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Thread: Chemistry 101

  1. #61

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    Just an FYI. Elemental Bromide will go right through a rubber glove in seconds (see post #55). I worked in lab with someone that was using it in a proper vented chemical hood. She was wearing rubber gloves and their left hand felt “itchy”. When she finished her work she peeled her gloves off and the skin of her left hand came off with the glove.

  2. #62
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    In photography, there is no need to use elemental Bromine. Any use of it is FAR outside the limits of photographic systems use or design.

    So, what is the point?

    PE

  3. #63

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    Mark your bottles so you and everyone else knows whats in that container.

    A few years back I used to do wet bench work in a lab. There was a well worn container which had been marked years ago but the bitches brew it contained had long since been cooked off. if you worked in the lab you absolutely knew it was a vicious mix of nitric acid, hydrofluoric acid and glacial acetic. The mix was designed to cook metals quickly and effectively.
    One day the boss came by to get a bottle of alcohol and go blow the frost off his windscreen. He mistakenly grabbed this brew of acid and walked out to his car. with no gloves he washed the windscreen using his bare hands. When the HF etched the glass he knew he was in trouble and ran for the snowbank to wash his hands. Were it not for the chilly winter night his fingers would have been gone, if the HF got into his bones possibly far worse. At the end of the day was it his fault for reaching for the wrong bottle in the lab or was it our fault for not clearly labeling the bottles we cooked with? As funny as we thought it was at the time it was of course our fault.

  4. #64

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    Quote Originally Posted by Gerald C Koch View Post
    Then there are the strong acids; acetic acid 28% can cause burns.
    Technically speaking, acetic acid is what's called a "weak acid".

    Dispite that classification, concentrated acetic acid is corrosive, and attacks the skin.
    Kirk

    For up from the ashes, up from the ashes, grow the roses of success!

  5. #65
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    Quote Originally Posted by brianmquinn View Post
    Just an FYI. Elemental Bromide will go right through a rubber glove in seconds (see post #55). I worked in lab with someone that was using it in a proper vented chemical hood. She was wearing rubber gloves and their left hand felt “itchy”. When she finished her work she peeled her gloves off and the skin of her left hand came off with the glove.
    It's not a problem with the amounts I use, I only 'fumigate' the film in a closed environment from a very small amount, which then I let air out.


    Quote Originally Posted by Photo Engineer View Post
    In photography, there is no need to use elemental Bromine. Any use of it is FAR outside the limits of photographic systems use or design.

    So, what is the point?

    PE

    I was 'dry' bleaching old film with very small amounts.



    Quote Originally Posted by Kirk Keyes View Post
    Technically speaking, acetic acid is what's called a "weak acid".

    Dispite that classification, concentrated acetic acid is corrosive, and attacks the skin.


    Glacial acetic acid is a bit of a hazzard if you check out he MSDS, it's also an acid that literally burns.. as in combusts, and has a low flash point.
    Last edited by Athiril; 10-04-2011 at 01:33 AM. Click to view previous post history.

  6. #66

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    Here is a good read on "advanced chemistry". http://pipeline.corante.com/archives...ont_work_with/

    Enjoy.
    Bob

  7. #67

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    Quote Originally Posted by Kirk Keyes View Post
    Technically speaking, acetic acid is what's called a "weak acid".

    Dispite that classification, concentrated acetic acid is corrosive, and attacks the skin.
    You're right, I should have phrased the sentence better. I did put a semicolon before the "acetic acid" to separate it from the first part of the sentence. What I wanted to express was that even a weak acid found in many darkrooms can cause burns.
    A rock pile ceases to be a rock pile the moment a single man contemplates it, bearing within him the image of a cathedral.

    ~Antoine de Saint-Exupery

  8. #68

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    When i used to cook with HF/Nitric/Acetic the acetic was the least of our worries even if the acetic was 99% pure. it was after all a semiconductor and optics lab so in theory we knew what we were doing. That said, I did watch a fellow burn himself quite badly with acetic. i was at a large, well known optics facility and had some prototype lens blanks used for IR lenses. There was a bit of mounting material left on the blank after I cut the metallic crystal to shape. I suggested the optician remove the material with some acetic which he did. However, he literally stuck his fingers into glacial acetic and promptly burned himself badly. I should have known he was unfamiliar with the material when he said: "you mean like vinegar?" His fingers swelled to 4x the nornmal size and were rock lobster red. I felt badly for him.

  9. #69
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    I'm wondering what you stored that HF solution in. Not a glass bottle for sure!!!

    I knew of a guy who mistook HF for cleaning solution and put some on his pants. He flew across the Pacific! He started as Charlie and ended up as Charlene. No pain, no notice of loss with HF!!!!!! Just a bit of an itch!

    PE

  10. #70

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    Didn't old time chemists call a mixture of nitric and hydrofluoric acids Aqua Regis because it reputedly was the only thing that could dissolve the noble metals? Not being a chemist I'm unsure what glacial acetic acid contributes to the power of this combination but I can certainly vouch for its corrosive powers on skin. I was not aware that it is flammable - you live and learn. OzJohn

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