-2017 by TheNerdyFarmer]

LearnedAmateur - 6-11-2017 at 11:45

Several months ago I was playing with some sodium metal, first thing that came to mind was the addition to water since it's always exciting to watch the little fiery balls dance across the surface. At first I was using little cubes about 2mm each side which lasted a few seconds and quickly got boring. 'Why not scale it up?' I thought, so I doubled the dimensions to 4mm. A lot more in the way of sparks and acrid fumes, so I stepped back and the little chunk exploded, sending specks of the flaming metal upward about 1.5m where they still exist to this day as a collection of black dots on my ceiling. Glad that it ended that way and not in my eyes or mouth, I've since well warmed up to the necessity of PPE even on such a micro scale.

MrHomeScientist - 6-11-2017 at 11:57

Sodium, especially, illustrates that in chemistry scaling up amounts does not always mean scaling up the reaction at the same rate. Small bits fizzle and occasionally catch fire, but larger pieces explode and can splatter flaming sodium everywhere. Even larger pieces can explode violently, launching the majority of the sodium intact into the air to land who knows where and explode again. See the videos of people throwing sodium into lakes - there are always many explosions after the initial one as bits hop around the lake. Scary!

TheNerdyFarmer - 7-11-2017 at 05:02

I have not had bad experiences particularly with sodium, but with making it. I was using the magnesium oxide aggregate method that nurdrage used. I had a small crucible that I could not find the lid to. Somehow I decided that a large, oblong rock would serve as a good lid. So I stuck it on top and lit up the reaction. Of course, it tipped over sending the flaming mixture onto my fume hood bench. Luckily, the bench was made of a relatively flame retardant so it just left a large char Mark.

Mistake number 1: Rushing into a reaction that I wasn't ready for.
Mistake number 2: Performing a reaction that involved fire and very high temperatures indoors.

I do intend on trying this reaction again except I will be using proper equipment and performing it outdoors.

The Volatile Chemist - 7-11-2017 at 18:50

Quote: Originally posted by owie  
Quote: Originally posted by BromicAcid  
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


LOL that phosphorus story is crazy. Had me laughing and made me realize this is something I never want to do.


Bromic Acid's website, along with Woelen's and AX10whatever his name is (Tim, sorry...)'s websites, are what made me join Sciencemadness. And I got a huge laugh out of his stories, too...definitely told well, they're Max Gergel quality...

wg48 - 9-11-2017 at 09:48

Quote: Originally posted by wg48  
I was experimenting with a microwave oven magnetron on my bench. I was careful to avoid significant microwave exposure. When I moved an earthed piece of metal the back of my little finger come too close to a wire connected to the transformer HT output.
.
Ouch zap, about 2kV between my little finger and my earthed index finger and thumb. I cannot say with certainty, as my brain was overload by the sensory input from my hand but it looked like a draw out an arc to several inches with my little finger as I pulled my hand away very very quickly. The were several burn spots on my little finger and big one on my index finger with a smaller one on my thumb. Initially no pain but the fingers where numb and my hand throbbed a lot. All the finger moved ok. Oh and the strange smell of burnt skin. Fortunately and painfully within an hour or so the sensation had returned to my hand and the burns hurt but not particularly so.

Sorry no pics I seem to have lost them or forgot to save them when I viewed them on my pc. It surprisingly how easy it was for me to forget to avoid that wire when I was preoccupied by the experiment. The outcome could have been much worse. I am getting a bit too elderly to chance shock testing my heart. I will not be experimenting with that set up again until the power supply and connections to the magnetron are fully enclosed.

Ok its a "When physics goes wrong" or perhaps a "call me stupid"


Found one of the pics

files.php.jpg - 11kB

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