6dthjd1
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On the heating of Arsenic in H2SO4
For the past two hours I have 107 g of Arsenic rock in 114 ml of Rooto Sulfuric acid
So far barely any acid seems to be consumed. Although dropping the Arsenic in the H2SO4 did result in white swirls within 10 minutes and within 1 hr
the solution went dark.
The hotplate used is a 120 volt 8 amp hotplate stirrer combo. The heat is set to high with no covering used to shield the beaker (I would usually use
aluminum foil). There is evolution of SO2 and some bubbling does exist. As the acid has receded a white film appears on the beaker. This hotplate
barely is able to boil water even with a shield IIRC.
I estimate I will have a low yield of arsenic trioxide. Perhaps I shall dissolve the remnants in 70% nitric acid and heat at around 100 C to get the
trioxide.
It very much does seem that heating sulfuric acid and arsenic may result in an appreciable quantity of some white arsenic compound by only with great
patience.
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Texium
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Going into arsenic chemistry on a 100 gram scale with seemingly no reference or plan is a really bad idea…
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clearly_not_atara
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Use a real oxidizer you suicidal maniac
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6dthjd1
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The reaction with nitric is a bit more vigorous and would still require heating to form the trioxide. The late and post 19th century literature
prefers the use of nitric for oxidizing elemental arsenic though some of the 19th century literature also mentions this as well. Some of this
literature exists in the sciencemadness library.
Care must be taken not to heat too vigorously as sublimation of the trioxide is a real possibility. Also it goes without saying doing this inside in
unventilated places is a no no.
I should note formation of the trioxide by even more dangerous processes such as heating auripigmentum or burning arsenic in air were done by
alchemists and early chemists with little ventilation. In some of this literature they were mostly concerned with ingestion of arsenic. They
unfortunately did not do anything outside on windy days and maintaining fires outside on windy days would be a chore using old technology.
My review of the literature over the years suggests that many of the group 15 elements react slowly or very slowly with concentrated sulphuric acid.
Like antimony.
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Admagistr
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I wonder how old these ancient chemists and alchemists lived?How old did they die.Take care of yourself,make sure you are here for a long time,so you
can do many more interesting experiments!You can get partial immunity to arsenic.But they say it can cause cancer...Are you planning experiments with
other risky elements?
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andyloris
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How are you going to dispose of the waste ?
Always trust your first idea, especially if you only have one.
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Rainwater
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Chemistry without a plan, is like a racecar without a track. Hes got to have one, just not saying what it is.
I had no trouble, accidentally bringing almost 20g of arsenic ore into solution with aqua regia once.
Nice colors. Scary situation.
https://www.sciencemadness.org/whisper/viewthread.php?tid=15...
[Edited on 7-11-2023 by Rainwater]
"You can't do that" - challenge accepted
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RU_KLO
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Quote: Originally posted by 6dthjd1 |
My review of the literature over the years suggests that many of the group 15 elements react slowly or very slowly with concentrated sulphuric acid.
Like antimony.
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This is not my experience with antimony. OK, I worked with 10 mgr. (hand filed from pure antimony metal in 2 cm3 of 98% H2SO4 in a test tube. it
disolved compleatly on heating in 30 minutes)
Maybe you could speed your reaction by grinding/pulverizing the rock.
Also I read a lot of 19th century books, it seems that "safety and responsible practices" where not an issue. For example they use mercury and lead as
they where as safe as sodium bicarbonate.....
Go SAFE, because stupidity and bad Luck exist.
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woelen
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@6dthjd1: If I read your posts, then it really raises my concerns. If you had white 'frost' on your beaker and near your beaker, then some arsenic
trioxode may have escaped. If the solution bubbled with SO2, then the bubbles of SO2 also may have taken with them small droplets, containing
dissolved arsenious compounds. Did you smell the SO2 (it has quite a pungent smell, somewhat reminiscent of burning matches)? If so, then you also may
have inhaled some arsenic compounds with it!
Your experiments sound like sollicitating for health issues. Keep in mind that arsenic is both an acute poison and a long-term poison.
I never would do this kind of experiments on a large 100 g scale. I do not say that you should not do this kind of experiments (I myself also did some
small-scale experiments with arsenic compounds), but keep things small (100's of milligrams) and keep things confined to liquids. No bubbling of gases
from these toxic liquids should occur, unless you are really sure that you do not inhale anything from the produced gases. Waste also must be
processed correctly. With your scale of experimenting you also produce quite some really nasty toxic waste, which must be safely disposed of.
[Edited on 8-11-23 by woelen]
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6dthjd1
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Quote: Originally posted by woelen | @6dthjd1: If I read your posts, then it really raises my concerns. If you had white 'frost' on your beaker and near your beaker, then some arsenic
trioxode may have escaped. If the solution bubbled with SO2, then the bubbles of SO2 also may have taken with them small droplets, containing
dissolved arsenious compounds. Did you smell the SO2 (it has quite a pungent smell, somewhat reminiscent of burning matches)? If so, then you also may
have inhaled some arsenic compounds with it!
Your experiments sound like sollicitating for health issues. Keep in mind that arsenic is both an acute poison and a long-term poison.
I never would do this kind of experiments on a large 100 g scale. I do not say that you should not do this kind of experiments (I myself also did some
small-scale experiments with arsenic compounds), but keep things small (100's of milligrams) and keep things confined to liquids. No bubbling of gases
from these toxic liquids should occur, unless you are really sure that you do not inhale anything from the produced gases. Waste also must be
processed correctly. With your scale of experimenting you also produce quite some really nasty toxic waste, which must be safely disposed of.
[Edited on 8-11-23 by woelen] |
I did catch a few wiffs of sulfur dioxide. I worked hard to stay more than 6 feet away from the setup as much as possible.
I did this outside. It was one of this windy months in the Great Lakes. wind speeds exceed appx 20km/h at times.
I'm too scared to do this inside
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6dthjd1
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Quote: Originally posted by Admagistr | I wonder how old these ancient chemists and alchemists lived?How old did they die.Take care of yourself,make sure you are here for a long time,so you
can do many more interesting experiments!You can get partial immunity to arsenic.But they say it can cause cancer...Are you planning experiments with
other risky elements? |
Some of them died in their 60s like most people then who lived to see 20.
Others like Scheele died in their 30s or 40s. Scheele ate at lot of his chemicals over time. It was known that many apothecaries did die in his day.
Makes sense if you are going to taste the butter of arsenic and more
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6dthjd1
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Quote: Originally posted by RU_KLO | Quote: Originally posted by 6dthjd1 |
My review of the literature over the years suggests that many of the group 15 elements react slowly or very slowly with concentrated sulphuric acid.
Like antimony.
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This is not my experience with antimony. OK, I worked with 10 mgr. (hand filed from pure antimony metal in 2 cm3 of 98% H2SO4 in a test tube. it
disolved compleatly on heating in 30 minutes)
Maybe you could speed your reaction by grinding/pulverizing the rock.
Also I read a lot of 19th century books, it seems that "safety and responsible practices" where not an issue. For example they use mercury and lead as
they where as safe as sodium bicarbonate..... |
When Robert Bunsen first worked with Cacodyl derivatives he would pass out from the acute toxicitiy imminently
It was so bad he had to breathe through a tube which projected from the window.
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6dthjd1
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Eventually i may use the trioxide to heat with anhydrous copper (ii) sulfate and sodium chloride to generate Arsenic trichloride in a manner similar
to how Glauber did it.
I will likely acquire different glassware and use a charcoal fire to do so. I know Newton's method of generating sulfuric acid using virtriol as
repeated by modern chemists resulted in the deformation of glass
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Rainwater
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Crazy hard to work with in a professional environment.
In the states, it's labled as "extremely hazardous substance" and requires permits to produce/store/use in any amounts.
The only legitimate purpose for this compound I know of is the purification of arsenic for use in semiconductors.
"You can't do that" - challenge accepted
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woelen
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Making AsCl3 in a home-setting, while I read this in the "beginnings" subforum??? Don't do this!
AsCl3 is volatile and very reactive. Even professional labs shy away from using this. Keeping it contained and avoiding exposure is nearly impossible
due to its properties. The only safe way of storing it is in a completely sealed glass ampoule, and once you break it to do something with it, you put
yourself at great risk. Making this stuff in or around your home is even more dangerous.
You inhaled some of the SO2, possibly contaminated with arsenic compounds. This already demonstrates how difficult it is to get not exposed. With the
SO2 mixed in, you at least know that you might have been exposed to arsenic compounds, but in many experiments you will not have such a
warning-compound besides the arsenic.
My advice: quit this endeavor, there are better ways to fill your time.
[Edited on 9-11-23 by woelen]
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B(a)P
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If you are going to embark on the synthesis of arsenic trichloride, you should know that it adsorbs through most types of PPE, it can not be detected
by smell until you are exposed at a concentration that is doing serious damage to your body. A half or full faced respirator will not provide you
adequate protection.
I once worked on the clean up of an old chemical warfare facility and arsenic trichloride was one of the contaminants. We were working outside in a
well ventilated area. Despite this we still needed to be in fully enclosed suits with supplied air. This is not something that is possible to do
safely in the home chemistry environment.
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Texium
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Do not even think of posting about making arsenic trichloride. I can assure you it will immediately be sent to Detritus and you may be banned.
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clearly_not_atara
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The two safest ways I can think of to do this are:
- bubble ozone through the sulfuric acid with a cooling bath
- anodic oxidation in KOH solution to the arsenite
Thermal oxidation ain't it.
But even then, it's sort of like asking the safest way to go over Niagra Falls in a barrel. Think carefully about whether you want to risk a
potentially permanent injury to mess with the king of poisons.
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Bedlasky
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Quote: Originally posted by clearly_not_atara | The two safest ways I can think of to do this are:
- bubble ozone through the sulfuric acid with a cooling bath
- anodic oxidation in KOH solution to the arsenite |
I think that nitric acid is probably the safest and easiest way of doing it. However after reading 6dthjd1's posts, I strongly recommended him to
abandon this stupid idea. Working with arsenic require experience and very good safety precautions.
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Rainwater
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Lookup David Hahn, Robert Oppenheimer, Marie Curie,Harold Maxwell, Louis Slotin, Karen Wetterhahn.
Their research should help you with your experment.
"You can't do that" - challenge accepted
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clearly_not_atara
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Quote: Originally posted by Bedlasky | Quote: Originally posted by clearly_not_atara | The two safest ways I can think of to do this are:
- bubble ozone through the sulfuric acid with a cooling bath
- anodic oxidation in KOH solution to the arsenite |
I think that nitric acid is probably the safest and easiest way of doing it. However after reading 6dthjd1's posts, I strongly recommended him to
abandon this stupid idea. Working with arsenic require experience and very good safety precautions. |
I would expect ozone to work at lower temperatures than nitric acid and for oxidation in sodium hydroxide to produce the least volatilization of any
method. Why would you prefer nitric acid?
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Bedlasky
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Oxidation by nitric acid is relatively quick. You must bubble ozone through solution for prolonged time, because its inefficient generation from the
air. Electrolysis also needs to be run for long time. So even though volatilization of arsenic is less significant than with nitric acid method, you
create arsenic containing aerosols for longer.
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j_sum1
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This just seems like a disaster on so many fronts.
The scale is ridiculous.
As is seriously nasty and unforgiving.
The required level of knowledge and skill just isn't there.
Numerous chemists better than me have itemised specific risks, which are just frightening.
And, thus far, there has not been any thought given to waste and disposal.
Time to just drop this fool's errand.
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6dthjd1
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Quote: Originally posted by clearly_not_atara | Quote: Originally posted by Bedlasky | Quote: Originally posted by clearly_not_atara | The two safest ways I can think of to do this are:
- bubble ozone through the sulfuric acid with a cooling bath
- anodic oxidation in KOH solution to the arsenite |
I think that nitric acid is probably the safest and easiest way of doing it. However after reading 6dthjd1's posts, I strongly recommended him to
abandon this stupid idea. Working with arsenic require experience and very good safety precautions. |
I would expect ozone to work at lower temperatures than nitric acid and for oxidation in sodium hydroxide to produce the least volatilization of any
method. Why would you prefer nitric acid? |
I prefer nitric for greater certainty. The nitric acid comes up more consistently across 19th and 20th century literature at least from what I have
seen since 2011. I also happen to have around 600 ml of it at the moment as reagent grade ACS purity and it's more convenient for me to make more
nitric of an inferior purity if need be.
The nitric acid method isn't incompatible with the final waste product which will be a calcium arsenite which is insoluble in water. (Sodium
hydroxide dissolves residues to form sodium arsenite/nitrate in a container dedicated to arsenic which will then be charged with calcium chloride to
form calcium arsenite).
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