UnintentionalChaos
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Things learned in the lab
If you're anything like me, when you're messing around in your lab, you get some weird, unexpected result and end up going on a literature chase to
try to explain it....or you found something after a long literature search and it turns out to be not so valid when you try it. Let's hear a few of
yours.
Two of mine:
Any reference in the literature to antimony being attacked by hot, concentrated HCl is a load. Maybe if you're working with ultra fine powder, but 40
minutes of reflux didn't notably change crushed antimony about the texture of coarse sand.
While using Na2S2O5 to reduce MnO2 in solution, I started getting a coarse gray ppt about the texture of sand that turned my beaker of liquid into
paste. Well, it turns out that I'd unintentionally made gravegliaite, the trihydrate of manganous sulfite.
http://rruff.geo.arizona.edu/doclib/zk/vol197/ZK197_97.pdf
The solution is to start chucking in concentrated acid to displace the sulfite anion, which it does fairly readily.
Department of Redundancy Department - Now with paperwork!
'In organic synthesis, we call decomposition products "crap", however this is not a IUPAC approved nomenclature.' -Nicodem
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Sedit
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Good Idea for a thread UC since more often then not the greatest joy of chemistry to to stumble on something you just didn't expect.
One of mine would have to be the extremely low temperatures that Snow and HCl mixture reaches. I was just messing around with various salts
like NaCl and what not to see what kind of temperatures I could achieve when I decided to add HCl to snow and was completely shocked (and frozen ) when the cup I held in my hand quickly dropped to -48degrees F . I surely did not expect this and a quick literature search showed that others
performed this experiment many moons ago achieving simular results. I think the 15 inches or more of snow outside means I may revive the experimenting
on this tommorow matter of fact.
Knowledge is useless to useless people...
"I see a lot of patterns in our behavior as a nation that parallel a lot of other historical processes. The fall of Rome, the fall of Germany — the
fall of the ruling country, the people who think they can do whatever they want without anybody else's consent. I've seen this story
before."~Maynard James Keenan
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UnintentionalChaos
International Hazard
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Quote: Originally posted by Sedit  | Good Idea for a thread UC since more often then not the greatest joy of chemistry to to stumble on something you just didn't expect.
One of mine would have to be the extremely low temperatures that Snow and HCl mixture reaches. I was just messing around with various salts
like NaCl and what not to see what kind of temperatures I could achieve when I decided to add HCl to snow and was completely shocked (and frozen) when the cup I held in my hand quickly dropped to -48degrees F. I surely did not expect this and a quick literature search showed that others
performed this experiment many moons ago achieving simular results. I think the 15 inches or more of snow outside means I may revive the experimenting
on this tommorow matter of fact. |
Thanks for reminding me....I have tons of fluffy snow, a -20C freezer, and a 10lb pail of MgCl2*6H2O...and an ultra low temp thermometer to measure it
with. I'm storing it in the -20C freezer because room temperature is at the very top end of the thing and I dont need it to overheat.
[Edited on 12-20-09 by UnintentionalChaos]
Department of Redundancy Department - Now with paperwork!
'In organic synthesis, we call decomposition products "crap", however this is not a IUPAC approved nomenclature.' -Nicodem
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The_Davster
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| Quote: Originally posted by UnintentionalChaos |
Two of mine:
Any reference in the literature to antimony being attacked by hot, concentrated HCl is a load. Maybe if you're working with ultra fine powder, but 40
minutes of reflux didn't notably change crushed antimony about the texture of coarse sand.
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Sorry to have to say this, but it does dissolve in HCl, and indeed it does require very finely divided antimony. A bit of the powder will even
dissolve overnight in room temperature conc. HCl.
I was making a series of tungsten alkoxides from tungsten hexachloride and alcohols and upon trying it with a phenol realized that the colour of the
product changes depending on whether an alcohol or phenol is reacting with it. A neat little indicator discovery. Never found anything in the
literature about it...
Some of you may remember my old thread where I found out the hard way that unlike dilute acid and aqueous hypochlorite, conc. sulfuric and solid
hypochlorite does not make chlorine, it makes chlorine dioxide... (The scar has
finally gone! )
[Edited on 20-12-09 by The_Davster]
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crazyboy
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A while ago I learned about passivation, , it turns out just upping the concentration of acid doesn't always help attack the metal, sometimes it makes
it harder. I knew about passivation before but I had never actually experienced it. A bit counter intuitive that dilute acids would attack metals less
than highly concentrated ones but it's true.
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len1
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Mood: NZ 1 (goal) - Italy 1 (dive)
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| Quote: Originally posted by Sedit | Good Idea for a thread UC since more often then not the greatest joy of chemistry to to stumble on something you just didn't expect.
One of mine would have to be the extremely low temperatures that Snow and HCl mixture reaches. I was just messing around with various salts
like NaCl and what not to see what kind of temperatures I could achieve when I decided to add HCl to snow and was completely shocked (and frozen) when the cup I held in my hand quickly dropped to -48degrees F. I surely did not expect this and a quick literature search showed that others
performed this experiment many moons ago achieving simular results. I think the 15 inches or more of snow outside means I may revive the experimenting
on this tommorow matter of fact. |
This is very interesting - I didnt know. Ive read about HNO3 and ice - but that is wasetful as HNO3 is expensive, and is needed concentrated for most
purposes. Not so HCl.
Can you please provide more info. What were the initial snow and HCl temperatures, what ratio did you use?
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