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Vinegar to methanol?

  1. May 12, 2005 #1
    is this possible?
    see what i did was poured some apple cider vinegar into a cup and coverd it with saran wrap and overlapped so it would catch in my little aluminum foil base. i left it out in the sun for 2 days and when i approached it i may just be crazy but i could feintly smell the scent of methanol. i know methanol is used to make vinegar but is this possible. i didnt get too up close and personal with the cup b\c of fear it may have become methanol or some sort of aldehyde, so i just tossed it. so any chemists and this may be a tough one cause my mom wasnt sure and she is a chemist.
  2. jcsd
  3. May 12, 2005 #2


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    Acetic or ethanoic acid is one of the simplest carboxylic acids (fatty acids). In the pure state it is a colourless liquid with an unpleasant pungent odour. It solidifies to an white or ice-like crystalline mass at 16.7°C (62.4°F), and hence is often called glacial ethanoic (acetic) acid. In a dilute form, mixed with water, it is the acid found in vinegar. Vinegar contains ~5%; or more ethanoic acid, produced by fermentation.

    Ethanoic acid, known commonly as acetic acid (CH3COOH), is produced by the oxidation of ethanol. Ethanol is oxidized to acetaldehyde.

    Methanoic acid, known commonly as formic acid (HCOOH), can be produced by oxidation of methanol (CH3OH). Methanol is oxidized to formaldehyde.



    Also check this site for an overview of organic chem. I haven't scrutinized it, so I can't endorse it, but it may be useful.

  4. May 12, 2005 #3
    so its unlikely i made methanol?
  5. May 12, 2005 #4
    OK let's use some common sense here. Clearly this is not a thermal reaction since I have been cooking with various vinegars (including cider) for more years than I care to mention, and I have not gone blind. So this effect must be photochemical. Acetic acid does not absorb visible light, but cider vinegar is colored. Hence there is the potential for photochemical reactions with the chemicals that make it colored. What the exact composition of these chemicals are I have no idea so I can't speculate are to what the products would be. I would doubt methanol is a product since I've never seen a light sensitive warning on vinegars and many come in "clear" bottles.
  6. May 12, 2005 #5
    but it was in the sun. and there was the presense of aluminum foil, in which aluminum is sometimes a catalyst in a chemical reaction.
  7. May 12, 2005 #6
    OK I'm confused. You had the Al in the vinigar ?
  8. May 12, 2005 #7
    the vinegar was in the cup and the cup was covered with saran wrap and the aluminum foil was placed under to collect any type of condensation that may have evolved
  9. May 12, 2005 #8
    OK so how could the Al have any catalytic effect, outside of reflecting the light ?
  10. May 12, 2005 #9
    im not sure. is it possible that i produced methanol?
  11. May 13, 2005 #10


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    I doubt that aluminum foil would have had any catalytic effect, from what I remember the cationic form of aluminum does react with water in some sense...overall I doubt that you obtained methanol, how exactly are you familiar with the smell of methanol?
  12. May 13, 2005 #11
    not too familiar. i smelled it last year once in an octane booster. it has a really pungent methane like smell from what i remember. is it possible that other chemicals could have similar smell to it. anyways i really dont go around smelling chemicals.
  13. May 13, 2005 #12
    HCl form decomposition of the saran wrap (PVDC) would be one possibility.
  14. May 14, 2005 #13
    Doesn't methanol smell slightly sweet? Or am I confused? I use it frequently to clean spectrophotometer lenses, BUT I have a very weak sense of smell so I often confuse things.

    Regarding the saran wrap, does it decompose in sunlight? That would be somewhat worrying.
  15. May 15, 2005 #14
    I agree with the comment about alcohols. I do not consider methanol, ethanol, or propanol to have a pungent odors. As for the saran wrap thought, HCl has a quite pungent odor. PCDV will photochemically decompose very very slowly (sorry I don't have a quantum yield for it), but the question would be can acetic acid accelerate it.
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