Glacial isn't a dimer, you are thinking acetic acid anhydride, not anhydrous.
Galcial acetic acid is anhydrous and is a dimer via hydrogen bond; not thinking anhydride.
"...In solid acetic acid, the molecules form pairs (
dimers), being connected by
hydrogen bonds.
[17>>"
From this:
http://en.wikipedia.org/wiki/Acetic_acid#cite_note-jones-16
and this:
http://en.wikipedia.org/wiki/Acetic_acid#cite_note-jones-16
^ Jones, R.E.; Templeton, D.H. (1958). "The crystal structure of acetic acid".
Acta Crystallogr. 11 (7): 484–87.
doi:
10.1107/S0365110X58001341
I call it the real stuff cause it's concentrated, yes it's the same acetic acid as wegmans vinegar.
It may have the same chemical formula as Wegaman's vinegar without water but what's in the package may not be th same depending on how a particular galacial acetic acid was made , processed and packaged and what impurities if any are present.
Note:
"Acetic acid is produced industrially both synthetically and by bacterial
fermentation. About 75% of acetic acid made for use in the chemical industry is made by the
carbonylation of methanol ...<sup id="cite_ref-Ullmann_8-2" class="reference">
http://en.wikipedia.org/wiki/Acetic_acid#cite_note-Ullmann-8</sup> Alternative methods account for the rest. The biological route accounts for only about 10% of world production, but it remains important for the production of vinegar, as many food purity laws stipulate that vinegar used in foods must be of biological origin"
and
"...oxidation of
acetaldehyde ...remains the second-most-important manufacturing method, although it is usually uncompetitive with the carbonylation of methanol....
Side-products may also form, including
butanone,
ethyl acetate,
formic acid, and
propionic acid. These side-products are also commercially valuable, and the reaction conditions may be altered to produce more of them where needed. However, the separation of acetic acid from these by-products adds to the cost of the process.... and ...
Using modern catalysts, this reaction can have an acetic acid yield greater than 95%. The major side-products are
ethyl acetate,
formic acid, and
formaldehyde, all of which have lower
boiling points than acetic acid and are readily separated by
distillation.
http://en.wikipedia.org/wiki/Acetic_acid#cite_note-NIST-25