H
|
H - C = O H - C - C = O O = C - C = O
| | | | |
H H H H H
Formaldehyde Acetaldehyde Glyoxal Common Name
Methanal Ethanal Ethanedial Systematic Name
bp = -21 C bp = +21 C bp = 51 C Boiling point
Common names and semistructural formulas are often misleading. I thought
you might be interested in the two aldehydes which have been mentioned.
For comparison, I have also included the aldehyde which would come between
those two. I have included the systematic names. The prefixes form- and
meth- both mean there is 1 carbon in the molecule. Acet- and eth- both
mean two carbons. I'm not sure about the origian of gly-, and I see
nothing in my dictionary. The suffix -al means aldehyde, the
- C = O
|
H
group or end of the molecule. -dial, of course, means two aldehyde groups.
I give the boiling points. These point out that at a room temperature of
25-30 C, roughly 78-86 F, one would expect pure formaldehyde and pure
acetaldehyde to be entirely in the gas phase. Glyoxal would have a
significant vapor pressure at the same temperatures, but in a closed bottle
would contain a good amount of liquid. All are very water soluble, which
explains the availability of the water solutions that several have
mentioned.
Hope this is of some interest and use.
John L. Bordley, Jr.
Department of Chemistry
The University of the South
735 University Ave.
Sewanee, TN 37383-1000
615-598-1801