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Variations in bubble persistance

  1. Oct 22, 2015 #1
    The apparatus consisted of a one gallon air tight clear plastic jug one quarter filled with ferrous chloride (uh, Fe(II)Cl ?), water and sufficient hydrochloric acid to complete the transformation. The remaining space was filled with oxygen at atmospheric pressure. When triggered a mechanism shook the jug for two seconds. The trigger could be set to repeat.

    I recorded* four bubble types; small, medium, large and foam ignoring the subtle changes in shape, most notably wall thickness, during the course of the experiment. I also used various colored red laser pointers to evaluate changes in color, but I eye balled it.


    At first the solution was a dirty green. The bubbles yellow green in color, foamy, and persistent. Lasting upwards to a minute. The foam disintegrates quickly leaving piles of small bubble and more and more mediums. The destruction of the assembly slows as it progresses.

    After thirty seconds of shaking the bottle was substantially "sucked in"^. Oxygen was added to compensate. This was repeated slowing to every few minutes over the next half hour. All the while the persistence of the bubbles fell until no significant foam formed but rather mostly large bubbles collapsing quickly to short lived small and medium ones. The surface would clear within two seconds. The bubbles had turned bright yellow with little trace of green then just yellow then yellow with a trace of brown. It was noted that persistence was unchanged by the equalization of pressure. They lasted just as long and looked the same but there's a scribble "tiny bit greener?"

    The absence of persistent bubbles persisted for half an hour then slowly the persistence grew. The color deepened and the yellowish brown adding a tinge of orange.

    Over the next half hour a fine persistent foam formed on the surface encircling mostly medium and a few large bubbles floated in islands. The rest of the surface would suddenly collapse a bit like a single bubble bursting leaving those seemingly foam stabilize formations. The color became browner.

    Over the next hour the persistence grew as did the size of the bubbles. A botryoidal surface formed and was slow to dissipate. Even after its collapse bubbles would continue clinging to the surface lasting well over a minute. The color became the unmistakable lightish darkish orange brown of (OK uh) Fe(III)Cl. Love that color. There's something enticing about it, like gold.

    So there are many different fields represented there and asking leading questions tends to limit thinking. I guess I could just write, "explain all the observed phenomena" and hope for the best. I think that would take more than an hour. Maybe just explain a few. Obviously I have some idea of what's going on, I've researched, but I'm no expert in fluidity or how a thin wall breaking can alter chemistry and trigger a cascade. I'd like to not get called on a glaring mistake in understanding.


    *Bits of paper stuffed between the pages of a note book along with folded sheets of scribbles I added later to remind myself.

    ^Yeah yeah, poetic license. The pull of gravity makes no sense either.
  2. jcsd
  3. Oct 22, 2015 #2
    Clarification. I didn't mean to imply that the large bubbles became smaller bubbles. I miswrote. It seems a little like that but of course the other bubbles were already present.

    And I just want my mentor to know, it took all my doing to not title the thread;
    "Bubbles bubbles toils and troubles"
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