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Old 2012-07-05, 9:24pm
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PerfectDeb PerfectDeb is offline
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Quote:
Originally Posted by silverlilly1 View Post
Hydrofluoric acid is used in high school chemistry classes.

Glacial acids (highest concentration) are actually less dangerous that diluted acids. Diluting with water causes the hydrogen and the halogen to separate into ions (the hydrogen portion of it reacts with water to form a hydronium ion, or H3O) which are what react with other things on contact. Since HF is relatively stable and likes to stay balanced towards less separation in water, hydrofluoric acid is actually one of the weakest acids. This is because the hydrogen and fluorine do not want to separate into their ions.

Ammonium bifluoride, when mixed with water, "can release hydrogen fluoride" (hydrofluoric acid).
http://www.solvaynorthamerica.com/Si...orideFinal.pdf
This does not mean that everything in the solution is HF. It means that there may be SOME in the solution. A 9% solution of ammonium bifluoride does not mean it's 9% hydrofluoric acid. David said above that the HF will be approximately 1/3 of the percentage solution of ammonium bifluoride. I have not verified this, but if it is true, you would be looking at 3% HF.

I'm not debating effects, as I don't know anything about them, but simply how reactive hydrofluoric acid is, and what's actually in that etching solution. As with any chemicals, wearing gloves is key, and safety glasses are a good idea.
if by the 9% you're referring to DipnEtch - its 27% ammonium bifluoride so is approx 9% HFA ( i double checked the bottle i have here)

the fact that its classified as a "weak" acid is actually what makes it more dangerous - people misunderstand the term and think it means its not dangerous, which is not the case.
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Last edited by PerfectDeb; 2012-07-05 at 9:28pm.
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