Hello Janet, My greeting to you in my last post disappeared as did my
name at the end. Gremlins? I think it has more to do with this Mac
G4 being new and we still have a lot to learn. I’ll try to get it
right this time.
Glacial acetic acid is pure acetic acid, usually 99.5 percent pure
(17.5 molar). It is a clear colorless liquid which freezes on a
cold day (f.p. = 16.6 deg. C) to give an ice-like solid. The icy
appearance gave it the name “glacial”. Acetic acid (also named
ethanoic acid, CH3COOH) boils at 117.9 deg. C and has a flash point
of 40 deg. C (closed cup). The density is 1.0446 grams per cc. The
acid has a very sharp nasal membrane ripping odor. It is quite
corrosive, especially on skin. Like most of the concentrated acids,
it liberates heat on dilution with water, but it is not nearly as
exothermic as concentrated sulfuric acid.
Acetic acid (Ethanoic acid) is prepared in small amounts by
fermentation processes (vinegars - about 5 percent acetic acid).
The large quantity used in industry is prepared by the hydration of
ethylene over an acid catalyst to yield ethyl alcohol. The ethyl
alcohol is oxidized to acetaldehde over a silver catalyst and the
acetaldehyde is then oxidized to acetic acid. Another process
oxidizes ethylene directly to acetaldehyde using a palladium/Cu2O2
catalyst in hydrochloric acid. The process looks like this (all of
these steps are carried out in the vapor phase at high temperatures
(1) H2O + CH2=CH2 over H3PO4 on celetom yields CH3-CH2OH
(2) Then: CH3-CH2OH + O2 over Ag on alumina yields CH3-CHO
(3) Then: CH3-CHO + O2 with Mn /Co acetates yields CH3-COOH
The acid is concentrated and purified by fractional distillation.
That is probably more than you wanted to know about glacial acetic
acid. But, more has to be better than the bare minimum
"Marlinespike Seamanship in Precious Metals"