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Author: Subject: Hydrofluoric Acid experiments
FatihTaskiran
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[*] posted on 6-4-2006 at 01:06


oguz I have already tried it but I don't would lıke to decompose h2so4 and hf I would lıke to purify them because we use these acids and we neutralıze naoh (%48)
thank you very much your help
if you find what I said, can you call me? you know I said if there are some company whıch they use thıs mixture we can sell ok see you soon byee
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atabilgin
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[*] posted on 6-4-2006 at 13:04


hi! mr.taskiran
if I find I will call you. ( can you speak turkish?)
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FatihTaskiran
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[*] posted on 10-4-2006 at 22:19


how are you my frıend?
Is there any news for me? I try to fınd somewhere whıch using that mıxed.
see you later byee
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Madandcrazy
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[*] posted on 19-4-2006 at 08:18


Eventually a good method beside the acid method ;) is when a NaF/H2O mix is in a big glas beaker treated per electrolysis with two carbide electrodes and a stong DC-Power Supply to get flourin and dilute HF.
The dilute acid can easy filtered off or the fluorine gas is bubbled through a nextbeaker with H2O.

[Edited on 19-4-2006 by Madandcrazy]
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woelen
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[*] posted on 19-4-2006 at 09:31


What you tell is not true. Fluorine cannot be made from aqueous solution. Fluorine immediately reacts with water, giving HF and oxygen. Fluorine can only be obtained from molten fluorides or from solutions of fluoride-salts in liquid HF.

What you tell can indeed be done with chlorine, made from dilute HCl. But for chlorine there are other faster methods of preparation.




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[*] posted on 19-4-2006 at 12:35


If it is going right, I will at some point in the future present a non- electrochemical method to make fluorine, relying on the thermal decomposition of tripotassium-monohydro-ortho-fluoroplumbate.
This compound contains lead(IV), and on strong heating, it decomposes into lead(II)compound under release of fluorine.
I already have the method for synthesizing this compound.

One needs a lot of concentrated HF solution (40%) for its preparation. It will put my bottle of HF to very good use.




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[*] posted on 19-4-2006 at 13:42


There is another method of making fluorine without the need of electrolysis. This is by formation of K2MnF6, which easily decomposes, giving KF, MnF3 and F2. This compound K2MnF6 can be formed by mixing KMnO4, HF and SbF5. Especially the latter is not an easily obtained chemical, but I mention this just as a curiousity.



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[*] posted on 12-5-2006 at 09:00


Hi All:

This is my first post to your group. You are a lot of fun. However, you have greatly discouraged me from experimenting with a practical use of F gas to create a barrier inside my bike's HPDE gas tank.

I know it is widely used because of this website:
http://www.fluoroseal.com/

However, they want to charge me $350 minimum and that is to cover 100 tanks. But I guess my life is worth that much.

Joe
Buckley, WA
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[*] posted on 14-5-2006 at 00:39


How actually is Fluorine gas made? and what are it's properties?
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[*] posted on 14-5-2006 at 03:38


Electrolysis of KF + HF in a copper apparatus is pretty common. Some salts can be heated, also (CoF3 isn't particularly stable IIRC).

Properties? Yellowish, slightly heavier than air, reactive as FUCK... :P

Tim




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[*] posted on 14-5-2006 at 04:20


I'm starting to wonder how reactive it really is. Chlorine is also reactive as fuck (not FUCK but fuck) but when I dropped shards of freshly ploished metals into stoppered flasks with chlorine gas in the most of the metals did not react very hard.
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[*] posted on 14-5-2006 at 06:28


Chlorine isn't nearly as reactive as fluorine. Just look at the electronegativities: F is 4.0, while Cl is only ~3.1. Even oxygen is 3.5.

Chlorine will react with metals, but not as easily as fluorine. Chlorine can be stored in a stainless steel tank without problem. Fluorine, on the other hand, will ignite glass. :o Controlled chlorination reactions are possible, but fluorination...well, that doesn't work so well.

To sum it up, chlorine isn't anywhere near as reactive as fluorine. Few things are, for that matter.

[Edited on 14-5-2006 by neutrino]




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[*] posted on 14-5-2006 at 09:53


Chlorine is a children's toy compared to chlorine. If you would call fluorine just 'reactive', then I would call chlorine 'inert'.



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[*] posted on 15-5-2006 at 05:59


Didn't read the whole thread, anyways 1 part calcium gluconate 1 part sterile saline mixed, giving 5% calcium gluconate should be kept handy when working with HF, also a sharp knife/scalpel so that you can split the nail in case HF gets under the nail then apply the calcium gluconate saline on the flesh, this must be done fast and without hesitation...

I'm not sure what materials can take it, but following is synthesis of fluoroboric acid

Ethereal fluoboric acid can be prepared as follows: 19 ml. (19 g., 0.95 mole) of anhydrous hydrofluoric acid, b.p. 19.4° (760 mm.) is added in small portions with shaking or stirring to 126 ml. (142 g., 1.00 mole) of distilled boron trifluoride etherate, b.p. 126° (760 mm.), contained in a 500-ml. polyethylene flask that is cooled in an ice bath to 0°. The concentration of the resulting yellowish solution of fluoboric acid in ether is about 52% by weight (ca. 6.6 moles per l.).


"Whilst sitting at a fume cupboard processing mineral samples a laboratory technician knocked approximately 100 mls of hydrofluoric acid onto his thighs. Immediate 10% body burns ensued. Despite rapid flushing with water and emergency hospitalisation he died 15 days later. "

http://www.safetyline.wa.gov.au/pagebin/pg001383.htm

[Edited on 15-5-2006 by Sandmeyer]
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[*] posted on 28-8-2006 at 19:01


I have used a product called "whink rust stain remover" to remove iron stains
from clothing, made of 2 - 3% hydrofluoric acid. I did not heed the precautions
"causes burns which do not heal and may not be immediately painful or visible"
and I carelessly applied it without concern. Not thinking , with my finger wet
with the cleaner, I rubbed my forehead to scratch myself between my brows.
It's twelve years later and I still have the same slightly reddish skin blotch
which later developed. The fluorine combines with the calcium electrolyte of
your skin cells and remains embedded there as calcite. The prospect of
whiffing this into your lungs should make you think hard on what precautions
to take. See MSDS -> http://www.whink.com/msdsrr.pdf

[Edited on 29-8-2006 by franklyn]
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[*] posted on 28-8-2006 at 21:01


Quote:
... The fluorine combines with the calcium electrolyte of
your skin cells and remains embedded there as calcite. The prospect of whiffing this into your lungs should make you think hard on what precautions to take. See MSDS -> http://www.whink.com/msdsrr.pdf


Fluorite or fluorspar, CaF2, note calcite. Otherwise, I agree - be carefull around F2, HF (well, HnFn), metal fluorides where the metal is in a higher oxidation state, and any fluorides that react with water (HF again).

Another have-at-hand first aid for HF accidents was/is a mix of MgO and CaCO3, wet with CaCl2 solution. Same general idea, convert HF to an insoluble fluoride - Mg and Ca, mop up any other acid around.

A test for fluorine, used to see if it was being generated or not all reacting, was to put a bit of elemental silicon into the gas stream, the Si ignites if there is much fluorine there. There are better and safer tests than this.
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[*] posted on 28-8-2006 at 22:37


Franklyn, that sounds really nasty. Just a 2 .. 3% solution of HF, which does this nasty thing. I warned about playing with fluorides, but this is even nastier than I expected.

I have quite some NaF, but I'm VERY careful with that. The salt itself is not that dangerous, but any acid may release HF, even weak organic acids. HF itself also is a weak acid, so it is easily released.

I also noticed, that solutions of NaF do attack glass, albeit very slowly. The glass becomes somewhat milky and cannot be made fully clear again. This is an indication of hydrolysis of F(-) ions to HF, which in turn attacks the glass. So, I do not do experiments with NaF in new test tubes, I use the ones, which are somewhat spoiled anyway.




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[*] posted on 31-8-2006 at 21:31


http://www.sciencemadness.org/talk/viewthread.php?tid=6261#p...

Hydrofluoric Acid
All forms - dilute or concentrated solutions or the vapor - of hydrofluoric acid (HF) cause severe
burns. Inhalation of anhydrous HF or HF mist or vapors can cause severe respiratory tract
irritation that may be fatal. Death from pulmonary edema occurred within 2 hours in three of six
workers splashed with 70% HF solution despite prompt showering with water. Anhydrous HF is a
clear, colorless liquid that boils at 19.5o C. Because of its low boiling point and high vapor
pressure, anhydrous HF must be stored in pressure containers. A 70% aqueous solution is a
common form of HF. Hydrofluoric acid is miscible with water in all proportions and forms an
azeotrope (38.3% HF) that boils at 112o C. Anhydrous or concentrated aqueous HF causes
immediate and serious burns to any part of the body. Dilute solutions (<30%) and gaseous HF are
also harmful, although several hours may pass before redness or a burning sensation is noticed.
These burns may still by quite severe and progressively damaging to the skin and deeper tissues.
"Undissociated HF readily penetrates skin and deep tissue where the corrosive fluoride ion can
cause necrosis of soft tissues and decalcification of bone; the destruction produced is
excruciatingly painful. Fluoride ion also attacks enzymes (e.g. of glycolysis) and cell membranes.
The process of tissue destruction and neutralization of the hydrofluoric acid is prolonged for days,
unlike other acids that are rapidly neutralized. Because of the insidious manner of penetration, a
relatively mild or minor exposure can cause a serious burn" [Proctor, N. H.; Hughes, J. P.;
Fischman, M. L. Chemical Hazards of the Workplace, J. B. Lippincott Co., Philadelphia, 1988,
p.279]. Occasionally workers fail to recognize the importance of seeking medical attention for HF
before pain commences. By the time the victim is affected with progressively deep and more
painful throbbing and burning, serious damage may have taken place. Exposures under
fingernails can be a particularly painful problem if ignored. Wearing clothing (including leather
shoes and gloves) that has absorbed small amounts of HF can result in serious delayed effects
such as painful slow-healing skin ulcers.
When handling HF, it is crucial to ensure adequate ventilation by working only in a hood so that
safe levels (3 ppm) are not exceeded. All contact of the vapor of the liquid with eyes, skin,
respiratory system, or digestive system must be avoided by using protective equipment such as a
face shield and neoprene or polyvinyl chloride gloves. The protective equipment should be
washed after each use to remove any HF on it. Safety showers and eyewash fountains should be
nearby. Anyone working with HF should have received prior instructions about its hazards and in
proper protective measures and should know the recommended procedure for treatment in the
event of exposure (Reinhardt, C.F> et al.; Am. Ind. Hyg. Assn. J., 1966, 27, 166.)
Spills and leaks - The vapors of both anhydrous HF and aqueous 70% HF produce visible fumes
if they contact moist air. This characteristic can be useful in detecting leaks but cannot be relied
on because of atmospheric variations. Spills of HF must be treated immediately to minimize the
dangers of vapor inhalation, body contact, corrosion of equipment, and possible generation of
hazardous gases. Spills should be contained and diluted with water. The resulting solution should
be neutralized with lime before disposal.
Waste disposal - Waste HF should be slowly added to a larger volume of a stirred solution of
slaked lime to precipitate calcium fluoride, which is chemically inert and poses little toxic hazard
(sodium fluoride is highly soluble and toxic). Alternatively, hydrofluoric acid can be diluted to
about 2% concentration with cold water in a polyethylene vessel, neutralized with aqueous
sodium hydroxide, and treated with excess calcium chloride solution to precipitate calcium
fluoride.
In the event of exposure - Anyone who knows or even suspects that he or she has come into direct
contact with HF should immediately flush the exposed area with large quantities of cool water.
Exposed clothing should be removed as quickly as possible while flushing. Medical attention
should be obtained promptly, even if the injury appears slight. On the way to the physician, the
burned area should be immersed in a mixture of ice and water. If immersion is impractical, a
compress made by inserting ice cubes between layers of gauze should be used. Make sure that the
physician understands that the injury was cause by HF and requires treatment very different from
other acid burns. Even in the case of very small exposure, washing alone may not be sufficient to
completely prevent injury. For minor exposures such as small hole in glove, application of a
calcium glutaconate antidote gel can bind free fluoride ion not removed by washing.
If HF liquid or vapor has contacted the eyes, these organs should be flushed with large quantities
of clean water while the eyelids are held apart. This flushing should be continued for 15 minutes.
Medical attention should be obtained promptly.
Anyone who has inhaled HF vapor should be removed immediately to an uncontaminated
atmosphere and kept warm. Medical help should be obtained promptly. Anyone who has ingested
HF should drink a large quantity of water as quickly as possible. Do not induce vomiting. Again,
medical help should be obtained promptly. After the acid has been thoroughly diluted with water,
if medical attention is delayed, the person should be given milk or two fluid ounces of milk of
magnesia to drink to sooth the burning effect.

.

[Edited on 24-7-2007 by franklyn]
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[*] posted on 13-8-2020 at 17:26


Quote: Originally posted by oneup  
I think i'll just put a gram or so sodium fluoride in a test tube, outside of course, pour is some concentrated sulfuric acid and run!
BTW, how do I get/make calcium gluconate? sounds like a good idea.


Ah yes, let's just expose the neighbors and everyone around you to it. Stop fucking with chemicals like that.

I know this was years ago but this is just to serve as a warning to others. Outside =/= fume hood.
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[*] posted on 13-8-2020 at 18:18


Quote: Originally posted by woelen  
What you tell is not true. Fluorine cannot be made from aqueous solution. Fluorine immediately reacts with water, giving HF and oxygen. Fluorine can only be obtained from molten fluorides or from solutions of fluoride-salts in liquid HF.

What you tell can indeed be done with chlorine, made from dilute HCl. But for chlorine there are other faster methods of preparation.


Oh that's right fluorine reacts with water forming HF damn it sounds like it's reactive like sodium metal except being electronegative the only way I could see getting around it is desolving the salt in a low melting Flourine based eutetic ionic solution
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