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AJKOER
Radically Dubious
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As a kid, I managed to prepare approximately 7 cc of very pure NCl3!
What was unexpected was not the magnitude of explosion as witnessed from 300 meters, but the shockwave at around 50 meters that apparently was strong
enough to knocked someone over.
A good general rule, the power of an explosive follows a cubic rule with respect to weight. So, for example, increasing the weight from 1 mg to 10 mg,
creates an explosion that is roughly a 1,000 times larger then was observed with the 1 mg. Double the weight, eight times, etc.
By the way in comparison to NI3, the latter is a harmless toy in my opinion.
Some advice, avoid accidental formation of NCl3 if you value your body parts.
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Metacelsus
International Hazard
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Location: Boston, MA
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Umm, I though it scaled with respect to the cube root (8x the explosive will produce the same overpressure at twice the distance).
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Amos
International Hazard
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Nitrogen Triiodide. I set some up for a demonstration once and was working on something else outside. It unexpectedly blew up about 15 feet away as it
finished drying, despite being under a heavy plastic dome. The top blew off several yards into the air, and it was scary but totally exhilarating. I
think the cause of initiation may have been a small insect touching it.
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Mailinmypocket
International Hazard
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I prepared some methyl iodide this week, with full safety precautions of course. Still though, that chemical makes me nervous as far as toxicity is
concerned.
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smaerd
International Hazard
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Hm, nothing too crazy for me. Again mostly the fumes/byproducts that are scary.
Well I made some concentrated ammonia solutions by passing anhydrous ammonia gas into aqueas solution also into ethanol for an attempt at
triethylamine. Had a leak, in one of my tubes, was pretty scary for me, nothing compared to the things people do on here hah.
Nitric acid scared me a little due to the fuming and make shift apparatus.
Tosylic acid scared me because I tried to recrystallize it way too hot, and met a nice plume of unexpected HCl gas.Gassing HCl to purify it from
stupid driveway cleaner scared me a bit too, kind of dangerous on the scale I did it on. Since then I have decided to purchase it.
Phenylhydrazine freaked me out a little, nitrous acid and the fumes associated bother me.
Methyl tosylate scared me a little too, but not all that hazardous if handled properly (make shift glove box). Yahoo for low volatility.
At school I had to use ethyl iodide without a fume-hood. Gloved up parafilmed the bottles and dispensed it quickly and carefully. Since then I
recommended putting a scale in the fume-hood...
Yep, pretty much the fumes, nothing else really presents much of a hazard for the things I'm interested in.
[Edited on 16-6-2014 by smaerd]
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woelen
Super Administrator
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Quote: Originally posted by AJKOER  | [...]
A good general rule, the power of an explosive follows a cubic rule with respect to weight. So, for example, increasing the weight from 1 mg to 10 mg,
creates an explosion that is roughly a 1,000 times larger then was observed with the 1 mg. Double the weight, eight times, etc.[...]
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This is nonsense. The impact and energy of the explosion will grow more or less linearly with weight. This is so, simply because the amount of energy
is proportional to the amount of explosive used. Ten times as much of explosive will give ten times as much impact at a given distance. The impact is
inversely proportional to the square of distance. All this is with a spherical charge and a spherical space in which the energy can be dispersed. Of
course, in reality the behavior will be more complicated, but still this is a decent approximation.
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Texium
Administrator
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| Quote: Originally posted by woelen |
This is nonsense. The impact and energy of the explosion will grow more or less linearly with weight. |
It
would have to work like that due to the law of the conservation of energy, right? If 1 gram of a substance would release x amount of energy, then 10
grams of the substance would release 10x amount of energy, as 10 individual grams of the substance would release x amount of energy each, no more, no
less, assuming the reaction is completed in all scenarios.
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alexleyenda
Hazard to Others
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Location: Québec, Canada
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| Quote: Originally posted by zts16 | | Quote: Originally posted by woelen |
This is nonsense. The impact and energy of the explosion will grow more or less linearly with weight. |
It
would have to work like that due to the law of the conservation of energy, right? If 1 gram of a substance would release x amount of energy, then 10
grams of the substance would release 10x amount of energy, as 10 individual grams of the substance would release x amount of energy each, no more, no
less, assuming the reaction is completed in all scenarios. |
It is a way to see it, considering chemical bonds as potential chemical energy locked into the molecules, but this law is more suitable to explain
physics phenomenon in closed systems. A more "chemical" explanation would be that in a chemical reaction, chemical bonds break, then new bonds form.
The energy absorbed to break a bond is always the same for a given bond in a given molecule, and the energy variation when a given bond is created is
also always the same. If you add up the energy for breaking the bond and to create the new ones, you get the overall energy variation, it is usually
measured in Joules (J or KJ) per mole. the bonds are always the same, if you break and recreate 10 times more bonds, you get 10 times more energy (or
absorb if endothermic :p ). More weight = more moles = more energy, it's a linear relation and it's as simple as that.
The only thing related to physics I see which could a bit explain Joker's statement (which remains false anyways) is that when energy is dispersed in
a spheric 3D way, the power decreases in a cubic way because the area covered by the power increases in a cubic way, so the power becomes a lot less
concentrated very fast in comparison with the radius (linear distance from the explosion). The power of small amount of explosive can get "diluted" so
fast that it appears that using a bigger charge is a lot more powerful as it takes more distance ( a bit more than a linear relation) for the power to
be cubic rooted down to the same level.
By the way i'm aware that my level of language in the seconth paragraph probably sucks, explaining physics theories in your seconth language is not
easy :p
[Edited on 23-6-2014 by alexleyenda]
[Edited on 23-6-2014 by alexleyenda]
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woelen
Super Administrator
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| Quote: Originally posted by alexleyenda | [...]
The only thing related to physics I see which could a bit explain Joker's statement (which remains false anyways) is that when energy is dispersed in
a spheric 3D way, the power decreases in a cubic way because the area covered by the power increases in a cubic way, so the power becomes a lot less
concentrated very fast in comparison with the radius (linear distance from the explosion). The power of small amount of explosive can get "diluted" so
fast that it appears that using a bigger charge is a lot more powerful as it takes more distance ( a bit more than a linear relation) for the power to
be cubic rooted down to the same level. |
There are some errors in your last paragraph:
The power is not inversely proportional to the cube of the distance, but to the square of the distance. Assume that power is transmitted as a
spherical shockwave and no power is lost between center of explosion and the distance where the explosion is observed. The power is distributed over a
sphere, whose surface area is proportional to the distance of center of explosion. So, this makes the perceived impact of the explosion inversely
proportional to the square of the distance from the center of explosion. In reality, the exponent will be slightly larger than 2, but much less than
3, due to losses of power (e.g. frictional losses between air molecules while the shock wave travels through the air).
If you do not change the distance from the center of explosion, then the perceived impact will be linearly proportional to the amount of explosive,
provided that the explosion is as fast as with the smaller amount and will have the same percentage of losses.
In reality, the relations will be more complicated, due to losses of energy, due to widening of the shock wave while it travels outwards and due to
different characteristics of explosion for different masses. At a larger distance, the explosive power is not only distributed over a larger surface
area, but it also is distributed over a larger amount of time (widening of shock wave). If all these effects are taken into account, then you get very
complicated relations and understanding all of these requires a lot of physics and advanced mathematics.
[Edited on 23-6-14 by woelen]
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aga
Forum Drunkard
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Inverse square rule.
Power at distance X is inversely proportional to the square of X.
This works for radio wave propagation for example.
A woelen points out, it is hugely more complex for chemical explosions, and will give just an average.
For starters, the explosive may not be a perfect sphere to begin with.
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alexleyenda
Hazard to Others
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You're right woelen, in my head it was a cubic root but I checked and I was wrong, it's a square root :p And yeah of course aga, it is not going to be
a sphere in real life except if it floats in space but I think we are really digging this too deep now, let's keep this to an average rule :p
[Edited on 24-6-2014 by alexleyenda]
Help us build the Sciencemadness Wiki! Every question and tips about amateur chemistry two clicks away, wouldn't that be awesome?!
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froot
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Location: South Africa
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| Quote: | | As a kid, I managed to prepare approximately 7 cc of very pure NCl3! |
That statement is the topic clincher for me.
And perhaps why you're still here with us is because you did an excellent job of making a high purity product - thankfully! If I were you the
recollection of the deed would give me shivers for the rest of my life. I wonder if your parents know how close they came to losing you. No matter how
thorough your synthesis procedure was you can still consider yourself very lucky.
So many kids tried daring stunts like this and never made it to the other side.
We salute the improvement of the human genome by honoring those who remove themselves from it.
Of necessity, this honor is generally bestowed posthumously. - www.darwinawards.com |
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ave369
Eastern European Lady of Mad Science
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Of the stable, storable kind - chromium trioxide, sitting now in a small glass jar on a shelf. Of the unstable, unstorable kind - manganese heptoxide.
And I've heard about a reported experiment when a small amount of FeO3 was stabilized in Et2O during the acid decomposition of a ferrate. I want to
continue the line and perform this experiment during my next ferrate frenzy.
[Edited on 9-12-2015 by ave369]
Smells like ammonia....
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Praxichys
International Hazard
Posts: 1063
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Location: Detroit, Michigan, USA
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Recently, ketene. It plays with the big boys -
(IDLH values from NIOSH)
Carbon monoxide: 1200ppm
Hydrogen cyanide: 50ppm
Phosgene: 2ppm
Ketene: 5ppm
https://www.youtube.com/watch?v=g9sPlMkYEIw
The sinister part is that it's not irritating and it doesn't really have a noticeable smell, especially when there's lots of acetic acid laying about.
You'll know you got dosed 6-12 hours later when you enter severe pulmonary edema.
Mice recieved pulmonary damage at 1ppm for 7h. 7/10 died when exposed to 23ppm for 30 minutes. Monkeys exposed to 200ppm for 10 minutes died almost 8
hours later. Three mice exposed to 122ppm for 10 minutes died after 3 days.
Scary stuff.
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karlos³
International Hazard
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I am not into energetic materials, but NI3 was synthesised on many occasions, to faciliate amide synthesis from aldehydes. I don´t consider it as
very scary, but I´ve only worked with it in solution. I know how sensitive it is in dried form.
I don´t consider that the scariest chemical I´ve ever synthesised.
I guess HCN from self prepared NaCN was for me one of the most scariest. Also, to find out that one can smell it, and then, surprisingly not anymore
(during distillation of the acid), that was not pleasant to find out my sense of smell got numbed :-D
I´ve used a good portion of KSCN and sodium thiosulfate, consumed in capsules as safety measurement beforehand(it was not a small quantity of HCN I
was distilling), and had some butyl nitrite around as instant antidote. Not needed luckily.
But for the most dangerous chemicals I´ve ever worked with and synthesised, they are probably mercury salts.
Also i´ve made oxidation agents which are not considered healthy... I mean, pyridine is not really healthy, but PCC for itself?
Chemicals I´ve never synthesised but instead purchased straight to work with, there are many, many more which are probably a lot more dangerous.
Like NaN3, (COCl)2, alkali metal derivatives like their hydrides, and of course chromine compounds.
Oh, not to forget those nasty halogenating agents, like alkylhalogenides, I´ve worked with many of those...
What I would not touch with a ten foot pole, are HF, fluoride salts and sulfate esters like Me2SO4.
Also phosgene and ketene.
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BromicAcid
International Hazard
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In retrospect acryloyl azide was some pretty nasty stuff.
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phlogiston
International Hazard
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On purpose?
That must have consumed all of your karma points for you to have survived.
-----
"If a rocket goes up, who cares where it comes down, that's not my concern said Wernher von Braun" - Tom Lehrer |
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chemrox
International Hazard
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Knaus opiate w-18. It went into a ball mill with 1 lb of mannitol. Don't do this-recovery was a bitch!
"When you let the dumbasses vote you end up with populism followed by autocracy and getting back is a bitch." Plato (sort of)
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aga
Forum Drunkard
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Erm, a cloud (literally) of HCl gas.
Maybe the chromates were worse, although they didn't threaten to engulf a neighbour's house, so 'Most Dangerous' really depends on the consequences.
Time for a sig change.
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The Volatile Chemist
International Hazard
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HCl isn't that great...I definitely want stuff that isn't yellow from iron (It's useless except for chlorination of alcohols...). Any suggestions on
purification?
Scariest probably was getting a half-lung of chlorine gas, and dealing with a chlorine generator making way too much chlorine in the basement (2 years
ago I didn't plan ahead...not really something to be proud of.)
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Amos
International Hazard
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| Quote: Originally posted by The Volatile Chemist | HCl isn't that great...I definitely want stuff that isn't yellow from iron (It's useless except for chlorination of alcohols...). Any suggestions on
purification?
Scariest probably was getting a half-lung of chlorine gas, and dealing with a chlorine generator making way too much chlorine in the basement (2 years
ago I didn't plan ahead...not really something to be proud of.) |
Useless for anything except for chlorination of alcohols? How about generally acidifying things, making metal chlorides, etc? The iron content is
quite low even in the hardware grade stuff. Fe(III) is just a very potent colorant in solution. As for iron contamination in general, check Lowe's.
The new brand of HCl they stock, at least in all of my city's locations, is water-clear.
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Sakomekieh
Harmless
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When i was 10 i made a lot of chlorine gas and reacted with various substances that i got(Aluminium, Iron, paper, red phosphorus), but thank god
nothing bad happened.
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fluorescence
Hazard to Others
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Most dangerous Compound ... good question.
- I work with a lot of Cyanides so HCN is something really common in my lab and always present in small quantities.
- Arsenic Compounds: I pulverized some Arsenic and boiled it in Nitric Acid and tried to dry the Acid into the Arsenic Oxide.
- Like the others Bromine and Chlorine
- Chromylchloride and Chromylfluoride
- HF
- Dimanganeseheptoxide
- White Phosphorus
- Various Chromium(VI) Compounds
That's pretty much it. Worked with some highly toxic compounds, too but never made them myself.
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JJay
International Hazard
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Most dangerous? Elemental bromine, although I will say that diethyl sulfate sure does smell nice....
Right now I am doing the final distillation of a nice batch of benzene, which seems to be regarded as some sort of unholy abomination by everyone who
has seen my setup, but I don't think it's that bad compared to everything else people in industrialized nations get exposed to on a regular basis.
[Edited on 13-12-2015 by JJay]
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The Volatile Chemist
International Hazard
Posts: 1981
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Location: 'Stil' in the lab...
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| Quote: Originally posted by Amos | | Quote: Originally posted by The Volatile Chemist | HCl isn't that great...I definitely want stuff that isn't yellow from iron (It's useless except for chlorination of alcohols...). Any suggestions on
purification?
Scariest probably was getting a half-lung of chlorine gas, and dealing with a chlorine generator making way too much chlorine in the basement (2 years
ago I didn't plan ahead...not really something to be proud of.) |
Useless for anything except for chlorination of alcohols? How about generally acidifying things, making metal chlorides, etc? The iron content is
quite low even in the hardware grade stuff. Fe(III) is just a very potent colorant in solution. As for iron contamination in general, check Lowe's.
The new brand of HCl they stock, at least in all of my city's locations, is water-clear. |
OK, for generally acidifying things and cleaning stuff.  I wouldn't say for
making metal chlorides, though. It's so dirty...the stuff is almost as yellow as dilute dichromate solution...comes out of the container clear, but
turns yellow on standing or combining with basically anything. Perhaps I should look into it, though, as it's basically sitting there. I'll do
something with it tonight, look into what the impurities are...
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